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Gustafsson M, Strand Å, Laugen AT, Albretsen J, André C, Broström G, Jorde PE, Knutsen H, Ortega‐Martinez O, Sodeland M, Waern M, Wrange A, De Wit P. Unlocking the secret life of blue mussels: Exploring connectivity in the Skagerrak through biophysical modeling and population genomics. Evol Appl 2024; 17:e13704. [PMID: 38770102 PMCID: PMC11104481 DOI: 10.1111/eva.13704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 02/27/2024] [Accepted: 04/29/2024] [Indexed: 05/22/2024] Open
Abstract
Knowledge of functional dispersal barriers in the marine environment can be used to inform a wide variety of management actions, such as marine spatial planning, restoration efforts, fisheries regulations, and invasive species management. Locations and causes of dispersal barriers can be studied through various methods, including movement tracking, biophysical modeling, demographic models, and genetics. Combining methods illustrating potential dispersal, such as biophysical modeling, with realized dispersal through, e.g., genetic connectivity estimates, provides particularly useful information for teasing apart potential causes of observed barriers. In this study, we focus on blue mussels (Mytilus edulis) in the Skagerrak-a marginal sea connected to the North Sea in Northern Europe-and combine biophysical models of larval dispersal with genomic data to infer locations and causes of dispersal barriers in the area. Results from both methods agree; patterns of ocean currents are a major structuring factor in the area. We find a complex pattern of source-sink dynamics with several dispersal barriers and show that some areas can be isolated despite an overall high dispersal capability. Finally, we translate our finding into management advice that can be used to sustainably manage this ecologically and economically important species in the future.
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Affiliation(s)
- Malin Gustafsson
- Environmental IntelligenceIVL Swedish Environmental Research InstituteGothenburgSweden
| | - Åsa Strand
- Environmental IntelligenceIVL Swedish Environmental Research InstituteFiskebäckskilSweden
| | - Ane T. Laugen
- Department of EcologySwedish University of Agricultural Sciences‐SLUUppsalaSweden
- Centre for Coastal Research‐CCR, Department of Natural SciencesUniversity of AgderKristiansandNorway
| | | | - Carl André
- Department of Marine SciencesUniversity of Gothenburg. Tjärnö Marine LaboratoryStrömstadSweden
| | - Göran Broström
- Department of Marine SciencesUniversity of GothenburgGothenburgSweden
| | | | - Halvor Knutsen
- Centre for Coastal Research‐CCR, Department of Natural SciencesUniversity of AgderKristiansandNorway
- Institute of Marine Research, FlødevigenHisNorway
| | - Olga Ortega‐Martinez
- Department of Marine SciencesUniversity of Gothenburg. Tjärnö Marine LaboratoryStrömstadSweden
| | - Marte Sodeland
- Centre for Coastal Research‐CCR, Department of Natural SciencesUniversity of AgderKristiansandNorway
| | - Malin Waern
- Department of Marine SciencesUniversity of Gothenburg. Tjärnö Marine LaboratoryStrömstadSweden
- Leibniz‐Institute for Baltic Sea Research WarnemündeRostockGermany
| | - Anna‐Lisa Wrange
- Environmental IntelligenceIVL Swedish Environmental Research InstituteFiskebäckskilSweden
- Department of Biological and Environmental SciencesUniversity of GothenburgGothenburgSweden
| | - Pierre De Wit
- Department of Marine SciencesUniversity of Gothenburg. Tjärnö Marine LaboratoryStrömstadSweden
- Department of Biological and Environmental SciencesUniversity of GothenburgGothenburgSweden
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2
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D'Antonio B, Ferreira LC, Meekan M, Thomson PG, Lieber L, Virtue P, Power C, Pattiaratchi CB, Brierley AS, Sequeira AMM, Thums M. Links between the three-dimensional movements of whale sharks (Rhincodon typus) and the bio-physical environment off a coral reef. MOVEMENT ECOLOGY 2024; 12:10. [PMID: 38297368 PMCID: PMC10829290 DOI: 10.1186/s40462-024-00452-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 01/17/2024] [Indexed: 02/02/2024]
Abstract
BACKGROUND Measuring coastal-pelagic prey fields at scales relevant to the movements of marine predators is challenging due to the dynamic and ephemeral nature of these environments. Whale sharks (Rhincodon typus) are thought to aggregate in nearshore tropical waters due to seasonally enhanced foraging opportunities. This implies that the three-dimensional movements of these animals may be associated with bio-physical properties that enhance prey availability. To date, few studies have tested this hypothesis. METHODS Here, we conducted ship-based acoustic surveys, net tows and water column profiling (salinity, temperature, chlorophyll fluorescence) to determine the volumetric density, distribution and community composition of mesozooplankton (predominantly euphausiids and copepods) and oceanographic properties of the water column in the vicinity of whale sharks that were tracked simultaneously using satellite-linked tags at Ningaloo Reef, Western Australia. Generalised linear mixed effect models were used to explore relationships between the 3-dimensional movement behaviours of tracked sharks and surrounding prey fields at a spatial scale of ~ 1 km. RESULTS We identified prey density as a significant driver of horizontal space use, with sharks occupying areas along the reef edge where densities were highest. These areas were characterised by complex bathymetry such as reef gutters and pinnacles. Temperature and salinity profiles revealed a well-mixed water column above the height of the bathymetry (top 40 m of the water column). Regions of stronger stratification were associated with reef gutters and pinnacles that concentrated prey near the seabed, and entrained productivity at local scales (~ 1 km). We found no quantitative relationship between the depth use of sharks and vertical distributions of horizontally averaged prey density. Whale sharks repeatedly dove to depths where spatially averaged prey concentration was highest but did not extend the time spent at these depth layers. CONCLUSIONS Our work reveals previously unrecognized complexity in interactions between whale sharks and their zooplankton prey.
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Affiliation(s)
- Ben D'Antonio
- Oceans Graduate School and the UWA Oceans Institute, The University of Western Australia, 35 Stirling Highway, Perth, WA, 6009, Australia.
- Australian Institute of Marine Science, Indian Ocean Marine Research Centre, University of Western Australia, Perth, WA, Australia.
| | - Luciana C Ferreira
- Australian Institute of Marine Science, Indian Ocean Marine Research Centre, University of Western Australia, Perth, WA, Australia
| | - Mark Meekan
- The Oceans Institute, University of Western Australia, Perth, WA, Australia
| | - Paul G Thomson
- Oceans Graduate School and the UWA Oceans Institute, The University of Western Australia, 35 Stirling Highway, Perth, WA, 6009, Australia
| | - Lilian Lieber
- Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth, PL1 2PB, UK
| | - Patti Virtue
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
- CSIRO Environment, Battery Point, TAS, 7004, Australia
| | - Chloe Power
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
| | - Charitha B Pattiaratchi
- Oceans Graduate School and the UWA Oceans Institute, The University of Western Australia, 35 Stirling Highway, Perth, WA, 6009, Australia
| | - Andrew S Brierley
- Pelagic Ecology Research Group, Scottish Oceans Institute, Gatty Marine Laboratory, School of Biology, University of St. Andrews, St Andrews, KY16 8LB, Scotland, UK
| | - Ana M M Sequeira
- The Oceans Institute, University of Western Australia, Perth, WA, Australia
- Research School of Biology, Division of Ecology and Evolution, The Australian National University, 46 Sullivans Creek Road, Canberra, ACT, 2600, Australia
| | - Michele Thums
- Australian Institute of Marine Science, Indian Ocean Marine Research Centre, University of Western Australia, Perth, WA, Australia
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Goetsch C, Gulka J, Friedland KD, Winship AJ, Clerc J, Gilbert A, Goyert HF, Stenhouse IJ, Williams KA, Willmott JR, Rekdahl ML, Rosenbaum HC, Adams EM. Surface and subsurface oceanographic features drive forage fish distributions and aggregations: Implications for prey availability to top predators in the US Northeast Shelf ecosystem. Ecol Evol 2023; 13:e10226. [PMID: 37441097 PMCID: PMC10334121 DOI: 10.1002/ece3.10226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 06/03/2023] [Accepted: 06/07/2023] [Indexed: 07/15/2023] Open
Abstract
Forage fishes are a critical food web link in marine ecosystems, aggregating in a hierarchical patch structure over multiple spatial and temporal scales. Surface-level forage fish aggregations (FFAs) represent a concentrated source of prey available to surface- and shallow-foraging marine predators. Existing survey and analysis methods are often imperfect for studying forage fishes at scales appropriate to foraging predators, making it difficult to quantify predator-prey interactions. In many cases, general distributions of forage fish species are known; however, these may not represent surface-level prey availability to predators. Likewise, we lack an understanding of the oceanographic drivers of spatial patterns of prey aggregation and availability or forage fish community patterns. Specifically, we applied Bayesian joint species distribution models to bottom trawl survey data to assess species- and community-level forage fish distribution patterns across the US Northeast Continental Shelf (NES) ecosystem. Aerial digital surveys gathered data on surface FFAs at two project sites within the NES, which we used in a spatially explicit hierarchical Bayesian model to estimate the abundance and size of surface FFAs. We used these models to examine the oceanographic drivers of forage fish distributions and aggregations. Our results suggest that, in the NES, regions of high community species richness are spatially consistent with regions of high surface FFA abundance. Bathymetric depth drove both patterns, while subsurface features, such as mixed layer depth, primarily influenced aggregation behavior and surface features, such as sea surface temperature, sub-mesoscale eddies, and fronts influenced forage fish diversity. In combination, these models help quantify the availability of forage fishes to marine predators and represent a novel application of spatial models to aerial digital survey data.
