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Schaub J, McLaskey AK, Forster I, Hunt BPV. Size‐based changes in trophic ecology and nutritional quality of moon jellyfish (
Aurelia labiata
). Ecosphere 2023. [DOI: 10.1002/ecs2.4430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023] Open
Affiliation(s)
- Jessica Schaub
- Institute for the Oceans and Fisheries University of British Columbia Vancouver British Columbia Canada
- Department of Earth, Ocean, and Atmospheric Sciences University of British Columbia Vancouver British Columbia Canada
| | - Anna K. McLaskey
- Institute for the Oceans and Fisheries University of British Columbia Vancouver British Columbia Canada
- Hakai Institute Heriot Bay British Columbia Canada
| | - Ian Forster
- Pacific Science Enterprise Center Fisheries and Oceans Canada West Vancouver British Columbia Canada
| | - Brian P. V. Hunt
- Institute for the Oceans and Fisheries University of British Columbia Vancouver British Columbia Canada
- Department of Earth, Ocean, and Atmospheric Sciences University of British Columbia Vancouver British Columbia Canada
- Hakai Institute Heriot Bay British Columbia Canada
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2
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Using Drones to Measure Jellyfish Density in Shallow Estuaries. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2021. [DOI: 10.3390/jmse9060659] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Understanding jellyfish ecology and roles in coastal ecosystems is challenging due to their patchy distribution. While standard net sampling or manned aircraft surveys are inefficient, Unmanned Aerial Vehicles (UAVs) or drones represent a promising alternative for data collection. In this technical report, we used pictures taken from a small drone to estimate the density of Aurelia sp. in a shallow fjord with a narrow entrance, where the population dynamic is well-known. We investigated the ability of an image processing software to count small and translucent jellyfish from the drone pictures at three locations with different environmental conditions (sun glare, waves or seagrass). Densities of Aurelia sp. estimated from semiautomated and manual counts from drone images were similar to densities estimated by netting. The semiautomated program was able to highlight the medusae from the background in order to discard false detections of items unlikely to be jellyfish. In spite of this, some objects (e.g., seagrass) were hardly distinguishable from jellyfish and resulted in a small number of false positives. This report presents a preview of the possible applications of drones to observe small and fragile jellyfishes, for which in situ sampling remains delicate. Drones may represent a noninvasive approach to monitoring jellyfish abundance over time, enabling the collection of a large amount of data in a short time. Software development may be useful for automatically measuring jellyfish size and even population biomass.
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Stenvers V, Chi X, Javidpour J. Seasonal variability of the fatty acid composition in Aurelia aurita (Cnidaria: Scyphozoa): implications for gelativore food web studies. JOURNAL OF PLANKTON RESEARCH 2020; 42:440-452. [PMID: 32665765 PMCID: PMC7344386 DOI: 10.1093/plankt/fbaa026] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 05/04/2020] [Indexed: 06/11/2023]
Abstract
Jellyfish population play an important role in aquatic food chains, and many animals predate on this 'mostly water containing' organisms. However, what gelativores predators could gain from their prey is still poorly understood. This study provides insight into the nutritional value of the moon jelly (Aurelia aurita) by means of its fatty acid (FA) composition, while investigating seasonal variability and differences between its free-swimming life stages. A biweekly sampling was carried out in a temperate coastal ecosystem, the Kiel Fjord, Germany and during two consecutive years. FA profile of A. aurita showed significant seasonal variability, while mature medusae (due to reproductive tissues) possessed highest FA content. In addition, moon jelly contained several essential FAs (i.e. arachidonic acid, 20:4ω6; eicosapentaenoic acid, 20:5ω3; docosahexaenoic acid, 22:6ω3), which likely support predator's vital physiological functions. Even though total FA contents proved to be low (7 × 10-3-34 × 10-3% per g dry weight), evidence supporting A. aurita's capability to meet the dietary requirements of predators such as fish and crustaceans is provided. Finally, implications for gelativore and future food web configurations are discussed, while proposing that jellyfish are likely to be, and become, more than an opportunistic prey to many organisms.
