1
|
Agnetta D, Badalamenti F, Sweeting CJ, D'Anna G, Libralato S, Pipitone C. Erosion of fish trophic position: an indirect effect of fishing on food webs elucidated by stable isotopes. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230167. [PMID: 39034698 PMCID: PMC11293850 DOI: 10.1098/rstb.2023.0167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 01/08/2024] [Accepted: 01/23/2024] [Indexed: 07/23/2024] Open
Abstract
Fishing has significant trophodynamic impacts on marine communities, including reductions in the mean trophic position (TP) of the ecosystem resulting from a decrease in the abundance and size of species and individuals with high TPs. This study demonstrates the erosion of fish TP, an additional process that results in lower TP of individuals of a given size, which may exacerbate the effects of fishing on the food web. A stable isotope approach based on the tRophicPosition Bayesian method was used to quantify the TP of 12 target marine species at a given length, and compare their TP between fishery-restricted areas and trawled areas. The results show a difference in the TP of six benthic and apical nekto-benthic predators, which feed in the median at about 0.5 TP lower in trawled areas. It appears that current 'fishing down marine food webs' analyses may underestimate the trophic effects of fishing. Accounting for changes in trophodynamics of individuals at a given size is important to detect indirect effects through food web interactions. The application of a trawling ban may lead to the restoration of lost trophic structure; however, trophic changes may occur more slowly than changes in biomass. This article is part of the theme issue 'Connected interactions: enriching food web research by spatial and social interactions'.
Collapse
Affiliation(s)
- Davide Agnetta
- National Institute of Oceanography and Applied Geophysics (OGS), Trieste34151, Italy
- NBFC, National Biodiversity Future Center, Palermo90133, Italy
| | - Fabio Badalamenti
- NBFC, National Biodiversity Future Center, Palermo90133, Italy
- CNR-IAS, Lungomare Cristoforo Colombo 4521, Palermo90149, Italy
- School of Geosciences, University of Edinburgh, The King’s Buildings, EdinburghEH9 3FE, UK
| | - Christopher J. Sweeting
- Marine Management Organisation Lancaster House, Newcastle Business Park, Newcastle Upon TyneNE4 7YH, UK
| | - Giovanni D'Anna
- NBFC, National Biodiversity Future Center, Palermo90133, Italy
- CNR-IAS, Via Giovanni da Verrazzano 17, Castellammare91014, Italy
| | - Simone Libralato
- National Institute of Oceanography and Applied Geophysics (OGS), Trieste34151, Italy
| | - Carlo Pipitone
- NBFC, National Biodiversity Future Center, Palermo90133, Italy
- CNR-IAS, Lungomare Cristoforo Colombo 4521, Palermo90149, Italy
| |
Collapse
|
2
|
Shen Y, Hussey NE, David M, Wu F, Li Y. Vertebral microchemistry as an indicator of habitat use of the oceanic whitetip shark Carcharhinus longimanus in the central and eastern Pacific Ocean. JOURNAL OF FISH BIOLOGY 2024; 104:1732-1742. [PMID: 38445757 DOI: 10.1111/jfb.15705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 02/13/2024] [Indexed: 03/07/2024]
Abstract
The oceanic whitetip shark, Carcharhinus longimanus, is a highly migratory, epipelagic top predator that is classified as critically endangered. Although this species is widely distributed throughout the world's tropical oceans, its assumed mobility and pelagic behavior limit studies to derive required lifetime data for management. To address this data deficiency, we assessed variation in the habitat use of C. longimanus by oceanic region and over ontogeny through time series trace element and stable isotope values conserved along the vertebral centra (within translucent annulus bands) of 13 individuals sampled from the central and eastern Pacific Ocean. Elemental ratios of Mg:Ca, Mn:Ca, Fe:Ca, Zn:Ca, and Ba:Ca varied significantly among individuals from both sampling regions while principal component analysis of combined standardized elements revealed minimal overlap between the two areas. The limited overlap was also in agreement with stable isotope niches. These findings indicate that C. longimanus exhibit a degree of fidelity to sampling regions but also connectivity in a proportion of the population. The relatively stable Sr:Ca ratio supports its occurrence in oceanic environments. The decreasing trends in Ba:Ca, Mn:Ca, and Zn:Ca ratios, as well as in carbon and nitrogen isotope values along vertebral transects, indicate that C. longimanus undergo a directional habitat shift with age. Combined elemental and stable isotope values in vertebral centra provide a promising tool for elucidating lifetime data for complex pelagic species. For C. longimanus, management will need to consider subpopulation movement behavior in the Pacific to minimize the potential for localized depletions. Further work is now required to sample individuals across the entire Pacific and to link these findings with genetic and movement data to define population structure.
Collapse
Affiliation(s)
- Yongfu Shen
- College of Marine Living Resources and Management, Shanghai Ocean University, Shanghai, China
| | - Nigel E Hussey
- Department of Integrative Biology, University of Windsor, Windsor, Ontario, Canada
| | - Mboglen David
- College of Marine Living Resources and Management, Shanghai Ocean University, Shanghai, China
| | - Feng Wu
- College of Marine Living Resources and Management, Shanghai Ocean University, Shanghai, China
- The Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources, Ministry of Education, Shanghai, China
- National Engineering Research Centre for Oceanic Fisheries, Shanghai Ocean University, Shanghai, China
| | - Yunkai Li
- College of Marine Living Resources and Management, Shanghai Ocean University, Shanghai, China
- The Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources, Ministry of Education, Shanghai, China
- National Engineering Research Centre for Oceanic Fisheries, Shanghai Ocean University, Shanghai, China
| |
Collapse
|
3
|
Xing D, Zhu X. Niche overlap between native Cirrhinus molitorella and potential invasive competitors. ENVIRONMENTAL RESEARCH 2024; 248:118407. [PMID: 38311201 DOI: 10.1016/j.envres.2024.118407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Revised: 01/15/2024] [Accepted: 02/01/2024] [Indexed: 02/09/2024]
Abstract
Biological invasion is one of the important reasons for the decline of freshwater biodiversity in China and even in the world. The Pearl river basin is one of the most threatened areas in China by biological invasion. Over the past four decades, mrigal carp Cirrhinus mrigala and rohu Labeo rohita have invaded the Pearl river. They potentially pose a huge threat to a well-known economic species, native mud carp Cirrhinus molitorella. However, little is known about the likely habitat distributions of these two invasive species, which limits our management of them. In this study, we detected the stable isotope ratios of nitrogen and carbon for fish and quantified their niche overlap with nicheROVER in R. The result showed that the individuals of two invasive species had a higher probability to be found in niche region of native C. molitorella (i.e., 65 % for C. mrigala and 74 % for L. rohita). Moreover, to increase understanding of their habitat distributions and potential range of spread, the existing habitats data of these three fish species obtained from previous literatures and the high-resolution bioclimatic parameters from WorldClim were analyzed via Maxent model. The results stressed that niche overlap was high among species, which could have an impact on local biodiversity in future. Furthermore, the visualization of habitat distributions could help show the dynamic habitat changes of invasive and native species over time, while also provide new insights into the subsequent prevention and control for invasive species in other river regions around the world.
Collapse
Affiliation(s)
- Daochao Xing
- Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Xiaoshan Zhu
- School of Ecology and Environment, Hainan University, Haikou, 570228, China.
| |
Collapse
|
4
|
Martins K, Niella Y, Albuquerque F, Eduardo LN, Oliveira P, Travassos P. Feeding behavior of yellowfin tuna around two insular regions of the western Atlantic Ocean. JOURNAL OF FISH BIOLOGY 2024; 104:1112-1121. [PMID: 38174622 DOI: 10.1111/jfb.15646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 10/27/2023] [Accepted: 12/11/2023] [Indexed: 01/05/2024]
Abstract
The yellowfin tuna is a very abundant tropical tuna species in the western equatorial Atlantic Ocean and an important fishery resource for the Brazilian tuna fleet. In this study we performed stable isotope analysis to better understand the spatial trophodynamics and dietary changes in yellowfin tuna around two insular marine protected areas in Brazil. A total of 65 yellowfin tuna specimens measuring between 47 and 138 cm LT (total length) were sampled around the archipelagos of Fernando de Noronha (FNA; n = 34) and Saint Peter and Saint Paul (SPSPA; n = 31) between July 2018 and September 2019. Bayesian mixing models and generalized additive models were used to investigate the contributions of four different prey items (zooplankton, cephalopods, fish larvae, and flying fish) to yellowfin tuna diet in each area and their potential changes in relation to predator growth. The four prey items were found to have different overall contributions between the two studied areas, with zooplankton being the most important prey in FNA, whereas flying fish was the most relevant prey to the species' diet in SPSPA. Significant changes in the species diet by size were also found, with fish smaller than 90 cm (TL) having a more generalist diet and larger animals relying more on consuming larger and more nutritious prey (i.e., flying fish). Our results suggest that these two marine protected areas play an important role in ocean dynamics, providing important and different foraging grounds for the development of this predator species.
Collapse
Affiliation(s)
- Karla Martins
- Laboratório de Ecologia Marinha, Universidade Federal Rural de Pernambuco, Recife, Brazil
| | - Yuri Niella
- School of Natural Sciences, Macquarie University, Sydney, Australia
| | - Fernanda Albuquerque
- Laboratório de Etologia de Peixes, Universidade Federal Rural de Pernambuco, Recife, Brazil
| | | | - Paulo Oliveira
- Laboratório de Etologia de Peixes, Universidade Federal Rural de Pernambuco, Recife, Brazil
| | - Paulo Travassos
- Laboratório de Ecologia Marinha, Universidade Federal Rural de Pernambuco, Recife, Brazil
| |
Collapse
|
5
|
Miller EA, Singer GP, Peterson ML, Webb M, Klimley AP. Comparative stable isotope analyses of green sturgeon (Acipenser medirostris) and white sturgeon (A. transmontanus) in the San Francisco estuary. JOURNAL OF FISH BIOLOGY 2024; 104:240-251. [PMID: 37799016 DOI: 10.1111/jfb.15579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 09/30/2023] [Accepted: 10/03/2023] [Indexed: 10/07/2023]
Abstract
Green sturgeon (Acipenser medirostris) and white sturgeon (A. transmontanus) are closely related, sympatric species that inhabit the San Francisco estuary. Green sturgeon have a more marine life history but both species spawn in the Sacramento River and reside for some duration in San Francisco Bay. These sturgeons are of conservation concern, yet little is known about their dietary competition when they overlap in space and time. To examine evidence of dietary differentiation, we collected whole blood and blood plasma from 26 green sturgeon and 35 white sturgeon in San Francisco Bay. Using carbon and nitrogen stable isotope analyses, we compared their relative trophic levels and foraging locations along the freshwater to marine gradient. Sampling blood plasma and whole blood allowed comparison of dietary integration over shorter and longer time scales, respectively. Plasma and whole blood δ13 C values confirmed green sturgeon had more marine dietary sources than white sturgeon. Plasma δ15 N values revealed white sturgeon fed at lower trophic levels than green sturgeon recently, however, whole blood δ15 N values demonstrated the two species fed at the same trophic level over longer time scales. Larger individuals of both species had higher δ13 C values than smaller individuals, reflecting more marine food sources in adulthood. Length did not affect δ15 N values of either species. Isotope analyses supported the more marine life history of green than white sturgeon and potentially highlight a temporary trophic differentiation of diet between species during and preceding the overlapping life stage in San Francisco Bay.
Collapse
Affiliation(s)
- Emily A Miller
- Graduate Group in Ecology, University of California, Davis, California, USA
- Department of Wildlife, Fish, and Conservation Biology, University of California, Davis, California, USA
| | - Gabriel P Singer
- Department of Wildlife, Fish, and Conservation Biology, University of California, Davis, California, USA
| | - Matthew L Peterson
- Department of Wildlife, Fish, and Conservation Biology, University of California, Davis, California, USA
| | - Molly Webb
- US Fish and Wildlife Service, Bozeman Fish Technology Center, Bozeman, Montana, USA
| | - A Peter Klimley
- Department of Wildlife, Fish, and Conservation Biology, University of California, Davis, California, USA
| |
Collapse
|
6
|
Olin JA, Urakawa H, Frisk MG, Newton AL, Manz M, Fogg M, McMullen C, Crawford L, Shipley ON. DNA metabarcoding of cloacal swabs provides insight into diets of highly migratory sharks in the Mid-Atlantic Bight. JOURNAL OF FISH BIOLOGY 2023; 103:1409-1418. [PMID: 37640692 DOI: 10.1111/jfb.15543] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 07/27/2023] [Accepted: 08/26/2023] [Indexed: 08/31/2023]
Abstract
The abundances of migratory shark species observed throughout the Mid-Atlantic Bight (MAB) during productive summer months suggest that this region provides critical habitat and prey resources to these taxa. However, the principal prey assemblages sustaining migratory shark biomass in this region are poorly defined. We applied high-throughput DNA metabarcoding to shark feces derived from cloacal swabs across nine species of Carcharhinid and Lamnid sharks to (1) quantify the contribution of broad taxa (e.g., invertebrates, fishes) supporting shark biomass during seasonal residency in the MAB and (2) determine whether the species displayed distinct dietary preference indicative of resource partitioning. DNA metabarcoding resulted in high taxonomic (species-level) resolution of shark diets with actinopterygian and elasmobranch fishes as the dominant prey categories across the species. DNA metabarcoding identified several key prey groups consistent across shark taxa that are likely integral for sustaining their biomass in this region, including Atlantic menhaden (Brevoortia tyrannus), Atlantic mackerel (Scomber scombrus), and benthic elasmobranchs, including skates. Our results are consistent with previously published stomach content data for the shark species of similar size range in the Northwest Atlantic Ocean, supporting the efficacy of cloacal swab DNA metabarcoding as a minimally invasive diet reconstruction technique. The high reliance of several shark species on Atlantic menhaden could imply wasp-waist food-web conditions during the summer months, whereby high abundances of forage fishes sustain a diverse suite of migratory sharks within a complex, seasonal food web.