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Affiliation(s)
| | - Julia Gulka
- Biodiversity Research InstitutePortlandMaineUSA
| | | | - Arliss J. Winship
- CSS, Inc.FairfaxVirginiaUSA
- National Centers for Coastal Ocean ScienceNOAASilver SpringMarylandUSA
| | - Jeff Clerc
- Normandeau AssociatesGainesvilleFloridaUSA
| | | | - Holly F. Goyert
- CSS, Inc.FairfaxVirginiaUSA
- National Centers for Coastal Ocean ScienceNOAASilver SpringMarylandUSA
| | | | | | | | - Melinda L. Rekdahl
- Wildlife Conservation Society, Ocean Giants Program, Bronx ZooBronxNew YorkUSA
| | - Howard C. Rosenbaum
- Wildlife Conservation Society, Ocean Giants Program, Bronx ZooBronxNew YorkUSA
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4
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Peña M, Moyà M, Carbonell A, González-Quirós R. Vertical distribution and acoustic characteristics of deep water micronektonic crustacean in the Bay of Biscay. MARINE ENVIRONMENTAL RESEARCH 2023; 188:105967. [PMID: 37094526 DOI: 10.1016/j.marenvres.2023.105967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 02/16/2023] [Accepted: 03/20/2023] [Indexed: 05/03/2023]
Abstract
Vertical distribution of meso- and bathypelagic crustacean are scarcely known. The logistics involved in their studies hinder an adequate assessment of their role in the deep ecosystems. As a result, the literature on zooplankton scattering models is mainly focused on epipelagic organisms, particularly krill species. This study analyses data of the plankton community classified by family from the surface down to 2000 m taken in the Bay of Biscay, but focusses on the meso- and bathypelagic zone. Photographic data was employed to obtain a micronektonic crustacean shape catalogue. The Distorted Wave Born Approximation (DWBA) model was employed to estimate target strength. Pasiphaeidae, Euphausiidae and Acanthephyridae were mainly distributed above 500 m depth, while Benthesicymidae, Sergestidae and Mysidae were concentrated in the lower mesopelagic to upper bathypelagic area. The most abundant species were Euphausiidae and Benthesicymidae with up to 30 and 40 individuals per cubic meter respectively. Standard length ranged from 8 to 85 mm and was significantly related with height but not with depth. The Pasiphaeidae family presented the largest individuals followed by Acanthephyridae and Sergestidae while Euphausiidae, Benthesicymidae, and Mysidae were shorter. An smooth fluid-like response was estimated for shorter organisms, while individuals of 60 mm or higher present TS oscillations from around 60 kHz. Pasiphaeidae present an almost 10 dB higher TS than Sergestidae, Acanthephyridae and Benthesicymidae while Mysidae followed by Euphausiidae produce the lower TS. Simple models of TS values at broadside versus the logarithm of standard length (SL) that can be employed as an approximation of their scattering are provided for four common frequencies (TS = 58.5*log10(SL)-188.7, TS = 57.03*log10(SL)-174.1, TS = 22.48*log10(SL)-157.14, TS = 17.55*log10(SL)-135 and TS = 10.53*log10(SL)-109 at 18, 38, 70, 120 and 200 kHz respectively). Changes in body density and sound speed contrast may increase by 10 or 2 dB the resulting TS respectively but are constant in phase, while orientation can decrease the TS by up to 20 dB at the higher frequencies and alter the spectra to an almost flat trend. This study provides further insight into the vertical distribution and physical characteristics of the micronektonic crustacean families inhabiting the Bay of Biscay down to 2000 m depth. It also estimates their echo from a real-shape catalogue that can be employed to infer knowledge from acoustic recordings, particularly of the lower mesopelagic and the bathypelagic zones.
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Affiliation(s)
- Marian Peña
- Centro Oceanográfico de Baleares (IEO, CSIC), Muelle de Poniente s/n, Palma, Spain.
| | - María Moyà
- Universitat de les Illes Balears, Palma de Mallorca, Spain
| | - Aina Carbonell
- Centro Oceanográfico de Baleares (IEO, CSIC), Muelle de Poniente s/n, Palma, Spain
| | - Rafael González-Quirós
- Centro Oceanográfico de Gijón (IEO, CSIC), Avenida Príncipe de Asturias, 70bis, Gijón, Spain
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Rühle F, Zantop AW, Stark H. Gyrotactic cluster formation of bottom-heavy squirmers. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2022; 45:26. [PMID: 35304659 PMCID: PMC8933315 DOI: 10.1140/epje/s10189-022-00183-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 03/07/2022] [Indexed: 06/14/2023]
Abstract
Squirmers that are bottom-heavy experience a torque that aligns them along the vertical so that they swim upwards. In a suspension of many squirmers, they also interact hydrodynamically via flow fields that are initiated by their swimming motion and by gravity. Swimming under the combined action of flow field vorticity and gravitational torque is called gyrotaxis. Using the method of multi-particle collision dynamics, we perform hydrodynamic simulations of a many-squirmer system floating above the bottom surface. Due to gyrotaxis they exhibit pronounced cluster formation with increasing gravitational torque. The clusters are more volatile at low values but compactify to smaller clusters at larger torques. The mean distance between clusters is mainly controlled by the gravitational torque and not the global density. Furthermore, we observe that neutral squirmers form clusters more easily, whereas pullers require larger gravitational torques due to their additional force-dipole flow fields. We do not observe clustering for pusher squirmers. Adding a rotlet dipole to the squirmer flow field induces swirling clusters. At high gravitational strengths, the hydrodynamic interactions with the no-slip boundary create an additional vertical alignment for neutral squirmers, which also supports cluster formation.
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Affiliation(s)
- Felix Rühle
- Institut für Theoretische Physik, Technische Universität Berlin, Hardenbergstr. 36, D-10623, Berlin, Germany.
| | - Arne W Zantop
- Institut für Theoretische Physik, Technische Universität Berlin, Hardenbergstr. 36, D-10623, Berlin, Germany
| | - Holger Stark
- Institut für Theoretische Physik, Technische Universität Berlin, Hardenbergstr. 36, D-10623, Berlin, Germany
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6
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Maier SR, Jantzen C, Laudien J, Häussermann V, Försterra G, Cornils A, Niggemann J, Dittmar T, Richter C. The carbon and nitrogen budget of Desmophyllum dianthus-a voracious cold-water coral thriving in an acidified Patagonian fjord. PeerJ 2021; 9:e12609. [PMID: 34966598 PMCID: PMC8667745 DOI: 10.7717/peerj.12609] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 11/17/2021] [Indexed: 11/20/2022] Open
Abstract
In the North Patagonian fjord region, the cold-water coral (CWC) Desmophyllum dianthus occurs in high densities, in spite of low pH and aragonite saturation. If and how these conditions affect the energy demand of the corals is so far unknown. In a laboratory experiment, we investigated the carbon and nitrogen (C, N) budget of D. dianthus from Comau Fjord under three feeding scenarios: (1) live fjord zooplankton (100–2,300 µm), (2) live fjord zooplankton plus krill (>7 mm), and (3) four-day food deprivation. In closed incubations, C and N budgets were derived from the difference between C and N uptake during feeding and subsequent C and N loss through respiration, ammonium excretion, release of particulate organic carbon and nitrogen (POC, PON). Additional feeding with krill significantly increased coral respiration (35%), excretion (131%), and POC release (67%) compared to feeding on zooplankton only. Nevertheless, the higher C and N losses were overcompensated by the threefold higher C and N uptake, indicating a high assimilation and growth efficiency for the krill plus zooplankton diet. In contrast, short food deprivation caused a substantial reduction in respiration (59%), excretion (54%), release of POC (73%) and PON (87%) compared to feeding on zooplankton, suggesting a high potential to acclimatize to food scarcity (e.g., in winter). Notwithstanding, unfed corals ‘lost’ 2% of their tissue-C and 1.2% of their tissue-N per day in terms of metabolism and released particulate organic matter (likely mucus). To balance the C (N) losses, each D. dianthus polyp has to consume around 700 (400) zooplankters per day. The capture of a single, large krill individual, however, provides enough C and N to compensate daily C and N losses and grow tissue reserves, suggesting that krill plays an important nutritional role for the fjord corals. Efficient krill and zooplankton capture, as well as dietary and metabolic flexibility, may enable D. dianthus to thrive under adverse environmental conditions in its fjord habitat; however, it is not known how combined anthropogenic warming, acidification and eutrophication jeopardize the energy balance of this important habitat-building species.
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Affiliation(s)
- Sandra R Maier
- Department of Biosciences, Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany.,Department of Estuarine and Delta Systems, Royal Netherlands Institute for Sea Research (NIOZ-Yerseke), Yerseke, Netherlands
| | - Carin Jantzen
- Department of Biosciences, Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany
| | - Jürgen Laudien
- Department of Biosciences, Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany
| | - Verena Häussermann
- Facultad de Economía y Negocios, Universidad San Sebastián, Puerto Montt, Chile.,Huinay Foundation, Puerto Montt, Chile
| | - Günter Försterra
- Escuela de Ciencias del Mar, Facultad de Recursos Naturales, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
| | - Astrid Cornils
- Department of Biosciences, Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany
| | - Jutta Niggemann
- Institute for Chemistry and Biology of the Marine Environment (ICBM), University of Oldenburg, Oldenburg, Germany
| | - Thorsten Dittmar
- Institute for Chemistry and Biology of the Marine Environment (ICBM), University of Oldenburg, Oldenburg, Germany.,Helmholtz Institute for Functional Marine Biodiversity (HIFMB), University of Oldenburg, Oldenburg, Germany
| | - Claudio Richter
- Department of Biosciences, Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany.,Department of Biology/Chemistry, University of Bremen, Bremen, Germany
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7
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Baudena A, Ser-Giacomi E, D’Onofrio D, Capet X, Cotté C, Cherel Y, D’Ovidio F. Fine-scale structures as spots of increased fish concentration in the open ocean. Sci Rep 2021; 11:15805. [PMID: 34349142 PMCID: PMC8338936 DOI: 10.1038/s41598-021-94368-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 06/24/2021] [Indexed: 02/07/2023] Open
Abstract
Oceanic frontal zones have been shown to deeply influence the distribution of primary producers and, at the other extreme of the trophic web, top predators. However, the relationship between these structures and intermediate trophic levels is much more obscure. In this paper we address this knowledge gap by comparing acoustic measurements of mesopelagic fish concentrations to satellite-derived fine-scale Lagrangian Coherent Structures in the Indian sector of the Southern Ocean. First, we demonstrate that higher fish concentrations occur more frequently in correspondence with strong Lagrangian Coherent Structures. Secondly, we illustrate that, while increased fish densities are more likely to be observed over these structures, the presence of a fine-scale feature does not imply a concomitant fish accumulation, as other factors affect fish distribution. Thirdly, we show that, when only chlorophyll-rich waters are considered, front intensity modulates significantly more the local fish concentration. Finally, we discuss a model representing fish movement along Lagrangian features, specifically built for mid-trophic levels. Its results, obtained with realistic parameters, are qualitatively consistent with the observations and the spatio-temporal scales analysed. Overall, these findings may help to integrate intermediate trophic levels in trophic models, which can ultimately support management and conservation policies.