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Affiliation(s)
- Vanessa Stenvers
- Faculty of Science and Engineering, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Xupeng Chi
- Key Laboratory of Marine Ecology & Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences (IOCAS), Nanhai Road 7, Qingdao 266071, China
| | - Jamileh Javidpour
- Department of Biology, University of Southern Denmark, Campusvej 55, 5230-Odense, Denmark
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Chow S, Inaba N, Nagai S, Kurogi H, Nakamura Y, Yanagimoto T, Tanaka H, Hasegawa D, Asakura T, Kikuchi J, Tomoda T, Kodama T. Molecular diet analysis of Anguilliformes leptocephalus larvae collected in the western North Pacific. PLoS One 2019; 14:e0225610. [PMID: 31774866 PMCID: PMC6881025 DOI: 10.1371/journal.pone.0225610] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 11/07/2019] [Indexed: 11/18/2022] Open
Abstract
Natural diets of leptocephalus larvae have been enigmatic. In this study, we collected DNA samples from the gut contents and body surface of leptocephali belonging to the five Anguilliform families (Anguillidae, Chlopsidae, Congridae, Muraenidae, and Serrivomeridae) from the northwest Pacific and performed next-generation 18S rDNA sequencing. Wide variety of eukaryotes was detected in both samples, from which eight eukaryotic groups (jellyfish, conoid parasite, tunicate, copepod, krill, segmented worm, fungi, and dinoflagellate) were selected on the basis of abundance. All groups except conoid parasites were common in both the samples. Cnidarian 18S rDNA reads were the most abundant in both the samples; however, the number of samples having cnidarian reads and the read counts were significantly higher in the body surface scraping samples than in the gut content samples, regardless of careful rinsing of the body surface. These results indicate that the cnidarian DNAs are most likely found because of cross contamination from the body surface and/or environment. 18S rDNA read counts of copepod and tunicate in the gut contents were greater than or comparable with those in the body surface scraping samples, which may correspond to the previous observations of fecal pellets and larvacean houses in the leptocephali gut. Thus, the present study supports previous implications that leptocephali utilize detritus materials, so called marine snow.
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Affiliation(s)
- Seinen Chow
- National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, Kanazawa, Yokohama, Japan
- * E-mail:
| | - Nobuharu Inaba
- National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, Kanazawa, Yokohama, Japan
- Civil Engineering Research Institute for Cold Region, Public Works Research Institute, Sapporo, Hokkaido, Japan
| | - Satoshi Nagai
- National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, Kanazawa, Yokohama, Japan
| | - Hiroaki Kurogi
- National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, Kanazawa, Yokohama, Japan
| | - Yoji Nakamura
- National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, Kanazawa, Yokohama, Japan
| | - Takashi Yanagimoto
- National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, Kanazawa, Yokohama, Japan
| | - Hideki Tanaka
- Aquaculture Research Institute, Kindai University, Higashimuro, Wakayama, Japan
| | - Daisuke Hasegawa
- Tohoku National Fisheries Research Institute, Japan Fisheries Research and Education Agency, Shiogama, Miyagi, Japan
| | - Taiga Asakura
- RIKEN Center for Sustainable Resource Science, Tsurumi, Yokohama, Japan
| | - Jun Kikuchi
- RIKEN Center for Sustainable Resource Science, Tsurumi, Yokohama, Japan
| | - Tsutomu Tomoda
- Shibushi Station, National Research Institute of Aquaculture, Japan Fisheries Research and Education Agency, Shibushi, Kagoshima, Japan
| | - Taketoshi Kodama
- National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, Kanazawa, Yokohama, Japan
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Yang Z, Chen X, Zhao N, Tang H, Tao J, Zhang P, Shi F, Wan C. The Effect of Different Habitat Types and Ontogenetic Stages on the Diet Shift of a Critically Endangered Fish Species, Coreius guichenoti (Sauvage and Dabry de Thiersant, 1874). INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2018; 15:ijerph15102240. [PMID: 30322085 PMCID: PMC6210248 DOI: 10.3390/ijerph15102240] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 09/18/2018] [Accepted: 10/09/2018] [Indexed: 11/16/2022]
Abstract
This study examined the effect of habitat types and ontogenetic stages on the diet shift of Coreius guichenoti (Sauvage and Dabry de Thiersant, 1874), a critically endangered fish species. Based on the stable isotope analysis method, the following was explored: the variations in δ13C and δ15N values, isotopic niche width and four basal food sources (Mollusks, Macrocrustaceans, Aquatic insect larvae and particulate organic matters (POMs)) among three essential habitat types (the spawning ground, natural riverine feeding and nursery area, and Three Gorges Reservoir area) and between two ontogenetic stages (immature and fully mature stages). A diet shift associated with habitat type changes was observed, but there were no obvious differences in diet composition between the two ontogenetic stages. Dietary plasticity and a preference for specific foods were the important determinants of feeding behavior through the life history of this species. POM was important for the survival of this species in the resource-limited spawning ground, but this species fed more heavily on higher-order consumers in resource-abundant areas. This study highlights the importance of maintaining free connectivity among different habitats (particularly spawning grounds) to ensure the long-term sustainability of potamodromous fish species as well as the full investigation of all types of critical habitats for understanding the trophic ecology of a single fish species.