Collapse
Affiliation(s)
- Jill A Olin
- Department of Biological Sciences, Great Lakes Research Center, Michigan Technological University, Houghton, Michigan, USA
| | - Hidetoshi Urakawa
- Department of Marine and Ecological Sciences, Florida Gulf Coast University, Fort Myers, Florida, USA
| | - Michael G Frisk
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, New York, USA
| | - Alisa L Newton
- New York Aquarium, Wildlife Conservation Society, Bronx, New York, USA
| | - Maria Manz
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, New York, USA
| | - Michael Fogg
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, New York, USA
| | - Colin McMullen
- Department of Marine and Ecological Sciences, Florida Gulf Coast University, Fort Myers, Florida, USA
| | - Lisa Crawford
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, New York, USA
| | - Oliver N Shipley
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, New York, USA
| |
Collapse
|
7
|
Enríquez-García AB, Cruz-Escalona VH, Carriquiry JD, Ehemann NR, Mejía-Falla PA, Marín-Enríquez E, Treinen-Crespo C, Vélez-Tacuri JR, Navia AF. Trophic assessment of three sympatric batoid species in the Southern Gulf of California. PeerJ 2023; 11:e16117. [PMID: 37753172 PMCID: PMC10519201 DOI: 10.7717/peerj.16117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 08/27/2023] [Indexed: 09/28/2023] Open
Abstract
The competitive exclusion principle establishes that the coexistence of closely related species requires a certain degree of resource partitioning. However, populations have individuals with different morphological or behavioral traits (e.g., maturity stages, sexes, temporal or spatial segregation). This interaction often results in a multi-level differentiation in food preferences and habits. We explored such resource partitioning between and within three batoid species: Hypanus dipterurus, Narcine entemedor, and Rhinoptera steindachneri in the southern Gulf of California, Mexico, using a combination of stomach content (excluding R. steindachneri) and stable isotope analyses. We found a clear differentiation between H. dipterurus and N. entemedor, where the latter exhibited more benthic habitats, supported by a greater association to infaunal prey and higher δ13C values. Though the degree and patterns of intra-specific segregation varied among species, there was a notable differentiation in both sex and stage of maturity, corresponding to changes in specialization (i.e., isotopic niche breadth) or trophic spectrum (varying prey importance and isotopic values per group). This work is a promising step towards understanding the dietary niche dynamics of these species in a potentially important feeding area within the southern Gulf of California, as well as the biological and ecological mechanisms that facilitate their coexistence.
Collapse
Affiliation(s)
- Arturo Bell Enríquez-García
- Departamento de Pesquerías y Biología Marina, Instituto Politécnico Nacional, Centro Interdisciplinario de Ciencias Marinas, La Paz, Baja California Sur, Mexico
| | - Víctor Hugo Cruz-Escalona
- Departamento de Pesquerías y Biología Marina, Instituto Politécnico Nacional, Centro Interdisciplinario de Ciencias Marinas, La Paz, Baja California Sur, Mexico
| | - José D. Carriquiry
- Instituto de Investigaciones Oceanológicas, Universidad Autónoma de Baja California, Ensenada, Baja California, Mexico
| | - Nicolás R. Ehemann
- Departamento de Pesquerías y Biología Marina, Instituto Politécnico Nacional, Centro Interdisciplinario de Ciencias Marinas, La Paz, Baja California Sur, Mexico
- Department of Biology, University of Konstanz, Zoology and Evolutionary Biology, Konstanz, Germany
| | - Paola A. Mejía-Falla
- Wildlife Conservation Society, Cali, Colombia
- Fundación Colombiana para la Investigación y Conservación de Tiburones y Rayas, SQUALUS, Cali, Colombia
| | - Emigdio Marín-Enríquez
- Facultad de Ciencias del Mar, CONACyT, Universidad Autónoma de Sinaloa, Mazatlán, Sinaloa, Mexico
| | - Christina Treinen-Crespo
- Instituto de Investigaciones Oceanológicas, Universidad Autónoma de Baja California, Ensenada, Baja California, Mexico
| | - José R. Vélez-Tacuri
- Facultad Ciencias del Mar, Universidad Laica Eloy Alfaro de Manabí, Manabí, Ecuador
- Fundación RACSE, Red de Agentes por la Conservación y Sostenibilidad de los Ecosistemas, Manta, Manabí, Ecuador
| | - Andrés F. Navia
- Fundación Colombiana para la Investigación y Conservación de Tiburones y Rayas, SQUALUS, Cali, Colombia
| |
Collapse
|
8
|
Radiation shielding performance of a borate-based glass system doped with bismuth oxide. Radiat Phys Chem Oxf Engl 1993 2023. [DOI: 10.1016/j.radphyschem.2023.110875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
|
9
|
Shipley ON, Matich P, Hussey NE, Brooks AML, Chapman D, Frisk MG, Guttridge AE, Guttridge TL, Howey LA, Kattan S, Madigan DJ, O'Shea O, Polunin NV, Power M, Smukall MJ, Schneider EVC, Shea BD, Talwar BS, Winchester M, Brooks EJ, Gallagher AJ. Energetic connectivity of diverse elasmobranch populations - implications for ecological resilience. Proc Biol Sci 2023; 290:20230262. [PMID: 37040803 PMCID: PMC10089721 DOI: 10.1098/rspb.2023.0262] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 03/08/2023] [Indexed: 04/13/2023] Open
Abstract
Understanding the factors shaping patterns of ecological resilience is critical for mitigating the loss of global biodiversity. Throughout aquatic environments, highly mobile predators are thought to serve as important vectors of energy between ecosystems thereby promoting stability and resilience. However, the role these predators play in connecting food webs and promoting energy flow remains poorly understood in most contexts. Using carbon and nitrogen isotopes, we quantified the use of several prey resource pools (small oceanic forage, large oceanics, coral reef, and seagrass) by 17 species of elasmobranch fishes (n = 351 individuals) in The Bahamas to determine their functional diversity and roles as ecosystem links. We observed remarkable functional diversity across species and identified four major groups responsible for connecting discrete regions of the seascape. Elasmobranchs were responsible for promoting energetic connectivity between neritic, oceanic and deep-sea ecosystems. Our findings illustrate how mobile predators promote ecosystem connectivity, underscoring their functional significance and role in supporting ecological resilience. More broadly, strong predator conservation efforts in developing island nations, such as The Bahamas, are likely to yield ecological benefits that enhance the resilience of marine ecosystems to combat imminent threats such as habitat degradation and climate change.
Collapse
Affiliation(s)
| | | | - Nigel E. Hussey
- Department of Integrative Biology, University of Windsor, Ontario, Canada
| | - Annabelle M. L. Brooks
- Cape Eleuthera Institute, Cape Eleuthera, Eleuthera, The Bahamas
- Oceanic Whitetip Shark Consortium, Ellicott City, MD, USA
- College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | | | - Michael G. Frisk
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY, USA
| | | | | | - Lucy A. Howey
- Oceanic Whitetip Shark Consortium, Ellicott City, MD, USA
- College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Sami Kattan
- Beneath The Waves, PO Box 126, Herndon, VA, USA
| | - Daniel J. Madigan
- Department of Integrative Biology, University of Windsor, Ontario, Canada
| | - Owen O'Shea
- The Center for Ocean Research and Education (CORE), Gregory Town, Eleuthera, The Bahamas
| | - Nicholas V. Polunin
- Department of Environmental Sciences, Newcastle University, Newcastle Upon Tyne, UK
| | - Michael Power
- Department of Biology, University of Waterloo, Ontario, Canada
| | | | | | - Brendan D. Shea
- Beneath The Waves, PO Box 126, Herndon, VA, USA
- Department of Fish and Wildlife Conservation, Virginia Tech, Blacksburg, VA, USA
| | - Brendan S. Talwar
- Cape Eleuthera Institute, Cape Eleuthera, Eleuthera, The Bahamas
- Oceanic Whitetip Shark Consortium, Ellicott City, MD, USA
- Department of Biological Sciences, Institute of Environment, Florida International University, Miami, FL, USA
| | | | - Edward J. Brooks
- Cape Eleuthera Institute, Cape Eleuthera, Eleuthera, The Bahamas
- Oceanic Whitetip Shark Consortium, Ellicott City, MD, USA
| | | |
Collapse
|
10
|
Weideli OC, Daly R, Peel LR, Heithaus MR, Shivji MS, Planes S, Papastamatiou YP. Elucidating the role of competition in driving spatial and trophic niche patterns in sympatric juvenile sharks. Oecologia 2023; 201:673-688. [PMID: 36930348 DOI: 10.1007/s00442-023-05355-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 02/28/2023] [Indexed: 03/18/2023]
Abstract
The coexistence of ecologically and morphologically similar species is often facilitated by the partitioning of ecological niches. While subordinate species can reduce competition with dominant competitors through spatial and/or trophic segregation, empirical support from wild settings, particularly those involving large-bodied taxa in marine ecosystems, are rare. Shark nursery areas provide an opportunity to investigate the mechanisms of coexistence. We used experimental and field studies of sympatric juvenile sharks (blacktip reef shark, Carcharhinus melanopterus; sicklefin lemon shark, Negaprion acutidens) to investigate how competitive ability influenced realized niches at St. Joseph Atoll, Seychelles. Captive trials revealed that sicklefin lemon sharks were dominant over blacktip reef sharks, consistently taking food rewards. In the field, blacktip reef sharks were captured over a broader area than sicklefin lemon sharks, but daily space use of actively tracked sharks showed a high degree of overlap across microhabitats. While stomach contents analysis revealed that blacktip reef shark diets included a broader range of prey items, stable isotope analysis demonstrated significantly higher mean δ13C values for sicklefin lemon sharks, suggesting diverging dietary preferences. Overall, our results matched theoretical predictions of subordinate competitors using a greater range of habitats and displaying broader feeding niches than competitively dominant species. While separating the realized and fundamental niche of marine predators is complicated, we provide evidence that resource partitioning is at least partially driven by interspecific competition.
Collapse
Affiliation(s)
- Ornella C Weideli
- PSL Research University, EPHE-UPVD-CNRS, USR 3278 CRIOBE, 66860, Perpignan, France.
- SOSF-D'Arros Research Centre (SOSF-DRC), c/o Save Our Seas Foundation (SOSF), 1201, Geneva, Switzerland.
- Soneva Fushi, Boduthakurufaanu Magu, Male, 20077, Maldives.
- Dr Risch Medical Laboratory, 9490, Vaduz, Liechtenstein.
| | - Ryan Daly
- South African Institute for Aquatic Biodiversity, Grahamstown, 6140, South Africa
- Oceanographic Research Institute, Marine Parade, Durban, 4056, South Africa
| | - Lauren R Peel
- SOSF-D'Arros Research Centre (SOSF-DRC), c/o Save Our Seas Foundation (SOSF), 1201, Geneva, Switzerland
| | - Michael R Heithaus
- Institute of Environment, Department of Biological Sciences, Florida International University, North Miami, FL, 33181, USA
| | - Mahmood S Shivji
- SOSF-Shark Research Center (SOSF-SRC) & Guy Harvey Research Institute, Nova Southeastern University, Dania Beach, FL, 33004, USA
| | - Serge Planes
- PSL Research University, EPHE-UPVD-CNRS, USR 3278 CRIOBE, 66860, Perpignan, France
- Laboratorie d'Excellence 'CORAIL', EPHE, PSL Research University, UPVD, CNRS, USR 3278 CRIOBE, Papetoai, Moorea, French Polynesia
| | - Yannis P Papastamatiou
- Institute of Environment, Department of Biological Sciences, Florida International University, North Miami, FL, 33181, USA
| |
Collapse
|
11
|
Graça Aranha S, Teodósio A, Baptista V, Erzini K, Dias E. A glimpse into the trophic ecology of deep-water sharks in an important crustacean fishing ground. JOURNAL OF FISH BIOLOGY 2023; 102:655-668. [PMID: 36625079 DOI: 10.1111/jfb.15306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 01/04/2023] [Indexed: 06/17/2023]
Abstract
Deep-water sharks are among the most vulnerable deep-water taxa because of their extremely conservative life-history strategies (i.e., late maturation, slow growth, and reproductive rates), yet little is known about their biology and ecology. Thus, this study aimed at investigating the trophic ecology of five deep-water shark species, the birdbeak dogfish (Deania calcea), the arrowhead (D. profundorum), the smooth lanternshark (Etmopterus pusillus), the blackmouth catshark (Galeus melastomus) and the knifetooth dogfish (Scymnodon ringens) sampled onboard a crustacean bottom-trawler off the south-west coast of Portugal. We combined carbon and nitrogen stable isotopes with RNA and DNA (RD) ratios to investigate the main groups of prey assimilated by these species and their nutritional condition, respectively. Stable isotopes revealed overall small interspecific variability in the contribution of different taxonomic groups to sharks' tissues, as well as in the origin of their prey. S. ringens presented higher δ15 N and δ13 C values than the other species, suggesting reliance on bathyal cephalopods, crustaceans and teleosts; the remaining species likely assimilated bathy-mesopelagic prey. The RD ratios indicated that most of the individuals had an overall adequate nutritional condition and had recently eaten. This information, combined with the fact that stable isotopes indicate that sharks assimilated prey from the local or nearby food webs (including commercially important shrimps), suggests a potential overlap between this fishing area and their foraging grounds, which requires further attention.
Collapse
Affiliation(s)
- Sofia Graça Aranha
- CCMAR - Centre of Marine Sciences, Universidade do Algarve, Faro, Portugal
| | - Alexandra Teodósio
- CCMAR - Centre of Marine Sciences, Universidade do Algarve, Faro, Portugal
| | - Vânia Baptista
- CCMAR - Centre of Marine Sciences, Universidade do Algarve, Faro, Portugal
| | - Karim Erzini
- CCMAR - Centre of Marine Sciences, Universidade do Algarve, Faro, Portugal
| | - Ester Dias
- CIIMAR/CIMAR - Interdisciplinary Centre of Marine and Environmental Research, Universidade do Porto, Terminal de Cruzeiros do Porto de Leixões, Matosinhos, Portugal
| |
Collapse
|
12
|
Lipid Extraction and Sample Preservation Techniques for Stable Isotope Analysis and Ecological Assays. Methods Mol Biol 2023; 2625:241-257. [PMID: 36653648 DOI: 10.1007/978-1-0716-2966-6_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Lipid extraction is an important component of many ecological and ecotoxicological measurements. For instance, percent lipid is often used as a measure of body condition, under the assumption that those individuals with higher lipid reserves are healthier. Likewise, lipids are depleted in 13C compared with protein, and it is consequently a routine to remove lipids prior to measuring carbon isotopes in ecological studies so that variation in lipid content does not obscure variation in diet. We provide detailed methods for two different protocols for lipid extraction: Soxhlet apparatus and manual distillation. We also provide methods for polar and non-polar solvents. Neutral (non-polar) solvents remove some lipids but few non-lipid compounds whereas polar solvents remove not only most lipids but also many non-lipid compounds. We discuss each of the methods and provide guidelines for best practices. We recommend that for stable isotope analysis, researchers test for a relationship between the change in the carbon stable isotope ratio and the amount of lipid extracted to see if the degree of extraction has an impact on isotope ratios. Stable isotope analysis is widely used by ecologists, and we provide a detailed methodology that minimizes known biases.