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Affiliation(s)
- Alberto Baudena
- grid.462844.80000 0001 2308 1657Sorbonne Université, CNRS, IRD, MNHN, Laboratoire d’Océanographie et du Climat: Expérimentations et Approches Numériques (LOCEAN-IPSL), Paris, France ,Sorbonne Université,CNRS, Laboratoire d’Océanographie de Villefranche, UMR 7093 LOV, Villefranche-sur-Mer, France
| | - Enrico Ser-Giacomi
- grid.462844.80000 0001 2308 1657Sorbonne Université, CNRS, IRD, MNHN, Laboratoire d’Océanographie et du Climat: Expérimentations et Approches Numériques (LOCEAN-IPSL), Paris, France ,grid.116068.80000 0001 2341 2786Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 02139 Cambridge, MA USA
| | - Donatella D’Onofrio
- grid.435667.50000 0000 9466 4203Institute of Atmospheric Sciences and Climate, National Research Council (CNR-ISAC), Torino, Italy ,grid.5477.10000000120346234
Copernicus Institute of Sustainable Development, Utrecht University, Utrecht, The Netherlands
| | - Xavier Capet
- grid.462844.80000 0001 2308 1657Sorbonne Université, CNRS, IRD, MNHN, Laboratoire d’Océanographie et du Climat: Expérimentations et Approches Numériques (LOCEAN-IPSL), Paris, France
| | - Cedric Cotté
- grid.462844.80000 0001 2308 1657Sorbonne Université, CNRS, IRD, MNHN, Laboratoire d’Océanographie et du Climat: Expérimentations et Approches Numériques (LOCEAN-IPSL), Paris, France
| | - Yves Cherel
- grid.452338.b0000 0004 0638 6741Centre d’Etudes Biologiques de Chizé (CEBC), UMR 7372 du CNRS-La Rochelle Université, 79360 Villiers-en-Bois, France
| | - Francesco D’Ovidio
- grid.462844.80000 0001 2308 1657Sorbonne Université, CNRS, IRD, MNHN, Laboratoire d’Océanographie et du Climat: Expérimentations et Approches Numériques (LOCEAN-IPSL), Paris, France
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Yoerger DR, Govindarajan AF, Howland JC, Llopiz JK, Wiebe PH, Curran M, Fujii J, Gomez-Ibanez D, Katija K, Robison BH, Hobson BW, Risi M, Rock SM. A hybrid underwater robot for multidisciplinary investigation of the ocean twilight zone. Sci Robot 2021; 6:6/55/eabe1901. [PMID: 34135116 DOI: 10.1126/scirobotics.abe1901] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 05/24/2021] [Indexed: 12/31/2022]
Abstract
Mesobot, an autonomous underwater vehicle, addresses specific unmet needs for observing and sampling a variety of phenomena in the ocean's midwaters. The midwater hosts a vast biomass, has a role in regulating climate, and may soon be exploited commercially, yet our scientific understanding of it is incomplete. Mesobot has the ability to survey and track slow-moving animals and to correlate the animals' movements with critical environmental measurements. Mesobot will complement existing oceanographic assets such as towed, remotely operated, and autonomous vehicles; shipboard acoustic sensors; and net tows. Its potential to perform behavioral studies unobtrusively over long periods with substantial autonomy provides a capability that is not presently available to midwater researchers. The 250-kilogram marine robot can be teleoperated through a lightweight fiber optic tether and can also operate untethered with full autonomy while minimizing environmental disturbance. We present recent results illustrating the vehicle's ability to automatically track free-swimming hydromedusae (Solmissus sp.) and larvaceans (Bathochordaeus stygius) at depths of 200 meters in Monterey Bay, USA. In addition to these tracking missions, the vehicle can execute preprogrammed missions collecting image and sensor data while also carrying substantial auxiliary payloads such as cameras, sonars, and samplers.
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Affiliation(s)
- Dana R Yoerger
- Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA.
| | | | | | - Joel K Llopiz
- Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - Peter H Wiebe
- Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - Molly Curran
- Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - Justin Fujii
- Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | | | - Kakani Katija
- Monterey Bay Aquarium Research Institute, Moss Landing, CA 95039, USA
| | - Bruce H Robison
- Monterey Bay Aquarium Research Institute, Moss Landing, CA 95039, USA
| | - Brett W Hobson
- Monterey Bay Aquarium Research Institute, Moss Landing, CA 95039, USA
| | - Michael Risi
- Monterey Bay Aquarium Research Institute, Moss Landing, CA 95039, USA
| | - Stephen M Rock
- Department of Aeronautics and Astronautics, Stanford University, Stanford, CA 94305, USA
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9
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Pattrick P, Weidberg N, Goschen WS, Jackson JM, McQuaid CD, Porri F. Larval Fish Assemblage Structure at Coastal Fronts and the Influence of Environmental Variability. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.684502] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Within the coastal zone, oceanographic features, such as fronts, can have major effects on the abundance and distribution of larval fish. We investigated the effects of fronts on larval fish assemblages by jointly collecting physical (ADCP and CTD) and biological (larvae) data in the nearshore waters of the south coast of South Africa, on four separate neap-tide occasions. Accumulation of fish larvae at predominantly internal wave-associated fronts was observed, with higher larval densities inshore of and within the front than farther offshore. On each occasion, larvae of coastal species with pelagic eggs (Mugillidae and Sparidae) were numerically dominant at the front itself, while inshore of the front, larvae of coastal species with benthic eggs (Gobiesocidae and Gobiidae) were more abundant. Offshore catches mainly comprised Engraulidae (pelagic species with pelagic eggs) larvae, which were generally restricted to the bottom, where current velocities were onshore on each occasion. On the occasion when fast (>100 cm/s) currents prevailed, however, accumulation of the larvae of coastal species occurred offshore of the front, and larvae were mixed throughout the water column. Thus, larval occurrence at these coastal frontal systems was strongly affected by the degree of mixing by currents, which on most occasions resulted in onshore retention. The results underline the importance of frontal systems in determining the nearshore distributions of fish larvae, particularly by retaining coastal fish species in the inshore region. The environmental variability observed at these frontal systems has potential implications for larval connectivity of fish populations.
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10
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Li SW, Lin PH, Ho TY, Hsieh CH, Sun CL. Change in rheotactic behavior patterns of dinoflagellates in response to different microfluidic environments. Sci Rep 2021; 11:11105. [PMID: 34045568 PMCID: PMC8160355 DOI: 10.1038/s41598-021-90622-8] [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: 12/30/2020] [Accepted: 05/12/2021] [Indexed: 11/15/2022] Open
Abstract
Plankton live in dynamic fluid environments. Their ability to change in response to different hydrodynamic cues is critical to their energy allocation and resource uptake. This study used a microfluidic device to evaluate the rheotactic behaviors of a model dinoflagellate species, Karlodinium veneficum, in different flow conditions. Although dinoflagellates experienced forced alignment in strong shear (i.e. “trapping”), fluid straining did not play a decisive role in their rheotactic movements. Moderate hydrodynamic magnitude (20 < |uf| < 40 µm s−1) was found to induce an orientation heading towards an oncoming current (positive rheotaxis), as dinoflagellates switched to cross-flow swimming when flow speed exceeded 50 µm s−1. Near the sidewalls of the main channel, the steric mechanism enabled dinoflagellates to adapt upstream orientation through vertical migration. Under oscillatory flow, however, positive rheotaxis dominated with occasional diversion. The varying flow facilitated upstream exploration with directional controlling, through which dinoflagellates exhibited avoidance of both large-amplitude perturbance and very stagnant zones. In the mixed layer where water is not steady, these rheotactic responses could lead to spatial heterogeneity of dinoflagellates. The outcome of this study helps clarify the interaction between swimming behaviors of dinoflagellates and the hydrodynamic environment they reside in.
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Affiliation(s)
- Si-Wei Li
- Department of Mechanical Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Po-Hsu Lin
- Department of Mechanical Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Tung-Yuan Ho
- Institute of Oceanography, National Taiwan University, Taipei, 10617, Taiwan.,Research Center for Environmental Changes, Academia Sinica, Taipei, 11529, Taiwan
| | - Chih-Hao Hsieh
- Institute of Oceanography, National Taiwan University, Taipei, 10617, Taiwan.,Research Center for Environmental Changes, Academia Sinica, Taipei, 11529, Taiwan.,Institute of Ecology and Evolutionary Biology and Department of Life Science, National Taiwan University, Taipei, 10617, Taiwan.,Mathematics Division, National Center for Theoretical Sciences, Taipei, 10617, Taiwan
| | - Chen-Li Sun
- Department of Mechanical Engineering, National Taiwan University, Taipei, 10617, Taiwan.
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11
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Harris JL, Hosegood P, Robinson E, Embling CB, Hilbourne S, Stevens GMW. Fine-scale oceanographic drivers of reef manta ray ( Mobula alfredi) visitation patterns at a feeding aggregation site. Ecol Evol 2021; 11:4588-4604. [PMID: 33976833 PMCID: PMC8093739 DOI: 10.1002/ece3.7357] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 02/10/2021] [Accepted: 02/18/2021] [Indexed: 12/18/2022] Open
Abstract
Globally, reef manta rays (Mobula alfredi) are in decline and are particularly vulnerable to exploitation and disturbance at aggregation sites. Here, passive acoustic telemetry and a suite of advanced oceanographic technologies were used for the first time to investigate the fine-scale (5-min) influence of oceanographic drivers on the visitation patterns of 19 tagged M. alfredi to a feeding aggregation site at Egmont Atoll in the Chagos Archipelago. Boosted regression trees indicate that tag detection probability increased with the intrusion of cold-water bores propagating up the atoll slope through the narrow lagoon inlet during flood tide, potentially transporting zooplankton from the thermocline. Tag detection probability also increased with warmer near-surface temperature close to low tide, with near-surface currents flowing offshore, and with high levels of backscatter (a proxy of zooplankton biomass). These combinations of processes support the proposition that zooplankton carried from the thermocline into the lagoon during the flood may be pumped back out through the narrow inlet during an ebb tide. These conditions provide temporally limited feeding opportunities for M. alfredi, which are tied on the tides. Results also provide some evidence of the presence of Langmuir Circulation, which transports and concentrates zooplankton, and may partly explain why M. alfredi occasionally remained at the feeding location for longer than that two hours. Identification of these correlations provides unique insight into the dynamic synthesis of fine-scale oceanographic processes which are likely to influence the foraging ecology of M. alfredi at Egmont Atoll, and elsewhere throughout their range.
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Affiliation(s)
- Joanna L. Harris
- The Manta TrustDorsetUK
- School of Biological and Marine SciencesUniversity of PlymouthPlymouthUK
| | - Phil Hosegood
- School of Biological and Marine SciencesUniversity of PlymouthPlymouthUK
| | - Edward Robinson
- School of Biological and Marine SciencesUniversity of PlymouthPlymouthUK
| | - Clare B. Embling
- School of Biological and Marine SciencesUniversity of PlymouthPlymouthUK
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12
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Whitney JL, Gove JM, McManus MA, Smith KA, Lecky J, Neubauer P, Phipps JE, Contreras EA, Kobayashi DR, Asner GP. Surface slicks are pelagic nurseries for diverse ocean fauna. Sci Rep 2021; 11:3197. [PMID: 33542255 PMCID: PMC7862242 DOI: 10.1038/s41598-021-81407-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 12/15/2020] [Indexed: 01/30/2023] Open
Abstract
Most marine animals have a pelagic larval phase that develops in the coastal or open ocean. The fate of larvae has profound effects on replenishment of marine populations that are critical for human and ecosystem health. Larval ecology is expected to be tightly coupled to oceanic features, but for most taxa we know little about the interactions between larvae and the pelagic environment. Here, we provide evidence that surface slicks, a common coastal convergence feature, provide nursery habitat for diverse marine larvae, including > 100 species of commercially and ecologically important fishes. The vast majority of invertebrate and larval fish taxa sampled had mean densities 2-110 times higher in slicks than in ambient water. Combining in-situ surveys with remote sensing, we estimate that slicks contain 39% of neustonic larval fishes, 26% of surface-dwelling zooplankton (prey), and 75% of floating organic debris (shelter) in our 1000 km2 study area in Hawai'i. Results indicate late-larval fishes actively select slick habitats to capitalize on concentrations of diverse prey and shelter. By providing these survival advantages, surface slicks enhance larval supply and replenishment of adult populations from coral reef, epipelagic, and deep-water ecosystems. Our findings suggest that slicks play a critically important role in enhancing productivity in tropical marine ecosystems.