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Affiliation(s)
- Zhi Yang
- Key Laboratory of Ministry of Water Resources for Ecological Impacts of Hydraulic-Projects and Restoration of Aquatic Ecosystem, Institute of Hydroecology, Ministry of Water Resources & Chinese Academy of Sciences, Wuhan 430079, China.
| | - Xiaojuan Chen
- Key Laboratory of Ministry of Water Resources for Ecological Impacts of Hydraulic-Projects and Restoration of Aquatic Ecosystem, Institute of Hydroecology, Ministry of Water Resources & Chinese Academy of Sciences, Wuhan 430079, China.
| | - Na Zhao
- Key Laboratory of Ministry of Water Resources for Ecological Impacts of Hydraulic-Projects and Restoration of Aquatic Ecosystem, Institute of Hydroecology, Ministry of Water Resources & Chinese Academy of Sciences, Wuhan 430079, China.
| | - Huiyuan Tang
- Key Laboratory of Ministry of Water Resources for Ecological Impacts of Hydraulic-Projects and Restoration of Aquatic Ecosystem, Institute of Hydroecology, Ministry of Water Resources & Chinese Academy of Sciences, Wuhan 430079, China.
| | - Jiangping Tao
- Key Laboratory of Ministry of Water Resources for Ecological Impacts of Hydraulic-Projects and Restoration of Aquatic Ecosystem, Institute of Hydroecology, Ministry of Water Resources & Chinese Academy of Sciences, Wuhan 430079, China.
| | - Peng Zhang
- State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China.
| | - Fang Shi
- Key Laboratory of Ministry of Water Resources for Ecological Impacts of Hydraulic-Projects and Restoration of Aquatic Ecosystem, Institute of Hydroecology, Ministry of Water Resources & Chinese Academy of Sciences, Wuhan 430079, China.
| | - Chengyan Wan
- Key Laboratory of Ministry of Water Resources for Ecological Impacts of Hydraulic-Projects and Restoration of Aquatic Ecosystem, Institute of Hydroecology, Ministry of Water Resources & Chinese Academy of Sciences, Wuhan 430079, China.
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Milisenda G, Rossi S, Vizzini S, Fuentes VL, Purcell JE, Tilves U, Piraino S. Seasonal variability of diet and trophic level of the gelatinous predator Pelagia noctiluca (Scyphozoa). Sci Rep 2018; 8:12140. [PMID: 30108231 PMCID: PMC6092325 DOI: 10.1038/s41598-018-30474-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 07/30/2018] [Indexed: 01/23/2023] Open
Abstract
Jellyfish populations apparently have increased in some places around the world and human problems with them also have increased. However, effects of jellyfish outbreaks in the ecosystems remain poorly understood and little or no information is available on their dietary preferences - in relation to the seasonal shifts of prey abundance - and on the potential variability of their impact on marine food webs. The mauve stinger Pelagia noctiluca (Forsskål, 1775) is by far the most common outbreak-forming scyphozoan jellyfish in the Western Mediterranean. By use of a combination of stomach contents, stable isotope (SI) and fatty acid (FA) analyses, we tested the hypothesis that changes in the seasonal dietary sources of P. noctiluca parallel changes in the FA and SI composition. Stomach content and biomarker analyses suggested that P. noctiluca is not a selective predator, cyclically shifting between carnivory and omnivory depending on the seasonality of accessible prey. The combination of SI and FA analyses highlighted the importance of microzooplankton as prey. Specific FA biomarkers showed that the diet of P. noctiluca changed seasonally depending on the availability of living plankton or suspended detritus. This study also revealed significant biochemical differences between jellyfish somatic and gonadal tissues, with total fatty acid concentration in the gonads up to ten times higher than in the somatic tissues.