Collapse
|
13
|
Alves LMF, Lemos MFL, Moutinho AB, Ceia FR, Muñoz-Arnanz J, Jiménez B, Cabral H, Novais SC. Assessment of contaminants in blue sharks from the Northeast Atlantic: Profiles, accumulation dynamics, and risks for human consumers. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 316:120467. [PMID: 36273690 DOI: 10.1016/j.envpol.2022.120467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 10/14/2022] [Accepted: 10/15/2022] [Indexed: 06/16/2023]
Abstract
Chemical pollution is a major threat to marine ecosystems, and top predators such as most shark species are extremely vulnerable to being exposed and accumulating contaminants such as metals and persistent organic pollutants (POPs). This work aimed to study the degree, composition, and the sources of contamination in the blue shark (Prionace glauca) inhabiting the Northeast Atlantic, as well as the potential risk faced by human consumers. A total of 60 sharks were sampled in situ aboard fishing vessels, and the concentrations of a set of metals and POPs were analysed in various tissues and complemented with stable isotope analyses. High levels of contaminants were found in most sharks sampled. The concentrations of most metals were higher in the muscle when compared with the liver. Regarding the dangers to consumers posed by the concentrations of arsenic (As), mercury (Hg), and lead (Pb), over 75% of the sharks presented muscle concentrations of at least one contaminant above the legal limits for human consumption, and a risk assessment determined that consumption of meat of these sharks exceeding 0.07 Kg per week could potentially expose human consumers to dangerous amounts of methylmercury (MeHg). Additionally, the assessment of single contaminants may lead to an underestimation of the risk for the human health. Finally, the overall accumulation of contaminants seems to be mostly influenced by the sharks' geographical distribution, rather than sex, size, or trophic level of their prey.
Collapse
Affiliation(s)
- Luís M F Alves
- MARE- Marine and Environmental Sciences Centre & ARNET - Aquatic Research Infrastructure Network Associated Laboratory, ESTM, Polytechnic of Leiria, Peniche, Portugal.
| | - Marco F L Lemos
- MARE- Marine and Environmental Sciences Centre & ARNET - Aquatic Research Infrastructure Network Associated Laboratory, ESTM, Polytechnic of Leiria, Peniche, Portugal
| | - Ariana B Moutinho
- MARE- Marine and Environmental Sciences Centre & ARNET - Aquatic Research Infrastructure Network Associated Laboratory, ESTM, Polytechnic of Leiria, Peniche, Portugal
| | - Filipe R Ceia
- University of Coimbra, MARE - Marine and Environmental Sciences Centre / ARNET - Aquatic Research Network, Department of Life Sciences, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal
| | - Juan Muñoz-Arnanz
- Dept. of Instrumental Analysis and Environmental Chemistry, Institute of Organic Chemistry, (IQOG-CSIC), Madrid, Spain
| | - Begoña Jiménez
- Dept. of Instrumental Analysis and Environmental Chemistry, Institute of Organic Chemistry, (IQOG-CSIC), Madrid, Spain
| | | | - Sara C Novais
- MARE- Marine and Environmental Sciences Centre & ARNET - Aquatic Research Infrastructure Network Associated Laboratory, ESTM, Polytechnic of Leiria, Peniche, Portugal
| |
Collapse
|
14
|
Vidal A, Cardador L, Garcia-Barcelona S, Macias D, Druon JN, Coll M, Navarro J. The relative importance of biological and environmental factors on the trophodynamics of a pelagic marine predator, the blue shark (Prionace glauca). MARINE ENVIRONMENTAL RESEARCH 2023; 183:105808. [PMID: 36403409 DOI: 10.1016/j.marenvres.2022.105808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 11/05/2022] [Accepted: 11/07/2022] [Indexed: 06/16/2023]
Abstract
Marine ecosystems have been significantly altered by the cumulative impacts of human activities. Pelagic sharks have become vulnerable to increases in mortality rates caused by fishing. The decrease in number of these top predators could have substantial cascading effects on wider marine communities. Concerns about these potential impacts, and the critical need for effective management, have led to an increased interest in assessing the trophic ecology of sharks. While stable isotope analyses have been used to provide relevant insights about the trophic ecology of sharks, the causal factors leading to trophic variation between individuals has been largely overlooked. Here, we investigated the relative effect of biological factors, geographic location, and environmental factors on the spatial trophodynamics of the blue shark (Prionace glauca). Specifically, stable isotope values of δ15N and δ13C, and the estimated trophic position (TP) were analysed for 180 blue sharks collected from south of the Canary Islands in the Atlantic Ocean, to the north-western Mediterranean Sea. The results showed that models which included combined variables explained the variation in δ15N, TP and δ13C values better than models which considered only stand-alone predictors. The independent contributions of environmental variables and biological factors seemed to be more important than geographic location for δ15N and TP. δ15N and TP increased in a curvilinear fashion with body size, and TP was higher for females. In the case of δ13C values, only an effect from sex was observed. Among environmental variables, chlorophyll-a, pelagic productivity, and sea-surface temperature proved to be reliable predictors, particularly for δ15N and TP, most likely due to their relationship with productivity and prey availability. This study provides new information on ranking the factors that influence the trophodynamics of the blue shark, namely the environment, the geographic location, and the biological factors of the species.
Collapse
Affiliation(s)
- Alba Vidal
- Institut de Ciències Del Mar (ICM), CSIC, Passeig Marítim de la Barceloneta 37, 08003, Barcelona, Spain; Ecological and Forestry Applications Research Centre, Campus de Bellaterra (UAB), Edifici C, 08193, Cerdanyola Del Vallès, Spain
| | - Laura Cardador
- Ecological and Forestry Applications Research Centre, Campus de Bellaterra (UAB), Edifici C, 08193, Cerdanyola Del Vallès, Spain
| | | | - David Macias
- Centro Oceanográfico de Málaga (IEO-CSIC), Puerto Pesquero, s/n, 29640, Fuengirola, Spain
| | - Jean-Noel Druon
- Joint Research Centre (JRC), European Commission, Ispra, Italy
| | - Marta Coll
- Institut de Ciències Del Mar (ICM), CSIC, Passeig Marítim de la Barceloneta 37, 08003, Barcelona, Spain
| | - Joan Navarro
- Institut de Ciències Del Mar (ICM), CSIC, Passeig Marítim de la Barceloneta 37, 08003, Barcelona, Spain.
| |
Collapse
|
15
|
Queiroz APN, Araújo MLG, Hussey NE, Lessa RPT. Trophic ecology of three stingrays (Myliobatoidei: Dasyatidae) off the Brazilian north-eastern coast: Habitat use and resource partitioning. JOURNAL OF FISH BIOLOGY 2023; 102:27-43. [PMID: 36153814 DOI: 10.1111/jfb.15226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 09/17/2022] [Indexed: 06/16/2023]
Abstract
Understanding the ecological role of species with overlapping distributions is central to inform ecosystem management. Here we describe the diet, trophic level and habitat use of three sympatric stingrays, Hypanus guttatus, H. marianae and H. berthalutzae, through combined stomach content and stable isotope (δ13 C and δ15 N) analyses. Our integrated approach revealed that H. guttatus is a mesopredator that feeds on a diverse diet of benthic and epibenthic marine and estuarine organisms, principally bivalve molluscs, Alpheus shrimp and teleost fishes. Isotopic data supported movement of this species between marine and estuarine environments. H. berthalutzae is also a marine generalist feeder, but feeds primarily on teleost fishes and cephalopods, and consequently occupies a higher trophic level. In contrast, H. marianae is a mesopredator specialized on shrimps and polychaetas occurring only in the marine environment and occupying a low niche breadth. While niche overlap occurred, the three stingrays utilized the same prey resources at different rates and occupied distinct trophic niches, potentially limiting competition for resources and promoting coexistence. These combined data demonstrate that these three mesopredators perform different ecological roles in the ecosystems they occupy, limiting functional redundancy.
Collapse
Affiliation(s)
- Aristóteles Philippe Nunes Queiroz
- Programa de Pós-graduação em Biologia Animal, Universidade Federal de Pernambuco, Recife, Brazil
- Laboratório de Dinâmica de Populações Marinhas - DIMAR, Departamento de Pesca e Aquicultura, Universidade Federal Rural de Pernambuco, Recife, Brazil
| | - Maria Lúcia Góes Araújo
- Laboratório de Dinâmica de Populações Marinhas - DIMAR, Departamento de Pesca e Aquicultura, Universidade Federal Rural de Pernambuco, Recife, Brazil
| | - Nigel E Hussey
- Department of Integrative Biology, University of Windsor, Windsor, Ontario, Canada
| | - Rosângela P T Lessa
- Laboratório de Dinâmica de Populações Marinhas - DIMAR, Departamento de Pesca e Aquicultura, Universidade Federal Rural de Pernambuco, Recife, Brazil
| |
Collapse
|
16
|
Goodman K, Niella Y, Bliss‐Henaghan T, Harcourt R, Smoothey AF, Peddemors VM. Ontogenetic changes in the tooth morphology of bull sharks (Carcharhinus leucas). JOURNAL OF FISH BIOLOGY 2022; 101:1033-1046. [PMID: 35848707 PMCID: PMC9804735 DOI: 10.1111/jfb.15170] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 07/14/2022] [Indexed: 06/15/2023]
Abstract
Teeth are an integral component of feeding ecology, with a clear link between tooth morphology and diet, as without suitable dentition prey cannot be captured nor broken down for consumption. Bull sharks, Carcharhinus leucas, undergo an ontogenetic niche shift from freshwater to marine habitats, which raises the question: does tooth morphology change with ontogeny? Tooth shape, surface area and thickness were measured using both morphometrics and elliptic Fourier analysis to determine if morphology varied with position in the jaw and if there was an ontogenetic change concordant with this niche shift. Significant ontogenetic differences in tooth morphology as a function of position in the jaw and shark total length were found, with upper and lower jaws of bull sharks presenting two different tooth morphologies. Tooth shape and thickness fell into two groupings, anterior and posterior, in both the upper and lower jaws. Tooth surface area, however, indicated three groupings, mesial, intermediate and distal, in both the upper and lower jaws. While tooth morphology changed significantly with size, showing an inflection at sharks of 135 cm total length, each morphological aspect retained the same tooth groupings throughout. These ontogenetic differences in tooth morphologies reflect tooth strength, prey handling and heterodonty.
Collapse
Affiliation(s)
- Kyle Goodman
- School of Natural SciencesMacquarie UniversitySydneyNew South WalesAustralia
| | - Yuri Niella
- School of Natural SciencesMacquarie UniversitySydneyNew South WalesAustralia
| | | | - Robert Harcourt
- School of Natural SciencesMacquarie UniversitySydneyNew South WalesAustralia
| | - Amy F. Smoothey
- NSW Department of Primary Industries, Fisheries ResearchSydney Institute of Marine ScienceMosmanNew South WalesAustralia
| | - Victor M. Peddemors
- NSW Department of Primary Industries, Fisheries ResearchSydney Institute of Marine ScienceMosmanNew South WalesAustralia
| |
Collapse
|
17
|
Riverón S, Raoult V, Slip DJ, Harcourt RG. Lipid extraction has tissue-dependent effects on isotopic values (δ 34 S, δ 13 C, and δ 15 N) from different marine predators. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2022; 36:e9346. [PMID: 35737589 PMCID: PMC9539579 DOI: 10.1002/rcm.9346] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 05/31/2022] [Accepted: 06/22/2022] [Indexed: 06/15/2023]
Abstract
RATIONALE The use of sulfur isotopes to study trophic ecology in marine ecosystems has increased in the past decade. Unlike other commonly used isotopes (e.g., carbon), sulfur can better discriminate benthic and pelagic productivity. However, how lipid extraction affects sulfur isotopic values has not been assessed, despite its frequent use to remove lipid effects on δ13 C values. METHODS We used white muscle and liver samples from two species of sharks and skin samples from two species of pinnipeds (sea lion and fur seal) to assess the effects of lipid extraction on stable isotope values for δ34 S, δ13 C, and δ15 N. Isotopic values were determined using a continuous flow-isotope ratio mass spectrometer coupled to an elemental analyzer. RESULTS Lipid extraction significantly decreased δ34 S values in shark tissues, more so for liver than muscle (-4.6 ± 0.9‰ vs -0.8 ± 0.3‰, average change), with nearly no change in their standard deviations. Lipid extraction did not affect δ34 S values from pinniped skin samples (0.2 ± 0.8‰, average change). After lipid extraction, consistent increases in δ13 C values (0.2‰-7.3‰) were detected as expected, especially in tissue with high lipid content (C:N >4). After lipid extraction, significant increases in δ15 N values (0.5‰-1.4‰) were found in shark muscle and liver tissues. For pinniped skin samples, δ15 N values were not significantly lower after lipid extraction (-0.4‰ to -0.1‰). CONCLUSIONS Lipid extraction did not have a strong impact on δ34 S values of shark muscle and pinniped skin (≤1‰). However, our results suggest it is essential to consider the effects of lipid extraction when interpreting results from δ34 S values of shark liver tissue, as they significantly depleted values relative to bulk tissue (~5‰). This may reflect selective removal of sulfolipids and glutathione present in higher concentrations in the liver than in muscle and skin and requires further investigation.
Collapse
Affiliation(s)
- Sabrina Riverón
- Marine Predator Research Group, School of Natural SciencesMacquarie UniversitySydneyNew South WalesAustralia
| | - Vincent Raoult
- School of Environmental and Life SciencesUniversity of NewcastleOurimbahNew South WalesAustralia
- Marine Ecology GroupSchool of Natural SciencesMacquarie UniversitySydneyNew South WalesAustralia
| | - David J. Slip
- Marine Predator Research Group, School of Natural SciencesMacquarie UniversitySydneyNew South WalesAustralia
- Taronga Institute of Science and LearningTaronga Conservation Society AustraliaSydneyNew South WalesAustralia
| | - Robert G. Harcourt
- Marine Predator Research Group, School of Natural SciencesMacquarie UniversitySydneyNew South WalesAustralia
| |
Collapse
|
18
|
Assemat A, Adnet S, Bayez K, Hassler A, Arnaud-Godet F, Mollen FH, Girard C, Martin JE. Exploring diet shifts and ecology in modern sharks using calcium isotopes and trace metal records of their teeth. JOURNAL OF FISH BIOLOGY 2022. [PMID: 36066000 DOI: 10.1111/jfb.15211] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 09/02/2022] [Indexed: 06/15/2023]
Abstract
Sharks occupy all living environments of the marine realm as well as some freshwater systems. They display varied and flexible feeding behaviours, but understanding their diet remains challenging due to their elusive ecology and the invasiveness of stomach content analyses in regard of their threatened status. As a potential alternative, we discuss the variability in δ44/42 Ca values recorded in the tooth enamel of size-graded individuals belonging to three species of large sharks with distinct diets (Isurus oxyrinchus, Hexanchus griseus and Carcharodon carcharias). The preliminary results highlight shifts in diet linked to ontogeny (I. oxyrinchus and H. griseus) and spatial distribution (C. carcharias) characterizing feeding behaviour in these species at individual and population level. These outcomes agree with the results of traditional stomach analyses supporting that nontraditional stable isotopes thus represent new perspectives for the study of modern and extinct shark ecology. In addition, for the first time, the Sr/Ca elemental ratios measured in H. griseus reflect sexual differences that could be interpreted in terms of spatial segregation or physiological heterogeneities.