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Affiliation(s)
- Jonathan L. Whitney
- grid.410445.00000 0001 2188 0957Joint Institute for Marine and Atmospheric Research, University of Hawai‘i at Mānoa, Honolulu, HI 96822 USA ,grid.3532.70000 0001 1266 2261Pacific Islands Fisheries Science Center, National Oceanic and Atmospheric Administration, Honolulu, HI 96818 USA ,grid.410445.00000 0001 2188 0957Department of Oceanography, University of Hawai‘i at Mānoa, Honolulu, HI 96822 USA
| | - Jamison M. Gove
- grid.3532.70000 0001 1266 2261Pacific Islands Fisheries Science Center, National Oceanic and Atmospheric Administration, Honolulu, HI 96818 USA
| | - Margaret A. McManus
- grid.410445.00000 0001 2188 0957Department of Oceanography, University of Hawai‘i at Mānoa, Honolulu, HI 96822 USA
| | - Katharine A. Smith
- grid.410445.00000 0001 2188 0957Joint Institute for Marine and Atmospheric Research, University of Hawai‘i at Mānoa, Honolulu, HI 96822 USA ,grid.410445.00000 0001 2188 0957Department of Oceanography, University of Hawai‘i at Mānoa, Honolulu, HI 96822 USA
| | - Joey Lecky
- grid.3532.70000 0001 1266 2261Pacific Islands Fisheries Science Center, National Oceanic and Atmospheric Administration, Honolulu, HI 96818 USA ,Lynker Technologies LLC, Marine, Ocean, and Coastal Science and Information Group, Leesburg, VA 20175 USA
| | - Philipp Neubauer
- grid.507875.8Dragonfly Data Science, 158 Victoria St, Level 4, Te Aro, Wellington, 6011 New Zealand
| | - Jana E. Phipps
- grid.410445.00000 0001 2188 0957Joint Institute for Marine and Atmospheric Research, University of Hawai‘i at Mānoa, Honolulu, HI 96822 USA ,grid.3532.70000 0001 1266 2261Pacific Islands Fisheries Science Center, National Oceanic and Atmospheric Administration, Honolulu, HI 96818 USA
| | - Emily A. Contreras
- grid.410445.00000 0001 2188 0957Joint Institute for Marine and Atmospheric Research, University of Hawai‘i at Mānoa, Honolulu, HI 96822 USA ,grid.3532.70000 0001 1266 2261Pacific Islands Fisheries Science Center, National Oceanic and Atmospheric Administration, Honolulu, HI 96818 USA
| | - Donald R. Kobayashi
- grid.3532.70000 0001 1266 2261Pacific Islands Fisheries Science Center, National Oceanic and Atmospheric Administration, Honolulu, HI 96818 USA
| | - Gregory P. Asner
- grid.215654.10000 0001 2151 2636Center for Global Discovery and Conservation Science, Arizona State University, Tempe, AZ 85281 USA
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13
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Torres G, Anger K, Giménez L. Effects of short-term and continuous exposure to reduced salinities on the biochemical composition of larval lobster, Homarus gammarus. ZOOLOGY 2021; 144:125885. [PMID: 33429190 DOI: 10.1016/j.zool.2020.125885] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 11/24/2020] [Accepted: 11/25/2020] [Indexed: 10/22/2022]
Abstract
In coastal areas with estuarine influence, exposure to hypo-osmotic conditions may affect larval survival, development and growth. Most knowledge about effects of reduced salinity on coastal organisms is based on keeping individuals under constant conditions in the laboratory. By contrast, little is known about the effects of more realistic situations where organisms are exposed to low salinity over short time scales. Such environmental short-term fluctuations are expected to increase due to climate change. Here, we experimentally evaluated the sublethal effects of both short-term and continuous exposure to moderately reduced salinities (salinity 20 and 25; compared to seawater, salinity 32) in larvae of European lobster Homarus gammarus. Total body dry mass and biochemical composition (measured as: protein and lipid contents) were measured as response variables in Mysis stages I to III. Short-term effects of low salinity were quantified in a group of larvae kept in seawater from hatching until the time of transfer to the test salinities. After ca. 40 % of each moult cycle in seawater (determined in preliminary experiments for Mysis I, II and III), larvae were assigned to a seawater control or reduced salinities lasting for 16 h (i.e. until ca. 50 % of the time spent within the moulting cycle). Effects of continuous exposure to low salinity were quantified when larvae were exposed to the different salinities from hatching, until they reached ca. 50 % of the successive moulting stage. Surprisingly, in the Mysis II and III stages, short-term exposure to low salinity had much stronger effects on accumulation of reserves than the continuous exposure. Such effects were manifested mostly as limited accumulation, or even losses, in the lipid content as compared to reductions in the amount of protein accumulated. The most sensitive stage to exposure to low salinity was the Mysis III; by contrast in Mysis I such effects were relative weak (not always significant). Chronic exposure to low salinity also led to an increase in developmental time especially at the advanced stages. Our results highlight the importance of quantifying effects of environmental fluctuations at different time scales in order to better understand how organisms cope with realistic environmental change in the coastal zones. For H. gammarus, our results suggest that larvae respond adaptively to low salinity by maintaining protein levels at expenses of reductions in lipid accumulation and by extending the developmental time, but the capacity to elicit a fully compensatory response varies ontogenetically.
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Affiliation(s)
- Gabriela Torres
- Biologische Anstalt Helgoland, Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Helgoland, Germany.
| | - Klaus Anger
- Kellerseestr. 38a, 23714, Bad Malente, Germany
| | - Luis Giménez
- Biologische Anstalt Helgoland, Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Helgoland, Germany; School of Ocean Sciences, Bangor University, Menai Bridge, LL59 5AB, UK
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14
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Michalec FG, Fouxon I, Souissi S, Holzner M. Efficient mate finding in planktonic copepods swimming in turbulence. eLife 2020; 9:e62014. [PMID: 33236986 PMCID: PMC7688315 DOI: 10.7554/elife.62014] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 10/30/2020] [Indexed: 11/16/2022] Open
Abstract
Zooplankton live in dynamic environments where turbulence may challenge their limited swimming abilities. How this interferes with fundamental behavioral processes remains elusive. We reconstruct simultaneously the trajectories of flow tracers and calanoid copepods and we quantify their ability to find mates when ambient flow imposes physical constrains on their motion and impairs their olfactory orientation. We show that copepods achieve high encounter rates in turbulence due to the contribution of advection and vigorous swimming. Males further convert encounters within the perception radius to contacts and then to mating via directed motion toward nearby organisms within the short time frame of the encounter. Inertial effects do not result in preferential concentration, reducing the geometric collision kernel to the clearance rate, which we model accurately by superposing turbulent velocity and organism motion. This behavioral and physical coupling mechanism may account for the ability of copepods to reproduce in turbulent environments.
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Affiliation(s)
| | - Itzhak Fouxon
- Institute of Environmental Engineering, ETH ZürichZürichSwitzerland
| | - Sami Souissi
- Univ. Lille, CNRS, Univ. Littoral Côte d'Opale, UMR 8187 - LOG - Laboratoire d'Océanologie et de Géosciences, Station Marine de Wimereux, Université de LilleWimereuxFrance
| | - Markus Holzner
- Swiss Federal Institute of Forest, Snow and Landscape ResearchBirmensdorfSwitzerland
- Swiss Federal Institute of Aquatic Science and TechnologyDübendorfSwitzerland
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15
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Morison F, Pierson JJ, Oikonomou A, Menden-Deuer S. Mesozooplankton grazing minimally impacts phytoplankton abundance during spring in the western North Atlantic. PeerJ 2020; 8:e9430. [PMID: 32742776 PMCID: PMC7370934 DOI: 10.7717/peerj.9430] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 06/06/2020] [Indexed: 11/20/2022] Open
Abstract
The impacts of grazing by meso- and microzooplankton on phytoplankton primary production (PP) was investigated in the surface layer of the western North Atlantic during spring. Shipboard experiments were performed on a latitudinal transect at three stations that differed in mixed layer depth, temperature, and mesozooplankton taxonomic composition. The mesozooplankton community was numerically dominated by Calanus finmarchicus at the northern and central station, with Calanus hyperboreus also present at the northern station. The southern station was >10 °C warmer than the other stations and had the most diverse mesozooplankton assemblage, dominated by small copepods including Paracalanus spp. Microzooplankton grazing was detected only at the northern station, where it removed 97% of PP. Estimated clearance rates by C. hyperboreus and C. finmarchicus suggested that at in-situ abundance these mesozooplankton were not likely to have a major impact on phytoplankton abundance, unless locally aggregated. Although mesozooplankton grazing impact on total phytoplankton was minimal, these grazers completely removed the numerically scarce > 10 µm particles, altering the particle-size spectrum. At the southern station, grazing by the whole mesozooplankton assemblage resulted in a removal of 14% of PP, and its effect on net phytoplankton growth rate was similar irrespective of ambient light. In contrast, reduction in light availability had an approximately 3-fold greater impact on net phytoplankton growth rate than mesozooplankton grazing pressure. The low mesozooplankton grazing impact across stations suggests limited mesozooplankton-mediated vertical export of phytoplankton production. The constraints provided here on trophic transfer, as well as quantitative estimates of the relative contribution of light and grazer controls of PP and of grazer-induced shifts in particle size spectra, illuminate food web dynamics and aid in parameterizing modeling-frameworks assessing global elemental fluxes and carbon export.
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Affiliation(s)
- Francoise Morison
- Graduate School of Oceanography, University of Rhode Island, Narragansett, RI, United States of America
| | | | - Andreas Oikonomou
- Graduate School of Oceanography, University of Rhode Island, Narragansett, RI, United States of America.,Institute of Balances of internal water, Hellenic Centre for Marine Research, Athens, Greece
| | - Susanne Menden-Deuer
- Graduate School of Oceanography, University of Rhode Island, Narragansett, RI, United States of America
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16
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Relative Influence of Environmental Factors on Biodiversity and Behavioural Traits of a Rare Mesopelagic Fish, Trachipterus trachypterus (Gmelin, 1789), in a Continental Shelf Front of the Mediterranean Sea. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2020. [DOI: 10.3390/jmse8080581] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Coastal environments can be influenced by water body masses with particular physical, chemical, and biological properties that create favourable conditions for the development of unique planktonic communities. In this study, we investigated a continental shelf front at Ponza Island (Tyrrhenian Sea) and discussed its diversity and complexity in relation to major environmental parameters. Moon phase and current direction were found to play a significant role in shaping species abundance and behaviour. During in situ observations, we also provided the first data on the behaviour of juveniles of a rare mesopelagic species, Trachipterus trachypterus, suggesting the occurrence of Batesian mimicry.