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Affiliation(s)
- Giacomo Milisenda
- Institute for Coastal Marine Environment (IAMC), National Research Council (CNR), Via L. Vaccara n 61, Mazara del Vallo (TP), 91026, Italy. .,CONISMA - Consorzio Nazionale Interuniversitario per le Scienze del Mare, 00196, Rome, Italy.
| | - Sergio Rossi
- CONISMA - Consorzio Nazionale Interuniversitario per le Scienze del Mare, 00196, Rome, Italy.,Department of Biological and Environmental Sciences and Technologies, University of Salento, 73100, Lecce, Italy
| | - Salvatrice Vizzini
- CONISMA - Consorzio Nazionale Interuniversitario per le Scienze del Mare, 00196, Rome, Italy.,Department of Earth and Marine Sciences, University of Palermo, via Archirafi 18, 90100, Palermo, Italy
| | - Veronica L Fuentes
- Institut de Ciències del Mar, ICM-CSIC, PG. Maritim de la Barceloneta, 08003, Barcelona, Spain
| | - Jennifer E Purcell
- Western Washington University, Department of Biology, Bellingham, WA, 98225, USA
| | - Uxue Tilves
- Institut de Ciències del Mar, ICM-CSIC, PG. Maritim de la Barceloneta, 08003, Barcelona, Spain
| | - Stefano Piraino
- CONISMA - Consorzio Nazionale Interuniversitario per le Scienze del Mare, 00196, Rome, Italy. .,Department of Biological and Environmental Sciences and Technologies, University of Salento, 73100, Lecce, Italy.
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Riascos JM, Aguirre W, Hopfe C, Morales D, Navarrete Á, Tavera J. Floating nurseries? Scyphozoan jellyfish, their food and their rich symbiotic fauna in a tropical estuary. PeerJ 2018; 6:e5057. [PMID: 29942701 PMCID: PMC6014317 DOI: 10.7717/peerj.5057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 06/03/2018] [Indexed: 11/20/2022] Open
Abstract
Background The anthropogenic modification of trophic pathways is seemingly prompting the increase of jellyfish populations at the expense of planktivorous fishes. However, gross generalizations are often made because the most basic aspects of trophic ecology and the diverse interactions of jellyfish with fishes remain poorly described. Here we inquire on the dynamics of food consumption of the medusoid stage of the scyphozoan jellyfish Stomolophus meleagris and characterize the traits and diversity of its symbiotic community. Methods S. meleagris and their associated fauna were sampled in surface waters between November 2015 and April 2017 in Málaga Bay, an estuarine system at the Colombian Pacific. Stomach contents of medusae were examined and changes in prey composition and abundance over time analysed using a multivariate approach. The associated fauna was identified and the relationship between the size of medusae and the size those organisms tested using least-square fitting procedures. Results The presence of S. meleagris medusa in surface waters was seasonal. The gut contents analysis revealed that algae, copepods and fish early life stages were the more abundant items, and PERMANOVA analysis showed that the diet differed within the seasons (P(perm) = 0.001) but not between seasons (P(perm) = 0.134). The majority of the collected medusae (50.4%) were associated with individuals of 11 symbiotic species, 95.3% of them fishes, 3.1% crustaceans and 1.6% molluscs. Therefore, this study reports 10 previously unknown associations. The bell diameter of S. meleagris was positively related to the body sizes of their symbionts. However, a stronger fit was observed when the size relationship between S. meleagris and the fish Hemicaranx zelotes was modelled. Discussion The occurrence of S. meleagris was highly seasonal, and the observed patterns of mean body size through the seasons suggested the arrival of adult medusae to the estuary from adjacent waters. The diet of S. meleagris in the study area showed differences with previous reports, chiefly because of the abundance of algae that are seemingly ingested but not digested. The low number of zooplanktonic items in gut contents suggest the contribution of alternative food sources not easily identifiable. The observed changes in the composition of food in the guts probably reflect seasonal changes in the availability of prey items. The regular pattern in the distribution of symbionts among medusae (a single symbiont per host) and the positive host-symbiont size relationship reflects antagonistic intraspecific and interspecific behaviour of the symbiont. This strongly suggest that medusa represent an “economically defendable resource” that potentially increases the survival and recruitment of the symbionts to the adult population. We argue that, if this outcome of the symbiotic association can be proven, scyphozoan jellyfish can be regarded as floating nurseries.