Collapse
Affiliation(s)
| | - Sylvain Adnet
- ISEM, Université Montpellier CNRS EPHE IRD, Montpellier, France
| | | | - Auguste Hassler
- Laboratoire de Géologie de Lyon: Terre, Planète, Environnement, Ecole Normale Supérieure de Lyon, Lyon, France
| | - Florent Arnaud-Godet
- Laboratoire de Géologie de Lyon: Terre, Planète, Environnement, Ecole Normale Supérieure de Lyon, Lyon, France
| | | | | | - Jeremy E Martin
- Laboratoire de Géologie de Lyon: Terre, Planète, Environnement, Ecole Normale Supérieure de Lyon, Lyon, France
| |
Collapse
|
19
|
Gül G, Demirel N. Ontogenetic shift in diet and trophic role of Raja clavata inferred by stable isotopes and stomach content analysis in the Sea of Marmara. JOURNAL OF FISH BIOLOGY 2022; 101:560-572. [PMID: 35638307 DOI: 10.1111/jfb.15123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 05/26/2022] [Indexed: 06/15/2023]
Abstract
Trophic ecology studies on predator-prey interactions reveal insights into ecological communities and help understand a species' role in the food web by contributing to improved fisheries management and conservation capabilities. Understanding the ecological role of overexploited and endangered predators is essential to deciphering how their feeding behaviour influences food web dynamics. In this study, the authors investigated the feeding behaviour of the common and IUCN-listed Near Threatened (NT) thornback ray Raja clavata, using carbon and nitrogen stable isotope and stomach content analysis (SCA). It has recently suffered an 87% decline in reported catches from the Sea of Marmara within the last decade. These results show that thornback ray mainly feeds on teleost species, except in summer, with both methods showing this species changes its diet ontogenetically by SCA. This ontogenetic diet shift was at lengths 40-50 cm by changing group preferences from Crustacea to Teleostei. MixSIAR results showed that both adult and juvenile individuals of R. clavata feed mainly on the crustaceans, but the contribution of teleosts represented by Trachurus sp. was very low (<15%). The trophic position increased total length and was higher than other batoid species in the Sea of Marmara.
Collapse
Affiliation(s)
- Güzin Gül
- Institute of Marine Sciences and Management, Istanbul University, Istanbul, Turkey
| | - Nazli Demirel
- Institute of Marine Sciences and Management, Istanbul University, Istanbul, Turkey
| |
Collapse
|
20
|
Gül G, Yokeş MB, Demirel N. The occurrence and feeding of a critically endangered shark species, Oxynotus centrina in the Sea of Marmara. JOURNAL OF FISH BIOLOGY 2022; 101:728-735. [PMID: 35642655 DOI: 10.1111/jfb.15119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 05/22/2022] [Indexed: 06/15/2023]
Abstract
The angular roughshark, Oxynotus centrina (Linnaeus, 1758), is a rarely encountered deep-sea demersal shark species. It is listed as "Critically Endangered" in the IUCN's regional assessment for the Mediterranean. Like other sharks and rays, the angular roughshark is subject to by-catch in demersal trawl and longline fisheries. This study contributes new knowledge on (a) its occurrence, size and sex information; and (b) its feeding ecology in the Sea of Marmara. Data were collected on total length (TL), total weight (TW) and sex from unpublished research survey reports performed intermittently from 1994 to 2020. According to the data, O. centrina was mainly recorded from the muddy sand bottom type in the southwest region of the Marmara Sea, which has higher biodiversity of macrobenthic species than other regions. Different methodological approaches were conducted to understand its feeding, such as DNA metabarcoding and isotope analysis to identify its prey spectra and assign a trophic level. Sampled specimens were full of liquid in their stomachs without any discernible visually identifiable prey items. The metabarcoding analyses were also unsuccessful in identifying any prey items. Trophic position calculation based on nitrogen isotope in muscles highlighted that O. centrina has the highest trophic position compared to the other sharks and rays in the Sea of Marmara. Although it was found mainly feeding on polychaetes and sipunculids species from previous studies, the δ15 N values made the authors cautious about the possibility of this species feeding on low trophic-level benthic invertebrates. Because the authors could not observe the presence of shark vitellus in the stomachs and could not succeed in DNA identification for prey, this study highlights high δ15 N values similar to top predators for O. centrina. The authors conclude that this species strategically feeds mainly on shark eggs to fulfil its nutritional requirements with minimum energy expenditure in line with its slow-moving behaviour and mouth morphology.
Collapse
Affiliation(s)
- Güzin Gül
- Institute of Marine Sciences and Management, Istanbul University, Istanbul, Turkey
| | | | - Nazli Demirel
- Institute of Marine Sciences and Management, Istanbul University, Istanbul, Turkey
| |
Collapse
|
21
|
Souza-Araujo JD, Hussey NE, Hauser-Davis RA, Rosa AH, Lima MDO, Giarrizzo T. Human risk assessment of toxic elements (As, Cd, Hg, Pb) in marine fish from the Amazon. CHEMOSPHERE 2022; 301:134575. [PMID: 35421445 DOI: 10.1016/j.chemosphere.2022.134575] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 03/21/2022] [Accepted: 04/07/2022] [Indexed: 06/14/2023]
Abstract
The present study evaluated As, Hg, Pb and Cd burdens in both ecologically and commercially important 314 marine fishes belonging to 47 species sampled along the Amazon Coast. We specifically investigated variations in these four elements among different habitats and their relationships with trophic position and estimated potential human health risk by calculating the hazard quotient (HQ), hazard index (HI), and target cancer risk (TR). Our analyses revealed that Hg concentrations in reef-associated fish were over 2-fold those recorded in demersal fish (p < 0.001). A stable isotope analysis indicated that most of the fish species analyzed herein are secondary consumers (i.e., TP > 2.9) and their trophic positions exhibited a significant negative correlation to As, Pb and Cd. Positive significant relationships were noted between As-Cd, As-Pb, As-Hg, Hg-Cd and Cd-Pb, suggesting that these elements exhibit similar dispersion properties and bioaccumulation homology, probably arising from natural fluvial inputs from the Amazon basin system. Detected As concentrations were higher than established guidelines and legal limits in 63.8% of the examined species (n = 30), whereas Cd, Hg and Pb levels were generally very low. Estimated daily intake (EDI) of iAs, Hg and Pb were above reference dose (RfD) in more almost half of species analyzed and HQ values were each found to pose potential non-carcinogenic health risks if high amounts are consumed over time. HI indicates that the determined elements attained levels considered as potential human health hazards trough consumption of eight cartilaginous fish. The TR values of iAs and Pb were higher than the guideline value and given this, individuals who continuously consume cartilaginous fish contaminated with the toxic elements determined here will likely be under increased cancer risks in the long term.
Collapse
Affiliation(s)
- Juliana de Souza-Araujo
- Grupo de Ecologia Aquática, Espaço Inovação do Parque de Ciência e Tecnologia do Guamá, Belém, PA, Brazil; Laboratório de Biogeoquímica Ambiental. Instituto de Ciência e Tecnologia, Universidade Estadual Paulista, Sorocaba, SP, Brazil.
| | - Nigel E Hussey
- Integrative Biology. University of Windsor, Windsor, Ontario, Canada.
| | - Rachel Ann Hauser-Davis
- Laboratório de Avaliação e Promoção da Saúde Ambiental, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil.
| | - André Henrique Rosa
- Laboratório de Biogeoquímica Ambiental. Instituto de Ciência e Tecnologia, Universidade Estadual Paulista, Sorocaba, SP, Brazil.
| | | | - Tommaso Giarrizzo
- Grupo de Ecologia Aquática, Espaço Inovação do Parque de Ciência e Tecnologia do Guamá, Belém, PA, Brazil; Instituto de Ciencias do Mar (LABOMAR), Universidade Federal do Ceará, Fortaleza, CE, Brazil.
| |
Collapse
|
22
|
Cerutti-Pereyra F, Salinas-De-León P, Arnés-Urgellés C, Suarez-Moncada J, Espinoza E, Vaca L, Páez-Rosas D. Using stable isotopes analysis to understand ontogenetic trophic variations of the scalloped hammerhead shark at the Galapagos Marine Reserve. PLoS One 2022; 17:e0268736. [PMID: 35687546 PMCID: PMC9187089 DOI: 10.1371/journal.pone.0268736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 05/02/2022] [Indexed: 11/25/2022] Open
Abstract
Changes in life-history requirements drive trophic variations, particularly in large marine predators. The life history of many shark species is still poorly known and understanding their dietary ontogeny is a challenging task, especially for highly migratory species. Stable isotope analysis has proven as a useful method for examining the foraging strategies of sharks and other marine predators. We assessed the foraging strategies and ontogenetic changes of scalloped hammerhead sharks, Sphyrna lewini, at Galapagos Marine Reserve (GMR), by analysing δ13C and δ15N signatures in different maturity stages. Our isotopic results suggest ontogenetic shifts in resource use between sub-adult and adult stages, but not between adult and juvenile stages. Carbon isotopic signatures found in the juvenile stage were enriched in contrast to sub-adults (~0.73‰) suggesting a combination of the maternal input and the use of coastal resources around the Galapagos Islands. Adult female sharks also showed enrichment in δ13C (~0.53‰) in comparison to sub-adult stages that suggest feeding in high primary productivity areas, such as the GMR. This study improves the understanding of the trophic ecology and ontogenetic changes of a highly migratory shark that moves across the protected and unprotected waters of the Eastern Tropical Pacific.
Collapse
Affiliation(s)
- Florencia Cerutti-Pereyra
- Charles Darwin Research Station, Charles Darwin Foundation, Puerto Ayora, Galapagos Islands, Ecuador
- * E-mail:
| | - Pelayo Salinas-De-León
- Charles Darwin Research Station, Charles Darwin Foundation, Puerto Ayora, Galapagos Islands, Ecuador
- Save Our Seas Foundation Shark Research Center and Guy Harvey Research Institute, Nova Southeastern University, Dania Beach, Florida, United States of America
| | - Camila Arnés-Urgellés
- Charles Darwin Research Station, Charles Darwin Foundation, Puerto Ayora, Galapagos Islands, Ecuador
| | | | - Eduardo Espinoza
- Galápagos National Park Directorate, Puerto Ayora, Galápagos, Ecuador
- Migramar Marine Research and Conservation Network, Olema, California, United States of America
| | - Leandro Vaca
- Galapagos Science Center, Universidad San Francisco de Quito, Puerto Baquerizo Moreno, Galápagos, Ecuador
| | - Diego Páez-Rosas
- Galapagos Science Center, Universidad San Francisco de Quito, Puerto Baquerizo Moreno, Galápagos, Ecuador
| |
Collapse
|
23
|
Seguel M, Molina-Burgos BE, Perez-Venegas DJ, Chiang G, Harrod C, DeRango E, Paves H. Shifts in maternal foraging strategies during pregnancy promote offspring health and survival in a marine top predator. Oecologia 2022; 199:343-354. [PMID: 35678930 DOI: 10.1007/s00442-022-05200-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 05/21/2022] [Indexed: 11/26/2022]
Abstract
The success of maternal foraging strategies during the rearing period can greatly impact the physiology and survival of dependent offspring. Surprisingly though, little is known on the fitness consequences of foraging strategies during the foetal period. In this study, we characterized variation in maternal foraging strategy throughout pregnancy in a marine top predator (South American fur seal, Arctocephalus australis), and asked if these shifts predicted neonatal health and postnatal survival. We found that during early pregnancy all pregnant females belonged to a single, homogenized foraging niche without evident clusters. Intriguingly though, during late pregnancy, individual fur seal mothers diverged into two distinct foraging niches characterized by a benthic-nearshore and a pelagic-offshore strategy. Females that shifted towards the benthic-nearshore strategy gave birth to pups with greater body mass, higher plasmatic levels of glucose and lower levels of blood urea nitrogen. The pups born to these benthic females were eight times more likely to survive compared to females using the pelagic-offshore foraging strategy during late pregnancy. These survival effects were mediated primarily by the impact of foraging strategies on neonatal glucose independent of protein metabolic profile and body mass. Benthic-nearshore foraging strategies during late pregnancy potentially allow for the greater maternal transfer of glucose to the foetus, leading to higher chances of neonatal survival. These results call for a deeper understanding of the balance between resource acquisition and allocation provided by distinct foraging polymorphisms during critical life-history periods, and how this trade-off may be adaptive under certain environmental conditions.
Collapse
Affiliation(s)
- Mauricio Seguel
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, 419 Gordon St, Guelph, ON, N1G2W1, Canada.
| | - Blanca E Molina-Burgos
- Facultad de Medicina Veterinaria y Agronomía, Universidad de las Americas, Manuel Montt 948, 7500000, Santiago, Chile
- Centro de Investigación Para La Sustentabilidad, Facultad de Ciencias de La Vida, Universidad Andres Bello, 8370251, Santiago, Chile
| | - Diego J Perez-Venegas
- Centro de Investigación y Gestión de Recursos Naturales (CIGREN), Instituto de Biología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Gustavo Chiang
- Departamento de Ecología y Biodiversidad and Centro de Investigación Para La Sustentabilidad (CIS), Facultad de Ciencias de La Vida, Universidad Andrés Bello, 8370251, Santiago, Chile
| | - Chris Harrod
- University of Antofagasta Stable Isotope Facility, University of Antofagasta, Antofagasta, Chile
- Instituto de Ciencias Naturales Alexander Von Humboldt, Universidad de Antofagasta, Antofagasta, Chile
- Nucleo Milenio INVASAL, Concepción, Chile
| | - Eugene DeRango
- Department of Animal Behaviour, Bielefeld University, Bielefeld, Germany
| | - Hector Paves
- Departamento de Ciencias Básicas, Facultad de Ciencias, Universidad Santo Tomas, Osorno, Chile
| |
Collapse
|
24
|
Kloskowski J, Nieoczym M. Strong Behavioral Effects of Omnivorous Fish on Amphibian Oviposition Habitat Selection: Potential Consequences for Ecosystem Shifts. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.856258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Perceived predation risk to offspring may have similar ultimate community-level impacts to those of consumptive trophic interactions. The present study investigated the behavioral effects of common carp Cyprinus carpio–an omnivorous fish capable of triggering an ecosystem shift to an algae-dominated state–on anurans, using a natural experiment conducted in a system of fish-stocked ponds. We compared oviposition patterns and larval densities of anurans and abundance of zooplankton and phytoplankton in ponds where fish were virtually absent and ponds where common carp was dominant. All studied anuran species bred in fish-poor ponds, while in ponds with high fish densities most of them oviposited infrequently or virtually did not breed. Oviposition habitat selection coupled with fish trophic pressure resulted in diametrically different tadpole densities between fish-poor and fish-dominated ponds. The alimentary tract contents of tadpoles of three locally common anurans, Pelobates fuscus, Hyla orientalis, and Rana temporaria, contained large numbers of unicellular algae, but also significant numbers of zooplanktonic grazers. According to stable nitrogen isotope analyses, tadpoles occupied a trophic level similar to a primary consumer, snail Lymnaea stagnalis, indicating that they fed mainly on algae. While total biomass of crustacean zooplankton did not differ between pond types, chlorophyll a concentrations were low in fish-poor ponds compared to fish-dominated ponds and negatively related to total tadpole biomass. Our findings indicate that scarcity of anuran larvae, resulting mainly from the behavioral responses of breeding anurans to fish predation risk, may facilitate algal production, although ecosystem shifts in the presence of fish occur along more pathways than a top-down cascade.