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17
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Chimienti M, Blasi MF, Hochscheid S. Movement patterns of large juvenile loggerhead turtles in the Mediterranean Sea: Ontogenetic space use in a small ocean basin. Ecol Evol 2020; 10:6978-6992. [PMID: 32760506 PMCID: PMC7391346 DOI: 10.1002/ece3.6370] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 04/23/2020] [Accepted: 04/24/2020] [Indexed: 01/07/2023] Open
Abstract
Mechanisms that determine how, where, and when ontogenetic habitat shifts occur are mostly unknown in wild populations. Differences in size and environmental characteristics of ontogenetic habitats can lead to differences in movement patterns, behavior, habitat use, and spatial distributions across individuals of the same species. Knowledge of juvenile loggerhead turtles' dispersal, movements, and habitat use is largely unknown, especially in the Mediterranean Sea. Satellite relay data loggers were used to monitor movements, diving behavior, and water temperature of eleven large juvenile loggerhead turtles (Caretta caretta) deliberately caught in an oceanic habitat in the Mediterranean Sea. Hidden Markov models were used over 4,430 spatial locations to quantify the different activities performed by each individual: transit, low-, and high-intensity diving. Model results were then analyzed in relation to water temperature, bathymetry, and distance to the coast. The hidden Markov model differentiated between bouts of area-restricted search as low- and high-intensity diving, and transit movements. The turtles foraged in deep oceanic waters within 60 km from the coast as well as above 140 km from the coast. They used an average area of 194,802 km2, where most individuals used the deepest part of the Southern Tyrrhenian Sea with the highest seamounts, while only two switched to neritic foraging showing plasticity in foraging strategies among turtles of similar age classes. The foraging distribution of large juvenile loggerhead turtles, including some which were of the minimum size of adults, in the Tyrrhenian Sea is mainly concentrated in a relatively small oceanic area with predictable mesoscale oceanographic features, despite the proximity of suitable neritic foraging habitats. Our study highlights the importance of collecting high-resolution data about species distribution and behavior across different spatio-temporal scales and life stages for implementing conservation and dynamic ocean management actions.
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Affiliation(s)
- Marianna Chimienti
- Department of Bioscience - Arctic Ecosystem EcologyAarhus UniversityRoskildeDenmark
| | - Monica F. Blasi
- Filicudi WildLife ConservationStimpagnato FilicudiLipariItaliaItaly
| | - Sandra Hochscheid
- Stazione Zoologica Anton DohrnMarine Turtle Research CenterPorticiItaly
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18
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Habitat Preferences and Trophic Position of Brachydiplax chalybea flavovittata Ris, 1911 (Insecta: Odonata) Larvae in Youngsan River Wetlands of South Korea. INSECTS 2020; 11:insects11050273. [PMID: 32365933 PMCID: PMC7290656 DOI: 10.3390/insects11050273] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 04/28/2020] [Accepted: 04/28/2020] [Indexed: 11/21/2022]
Abstract
In freshwater ecosystems, habitat heterogeneity supports high invertebrate density and diversity, and it contributes to the introduction and settlement of non-native species. In the present study, we identified the habitat preferences and trophic level of Brachydiplax chalybea flavovittata larvae, which were distributed in four of the 17 wetlands we examined in the Yeongsan River basin, South Korea. Larval density varied across four microhabitat types: open water area, and microhabitats dominated by Myriophyllum aquaticum, Paspalum distichum, and Zizania latifolia. Microhabitats dominated by M. aquaticum had the highest larval density, followed by those dominated by P. distichum. The larvae were more prevalent in silt sediments than in plant debris or sand. Stable isotope analysis showed that B. chalybea flavovittata is likely to consume, as a food source, other species of Odonata larvae. We conclude that successful settlement of B. chalybea flavovittata can be attributed to their habitat preferences. As temperature increases due to climate change, the likelihood of B. chalybea flavovittata spreading throughout South Korea increases. We, therefore, recommend continued monitoring of the spread and ecological impacts of B. chalybea flavovittata.
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19
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Bezares-Calderón LA, Berger J, Jékely G. Diversity of cilia-based mechanosensory systems and their functions in marine animal behaviour. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190376. [PMID: 31884914 PMCID: PMC7017336 DOI: 10.1098/rstb.2019.0376] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/03/2019] [Indexed: 12/12/2022] Open
Abstract
Sensory cells that detect mechanical forces usually have one or more specialized cilia. These mechanosensory cells underlie hearing, proprioception or gravity sensation. To date, it is unclear how cilia contribute to detecting mechanical forces and what is the relationship between mechanosensory ciliated cells in different animal groups and sensory systems. Here, we review examples of ciliated sensory cells with a focus on marine invertebrate animals. We discuss how various ciliated cells mediate mechanosensory responses during feeding, tactic responses or predator-prey interactions. We also highlight some of these systems as interesting and accessible models for future in-depth behavioural, functional and molecular studies. We envisage that embracing a broader diversity of organisms could lead to a more complete view of cilia-based mechanosensation. This article is part of the Theo Murphy meeting issue 'Unity and diversity of cilia in locomotion and transport'.
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Affiliation(s)
| | - Jürgen Berger
- Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany
| | - Gáspár Jékely
- Living Systems Institute, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
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20
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Schmid MS, Cowen RK, Robinson K, Luo JY, Briseño-Avena C, Sponaugle S. Prey and predator overlap at the edge of a mesoscale eddy: fine-scale, in-situ distributions to inform our understanding of oceanographic processes. Sci Rep 2020; 10:921. [PMID: 31969621 PMCID: PMC6976709 DOI: 10.1038/s41598-020-57879-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Accepted: 01/03/2020] [Indexed: 11/09/2022] Open
Abstract
Eddies can enhance primary as well as secondary production, creating a diverse meso- and sub-mesoscale seascape at the eddy front which can affect the aggregation of plankton and particles. Due to the coarse resolution provided by sampling with plankton nets, our knowledge of plankton distributions at these edges is limited. We used a towed, undulating underwater imaging system to investigate the physical and biological drivers of zoo- and ichthyoplankton aggregations at the edge of a decaying mesoscale eddy (ME) in the Straits of Florida. Using a sparse Convolutional Neural Network we identified 132 million images of plankton. Larval fish and Oithona spp. copepod concentrations were significantly higher in the eddy water mass, compared to the Florida Current water mass, only four days before the ME's dissipation. Larval fish and Oithona distributions were tightly coupled, indicating potential predator-prey interactions. Larval fishes are known predators of Oithona, however, Random Forests models showed that Oithona spp. and larval fish concentrations were primarily driven by variables signifying the physical footprint of the ME, such as current speed and direction. These results suggest that eddy-related advection leads to largely passive overlap between predator and prey, a positive, energy-efficient outcome for predators at the expense of prey.
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Affiliation(s)
- Moritz S Schmid
- Hatfield Marine Science Center, Oregon State University, Newport, OR, 97365, USA.
| | - Robert K Cowen
- Hatfield Marine Science Center, Oregon State University, Newport, OR, 97365, USA
| | - Kelly Robinson
- Department of Biology, University of Louisiana at Lafayette, Lafayette, LA, 70503, USA
| | - Jessica Y Luo
- NOAA Geophysical Fluid Dynamics Laboratory, Princeton, NJ, 08540, USA
| | - Christian Briseño-Avena
- Hatfield Marine Science Center, Oregon State University, Newport, OR, 97365, USA.,Department of Environmental and Ocean Sciences, University of San Diego, San Diego, CA, 92122, USA
| | - Su Sponaugle
- Department of Integrative Biology, Hatfield Marine Science Center, Oregon State University, Newport, OR, 97365, USA
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21
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White TP, Veit RR. Spatial ecology of long‐tailed ducks and white‐winged scoters wintering on Nantucket Shoals. Ecosphere 2020. [DOI: 10.1002/ecs2.3002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Affiliation(s)
- Timothy P. White
- Environmental Studies Program, Bureau of Ocean Energy Management U.S. Department of the Interior Sterling Virginia 20166 USA
| | - Richard R. Veit
- Department of Biology CSI/CUNY Staten Island New York 10314 USA
- The Graduate Center CUNY New York New York 10016 USA
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22
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Grecian WJ, Lane JV, Michelot T, Wade HM, Hamer KC. Understanding the ontogeny of foraging behaviour: insights from combining marine predator bio-logging with satellite-derived oceanography in hidden Markov models. J R Soc Interface 2019; 15:rsif.2018.0084. [PMID: 29875281 PMCID: PMC6030624 DOI: 10.1098/rsif.2018.0084] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 05/09/2018] [Indexed: 11/18/2022] Open
Abstract
The development of foraging strategies that enable juveniles to efficiently identify and exploit predictable habitat features is critical for survival and long-term fitness. In the marine environment, meso- and sub-mesoscale features such as oceanographic fronts offer a visible cue to enhanced foraging conditions, but how individuals learn to identify these features is a mystery. In this study, we investigate age-related differences in the fine-scale foraging behaviour of adult (aged ≥ 5 years) and immature (aged 2–4 years) northern gannets Morus bassanus. Using high-resolution GPS-loggers, we reveal that adults have a much narrower foraging distribution than immature birds and much higher individual foraging site fidelity. By conditioning the transition probabilities of a hidden Markov model on satellite-derived measures of frontal activity, we then demonstrate that adults show a stronger response to frontal activity than immature birds, and are more likely to commence foraging behaviour as frontal intensity increases. Together, these results indicate that adult gannets are more proficient foragers than immatures, supporting the hypothesis that foraging specializations are learned during individual exploratory behaviour in early life. Such memory-based individual foraging strategies may also explain the extended period of immaturity observed in gannets and many other long-lived species.
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Affiliation(s)
- W James Grecian
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK .,Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews KY16 8LB, UK
| | - Jude V Lane
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Théo Michelot
- School of Mathematics and Statistics, University of Sheffield, Sheffield S3 7RH, UK
| | - Helen M Wade
- Scottish Natural Heritage, Battleby, Redgorton, Perth PH1 3EW, UK
| | - Keith C Hamer
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
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23
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Burd BJ, Thomson RE. Seasonal patterns in deep acoustic backscatter layers near vent plumes in the northeastern Pacific Ocean. Facets (Ott) 2019. [DOI: 10.1139/facets-2018-0027] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We used moored 75 kHz acoustic Doppler current profilers (ADCPs) to examine seasonal cycles in zooplankton deep scattering layers (DSLs) observed below 1300 m depth at Endeavour Ridge hydrothermal vents. DSLs are present year-round in the lower water column near vent plumes. Temporal variations suggest passive, flow-induced displacements superimposed on migratory movements. Although the strongest DSLs are shallower than the neutrally buoyant plumes (1900–2100 m), anomalies also occur at and below plume depth. Upward movement from plume depth in the main DSL is evident in late summer/fall, resulting in shallower DSLs in winter, consistent with the timing of adult diapause/reproduction in upper-ocean migratory copepods. Movement from the upper ocean to plume depth coincides with pre-adult migration to greater depths in spring. Synchronous 20–40 d cycles in DSLs may account for patchiness in space and time of above-plume zooplankton layers observed in summer during previous net-sampling surveys, and suggests lateral and vertical migratory movements to counter current drift away from plume-derived food sources. Persistent near-bottom DSLs move vertically between the spreading plume and seafloor. Historical net data suggests that these are deep, resident fauna. Unlike upper ocean fauna, they seem to be advected considerable distances from the ridge axis, where they are evident as remnant scattering layers.