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Affiliation(s)
- José M Riascos
- Instituto de Ciencias del Mar y Limnología, Universidad del Valle, Cali, Colombia
| | - Willington Aguirre
- Bahía Málaga, Consejo Comunitario Comunidad Negra de La Plata Bahía Málaga, Buenaventura, Colombia
| | - Charlotte Hopfe
- Department of Biomaterials, Universität Bayreuth, Bayreuth, Germany
| | - Diego Morales
- Instituto de Ciencias del Mar y Limnología, Universidad del Valle, Cali, Colombia
| | - Ángela Navarrete
- Instituto de Ciencias del Mar y Limnología, Universidad del Valle, Cali, Colombia
| | - José Tavera
- Instituto de Ciencias del Mar y Limnología, Universidad del Valle, Cali, Colombia
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Höhn DP, Lucas CH, Thatje S. Respiratory response to temperature of three populations of Aurelia aurita polyps in northern Europe. PLoS One 2017; 12:e0177913. [PMID: 28545145 PMCID: PMC5435318 DOI: 10.1371/journal.pone.0177913] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 05/05/2017] [Indexed: 11/19/2022] Open
Abstract
The benthic life stage (polyp or scyphistoma) of the bloom-forming jellyfish, Aurelia aurita (Linnaeus, 1759), also known as the moon jellyfish, contributes to the seasonal occurrence and abundance of medusa blooms via asexual reproduction. A. aurita is widely distributed in coastal areas in northern Europe, and one of the most studied jellyfish species. While the physiology of the visible medusa is largely understood, understanding of the physiology of the perennial benthic life-stage is scarce. To measure the physiological tolerance of A. aurita, the scyphistoma's temperature sensitivity across its distributional range was investigated. Respiration rates of polyps from three northern European locations exposed to 11 temperatures between 2 and 22°C were measured. There was a significant difference in respiration rate among the three polyp populations, which may reflect on differences in their thermal tolerance window. A critical temperature was reached at 14°C with the metabolic rate decreasing below and above that temperature. This pattern was less pronounced in the Norwegian population but polyps were able to survive, at least temporarily, those temperatures exceeding their natural range. While polyps collected from northern Norway, with a narrow environmental thermal window, displayed a low baseline metabolism with a Q10 value of 1.2, polyps from southern England and Scotland had Q10 values of 1.6 and 2.5, respectively. Differences in polyps' respiration rates across their distributional range suggest that populations have evolved adaptations to local environmental thermal conditions.