Collapse
|
25
|
Almela P, Velázquez D, Rico E, Justel A, Quesada A. Marine Vertebrates Impact the Bacterial Community Composition and Food Webs of Antarctic Microbial Mats. Front Microbiol 2022; 13:841175. [PMID: 35464973 PMCID: PMC9023888 DOI: 10.3389/fmicb.2022.841175] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 02/28/2022] [Indexed: 01/04/2023] Open
Abstract
The biological activity of marine vertebrates represents an input of nutrients for Antarctic terrestrial biota, with relevant consequences for the entire ecosystem. Even though microbial mats assemble most of the biological diversity of the non-marine Antarctica, the effects of the local macrofauna on these microecosystems remain understudied. Using 16S rRNA gene sequencing, 13C and 15N stable isotopes, and by characterizing the P and N-derived nutrient levels, we evaluated the effects of penguins and other marine vertebrates on four microbial mats located along the Antarctic Peninsula. Our results show that P concentrations, C/N and N/P ratios, and δ15N values of "penguin-impacted" microbial mats were significantly higher than values obtained for "macrofauna-free" sample. Nutrients derived from penguin colonies and other marine vertebrates altered the trophic interactions of communities within microbial mats, as well as the relative abundance and trophic position of meiofaunal groups. Twenty-nine bacterial families from eight different phyla significantly changed with the presence of penguins, with inorganic nitrogen (NH4 + and NO3 -) and δ15N appearing as key factors in driving bacterial community composition. An apparent change in richness, diversity, and dominance of prokaryotes was also related to penguin-derived nutrients, affecting N utilization strategies of microbial mats and relating oligotrophic systems to communities with a higher metabolic versatility. The interdisciplinary approach of this study makes these results advance our understanding of interactions and composition of communities inhabiting microbial mats from Antarctica, revealing how they are deeply associated with marine animals.
Collapse
Affiliation(s)
- Pablo Almela
- Department of Biology, Universidad Autónoma de Madrid, Madrid, Spain
| | - David Velázquez
- Department of Biology, Universidad Autónoma de Madrid, Madrid, Spain
| | - Eugenio Rico
- Department of Ecology, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación en Biodiversidad y Cambio Global (CIBC-UAM), Universidad Autónoma de Madrid, Madrid, Spain
| | - Ana Justel
- UC3M-Santander Big Data Institute (IBiDat), Universidad Carlos III de Madrid, Madrid, Spain
- Department of Mathematics, Universidad Autónoma de Madrid, Madrid, Spain
| | - Antonio Quesada
- Department of Biology, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación en Biodiversidad y Cambio Global (CIBC-UAM), Universidad Autónoma de Madrid, Madrid, Spain
| |
Collapse
|
26
|
Chan AJ, Raoult V, Jaine FRA, Peddemors VM, Broadhurst MK, Williamson JE. Trophic niche of Australian cownose rays (Rhinoptera neglecta) and whitespotted eagle rays (Aetobatus ocellatus) along the east coast of Australia. JOURNAL OF FISH BIOLOGY 2022; 100:970-978. [PMID: 35225353 PMCID: PMC9310580 DOI: 10.1111/jfb.15028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 02/24/2022] [Accepted: 02/25/2022] [Indexed: 05/21/2023]
Abstract
Australian cownose rays (Rhinoptera neglecta) and whitespotted eagle rays (Aetobatus ocellatus) are large myliobatiform rays that co-occur off temperate eastern Australia. Here, we performed stable-isotope analyses (δ13 C, δ15 N and δ34 S) on fin clips of both species to gain insights into their trophic interactions and isotopic niches, and assess the effect of preservation (ethanol-stored versus frozen) on isotopic values of fin-clip tissue of R. neglecta. Linear mixed models identified species as the main factor contributing to variation among δ15 N and δ34 S values, and disc width for δ13 C. Bayesian ecological niche modelling indicated a 57.4% to 74.5% overlap of trophic niches, with the niche of R. neglecta being smaller and more constrained. Because values of δ13 C were similar between species, variation in isotopic niches were due to differences in δ15 N and δ34 S values. Linear mixed models failed to detect differences in isotopic values of ethanol-stored and frozen fin tissue of R. neglecta. This study provides the first examination of the trophic ecology of R. neglecta and the comparison of isotopic niche with A. ocellatus, which will facilitate future research into the trophic interactions of these species and aid better resource management.
Collapse
Affiliation(s)
- Alysha J. Chan
- School of Natural SciencesMacquarie UniversitySydneyNew South WalesAustralia
| | - Vincent Raoult
- School of Environmental and Life SciencesUniversity of NewcastleOurimbahNew South WalesAustralia
| | - Fabrice R. A. Jaine
- School of Natural SciencesMacquarie UniversitySydneyNew South WalesAustralia
- Sydney Institute of Marine ScienceMosmanNew South WalesAustralia
| | - Victor M. Peddemors
- New South Wales Department of Primary Industries, Fisheries ResearchSydney Institute of Marine ScienceMosmanNew South WalesAustralia
| | - Matt K. Broadhurst
- New South Wales Department of Primary Industries, Fisheries Conservation Technology Unit, National Marine Science CentreSouthern Cross UniversityCoffs HarbourNew South WalesAustralia
- Marine and Estuarine Ecology UnitSchool of Biological Sciences, University of QueenslandBrisbaneQueenslandAustralia
| | - Jane E. Williamson
- School of Natural SciencesMacquarie UniversitySydneyNew South WalesAustralia
| |
Collapse
|
27
|
Rieck LO, Sulliván SMP. Ecological Impacts of Altered Stream Hydrogeomorphic Characteristics Extend Beyond the Channel Boundary: Evidence From Urban Streams of Columbus, OH, United States. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.817289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Urbanization in stream catchments can have strong effects on stream channel hydrogeomorphic features including channel dimensions, channel-floodplain connectivity, and flood regime. However, the consequences of hydrogeomorphic alterations on aquatic-terrestrial subsidy dynamics are largely unexplored. We examined the associations among hydrogeomorphic characteristics, emergent aquatic insect assemblages, and the density and trophic dynamics of riparian spiders of the family Tetragnathidae at 23 small urban stream reaches in the Columbus, OH (United States) Metropolitan Area. Naturally abundant stable isotopes of 13C and 15N were used to quantify the relative contribution of aquatically derived energy (i.e., nutritional pathways deriving from algae) to tetragnathid spiders and their trophic position. Bankfull discharge was negatively related to both emergence rate and family richness. On average, tetragnathid spiders relied on aquatically derived energy for 36% of their nutrition, with the greatest reliance found for spiders next to channels with wider flood-prone widths and proportionally fewer emergent insects of the family Chironomidae. Mean emergent aquatic insect reliance on aquatically derived energy was 32% and explained 44% of the variation in tetragnathid aquatically derived energy. A positive relationship between δ13C of tetragnathid spiders and emergent insects provides additional evidence of tetragnathid reliance on emergent insects. Mean tetragnathid trophic position was 2.85 and was positively associated with channel sinuosity and negatively associated with aquatic insect emergence rate. Sinuosity was also positively related to aquatically derived energy of emergent aquatic insects; as well as emergent insect family richness; % Ephemeroptera, Plecoptera, and Trichoptera (EPT); and aquatic insect emergence rate; implicating instream habitat-mediated shifts in emergent aquatic insect communities as an indirect mechanistic link between hydrogeomorphic processes and spiders. Our findings underscore that the impacts of stream hydrogeomorphic alterations can cascade into terrestrial food webs. These results suggest that monitoring and restoration of fluvial geomorphic form and function (e.g., sinuosity, slope, and hydrology) confer benefits to both aquatic and terrestrial riparian ecosystems in urban catchments.
Collapse
|
28
|
Raoult V, Gaston TF, Smith C, Dolfo V, Park JM, Williamson JE. Patterns of mother-embryo isotope fractionation in batoids vary within and between species. JOURNAL OF FISH BIOLOGY 2022. [PMID: 35249223 DOI: 10.1111/jfb.15034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 02/02/2022] [Accepted: 03/02/2022] [Indexed: 06/14/2023]
Abstract
Patterns of mother-embryo fractionation of 13 C and 15 N were assessed for their predictability across three species of batoids caught as by-catch in south-eastern Australia. Stable isotope analysis of 24 mothers and their litters revealed that isotope ratios of embryos were significantly different from their corresponding mothers and that the scale and direction of the difference varied within and across species. The range of variation across species was 3.5‰ for δ13 C and 4‰ for δ15 N, equivalent to a difference in trophic level. In one species (Urolophus paucimaculatus) litters could be significantly enriched or depleted in 13 C and 15 N relative to their mothers' isotope signatures. These results suggest that patterns of mother-embryo isotope fractionation vary within and between species and that these patterns may not be explained only by developmental mode. Contrasting patterns of fractionation between and within species make it difficult to adjust mother-embryo fractionation with broad-scale correction factors.
Collapse
Affiliation(s)
- Vincent Raoult
- School of Environmental and Life Sciences, University of Newcastle, Ourimbah, New South Wales, Australia
- School of Natural Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Troy F Gaston
- School of Environmental and Life Sciences, University of Newcastle, Ourimbah, New South Wales, Australia
| | - Catrina Smith
- School of Natural Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Violaine Dolfo
- School of Natural Sciences, Macquarie University, Sydney, New South Wales, Australia
- PSL Research University, EPHE-UPVD-CNRS, USR 3278 CRIOBE, Perpignan, France
| | - Joo-Myun Park
- School of Natural Sciences, Macquarie University, Sydney, New South Wales, Australia
- Dokdo Research Center, East Sea Research Institute, Korea Institute of Ocean Science & Technology, Uljin, Korea
| | - Jane E Williamson
- School of Natural Sciences, Macquarie University, Sydney, New South Wales, Australia
| |
Collapse
|
29
|
Shen Y, Gong Y, Wu F, Li Y. Retrospective stable isotopes of vertebrae reveal sexual ontogenetic patterns and trophic ecology in oceanic whitetip shark, Carcharhinus longimanus. Ecol Evol 2022; 12:e8452. [PMID: 35127009 PMCID: PMC8796903 DOI: 10.1002/ece3.8452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 11/21/2021] [Accepted: 11/29/2021] [Indexed: 11/25/2022] Open
Abstract
There is a common phenomenon in nature whereby some animals have differences in their ontogenetic changes in dietary preferences between sexes, especially apex predators. These reflect changes in the needs of development during their lifetimes. Apex predators potentially have diverse dietary niches and a large impact on the trophic dynamics within ecosystems. However, the difference in life history between males and females often leads to increased difficulty in management and conservation. In this study, 25 oceanic whitetip sharks, Carcharhinus longimanus, were collected from the central and eastern tropical Pacific. Retrospective stable isotope analysis of vertebrae was used to evaluate the potential ontogenetic differences in feeding habits and niche width between sexes. Results showed that C. longimanus had a wide range of δ13C values (-18.1 to -12.3‰) and δ15N values (8.9-14.8‰). However, males and females had similar trophic positions with large niche overlap at similar growth stages. Both sexes had increasing δ13C values but relatively constant δ15N values along the vertebrae. These results indicated that male and female C. longimanus may share similar feeding strategies and movement patterns. The results presented in this study enhance our understanding of sexual ontogenetic patterns and ecological role of C. longimanus and highlighted the applicability of vertebrae for characterizing shark life-history traits.
Collapse
Affiliation(s)
- Yongfu Shen
- College of Marine SciencesShanghai Ocean UniversityShanghaiChina
| | - Yi Gong
- College of Marine SciencesShanghai Ocean UniversityShanghaiChina
- Laboratory for Marine Fisheries Science and Food Production ProcessesQingdao National Laboratory for Marine Science and TechnologyQingdaoChina
- The Key Laboratory of Sustainable Exploitation of Oceanic Fisheries ResourcesMinistry of EducationShanghaiChina
- National Engineering Research Centre for Oceanic FisheriesShanghai Ocean UniversityShanghaiChina
| | - Feng Wu
- College of Marine SciencesShanghai Ocean UniversityShanghaiChina
- Laboratory for Marine Fisheries Science and Food Production ProcessesQingdao National Laboratory for Marine Science and TechnologyQingdaoChina
- The Key Laboratory of Sustainable Exploitation of Oceanic Fisheries ResourcesMinistry of EducationShanghaiChina
- National Engineering Research Centre for Oceanic FisheriesShanghai Ocean UniversityShanghaiChina
| | - Yunkai Li
- College of Marine SciencesShanghai Ocean UniversityShanghaiChina
- Laboratory for Marine Fisheries Science and Food Production ProcessesQingdao National Laboratory for Marine Science and TechnologyQingdaoChina
- The Key Laboratory of Sustainable Exploitation of Oceanic Fisheries ResourcesMinistry of EducationShanghaiChina
- National Engineering Research Centre for Oceanic FisheriesShanghai Ocean UniversityShanghaiChina
| |
Collapse
|
30
|
Matich P, Bizzarro JJ, Shipley ON. Are stable isotope ratios suitable for describing niche partitioning and individual specialization? ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2021; 31:e02392. [PMID: 34164866 DOI: 10.1002/eap.2392] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 01/07/2021] [Accepted: 03/03/2021] [Indexed: 06/13/2023]
Abstract
As concerns about anthropogenic and natural disturbance grow, understanding animal resource use patterns has been increasingly prioritized to predict how changes in environmental conditions, food web structure, and population dynamics will affect biological resilience. Among the tools used to assess resource use, stable isotope analysis has proliferated in ecological studies, particularly in relation to describing intra- and interspecific variation in trophic interactions. Despite a growing need to disseminate scientific information, the inherent limitations of stable isotope ratios and inappropriate synonymizing of distinct evolutionary and ecological processes may mislead ecological inferences in natural systems. This situation necessitates a re-evaluation of the utility of stable isotope ratios to address certain ecological questions. Here, we assess the efficacy of stable isotope ratios to describe two fundamental ecological processes, niche partitioning and individual specialization. Investigation of these processes has increased substantially in accordance with increased access to stable isotope data. This article discusses the circumstances and approaches that are necessary to evaluate niche partitioning and individual specialization, and outlines key considerations for the associated application of stable isotope ratios.