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Affiliation(s)
- Brenda J. Burd
- Institute of Ocean Sciences, P.O. Box 6000, Sidney, BC V8L 5T5, Canada
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24
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Basedow SL, McKee D, Lefering I, Gislason A, Daase M, Trudnowska E, Egeland ES, Choquet M, Falk-Petersen S. Remote sensing of zooplankton swarms. Sci Rep 2019; 9:686. [PMID: 30679810 PMCID: PMC6346024 DOI: 10.1038/s41598-018-37129-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Accepted: 12/04/2018] [Indexed: 11/15/2022] Open
Abstract
Zooplankton provide the key link between primary production and higher levels of the marine food web and they play an important role in mediating carbon sequestration in the ocean. All commercially harvested fish species depend on zooplankton populations. However, spatio-temporal distributions of zooplankton are notoriously difficult to quantify from ships. We know that zooplankton can form large aggregations that visibly change the color of the sea, but the scale and mechanisms producing these features are poorly known. Here we show that large surface patches (>1000 km2) of the red colored copepod Calanus finmarchicus can be identified from satellite observations of ocean color. Such observations provide the most comprehensive view of the distribution of a zooplankton species to date, and alter our understanding of the behavior of this key zooplankton species. Moreover, our findings suggest that high concentrations of astaxanthin-rich zooplankton can degrade the performance of standard blue-green reflectance ratio algorithms in operational use for retrieving chlorophyll concentrations from ocean color remote sensing.
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Affiliation(s)
- Sünnje L Basedow
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway.
| | - David McKee
- Physics Department, University of Strathclyde, Glasgow, United Kingdom
| | - Ina Lefering
- Physics Department, University of Strathclyde, Glasgow, United Kingdom
| | | | - Malin Daase
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Emilia Trudnowska
- Marine Ecology Department, Institute of Oceanology, Polish Academy of Sciences, Sopot, Poland
| | | | - Marvin Choquet
- Faculty of Biosciences and Aquaculture, Nord University, Bodø, Norway
| | - Stig Falk-Petersen
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway.,Akvaplan-niva AS, Tromsø, Norway
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25
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Höfer J, González HE, Laudien J, Schmidt GM, Häussermann V, Richter C. All you can eat: the functional response of the cold-water coral Desmophyllum dianthus feeding on krill and copepods. PeerJ 2018; 6:e5872. [PMID: 30416885 PMCID: PMC6223235 DOI: 10.7717/peerj.5872] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Accepted: 10/04/2018] [Indexed: 12/02/2022] Open
Abstract
The feeding behavior of the cosmopolitan cold-water coral (CWC) Desmophyllum dianthus (Cnidaria: Scleractinia) is still poorly known. Its usual deep distribution restricts direct observations, and manipulative experiments are so far limited to prey that do not occur in CWC natural habitat. During a series of replicated incubations, we assessed the functional response of this coral feeding on a medium-sized copepod (Calanoides patagoniensis) and a large euphausiid (Euphausia vallentini). Corals showed a Type I functional response, where feeding rate increased linearly with prey abundance, as predicted for a tentaculate passive suspension feeder. No significant differences in feeding were found between prey items, and corals were able to attain a maximum feeding rate of 10.99 mg C h−1, which represents an ingestion of the 11.4% of the coral carbon biomass per hour. These findings suggest that D. dianthus is a generalist zooplankton predator capable of exploiting dense aggregations of zooplankton over a wide prey size-range.
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Affiliation(s)
- Juan Höfer
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile.,Centro FONDAP de Investigación en Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL), Valdivia, Chile
| | - Humberto E González
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile.,Centro FONDAP de Investigación en Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL), Valdivia, Chile
| | - Jürgen Laudien
- Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar und Meeresforschung, Bremerhaven, Germany
| | - Gertraud M Schmidt
- Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar und Meeresforschung, Bremerhaven, Germany
| | - Verena Häussermann
- Facultad de Recursos Naturales, Escuela de Ciencias del Mar, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile.,Huinay Scientific Field Station, Huinay, Chile
| | - Claudio Richter
- Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar und Meeresforschung, Bremerhaven, Germany.,Fachbereich Biologie/Chemie, Universität Bremen, Bremen, Germany
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26
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Abrahms B, Scales KL, Hazen EL, Bograd SJ, Schick RS, Robinson PW, Costa DP. Mesoscale activity facilitates energy gain in a top predator. Proc Biol Sci 2018; 285:rspb.2018.1101. [PMID: 30135161 DOI: 10.1098/rspb.2018.1101] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 07/24/2018] [Indexed: 01/29/2023] Open
Abstract
How animal movement decisions interact with the distribution of resources to shape individual performance is a key question in ecology. However, links between spatial and behavioural ecology and fitness consequences are poorly understood because the outcomes of individual resource selection decisions, such as energy intake, are rarely measured. In the open ocean, mesoscale features (approx. 10-100 km) such as fronts and eddies can aggregate prey and thereby drive the distribution of foraging vertebrates through bottom-up biophysical coupling. These productive features are known to attract predators, yet their role in facilitating energy transfer to top-level consumers is opaque. We investigated the use of mesoscale features by migrating northern elephant seals and quantified the corresponding energetic gains from the seals' foraging patterns at a daily resolution. Migrating elephant seals modified their diving behaviour and selected for mesoscale features when foraging. Daily energy gain increased significantly with increasing mesoscale activity, indicating that the physical environment can influence predator fitness at fine temporal scales. Results show that areas of high mesoscale activity not only attract top predators as foraging hotspots, but also lead to increased energy transfer across trophic levels. Our study provides evidence that the physical environment is an important factor in controlling energy flow to top predators by setting the stage for variation in resource availability. Such understanding is critical for assessing how changes in the environment and resource distribution will affect individual fitness and food web dynamics.
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Affiliation(s)
- Briana Abrahms
- NOAA Southwest Fisheries Science Center, Environmental Research Division, Monterey, CA, USA .,Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Kylie L Scales
- School of Science and Engineering, University of the Sunshine Coast, Sippy Downs, QLD, Australia
| | - Elliott L Hazen
- NOAA Southwest Fisheries Science Center, Environmental Research Division, Monterey, CA, USA.,Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Steven J Bograd
- NOAA Southwest Fisheries Science Center, Environmental Research Division, Monterey, CA, USA
| | - Robert S Schick
- Marine Geospatial Ecology Lab, Nicholas School of the Environment, Duke University, Durham, NC, USA
| | - Patrick W Robinson
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Daniel P Costa
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
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27
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Michalec FG, Fouxon I, Souissi S, Holzner M. Zooplankton can actively adjust their motility to turbulent flow. Proc Natl Acad Sci U S A 2017; 114:E11199-E11207. [PMID: 29229858 PMCID: PMC5748176 DOI: 10.1073/pnas.1708888114] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Calanoid copepods are among the most abundant metazoans in the ocean and constitute a vital trophic link within marine food webs. They possess relatively narrow swimming capabilities, yet are capable of significant self-locomotion under strong hydrodynamic conditions. Here we provide evidence for an active adaptation that allows these small organisms to adjust their motility in response to background flow. We track simultaneously and in three dimensions the motion of flow tracers and planktonic copepods swimming freely at several intensities of quasi-homogeneous, isotropic turbulence. We show that copepods synchronize the frequency of their relocation jumps with the frequency of small-scale turbulence by performing frequent relocation jumps of low amplitude that seem unrelated to localized hydrodynamic signals. We develop a model of plankton motion in turbulence that shows excellent quantitative agreement with our measurements when turbulence is significant. We find that, compared with passive tracers, active motion enhances the diffusion of organisms at low turbulence intensity whereas it dampens diffusion at higher turbulence levels. The existence of frequent jumps in a motion that is otherwise dominated by turbulent transport allows for the possibility of active locomotion and hence to transition from being passively advected to being capable of controlling diffusion. This behavioral response provides zooplankton with the capability to retain the benefits of self-locomotion despite turbulence advection and may help these organisms to actively control their distribution in dynamic environments. Our study reveals an active adaptation that carries strong fitness advantages and provides a realistic model of plankton motion in turbulence.
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Affiliation(s)
- François-Gaël Michalec
- Institute of Environmental Engineering, Swiss Federal Institute of Technology, 8093 Zurich, Switzerland;
| | - Itzhak Fouxon
- Institute of Environmental Engineering, Swiss Federal Institute of Technology, 8093 Zurich, Switzerland
| | - Sami Souissi
- Laboratoire d'Océanologie et de Géosciences, Université de Lille, CNRS, Université Littoral Côte d'Opale, UMR 8187, F 62930 Wimereux, France
| | - Markus Holzner
- Institute of Environmental Engineering, Swiss Federal Institute of Technology, 8093 Zurich, Switzerland
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28
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Michalec FG, Holzner M, Barras A, Lacoste AS, Brunet L, Lee JS, Slomianny C, Boukherroub R, Souissi S. Short-term exposure to gold nanoparticle suspension impairs swimming behavior in a widespread calanoid copepod. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 228:102-110. [PMID: 28527321 DOI: 10.1016/j.envpol.2017.04.084] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 03/13/2017] [Accepted: 04/29/2017] [Indexed: 06/07/2023]
Abstract
Calanoid copepods play an important role in the functioning of marine and brackish ecosystems. Information is scarce on the behavioral toxicity of engineered nanoparticles to these abundant planktonic organisms. We assessed the effects of short-term exposure to nonfunctionalized gold nanoparticles on the swimming behavior of the widespread estuarine copepod Eurytemora affinis. By means of three-dimensional particle tracking velocimetry, we reconstructed the trajectories of males, ovigerous and non-ovigerous females. We quantified changes in their swimming activity and in the kinematics and geometrical properties of their motion, three important descriptors of the motility patterns of zooplankters. In females, exposure to gold nanoparticles in suspension (11.4 μg L-1) for 30 min caused depressed activity and lower velocity and acceleration, whereas the same exposure caused minimal effects in males. This response differs clearly from the hyperactive behavior that is commonly observed in zooplankters exposed to pollutants, and from the generally lower sensitivity of female copepods to toxicants. Accumulation of gold nanoparticles on the external appendages was not observed, precluding mechanical effects. Only very few nanoparticles appeared sporadically in the inner part of the gut in some samples, either as aggregates or as isolated nanoparticles, which does not suggest systemic toxicity resulting from pronounced ingestion. Hence, the precise mechanisms underlying the behavioral toxicity observed here remain to be elucidated. These results demonstrate that gold nanoparticles can induce marked behavioral alterations at very low concentration and short exposure duration. They illustrate the applicability of swimming behavior as a suitable and sensitive endpoint for investigating the toxicity of nanomaterials present in estuarine and marine environments. Changes in swimming behavior may impair the ability of planktonic copepods to interact with their environment and with other organisms, with possible impacts on population dynamics and community structure.