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Affiliation(s)
- Danja P. Höhn
- National Oceanography Centre Southampton, University of Southampton, Southampton, United Kingdom
- * E-mail:
| | - Cathy H. Lucas
- National Oceanography Centre Southampton, University of Southampton, Southampton, United Kingdom
| | - Sven Thatje
- National Oceanography Centre Southampton, University of Southampton, Southampton, United Kingdom
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9
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Coastal leatherback turtles reveal conservation hotspot. Sci Rep 2016; 6:37851. [PMID: 27886262 PMCID: PMC5122952 DOI: 10.1038/srep37851] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 11/02/2016] [Indexed: 11/28/2022] Open
Abstract
Previous studies have shown that the world’s largest reptile – the leatherback turtle Dermochelys coriacea – conducts flexible foraging migrations that can cover thousands of kilometres between nesting sites and distant foraging areas. The vast distances that may be travelled by migrating leatherback turtles have greatly complicated conservation efforts for this species worldwide. However, we demonstrate, using a combination of satellite telemetry and stable isotope analysis, that approximately half of the nesting leatherbacks from an important rookery in South Africa do not migrate to distant foraging areas, but rather, forage in the coastal waters of the nearby Mozambique Channel. Moreover, this coastal cohort appears to remain resident year-round in shallow waters (<50 m depth) in a relatively fixed area. Stable isotope analyses further indicate that the Mozambique Channel also hosts large numbers of loggerhead turtles Caretta caretta. The rare presence of a resident coastal aggregation of leatherback turtles not only presents a unique opportunity for conservation, but alongside the presence of loggerhead turtles and other endangered marine megafauna in the Mozambique Channel, highlights the importance of this area as a marine biodiversity hotspot.
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Naman SM, Greene CM, Rice CA, Chamberlin J, Conway-Cranos L, Cordell JR, Hall JE, Rhodes LD. Stable isotope-based trophic structure of pelagic fish and jellyfish across natural and anthropogenic landscape gradients in a fjord estuary. Ecol Evol 2016; 6:8159-8173. [PMID: 27878085 PMCID: PMC5108267 DOI: 10.1002/ece3.2450] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 08/08/2016] [Accepted: 08/12/2016] [Indexed: 11/23/2022] Open
Abstract
Identifying causes of structural ecosystem shifts often requires understanding trophic structure, an important determinant of energy flow in ecological communities. In coastal pelagic ecosystems worldwide, increasing jellyfish (Cnidaria and Ctenophora) at the expense of small fish has been linked to anthropogenic alteration of basal trophic pathways. However, this hypothesis remains untested in part because baseline description of fish–jellyfish trophic dynamics, and the environmental features that influence them are lacking. Using stable isotopes of carbon (δ13C) and nitrogen (δ15N), we examined spatiotemporal patterns of fish and jellyfish trophic structure in greater Puget Sound, an urbanizing fjord estuary in the NW United States. We quantified niche positions of constituent species, niche widths and trophic overlap between fish and jellyfish assemblages, and several community‐level trophic diversity metrics (resource diversity, trophic length, and niche widths) of fish and jellyfish combined. We then related assemblage‐ and community‐level measures to landscape gradients of terrestrial–marine connectivity and anthropogenic influence in adjacent catchments. Relative niche positions among species varied considerably and displayed no clear pattern except that fish generally had higher δ15N and lower δ13C relative to jellyfish, which resulted in low assemblage‐level trophic overlap. Fish assemblages had larger niche widths than jellyfish in most cases and, along with whole community trophic diversity, exhibited contrasting seasonal patterns across oceanographic basins, which was positively correlated to landscape variation in terrestrial connectivity. In contrast, jellyfish niche widths were unrelated to terrestrial connectivity, but weakly negatively correlated to urban land use in adjacent catchments. Our results indicate that fish–jellyfish trophic structure is highly heterogeneous and that disparate processes may underlie the trophic ecology of these taxa; consequently, they may respond divergently to environmental change. In addition, spatiotemporal variation in ecosystem connectivity, in this case through freshwater influence, may influence trophic structure across heterogeneous landscapes.