Collapse
Affiliation(s)
- Philip Matich
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, Texas, 77553, USA
| | - Joseph J Bizzarro
- Moss Landing Marine Laboratories, California State University, 8272 Moss Landing Road, Moss Landing, California, 95039, USA
- Cooperative Institute for Marine Ecosystems and Climate, University of California, Santa Cruz, 110 McAllister Way, Santa Cruz, California, 95060, USA
| | - Oliver N Shipley
- Department of Biology, University of New Mexico, Albuquerque, New Mexico, 87131, USA
| |
Collapse
|
31
|
Riverón S, Raoult V, Baylis AMM, Jones KA, Slip DJ, Harcourt RG. Pelagic and benthic ecosystems drive differences in population and individual specializations in marine predators. Oecologia 2021; 196:891-904. [PMID: 34173892 DOI: 10.1007/s00442-021-04974-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Accepted: 06/13/2021] [Indexed: 11/24/2022]
Abstract
Individual specialization, which describes whether populations are comprised of dietary generalists or specialists, has profound ecological and evolutionary implications. However, few studies have quantified individual specialization within and between sympatric species that are functionally similar but have different foraging modes. We assessed the relationship between individual specialization, isotopic niche metrics and foraging behaviour of two marine predators with contrasting foraging modes: pelagic foraging female South American fur seals (Arctocephalus australis) and benthic foraging female southern sea lions (Otaria byronia). Stable isotope analysis of carbon and nitrogen was conducted along the length of adult female vibrissae to determine isotopic niche metrics and the degree of individual specialization. Vibrissae integrated time ranged between 1.1 and 5.5 years, depending on vibrissae length. We found limited overlap in dietary niche-space. Broader population niche sizes were associated with higher degrees of individual specialization, while narrower population niches with lower degrees of individual specialization. The degree of individual specialization was influenced by pelagic and benthic foraging modes. Specifically, South American fur seals, foraging in dynamic pelagic environments with abundant but similar prey, comprised specialist populations composed of generalist individuals. In contrast, benthic southern sea lions foraging in habitats with diverse but less abundant prey had more generalist populations composed of highly specialized individuals. We hypothesize that differences in specialization within and between populations were related to prey availability and habitat differences. Our study supports growing body of literature highlighting that individual specialization is a critical factor in shaping the ecological niche of higher marine predators.
Collapse
Affiliation(s)
- Sabrina Riverón
- Marine Predator Research Group, Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2113, Australia.
| | - Vincent Raoult
- School of Environmental and Life Sciences, University of Newcastle, Ourimbah, Australia
| | - Alastair M M Baylis
- Marine Predator Research Group, Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2113, Australia.,South Atlantic Environmental Research Institute, Stanley Cottage, PO Box 609, Stanley, FIQQ 1ZZ, Falkland Islands
| | - Kayleigh A Jones
- British Antarctic Survey, High Cross, Madingley Rd, Cambridge, CB3 0ET, UK.,University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK
| | - David J Slip
- Marine Predator Research Group, Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2113, Australia.,Taronga Conservation Society Australia, Bradley's Head Road, Mosman, NSW, 2088, Australia
| | - Robert G Harcourt
- Marine Predator Research Group, Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2113, Australia
| |
Collapse
|
32
|
Carlisle AB, Allan EA, Kim SL, Meyer L, Port J, Scherrer S, O'Sullivan J. Integrating multiple chemical tracers to elucidate the diet and habitat of Cookiecutter Sharks. Sci Rep 2021; 11:11809. [PMID: 34083578 PMCID: PMC8175345 DOI: 10.1038/s41598-021-89903-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 04/27/2021] [Indexed: 12/02/2022] Open
Abstract
The Cookiecutter shark (Isistius brasiliensis) is an ectoparasitic, mesopelagic shark that is known for removing plugs of tissue from larger prey, including teleosts, chondrichthyans, cephalopods, and marine mammals. Although this species is widely distributed throughout the world’s tropical and subtropical oceanic waters, like many deep-water species, it remains very poorly understood due to its mesopelagic distribution. We used a suite of biochemical tracers, including stable isotope analysis (SIA), fatty acid analysis (FAA), and environmental DNA (eDNA), to investigate the trophic ecology of this species in the Central Pacific around Hawaii. We found that large epipelagic prey constituted a relatively minor part of the overall diet. Surprisingly, small micronektonic and forage species (meso- and epipelagic) are the most important prey group for Cookiecutter sharks across the studied size range (17–43 cm total length), with larger mesopelagic species or species that exhibit diel vertical migration also being important prey. These results were consistent across all the tracer techniques employed. Our results indicate that Cookiecutter sharks play a unique role in pelagic food webs, feeding on prey ranging from the largest apex predators to small, low trophic level species, in particular those that overlap with the depth distribution of the sharks throughout the diel cycle. We also found evidence of a potential shift in diet and/or habitat with size and season. Environmental DNA metabarcoding revealed new prey items for Cookiecutter sharks while also demonstrating that eDNA can be used to identify recent prey in stomachs frozen for extended periods. Integrating across chemical tracers is a powerful tool for investigating the ecology of elusive and difficult to study species, such as meso- and bathypelagic chondrichthyans, and can increase the amount of information gained from small sample sizes. Better resolving the foraging ecology of these mesopelagic predators is critical for effective conservation and management of these taxa and ecosystems, which are intrinsically vulnerable to overfishing and exploitation.
Collapse
Affiliation(s)
- Aaron B Carlisle
- School of Marine Science and Policy, University of Delaware, Lewes, DE, USA.
| | - Elizabeth Andruszkiewicz Allan
- Department of Civil and Environmental Engineering, Stanford University, Palo Alto, CA, USA.,School of Marine and Environmental Affairs, University of Washington, Seattle, USA
| | - Sora L Kim
- Department of Life and Environmental Sciences, University of California Merced, Merced, CA, USA
| | - Lauren Meyer
- Southern Shark Ecology Group, College of Science and Engineering, Flinders University, Adelaide, SA, Australia.,Georgia Aquarium, Atlanta, GA, USA
| | - Jesse Port
- Center for Ocean Solutions, Stanford University, Monterey, CA, USA
| | - Stephen Scherrer
- Department of Oceanography, University of Hawaii, Honolulu, HI, USA
| | | |
Collapse
|
33
|
Niella Y, Raoult V, Gaston T, Peddemors VM, Harcourt R, Smoothey AF. Overcoming multi-year impacts of maternal isotope signatures using multi-tracers and fast turnover tissues in juvenile sharks. CHEMOSPHERE 2021; 269:129393. [PMID: 33383247 DOI: 10.1016/j.chemosphere.2020.129393] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 12/16/2020] [Accepted: 12/18/2020] [Indexed: 06/12/2023]
Abstract
Stable isotopes are often used to determine the ecological role of different age classes of animals, but particularly for young animals this approach may be compromised. During gestation and or incubation body tissues of the young are derived directly from the mother. In neonates or post hatching, there is a period of transformation as the young grow and forage independently, but during this period different organs will continue to reflect the maternal isotopic signature as a function of their turnover rate. How long this maternal hangover persists remains poorly understood. We applied a multi-tracer approach (δ15N, δ13C and δ34S) to stable isotope signatures in juvenile bull sharks (Carcharhinus leucas) up to 6.5 years post parturition. We found that maternal provisioning was detectable for up to 3.5 years after birth in muscle but only detectable in young-of-the-year for liver. Inclusion of sulphur revealed when maternal signatures disappeared from low-turnover tissue, while also identifying the spatial and trophic ecology patterns from fast-turnover tissue. These results reveal the importance of sampling fast turnover tissues to study the trophic ecology of juvenile elasmobranchs, and how the use of only δ15N and δ13C isotopes is likely to make maternal patterns more difficult to detect.
Collapse
Affiliation(s)
- Yuri Niella
- Department of Biological Sciences, Macquarie University, North Ryde, 2113, Sydney, New South Wales, Australia.
| | - Vincent Raoult
- School of Environmental and Life Sciences, University of Newcastle, Ourimbah, New South Wales, 2258, Australia
| | - Troy Gaston
- School of Environmental and Life Sciences, University of Newcastle, Ourimbah, New South Wales, 2258, Australia
| | - Victor M Peddemors
- NSW Department of Primary Industries, Fisheries Research, Sydney Institute of Marine Science, Mosman, 2088, Sydney, New South Wales, Australia
| | - Robert Harcourt
- Department of Biological Sciences, Macquarie University, North Ryde, 2113, Sydney, New South Wales, Australia
| | - Amy F Smoothey
- NSW Department of Primary Industries, Fisheries Research, Sydney Institute of Marine Science, Mosman, 2088, Sydney, New South Wales, Australia
| |
Collapse
|
34
|
Shipley ON, Newton AL, Frisk MG, Henkes GA, LaBelle JS, Camhi MD, Hyatt M, Walters H, Olin JA. Telemetry‐validated nitrogen stable isotope clocks identify ocean‐to‐estuarine habitat shifts in mobile organisms. Methods Ecol Evol 2021. [DOI: 10.1111/2041-210x.13567] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Oliver N. Shipley
- School of Marine and Atmospheric Sciences Stony Brook University Stony Brook NY USA
| | - Alisa L. Newton
- Wildlife Conservation Society, New York Aquarium Brooklyn NY USA
| | - Michael G. Frisk
- School of Marine and Atmospheric Sciences Stony Brook University Stony Brook NY USA
| | | | - Jake S. LaBelle
- Wildlife Conservation Society, New York Aquarium Brooklyn NY USA
| | - Merry D. Camhi
- Wildlife Conservation Society, New York Aquarium Brooklyn NY USA
| | - Michael Hyatt
- Wildlife Conservation Society, New York Aquarium Brooklyn NY USA
| | - Hans Walters
- Wildlife Conservation Society, New York Aquarium Brooklyn NY USA
| | - Jill A. Olin
- Great Lakes Research Center Michigan Technological University Houghton MI USA
| |
Collapse
|
35
|
Pahl KB, Yurkowski DJ, Wintner SP, Cliff G, Dicken ML, Hussey NE. Determining the appropriate pretreatment procedures and the utility of liver tissue for bulk stable isotope (δ 13 C and δ 15 N) studies in sharks. JOURNAL OF FISH BIOLOGY 2021; 98:829-841. [PMID: 33251592 DOI: 10.1111/jfb.14635] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 11/11/2020] [Accepted: 11/27/2020] [Indexed: 06/12/2023]
Abstract
Stable-isotope analysis (SIA) provides a valuable tool to address complex questions pertaining to elasmobranch ecology. Liver, a metabolically active, high turnover tissue (~166 days for 95% turnover), has the potential to reveal novel insights into recent feeding/movement behaviours of this diverse group. To date, limited work has used this tissue, but ecological application of SIA in liver requires consideration of tissue preparation techniques given the potential for high concentrations of urea and lipid that could bias δ13 C and δ15 N values (i.e., result in artificially lower δ13 C and δ15 N values). Here we investigated the effectiveness of (a) deionized water washing (WW) for urea removal from liver tissue and (b) chloroform-methanol for extraction of lipids from this lipid rich tissue. We then (a) established C:N thresholds for deriving ecologically relevant liver isotopic values given complications of removing all lipid and (b) undertook a preliminary comparison of δ13 C values between tissue pairs (muscle and liver) to test if observed isotopic differences correlated with known movement behaviour. Tests were conducted on four large shark species: the dusky (DUS, Carcharhinus obscurus), sand tiger (RAG, Carcharias taurus), scalloped hammerhead (SCA, Sphyrna lewini) and white shark (GRE, Carcharodon carcharias). There was no significant difference in δ15 N values between lipid-extracted (LE) liver and lipid-extracted/water washed (WW) treatments, however, WW resulted in significant increases in %N, δ13 C and %C. Following lipid extraction (repeated three times), some samples were still biased by lipids. Our species-specific "C:N thresholds" provide a method to derive ecologically viable isotope data given the complexities of this lipid rich tissue (C:N thresholds of 4.0, 3.6, 4.7 and 3.9 for DUS, RAG, SCA and GRE liverLEWW tissue, respectively). The preliminary comparison of C:N threshold corrected liver and muscle δ13 C values corresponded with movement/habitat behaviours for each shark; minor differences in δ13 C values were observed for known regional movements of DUS and RAG (δ13 CDiffs = 0.24 ± 0.99‰ and 0.57 ± 0.38‰, respectively), while SCA and GRE showed greater differences (1.24 ± 0.63‰ and 1.08 ± 0.71‰, respectively) correlated to large-scale movements between temperate/tropical and pelagic/coastal environments. These data provide an approach for the successful application of liver δ13 C and δ15 N values to examine elasmobranch ecology.
Collapse
Affiliation(s)
- K Blue Pahl
- Department of Integrative Biology, University of Windsor, Windsor, Ontario, Canada
| | - David J Yurkowski
- Fisheries and Oceans Canada, Freshwater Institute, Winnipeg, Manitoba, Canada
| | - Sabine P Wintner
- KwaZulu-Natal Sharks Board, Maritime Centre of Excellence, Umhlanga Rocks, Umhlanga, South Africa
- Biomedical Resource Unit, University of KwaZulu-Natal, Durban, South Africa
- College of Agriculture, Engineering and Science, School of Life Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Geremy Cliff
- KwaZulu-Natal Sharks Board, Maritime Centre of Excellence, Umhlanga Rocks, Umhlanga, South Africa
- Biomedical Resource Unit, University of KwaZulu-Natal, Durban, South Africa
- College of Agriculture, Engineering and Science, School of Life Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Matthew L Dicken
- KwaZulu-Natal Sharks Board, Maritime Centre of Excellence, Umhlanga Rocks, Umhlanga, South Africa
- Department of Development Studies, School of Economics, Development and Tourism, Nelson Mandela University, Port Elizabeth, South Africa
- College of Agriculture, Engineering and Science, School of Life Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Nigel E Hussey
- Department of Integrative Biology, University of Windsor, Windsor, Ontario, Canada
| |
Collapse
|
36
|
van Zinnicq Bergmann MPM, Postaire BD, Gastrich K, Heithaus MR, Hoopes LA, Lyons K, Papastamatiou YP, Schneider EVC, Strickland BA, Talwar BS, Chapman DD, Bakker J. Elucidating shark diets with DNA metabarcoding from cloacal swabs. Mol Ecol Resour 2021; 21:1056-1067. [PMID: 33527665 DOI: 10.1111/1755-0998.13315] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 12/07/2020] [Accepted: 12/18/2020] [Indexed: 12/20/2022]
Abstract
Animal dietary information provides the foundation for understanding trophic relationships, which is essential for ecosystem management. Yet, in marine systems, high-resolution diet reconstruction tools are currently under-developed. This is particularly pertinent for large marine vertebrates, for which direct foraging behaviour is difficult or impossible to observe and, due to their conservation status, the collection of stomach contents at adequate sample sizes is frequently impossible. Consequently, the diets of many groups, such as sharks, have largely remained unresolved. To address this knowledge gap, we applied metabarcoding to prey DNA in faecal residues (fDNA) collected on cotton swabs from the inside of a shark's cloaca. We used a previously published primer set targeting a small section of the 12S rRNA mitochondrial gene to amplify teleost prey species DNA. We tested the utility of this method in a controlled feeding experiment with captive juvenile lemon sharks (Negaprion brevirostris) and on free-ranging juvenile bull sharks (Carcharhinus leucas). In the captive trial, we successfully isolated and correctly identified teleost prey DNA without incurring environmental DNA contamination from the surrounding seawater. In the field, we were able to reconstruct high-resolution teleost dietary information from juvenile C. leucas fDNA that was generally consistent with expectations based on published diet studies of this species. While further investigation is needed to validate the method for larger sharks and other species, it is expected to be broadly applicable to aquatic vertebrates and provides an opportunity to advance our understanding of trophic interactions in marine and freshwater systems.