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Affiliation(s)
| | - Markus Holzner
- Institute of Environmental Engineering, ETH Zurich, 8093 Zurich, Switzerland
| | - Alexandre Barras
- Univ. Lille, CNRS, UMR 8520, IEMN, Institut d'Electronique, de Microélectronique et de Nanotechnologie, F 59652 Villeneuve d'Ascq, France
| | | | - Loïc Brunet
- Univ. Lille, Bio Imaging Center Lille, F 59000 Lille, France
| | - Jae-Seong Lee
- Department of Biological Science, College of Science, Sungkyunkwan University, Suwon 16419, South Korea
| | - Christian Slomianny
- Univ. Lille, INSERM U 1003, Laboratoire de Physiologie Cellulaire, F 59652 Villeneuve d'Ascq, France
| | - Rabah Boukherroub
- Univ. Lille, CNRS, UMR 8520, IEMN, Institut d'Electronique, de Microélectronique et de Nanotechnologie, F 59652 Villeneuve d'Ascq, France
| | - Sami Souissi
- Univ. Lille, CNRS, Univ. Littoral Cote d'Opale, UMR 8187, LOG, Laboratoire d'Océanologie et de Géosciences, F 62930 Wimereux, France
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29
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Smith JN, Richter C, Fabricius KE, Cornils A. Pontellid copepods, Labidocera spp., affected by ocean acidification: A field study at natural CO2 seeps. PLoS One 2017; 12:e0175663. [PMID: 28467414 PMCID: PMC5415112 DOI: 10.1371/journal.pone.0175663] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 03/29/2017] [Indexed: 11/18/2022] Open
Abstract
CO2 seeps in coral reefs were used as natural laboratories to study the impacts of ocean acidification on the pontellid copepod, Labidocera spp. Pontellid abundances were reduced by ∼70% under high-CO2 conditions. Biological parameters and substratum preferences of the copepods were explored to determine the underlying causes of such reduced abundances. Stage- and sex-specific copepod lengths, feeding ability, and egg development were unaffected by ocean acidification, thus changes in these physiological parameters were not the driving factor for reduced abundances under high-CO2 exposure. Labidocera spp. are demersal copepods, hence they live amongst reef substrata during the day and emerge into the water column at night. Deployments of emergence traps showed that their preferred reef substrata at control sites were coral rubble, macro algae, and turf algae. However, under high-CO2 conditions they no longer had an association with any specific substrata. Results from this study indicate that even though the biology of a copepod might be unaffected by high-CO2, Labidocera spp. are highly vulnerable to ocean acidification.
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Affiliation(s)
- Joy N. Smith
- Australian Institute of Marine Science, Townsville, Queensland, Australia
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
- University of Bremen, Bremen, Germany
- * E-mail:
| | - Claudio Richter
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
- University of Bremen, Bremen, Germany
| | | | - Astrid Cornils
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
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30
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Colabrese S, Gustavsson K, Celani A, Biferale L. Flow Navigation by Smart Microswimmers via Reinforcement Learning. PHYSICAL REVIEW LETTERS 2017; 118:158004. [PMID: 28452499 DOI: 10.1103/physrevlett.118.158004] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Indexed: 06/07/2023]
Abstract
Smart active particles can acquire some limited knowledge of the fluid environment from simple mechanical cues and exert a control on their preferred steering direction. Their goal is to learn the best way to navigate by exploiting the underlying flow whenever possible. As an example, we focus our attention on smart gravitactic swimmers. These are active particles whose task is to reach the highest altitude within some time horizon, given the constraints enforced by fluid mechanics. By means of numerical experiments, we show that swimmers indeed learn nearly optimal strategies just by experience. A reinforcement learning algorithm allows particles to learn effective strategies even in difficult situations when, in the absence of control, they would end up being trapped by flow structures. These strategies are highly nontrivial and cannot be easily guessed in advance. This Letter illustrates the potential of reinforcement learning algorithms to model adaptive behavior in complex flows and paves the way towards the engineering of smart microswimmers that solve difficult navigation problems.
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Affiliation(s)
- Simona Colabrese
- Department of Physics and INFN, University of Rome Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy
| | - Kristian Gustavsson
- Department of Physics and INFN, University of Rome Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy
- Department of Physics, University of Gothenburg, Origovägen 6 B, 41296 Göteborg, Sweden
| | - Antonio Celani
- Quantitative Life Sciences, The Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, 34151 Trieste, Italy
| | - Luca Biferale
- Department of Physics and INFN, University of Rome Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy
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31
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Cox SL, Miller PI, Embling CB, Scales KL, Bicknell AWJ, Hosegood PJ, Morgan G, Ingram SN, Votier SC. Seabird diving behaviour reveals the functional significance of shelf-sea fronts as foraging hotspots. ROYAL SOCIETY OPEN SCIENCE 2016; 3:160317. [PMID: 27703698 PMCID: PMC5043317 DOI: 10.1098/rsos.160317] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 08/19/2016] [Indexed: 06/06/2023]
Abstract
Oceanic fronts are key habitats for a diverse range of marine predators, yet how they influence fine-scale foraging behaviour is poorly understood. Here, we investigated the dive behaviour of northern gannets Morus bassanus in relation to shelf-sea fronts. We GPS (global positioning system) tracked 53 breeding birds and examined the relationship between 1901 foraging dives (from time-depth recorders) and thermal fronts (identified via Earth Observation composite front mapping) in the Celtic Sea, Northeast Atlantic. We (i) used a habitat-use availability analysis to determine whether gannets preferentially dived at fronts, and (ii) compared dive characteristics in relation to fronts to investigate the functional significance of these oceanographic features. We found that relationships between gannet dive probabilities and fronts varied by frontal metric and sex. While both sexes were more likely to dive in the presence of seasonally persistent fronts, links to more ephemeral features were less clear. Here, males were positively correlated with distance to front and cross-front gradient strength, with the reverse for females. Both sexes performed two dive strategies: shallow V-shaped plunge dives with little or no active swim phase (92% of dives) and deeper U-shaped dives with an active pursuit phase of at least 3 s (8% of dives). When foraging around fronts, gannets were half as likely to engage in U-shaped dives compared with V-shaped dives, independent of sex. Moreover, V-shaped dive durations were significantly shortened around fronts. These behavioural responses support the assertion that fronts are important foraging habitats for marine predators, and suggest a possible mechanistic link between the two in terms of dive behaviour. This research also emphasizes the importance of cross-disciplinary research when attempting to understand marine ecosystems.
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Affiliation(s)
- S L Cox
- Marine Biology and Ecology Research Centre, Plymouth University, Plymouth PL4 8AA, UK; Marine Physics Research Group, Plymouth University, Plymouth PL4 8AA, UK
| | - P I Miller
- Plymouth Marine Laboratory , Prospect Place, Plymouth PL1 3DH , UK
| | - C B Embling
- Marine Biology and Ecology Research Centre , Plymouth University , Plymouth PL4 8AA , UK
| | - K L Scales
- Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, UK; Institute of Marine Sciences, University of California, Santa Cruz, CA 95064, USA; National Oceanic and Atmospheric Administration (NOAA), Southwest Fisheries Science Centre, Environmental Research Division, 99 Pacific Street, Suite 255A, Monterey, CA 93940, USA
| | - A W J Bicknell
- Environment and Sustainability Institute , University of Exeter , Penryn TR10 9FE , UK
| | - P J Hosegood
- Marine Physics Research Group , Plymouth University , Plymouth PL4 8AA , UK
| | - G Morgan
- RSPB , Ramsey Island, St David's, Pembrokeshire SA62 6PY , UK
| | - S N Ingram
- Marine Biology and Ecology Research Centre , Plymouth University , Plymouth PL4 8AA , UK
| | - S C Votier
- Environment and Sustainability Institute , University of Exeter , Penryn TR10 9FE , UK
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32
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Sousa LL, López-Castejón F, Gilabert J, Relvas P, Couto A, Queiroz N, Caldas R, Dias PS, Dias H, Faria M, Ferreira F, Ferreira AS, Fortuna J, Gomes RJ, Loureiro B, Martins R, Madureira L, Neiva J, Oliveira M, Pereira J, Pinto J, Py F, Queirós H, Silva D, Sujit PB, Zolich A, Johansen TA, de Sousa JB, Rajan K. Integrated Monitoring of Mola mola Behaviour in Space and Time. PLoS One 2016; 11:e0160404. [PMID: 27494028 PMCID: PMC4975458 DOI: 10.1371/journal.pone.0160404] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 07/19/2016] [Indexed: 11/18/2022] Open
Abstract
Over the last decade, ocean sunfish movements have been monitored worldwide using various satellite tracking methods. This study reports the near-real time monitoring of fine-scale (< 10 m) behaviour of sunfish. The study was conducted in southern Portugal in May 2014 and involved satellite tags and underwater and surface robotic vehicles to measure both the movements and the contextual environment of the fish. A total of four individuals were tracked using custom-made GPS satellite tags providing geolocation estimates of fine-scale resolution. These accurate positions further informed sunfish areas of restricted search (ARS), which were directly correlated to steep thermal frontal zones. Simultaneously, and for two different occasions, an Autonomous Underwater Vehicle (AUV) video-recorded the path of the tracked fish and detected buoyant particles in the water column. Importantly, the densities of these particles were also directly correlated to steep thermal gradients. Thus, both sunfish foraging behaviour (ARS) and possibly prey densities, were found to be influenced by analogous environmental conditions. In addition, the dynamic structure of the water transited by the tracked individuals was described by a Lagrangian modelling approach. The model informed the distribution of zooplankton in the region, both horizontally and in the water column, and the resultant simulated densities positively correlated with sunfish ARS behaviour estimator (rs = 0.184, p<0.001). The model also revealed that tracked fish opportunistically displace with respect to subsurface current flow. Thus, we show how physical forcing and current structure provide a rationale for a predator’s fine-scale behaviour observed over a two weeks in May 2014.
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Affiliation(s)
- Lara L. Sousa
- CIBIO-InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Campus Agrário de Vairão, Universidade do Porto, 4485-661 Vairão, Portugal
- Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth PL1 2PB, United Kingdom
| | - Francisco López-Castejón
- Department of Chemical & Environmental Engineering/Underwater Vehicles Laboratory, Universidad Politécnica de Cartagena (UPCT), Alfonso XIII, 52, E-30203, Cartagena, Spain
| | - Javier Gilabert
- Department of Chemical & Environmental Engineering/Underwater Vehicles Laboratory, Universidad Politécnica de Cartagena (UPCT), Alfonso XIII, 52, E-30203, Cartagena, Spain
| | - Paulo Relvas
- Centre for Marine Sciences (CCMAR), University of Algarve, 8005-139 Faro, Portugal
| | - Ana Couto
- CIBIO-InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Campus Agrário de Vairão, Universidade do Porto, 4485-661 Vairão, Portugal
| | - Nuno Queiroz
- CIBIO-InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Campus Agrário de Vairão, Universidade do Porto, 4485-661 Vairão, Portugal
| | - Renato Caldas
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Paulo Sousa Dias
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Hugo Dias
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Margarida Faria
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Filipe Ferreira
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - António Sérgio Ferreira
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - João Fortuna
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Ricardo Joel Gomes
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Bruno Loureiro
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Ricardo Martins
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Luis Madureira
- Oceanscan-MST, Avenida Liberdade, Polo Mar UPTEC, 4450-718 Matosinhos, Portugal
| | - Jorge Neiva
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Marina Oliveira
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - João Pereira
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - José Pinto
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Frederic Py
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Hugo Queirós
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Daniel Silva
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - P. B. Sujit
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
- IIIT Delhi, New Delhi, 110020, India
| | - Artur Zolich
- Center for Autonomous Marine Operations and Systems, Department of Engineering Cybernetics, Norwegian University of Science and Technology, Gløshaugen, Trondheim, Norway
| | - Tor Arne Johansen
- Center for Autonomous Marine Operations and Systems, Department of Engineering Cybernetics, Norwegian University of Science and Technology, Gløshaugen, Trondheim, Norway
| | - João Borges de Sousa
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Kanna Rajan
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
- Center for Autonomous Marine Operations and Systems, Department of Engineering Cybernetics, Norwegian University of Science and Technology, Gløshaugen, Trondheim, Norway
- * E-mail:
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Chapman JW, Nilsson C, Lim KS, Bäckman J, Reynolds DR, Alerstam T, Reynolds AM. Detection of flow direction in high-flying insect and songbird migrants. Curr Biol 2016; 25:R751-2. [PMID: 26325133 DOI: 10.1016/j.cub.2015.07.074] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Goal-oriented migrants travelling through the sea or air must cope with the effect of cross-flows during their journeys if they are to reach their destination. In order to counteract flow-induced drift from their preferred course, migrants must detect the mean flow direction, and integrate this information with output from their internal compass, to compensate for the deflection. Animals can potentially sense flow direction by two nonexclusive mechanisms: either indirectly, by visually assessing the effect of the current on their movement direction relative to the ground; or directly, via intrinsic properties of the current. Here, we report the first evidence that nocturnal compass-guided insect migrants use a turbulence-mediated mechanism for directly assessing the wind direction hundreds of metres above the ground. By comparison, we find that nocturnally-migrating songbirds do not use turbulence to detect the flow; instead they rely on visual assessment of wind-induced drift to indirectly infer the flow direction.