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Affiliation(s)
- Sean M Naman
- Department of Zoology University of British Columbia Vancouver BC Canada
| | | | - Casimir A Rice
- NOAA Fisheries Mukilteo Research Station Mukilteo WA USA
| | | | - Letitia Conway-Cranos
- NOAA Fisheries Northwest Fisheries Science Center Seattle WA USA; Present address: Washington Department of Fish and Wildlife Habitat Program Olympia WA USA
| | - Jeffery R Cordell
- School of Aquatic and Fishery Sciences University of Washington Seattle WA USA
| | - Jason E Hall
- NOAA Fisheries Northwest Fisheries Science Center Seattle WA USA
| | - Linda D Rhodes
- NOAA Fisheries Northwest Fisheries Science Center Seattle WA USA
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Trueman CN, MacKenzie KM, St John Glew K. Stable isotope‐based location in a shelf sea setting: accuracy and precision are comparable to light‐based location methods. Methods Ecol Evol 2016. [DOI: 10.1111/2041-210x.12651] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Clive N. Trueman
- Ocean and Earth Science University of Southampton Waterfront Campus Southampton SO143ZH UK
| | - Kirsteen M. MacKenzie
- Ocean and Earth Science University of Southampton Waterfront Campus Southampton SO143ZH UK
- Institute of Marine Research Tromsø Department P.O Box 6404 9294 Tromsø Norway
| | - Katie St John Glew
- Ocean and Earth Science University of Southampton Waterfront Campus Southampton SO143ZH UK
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12
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Javidpour J, Cipriano-Maack AN, Mittermayr A, Dierking J. Temporal dietary shift in jellyfish revealed by stable isotope analysis. MARINE BIOLOGY 2016; 163:112. [PMID: 27194816 PMCID: PMC4841851 DOI: 10.1007/s00227-016-2892-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 04/10/2016] [Indexed: 06/05/2023]
Abstract
A temporal change in the stable isotope (SI) composition of jellyfish in the Kiel Fjord, Western Baltic Sea, was documented by analyzing δ13C, δ15N and δ34S of bell tissue of Aurelia aurita and Cyanea capillata in the period between June and October 2011. A strong and significant temporal change in all SI values of A. aurita was found, including an increase of ~3 ‰ in δ13C, a decrease of ~4 ‰ in δ15N and sharp decline of ~7 ‰ in δ34S. While knowledge gaps in jellyfish isotope ecology, in particular the lack of reliable trophic enrichment factors, call for a conservative interpretation of our data, observed changes in particular in δ34S, as indicated by means of a MixSIR mixing model, would be consistent with a temporal dietary shift in A. aurita from mesozooplankton (>150 µm) to microplankton and small re-suspended particles (0.8-20 µm) from the benthos. Presence of a hitherto unidentified food source not included in the model could also contribute to the shift. During the 2-month occurrence of C. capillata, its isotope composition remained stable and was consistent with a mainly mesozooplanktonic diet. Mixing model output, mainly driven by δ34S values, indicated a lower proportion of A. aurita in the diet of C. capillata than previously reported, and thus to a potentially lesser importance of intraguild predation among jellyfish in the Kiel Fjord. Overall, our results clearly highlighted the potential for substantial intraspecific isotopic seasonal variation in jellyfish, which should be taken into account in future feeding ecology studies on this group.
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Affiliation(s)
- Jamileh Javidpour
- />GEOMAR Helmholtz Centre for Ocean Research Kiel, Düsternbrooker Weg 20, 24105 Kiel, Germany
| | - Ashlie N. Cipriano-Maack
- />Biological, Earth and Environmental Science, University College Cork, Cooperage Building, Distillery Fields, North Mall, Cork, Ireland
| | - Agnes Mittermayr
- />Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA 02543 USA
| | - Jan Dierking
- />GEOMAR Helmholtz Centre for Ocean Research Kiel, Düsternbrooker Weg 20, 24105 Kiel, Germany
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13
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Glynn F, Houghton JDR, Provan J. Population genetic analyses reveal distinct geographical blooms of the jellyfishRhizostoma octopus(Scyphozoa). Biol J Linn Soc Lond 2015. [DOI: 10.1111/bij.12614] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Fergal Glynn
- School of Biological Sciences; Queen's University Belfast; 97 Lisburn Road BT9 7BL Belfast UK
- Institute for Global Food Security; Queen's University Belfast; Belfast UK
| | - Jonathan D. R. Houghton
- School of Biological Sciences; Queen's University Belfast; 97 Lisburn Road BT9 7BL Belfast UK
- Institute for Global Food Security; Queen's University Belfast; Belfast UK
- Queen's Marine Laboratory; 12-13 The Strand BT22 1PF Portaferry UK
| | - Jim Provan
- School of Biological Sciences; Queen's University Belfast; 97 Lisburn Road BT9 7BL Belfast UK
- Institute for Global Food Security; Queen's University Belfast; Belfast UK
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