Collapse
Affiliation(s)
- Maurits P M van Zinnicq Bergmann
- Institute of Environment, Department of Biological Sciences, Florida International University, North Miami, Florida, USA.,Bimini Biological Field Station Foundation, Bimini, The Bahamas
| | - Bautisse D Postaire
- Institute of Environment, Department of Biological Sciences, Florida International University, North Miami, Florida, USA
| | - Kirk Gastrich
- Institute of Environment, Department of Biological Sciences, Florida International University, North Miami, Florida, USA
| | - Michael R Heithaus
- Institute of Environment, Department of Biological Sciences, Florida International University, North Miami, Florida, USA
| | | | | | - Yannis P Papastamatiou
- Institute of Environment, Department of Biological Sciences, Florida International University, North Miami, Florida, USA
| | - Eric V C Schneider
- Exuma Sound Ecosystem Research Project, Cape Eleuthera Institute, Eleuthera, The Bahamas
| | - Bradley A Strickland
- Institute of Environment, Department of Biological Sciences, Florida International University, North Miami, Florida, USA
| | - Brendan S Talwar
- Institute of Environment, Department of Biological Sciences, Florida International University, North Miami, Florida, USA.,Exuma Sound Ecosystem Research Project, Cape Eleuthera Institute, Eleuthera, The Bahamas
| | - Demian D Chapman
- Institute of Environment, Department of Biological Sciences, Florida International University, North Miami, Florida, USA
| | - Judith Bakker
- Institute of Environment, Department of Biological Sciences, Florida International University, North Miami, Florida, USA
| |
Collapse
|
37
|
Shipley ON, Kelly JB, Bizzarro JJ, Olin JA, Cerrato RM, Power M, Frisk MG. Evolution of realized Eltonian niches across
Rajidae
species. Ecosphere 2021. [DOI: 10.1002/ecs2.3368] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Oliver N. Shipley
- School of Marine and Atmospheric Sciences Stony Brook University Stony Brook New York11794USA
| | - Joseph B. Kelly
- Department for Ecology and Evolution Stony Brook University Stony Brook New York11794USA
| | - Joseph J. Bizzarro
- Moss Landing Marine Laboratories California State University 8272 Moss Landing Road Moss Landing California95039USA
- Cooperative Institute for Marine Ecosystems and Climate University of California, Santa Cruz 110 McAllister Way Santa Cruz California95060USA
| | - Jill A. Olin
- Great Lakes Research Center Michigan Technological University Houghton Michigan49931USA
| | - Robert M. Cerrato
- School of Marine and Atmospheric Sciences Stony Brook University Stony Brook New York11794USA
| | - Michael Power
- Department of Biology University of Waterloo 200 University Avenue West Waterloo OntarioN2L 3G1Canada
| | - Michael G. Frisk
- School of Marine and Atmospheric Sciences Stony Brook University Stony Brook New York11794USA
| |
Collapse
|
38
|
Matich P, Plumlee JD, Weideli OC, Fisher M. New insights into the trophic ecology of blacktip sharks (Carcharhinus limbatus) from a subtropical estuary in the western Gulf of Mexico. JOURNAL OF FISH BIOLOGY 2021; 98:470-484. [PMID: 33058185 DOI: 10.1111/jfb.14592] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 10/09/2020] [Accepted: 10/13/2020] [Indexed: 06/11/2023]
Abstract
As environmental change persists, understanding resource use patterns is of value to predict the consequences of shifting trophic structures. While many sharks are opportunistic predators, some exhibit prey selectivity, putting them at higher risk compared to species with greater trophic plasticity. In the Gulf of Mexico (GOM), Clupeids and Sciaenids comprise 69% of blacktip shark (Carcharhinus limbatus) diets, which is consequential considering potential responses of these prey groups to disturbance and over harvesting. We assessed if blacktips exhibit selectivity for Clupeids and Sciaenids in the western GOM based on stomach contents from sharks in coastal Texas. Clupeids comprised <2% of diets, while striped mullet (Mugil cephalus) and red drum (Sciaenops ocellatus) comprised >70% of identifiable prey. Ontogenetic shifts from smaller (Clupeids, small Sciaenids) to larger, higher trophic level (Ariidae, Elasmobranchii) prey fits our understanding of foraging among coastal sharks, and suggests our regional understanding of blacktip trophic ecology may be limited by the sizes of sampled sharks. Observed increases in blacktip densities coupled with declines in prey (Mugilids, Sciaenids) is concerning if blacktips have limited diet plasticity. Yet GOM blacktips may be more generalized than previously thought, which is promising for conservation and management.
Collapse
Affiliation(s)
- Philip Matich
- Marine Biology Department, Texas A&M University at Galveston, Galveston, Texas, USA
| | - Jeffrey D Plumlee
- Institute of Marine Sciences, University of North Carolina at Chapel Hill, Morehead City, North Carolina, USA
| | - Ornella C Weideli
- PSL Research University, EPHE-UPVD-CNRS, USR 3278 CRIOBE, Université de Perpignan, Perpignan, France
| | - Mark Fisher
- Texas Parks and Wildlife Department, Coastal Fisheries Division, Rockport Marine Science Laboratory, Rockport, Texas, USA
| |
Collapse
|
39
|
Souza-Araujo J, Souza-Junior OG, Guimarães-Costa A, Hussey NE, Lima MO, Giarrizzo T. The consumption of shark meat in the Amazon region and its implications for human health and the marine ecosystem. CHEMOSPHERE 2021; 265:129132. [PMID: 33307506 DOI: 10.1016/j.chemosphere.2020.129132] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 11/23/2020] [Accepted: 11/25/2020] [Indexed: 06/12/2023]
Abstract
Here, we evaluated the levels of As, Hg, Pb, and Cd in shark meat sold along the Amazon Coast of Brazil and used nitrogen stable isotope values to determine trophic position and to assess element biomagnification. From market samples, a total of 13 species were identified via molecular analysis, including those listed as endangered and vulnerable by the IUCN Red List. Arsenic was present in significantly higher concentrations than all other elements, followed by Hg, with the highest mean concentrations recorded in M. higmani (As: 19.46 ± 8.79 μg/g ww) and C. acronotus (Hg: 1.12 ± 0.68 μg/g ww). Lead and Cd were recorded at much lower levels in all species. The EWI of individual elements were above PTWI for all species when considering Hg, seven species for inorganic arsenic (iAs), and one species for Pb. The weekly consumption of 10 species should be reduced to less than 416.39 g, which is equivalent to the daily estimated fish consumption rate in the region. The mean (±SD) δ15N values of species ranged from 10.7 ± 0.51‰ in M. higmani to 14.2 ± 0.59‰ in C. porosus, indicating feeding over >1 trophic level. Arsenic was negatively correlated with δ15N values, while Hg was positively correlated indicating biodilution and biomagnification, respectively. Our results indicate that the sale and consumption of shark meat will expose consumers to potentially harmful levels of iAs and Hg, as well as contributing to the population decline of species including those that are currently categorized as threatened.
Collapse
Affiliation(s)
- J Souza-Araujo
- Núcleo de Ecologia Aquática e Pesca da Amazônia, Universidade Federal Do Pará, Av. Perimetral 2651, 66040170, Belém, PA, Brazil.
| | - O G Souza-Junior
- Núcleo de Ecologia Aquática e Pesca da Amazônia, Universidade Federal Do Pará, Av. Perimetral 2651, 66040170, Belém, PA, Brazil.
| | - A Guimarães-Costa
- Instituto de Estudos Costeiros, Universidade Federal Do Pará, Alameda Leandro Ribeiro, 68600 - 000, Bragança, PA, Brazil.
| | - N E Hussey
- Integrative Biology, University of Windsor, Windsor, Ontario, N9B 3P4, Canada.
| | - M O Lima
- Instituto Evandro Chagas. Seção de Meio Ambiente. Rodovia BR-316, Km 7, S/N, 67030000, Ananindeua, PA, Brazil.
| | - T Giarrizzo
- Núcleo de Ecologia Aquática e Pesca da Amazônia, Universidade Federal Do Pará, Av. Perimetral 2651, 66040170, Belém, PA, Brazil.
| |
Collapse
|
40
|
McLennan LJ, Purnell MA. Dental microwear texture analysis as a tool for dietary discrimination in elasmobranchs. Sci Rep 2021; 11:2444. [PMID: 33510241 PMCID: PMC7844039 DOI: 10.1038/s41598-021-81258-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 12/18/2020] [Indexed: 11/09/2022] Open
Abstract
As abundant and widespread predators, elasmobranchs play influential roles in food-web dynamics of marine communities. Clearly, these trophic interactions have significant implications for fisheries management and marine conservation, yet elasmobranch diet is relatively understudied; for the majority of species little or no quantitative dietary data exist. This reflects the difficulties of direct observation of feeding and stomach contents analysis in wild elasmobranchs. Here, by quantifying the 3D surface textures that develop on tooth surfaces as a consequence of feeding, we show that tooth microwear varies with diet in elasmobranchs, providing a new tool for dietary analysis. The technique can be applied to small samples and individuals with no gut contents, and thus offers a way to reduce the impact on wild elasmobranch populations of analysing their dietary ecology, especially relevant in conservation of endangered species. Furthermore, because microwear accumulates over longer periods of time, analysis of texture overcomes the 'snapshot bias' of stomach contents analysis. Microwear texture analysis has the potential to be a powerful tool, complementing existing techniques such as stable isotope analysis, for dietary analysis in living and extinct elasmobranchs.
Collapse
Affiliation(s)
- Laura J McLennan
- Centre for Palaeobiology Research, School of Geography, Geology and the Environment, University of Leicester, Leicester, LE1 7RH, UK. .,Department of Environmental Science, University of Derby, Derby, DE22 1GB, UK.
| | - Mark A Purnell
- Centre for Palaeobiology Research, School of Geography, Geology and the Environment, University of Leicester, Leicester, LE1 7RH, UK.
| |
Collapse
|
41
|
Seasonal patterns in stable isotope and fatty acid profiles of southern stingrays (Hypanus americana) at Stingray City Sandbar, Grand Cayman. Sci Rep 2020; 10:19753. [PMID: 33184444 PMCID: PMC7661509 DOI: 10.1038/s41598-020-76858-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 10/22/2020] [Indexed: 11/24/2022] Open
Abstract
Ecotourism opportunities in the marine environment often rely heavily on provisioning to ensure the viewing of cryptic species by the public. However, intentional feeding of wildlife can impact numerous aspects of an animals’ behavior and ecology. Southern stingrays (Hypanus americana) provisioned at Stingray City Sandbar (SCS) in Grand Cayman have altered diel activity patterns and decreased measures of health. This study looked at seasonal changes in stable isotope (SI) and fatty acid (FA) profiles of provisioned stingrays at SCS. Plasma δ15N was higher in male stingrays (11.86 ± 1.71‰) compared to females (10.70 ± 1.71‰). Lower values for δ15N in males and females were measured in October during low tourist season, suggesting stingrays may be forced to rely on native prey items to supplement the decreased amount of provisioned squid available during this time. Plasma FA profiles were significantly different between sexes and across sampling time points, with FAs 22:6n3, 16:0, 20:5n3, 18:1n3C, 18:0 and 18:1n9T contributing to dissimilarity scores between groups. Dietary FAs primarily contributed to differences between males and females lending further evidence to differences in foraging patterns at SCS, likely due to intraspecific competition. Further, canonical analysis of principal coordinates (CAP) analysis of FA profiles suggest similar diets during peak tourist season and differences in diet between males and females during the low season. This study demonstrates alterations in feeding ecology in stingrays at SCS which is of critical importance for effective management of the SCS aggregation.
Collapse
|
42
|
de Souza-Araujo J, Andrades R, de Oliveira Lima M, Hussey NE, Giarrizzo T. Maternal and embryonic trace element concentrations and stable isotope fractionation in the smalleye smooth-hound (Mustelus higmani). CHEMOSPHERE 2020; 257:127183. [PMID: 32497841 DOI: 10.1016/j.chemosphere.2020.127183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/18/2020] [Accepted: 05/21/2020] [Indexed: 06/11/2023]
Abstract
Here, we evaluate maternal offloading of 16 trace elements (Essential: Co, Cr, Cu, Fe, Mn, Ni, Se and Zn; Nonessential: Al, As, Ba, Cd, Hg, Pb, Tl and U) and determine mother-offspring isotopic fractionation of δ13C and δ15N in muscle and liver tissue of four pregnant Mustelus higmani and 18 associated embryos sampled from the Amazon Coast of Brazil. Embryo muscle tissue had significantly higher concentrations of most trace elements when compared to mothers, with the exception of Hg. Embryo liver accumulated more nonessential elements than muscle (n = 7 vs. 0, respectively), while the Se:Hg molar ratio was >1 in liver and muscle of both mothers and embryos. Livers of embryos were moderately enriched in δ13C and δ15N when compared to that of their mother. Negative correlations were observed between embryo body length and δ13C and trace elements concentrations. We conclude that mothers offload a large portion of all essential elements and Al, As and Pb to their young and that the isotopic fractionation of embryos reflects maternal diet and habitat occupied, with δ13C diluted with embryonic growth. We also show that muscle and liver accumulate trace elements at different rates relative to the body length of embryos. The Se:Hg molar ratio suggests that Se could play a protective role against Hg toxicity during early stages of M. higmani embryonic development.
Collapse
Affiliation(s)
- Juliana de Souza-Araujo
- Núcleo de Ecologia Aquática e Pesca da Amazônia, Universidade Federal Do Pará, Belém, PA, Brazil.
| | - Ryan Andrades
- Núcleo de Ecologia Aquática e Pesca da Amazônia, Universidade Federal Do Pará, Belém, PA, Brazil; Laboratório de Ictiologia, Departamento de Oceanografia e Ecologia, Universidade Federal Do Espírito Santo, Vitória, ES, Brazil
| | - Marcelo de Oliveira Lima
- Laboratório de Toxicologia, Sessão de Meio Ambiente, Instituto Evandro Chagas, Ananindeua, PA, Brazil
| | - Nigel E Hussey
- Integrative Biology. University of Windsor. Windsor, Ontario, Canada
| | - Tommaso Giarrizzo
- Núcleo de Ecologia Aquática e Pesca da Amazônia, Universidade Federal Do Pará, Belém, PA, Brazil
| |
Collapse
|
43
|
Osgood GJ, Timmer B, Cox K, Juanes F, Baum JK. Differences in δ 15 N and δ 13 C between embryonic and maternal tissues of the ovoviviparous bluntnose sixgill shark Hexanchus griseus. JOURNAL OF FISH BIOLOGY 2020; 96:1060-1064. [PMID: 32060916 DOI: 10.1111/jfb.14294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 01/14/2020] [Accepted: 02/13/2020] [Indexed: 06/10/2023]
Abstract
Stable nitrogen (δ15 N) and carbon (δ13 C) isotope ratios from muscle, liver and yolk were analysed from the mother and embryos of an ovoviviparous shark, Hexanchus griseus. Embryonic liver and muscle had similar δ15 N and δ13 C ratios or were depleted in heavy isotopes, compared to the same maternal somatic and reproductive yolk tissues, but no relationship existed between δ15 N or δ13 C and embryo length, as expected, because a switch to placental nourishment is lacking in this species. This study expands the understanding of maternal nourishment and embryonic stable isotope differences in ovoviviparous sharks.
Collapse
Affiliation(s)
- Geoffrey J Osgood
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
| | - Brian Timmer
- Department of Geography, University of Victoria, Victoria, British Columbia, Canada
| | - Kieran Cox
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
- Hakai Institute, Calvert Island, British Columbia, Canada
| | - Francis Juanes
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
| | - Julia K Baum
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
| |
Collapse
|
44
|
Petta JC, Shipley ON, Wintner SP, Cliff G, Dicken ML, Hussey NE. Are you really what you eat? Stomach content analysis and stable isotope ratios do not uniformly estimate dietary niche characteristics in three marine predators. Oecologia 2020; 192:1111-1126. [DOI: 10.1007/s00442-020-04628-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Accepted: 02/27/2020] [Indexed: 10/24/2022]
|
45
|
Morgan C, Shipley ON, Gelsleichter J. Resource-use dynamics of co-occurring chondrichthyans from the First Coast, North Florida, USA. JOURNAL OF FISH BIOLOGY 2020; 96:570-579. [PMID: 31858583 DOI: 10.1111/jfb.14238] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 12/18/2019] [Indexed: 06/10/2023]
Abstract
Recent studies on shark assemblages on the northeast Florida and southeast Georgia coast (hereafter referred to collectively as the "First Coast") have demonstrated differences in species and age-class composition of catch from previously characterized estuaries and newly surveyed area beaches, demonstrating that these regions may provide a critical habitat to different segments (i.e., life stages) of local shark populations. In this study, carbon and nitrogen stable isotopes (δ13 C and δ15 N) from muscle tissue and blood plasma were used to examine trophic dynamics (and temporal variability thereof) of the three dominant co-occurring species found along First Coast beaches (the Atlantic Sharpnose shark Rhizoprionodon terraenovae, Blacknose shark Carcharhinus acronotus and Blacktip shark Carcharhinus limbatus) to determine if they exhibit overlap in resource use along with spatial and temporal habitat use. Although considered spatially segregated from the beach species, a dominant, age-class species found in First Coast estuaries (juvenile Sandbar sharks Carcharhinus plumbeus) was also included in this analysis for comparison. Temporal variability of resource-use characteristics was detected at the species level. Resource-use overlap among species varied by tissue type and was generally higher for blood plasma, suggesting greater resource sharing over more recent time periods. Over longer time periods Atlantic Sharpnose and Blacktip sharks exhibited resource-use expansion, whereas Blacknose sharks exhibited a narrowing in resource use, suggesting a more specialized foraging strategy compared to the other species. The resource-use breadth of Sandbar sharks also expanded between blood plasma and muscle tissue. Significant size relationships were detected in Blacktip and Sandbar sharks, indicating ontogenetic resource shifts for both species. A diversity of highly productive resource pools likely support shark populations along the First Coast such that resource-use differentiation is not required to facilitate species co-occurrence. This work may shed light on understanding patterns of species co-occurrence as well as aid in future conservation efforts.
Collapse
Affiliation(s)
- Clark Morgan
- Department of Biology, University of North Florida, Jacksonville, Florida, USA
| | - Oliver N Shipley
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, New York, USA
| | - James Gelsleichter
- Department of Biology, University of North Florida, Jacksonville, Florida, USA
| |
Collapse
|
46
|
Hancock TL, Poulakis GR, Scharer RM, Tolley SG, Urakawa H. High-resolution molecular identification of smalltooth sawfish prey. Sci Rep 2019; 9:18307. [PMID: 31797939 PMCID: PMC6892823 DOI: 10.1038/s41598-019-53931-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Accepted: 10/17/2019] [Indexed: 11/18/2022] Open
Abstract
The foundation of food web analysis is a solid understanding of predator-prey associations. Traditional dietary studies of fishes have been by stomach content analysis. However, these methods are not applicable to Critically Endangered species such as the smalltooth sawfish (Pristis pectinata). Previous research using the combination of stable isotope signatures from fin clips and 18S rRNA gene sequencing of fecal samples identified the smalltooth sawfish as piscivorous at low taxonomic resolution. Here, we present a high taxonomic resolution molecular technique for identification of prey using opportunistically acquired fecal samples. To assess potential biases, primer sets of two mitochondrial genes, 12S and 16S rRNA, were used alongside 18S rRNA, which targets a wider spectrum of taxa. In total, 19 fish taxa from 7 orders and 11 families native to the Gulf of Mexico were successfully identified. The sawfish prey comprised diverse taxa, indicating that this species is a generalist piscivore. These findings and the molecular approach used will aid recovery planning for the smalltooth sawfish and have the potential to reveal previously unknown predator-prey associations from a wide range of taxa, especially rare and hard to sample species.
Collapse
Affiliation(s)
- Taylor L Hancock
- Department of Ecology and Environmental Studies, The Water School, Florida Gulf Coast University, Fort Myers, Florida, 33965, USA
| | - Gregg R Poulakis
- Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission, Charlotte Harbor Field Laboratory, Port Charlotte, Florida, 33954, USA
| | - Rachel M Scharer
- Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission, Charlotte Harbor Field Laboratory, Port Charlotte, Florida, 33954, USA
| | - S Gregory Tolley
- Department of Marine and Earth Sciences, The Water School, Florida Gulf Coast University, Fort Myers, Florida, 33965, USA
| | - Hidetoshi Urakawa
- Department of Ecology and Environmental Studies, The Water School, Florida Gulf Coast University, Fort Myers, Florida, 33965, USA.
| |
Collapse
|
47
|
Weideli OC, Kiszka JJ, Matich P, Heithaus MR. Effects of anticoagulants on stable-isotope values (δ 13 C and δ 15 N) of shark blood components. JOURNAL OF FISH BIOLOGY 2019; 95:1535-1539. [PMID: 31621068 DOI: 10.1111/jfb.14164] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 10/15/2019] [Indexed: 06/10/2023]
Abstract
The effects of anticoagulant EDTA and sodium heparin (SH) on stable carbon δ13 C and nitrogen δ15 N isotopic values of red blood cells (RBC) and blood plasma in juvenile blacktip reef sharks Carcharhinus melanopterus were analysed. Plasma preserved with anticoagulants was not isotopically distinct from plasma stored in no-additive control tubes but RBC δ15 N values exhibited small enrichments when preserved with EDTA and SH. Results suggest EDTA and SH are viable anticoagulants for stable isotopic analyses of blood fractions but further studies are advised to validate results.
Collapse
Affiliation(s)
- Ornella C Weideli
- PSL Research University, EPHE-UPVD-CNRS, USR 3278 CRIOBE, Université de Perpignan, Perpignan, France
- Save Our Seas Foundation - D'Arros Research Centre (SOSF-DRC), Geneva, Switzerland
| | - Jeremy J Kiszka
- Marine Sciences Program, Department of Biological Sciences, Florida International University, North Miami, Florida
| | - Philip Matich
- Department of Marine Biology, Texas A & M University at Galveston, Galveston, Texas
| | - Michael R Heithaus
- Marine Sciences Program, Department of Biological Sciences, Florida International University, North Miami, Florida
| |
Collapse
|
48
|
Seubert EA, Hussey N, Powers SP, Valentine JF, Drymon JM. Assessing trophic flexibility of a predator assemblage across a large estuarine seascape using blood plasma stable isotope analysis. FOOD WEBS 2019. [DOI: 10.1016/j.fooweb.2019.e00132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
49
|
Raoult V, Broadhurst MK, Peddemors VM, Williamson JE, Gaston TF. Resource use of great hammerhead sharks (Sphyrna mokarran) off eastern Australia. JOURNAL OF FISH BIOLOGY 2019; 95:1430-1440. [PMID: 31613987 DOI: 10.1111/jfb.14160] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 09/27/2019] [Indexed: 06/10/2023]
Abstract
Great hammerhead sharks Sphyrna mokarran are the largest member of Sphyrnidae, yet the roles of these large sharks in the food webs of coastal ecosystems are still poorly understood. Here we obtained samples of muscle, liver and vertebrae from large S. mokarran (234-383 cm total length; LT ) caught as by-catch off eastern Australia and used stable-isotope analyses of δ15 N, δ13 C and δ34 S to infer their resource use and any associated ontogenetic patterns. The results indicated large S. mokarran are apex predators primarily relying on other sharks and rays for their diet, with a preference for benthic resources such as Australian cownose rays Rhinoperon neglecta during the austral summer. Teleosts, cephalopods and crustaceans were not significant components of S. mokarran diets, though some conspecifics appeared to rely on more diverse resources over the austral summer. Ontogenetic shifts in resource use were detected but trajectories of the increases in trophic level varied among individuals. Most S. mokarran had non-linear trajectories in ontogenetic resource-use shifts implying size was not the main explanatory factor. Stable isotope values of δ13 C and δ34 S in muscle suggest S. mokarran span coastal, pelagic and benthic food webs in eastern Australia.
Collapse
Affiliation(s)
- Vincent Raoult
- School of Environmlental and Life Sciences, University of Newcastle, Ourimbah, Australia
| | - Matt K Broadhurst
- New South Wales Department of Industries, Fisheries Conservation Technology Unit, National Marine Science Centre, Coffs Harbour, Australia
| | - Vic M Peddemors
- New South Wales of Department of Primary Industries, Fisheries, Sydney Institute of Marine Science, Mosman, Australia
| | - Jane E Williamson
- Department of Biological Sciences, Macquarie University, Sydney, Australia
| | - Troy F Gaston
- School of Environmlental and Life Sciences, University of Newcastle, Ourimbah, Australia
| |
Collapse
|
50
|
Peel LR, Daly R, Keating Daly CA, Stevens GMW, Collin SP, Meekan MG. Stable isotope analyses reveal unique trophic role of reef manta rays ( Mobula alfredi) at a remote coral reef. ROYAL SOCIETY OPEN SCIENCE 2019; 6:190599. [PMID: 31598296 PMCID: PMC6774984 DOI: 10.1098/rsos.190599] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 08/08/2019] [Indexed: 06/10/2023]
Abstract
Stable isotope analyses provide the means to examine the trophic role of animals in complex food webs. Here, we used stable isotope analyses to characterize the feeding ecology of reef manta rays (Mobula alfredi) at a remote coral reef in the Western Indian Ocean. Muscle samples of M. alfredi were collected from D'Arros Island and St. Joseph Atoll, Republic of Seychelles, in November 2016 and 2017. Prior to analysis, lipid and urea extraction procedures were tested on freeze-dried muscle tissue in order to standardize sample treatment protocols for M. alfredi. The lipid extraction procedure was effective at removing both lipids and urea from samples and should be used in future studies of the trophic ecology of this species. The isotopic signatures of nitrogen (δ15N) and carbon (δ13C) for M. alfredi differed by year, but did not vary by sex or life stage, suggesting that all individuals occupy the same trophic niche at this coral reef. Furthermore, the isotopic signatures for M. alfredi differed to those for co-occurring planktivorous fish species also sampled at D'Arros Island and St. Joseph Atoll, suggesting that the ecological niche of M. alfredi is unique. Pelagic zooplankton were the main contributor (45%) to the diet of M. alfredi, combined with emergent zooplankton (38%) and mesopelagic prey items (17%). Given the extent of movement that would be required to undertake this foraging strategy, individual M. alfredi are implicated as important vectors of nutrient supply around and to the coral reefs surrounding D'Arros Island and St. Joseph Atoll, particularly where substantial site fidelity is displayed by these large elasmobranchs.
Collapse
Affiliation(s)
- Lauren R. Peel
- School of Biological Sciences, The Oceans Graduate School, The University of Western Australia, Crawley, Western Australia 6009, Australia
- The Australian Institute of Marine Science, Crawley, Western Australia 6009, Australia
- Save Our Seas Foundation – D'Arros Research Centre (SOSF-DRC), Rue Philippe Plantamour 20, 1201 Genève, Switzerland
- The Manta Trust, Catemwood House, Norwood Lane, Corscombe, Dorset DT2 0NT, UK
| | - Ryan Daly
- Save Our Seas Foundation – D'Arros Research Centre (SOSF-DRC), Rue Philippe Plantamour 20, 1201 Genève, Switzerland
- South African Institute for Aquatic Biodiversity (SAIAB), Private Bag 1015, Grahamstown 6140, South Africa
| | - Clare A. Keating Daly
- Save Our Seas Foundation – D'Arros Research Centre (SOSF-DRC), Rue Philippe Plantamour 20, 1201 Genève, Switzerland
| | - Guy M. W. Stevens
- The Manta Trust, Catemwood House, Norwood Lane, Corscombe, Dorset DT2 0NT, UK
| | - Shaun P. Collin
- School of Biological Sciences, The Oceans Graduate School, The University of Western Australia, Crawley, Western Australia 6009, Australia
- School of Life Sciences, La Trobe University, Bundoora, Victoria 3086, Australia
| | - Mark G. Meekan
- The Australian Institute of Marine Science, Crawley, Western Australia 6009, Australia
| |
Collapse
|