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Affiliation(s)
- Jason W Chapman
- Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK; Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall, TR10 9EZ, UK.
| | - Cecilia Nilsson
- Department of Biology, Lund University, SE-223 62 Lund, Sweden
| | - Ka S Lim
- Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK
| | - Johan Bäckman
- Department of Biology, Lund University, SE-223 62 Lund, Sweden
| | - Don R Reynolds
- Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK; Natural Resources Institute, University of Greenwich, Chatham, Kent, ME4 4TB, UK
| | - Thomas Alerstam
- Department of Biology, Lund University, SE-223 62 Lund, Sweden
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Ardeshiri H, Benkeddad I, Schmitt FG, Souissi S, Toschi F, Calzavarini E. Lagrangian model of copepod dynamics: Clustering by escape jumps in turbulence. Phys Rev E 2016; 93:043117. [PMID: 27176400 DOI: 10.1103/physreve.93.043117] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Indexed: 11/07/2022]
Abstract
Planktonic copepods are small crustaceans that have the ability to swim by quick powerful jumps. Such an aptness is used to escape from high shear regions, which may be caused either by flow perturbations, produced by a large predator (i.e., fish larvae), or by the inherent highly turbulent dynamics of the ocean. Through a combined experimental and numerical study, we investigate the impact of jumping behavior on the small-scale patchiness of copepods in a turbulent environment. Recorded velocity tracks of copepods displaying escape response jumps in still water are here used to define and tune a Lagrangian copepod (LC) model. The model is further employed to simulate the behavior of thousands of copepods in a fully developed hydrodynamic turbulent flow obtained by direct numerical simulation of the Navier-Stokes equations. First, we show that the LC velocity statistics is in qualitative agreement with available experimental observations of copepods in turbulence. Second, we quantify the clustering of LC, via the fractal dimension D_{2}. We show that D_{2} can be as low as ∼2.3 and that it critically depends on the shear-rate sensitivity of the proposed LC model, in particular it exhibits a minimum in a narrow range of shear-rate values. We further investigate the effect of jump intensity, jump orientation, and geometrical aspect ratio of the copepods on the small-scale spatial distribution. At last, possible ecological implications of the observed clustering on encounter rates and mating success are discussed.
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Affiliation(s)
- H Ardeshiri
- Université de Lille, CNRS, FRE 3723, LML, Laboratoire de Mécanique de Lille, F 59000 Lille, France.,Université de Lille, CNRS, Université de Littoral Cote d'Opale, UMR 8187, LOG, Laboratoire d'Océanologie et de Géoscience, F 62930 Wimereux, France
| | - I Benkeddad
- Université de Lille, CNRS, Université de Littoral Cote d'Opale, UMR 8187, LOG, Laboratoire d'Océanologie et de Géoscience, F 62930 Wimereux, France
| | - F G Schmitt
- Université de Lille, CNRS, Université de Littoral Cote d'Opale, UMR 8187, LOG, Laboratoire d'Océanologie et de Géoscience, F 62930 Wimereux, France
| | - S Souissi
- Université de Lille, CNRS, Université de Littoral Cote d'Opale, UMR 8187, LOG, Laboratoire d'Océanologie et de Géoscience, F 62930 Wimereux, France
| | - F Toschi
- Department of Applied Physics and Department of Mathematics and Computer Science, Eindhoven University of Technology, 5600 MB, Eindhoven, The Netherlands.,Istituto per le Applicazioni del Calcolo CNR, Via dei Taurini 19, 00185 Rome, Italy
| | - E Calzavarini
- Université de Lille, CNRS, FRE 3723, LML, Laboratoire de Mécanique de Lille, F 59000 Lille, France
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35
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Michalec FG, Souissi S, Holzner M. Turbulence triggers vigorous swimming but hinders motion strategy in planktonic copepods. J R Soc Interface 2016; 12:rsif.2015.0158. [PMID: 25904528 DOI: 10.1098/rsif.2015.0158] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Calanoid copepods represent a major component of the plankton community. These small animals reside in constantly flowing environments. Given the fundamental role of behaviour in their ecology, it is especially relevant to know how copepods perform in turbulent flows. By means of three-dimensional particle tracking velocimetry, we reconstructed the trajectories of hundreds of adult Eurytemora affinis swimming freely under realistic intensities of homogeneous turbulence. We demonstrate that swimming contributes substantially to the dynamics of copepods even when turbulence is significant. We show that the contribution of behaviour to the overall dynamics gradually reduces with turbulence intensity but regains significance at moderate intensity, allowing copepods to maintain a certain velocity relative to the flow. These results suggest that E. affinis has evolved an adaptive behavioural mechanism to retain swimming efficiency in turbulent flows. They suggest the ability of some copepods to respond to the hydrodynamic features of the surrounding flow. Such ability may improve survival and mating performance in complex and dynamic environments. However, moderate levels of turbulence cancelled gender-specific differences in the degree of space occupation and innate movement strategies. Our results suggest that the broadly accepted mate-searching strategies based on trajectory complexity and movement patterns are inefficient in energetic environments.
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Affiliation(s)
- François-Gaël Michalec
- Institute of Environmental Engineering, ETH Zurich, Stefano-Franscini-Platz 5, 8093 Zurich, Switzerland
| | - Sami Souissi
- Université Lille 1 Sciences et Technologies, Laboratoire d'Océanologie et de Géosciences, CNRS, UMR 8187 LOG, 62930 Wimereux, France
| | - Markus Holzner
- Institute of Environmental Engineering, ETH Zurich, Stefano-Franscini-Platz 5, 8093 Zurich, Switzerland
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36
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Benoit-Bird KJ, Lawson GL. Ecological Insights from Pelagic Habitats Acquired Using Active Acoustic Techniques. ANNUAL REVIEW OF MARINE SCIENCE 2015; 8:463-490. [PMID: 26515810 DOI: 10.1146/annurev-marine-122414-034001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Marine pelagic ecosystems present fascinating opportunities for ecological investigation but pose important methodological challenges for sampling. Active acoustic techniques involve producing sound and receiving signals from organisms and other water column sources, offering the benefit of high spatial and temporal resolution and, via integration into different platforms, the ability to make measurements spanning a range of spatial and temporal scales. As a consequence, a variety of questions concerning the ecology of pelagic systems lend themselves to active acoustics, ranging from organism-level investigations and physiological responses to the environment to ecosystem-level studies and climate. As technologies and data analysis methods have matured, the use of acoustics in ecological studies has grown rapidly. We explore the continued role of active acoustics in addressing questions concerning life in the ocean, highlight creative applications to key ecological themes ranging from physiology and behavior to biogeography and climate, and discuss emerging avenues where acoustics can help determine how pelagic ecosystems function.
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Affiliation(s)
- Kelly J Benoit-Bird
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, Oregon 97333;
| | - Gareth L Lawson
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543;
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Michalec FG, Schmitt FG, Souissi S, Holzner M. Characterization of intermittency in zooplankton behaviour in turbulence. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2015; 38:108. [PMID: 26490249 DOI: 10.1140/epje/i2015-15108-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 09/16/2015] [Accepted: 09/24/2015] [Indexed: 06/05/2023]
Abstract
We consider Lagrangian velocity differences of zooplankters swimming in still water and in turbulence. Using cumulants, we quantify the intermittency properties of their motion recorded using three-dimensional particle tracking velocimetry. Copepods swimming in still water display an intermittent behaviour characterized by a high probability of small velocity increments, and by stretched exponential tails. Low values arise from their steady cruising behaviour while heavy tails result from frequent relocation jumps. In turbulence, we show that at short time scales, the intermittency signature of active copepods clearly differs from that of the underlying flow, and reflects the frequent relocation jumps displayed by these small animals. Despite these differences, we show that copepods swimming in still and turbulent flow belong to the same intermittency class that can be modelled by a log-stable model with non-analytical cumulant generating function. Intermittency in swimming behaviour and relocation jumps may enable copepods to display oriented, collective motion under strong hydrodynamic conditions and thus, may contribute to the formation of zooplankton patches in energetic environments.
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Affiliation(s)
- François-Gaël Michalec
- Institute of Environmental Engineering, ETH Zurich, Stefano-Franscini-Platz 5, 8093, Zurich, Switzerland.
| | - François G Schmitt
- UMR 8187, LOG, Laboratoire d'Océanologie et de Géosciences, CNRS, Univ. Lille, Univ. Littoral Cote d'Opale, F62930, Wimereux, France
| | - Sami Souissi
- UMR 8187, LOG, Laboratoire d'Océanologie et de Géosciences, Univ. Lille, CNRS, Univ. Littoral Cote d'Opale, F62930, Wimereux, France
| | - Markus Holzner
- Institute of Environmental Engineering, ETH Zurich, Stefano-Franscini-Platz 5, 8093, Zurich, Switzerland
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38
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McGillicuddy DJ. Mechanisms of Physical-Biological-Biogeochemical Interaction at the Oceanic Mesoscale. ANNUAL REVIEW OF MARINE SCIENCE 2015; 8:125-159. [PMID: 26359818 DOI: 10.1146/annurev-marine-010814-015606] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Mesoscale phenomena are ubiquitous and highly energetic features of ocean circulation. Their influence on biological and biogeochemical processes varies widely, stemming not only from advective transport but also from the generation of variations in the environment that affect biological and chemical rates. The ephemeral nature of mesoscale features in the ocean makes it difficult to elucidate the attendant mechanisms of physical-biological-biogeochemical interaction, necessitating the use of multidisciplinary approaches involving in situ observations, remote sensing, and modeling. All three aspects are woven through this review in an attempt to synthesize current understanding of the topic, with particular emphasis on novel developments in recent years.
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Affiliation(s)
- Dennis J McGillicuddy
- Department of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543;
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39
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Scales KL, Miller PI, Embling CB, Ingram SN, Pirotta E, Votier SC. Mesoscale fronts as foraging habitats: composite front mapping reveals oceanographic drivers of habitat use for a pelagic seabird. J R Soc Interface 2015; 11:20140679. [PMID: 25165595 DOI: 10.1098/rsif.2014.0679] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The oceanographic drivers of marine vertebrate habitat use are poorly understood yet fundamental to our knowledge of marine ecosystem functioning. Here, we use composite front mapping and high-resolution GPS tracking to determine the significance of mesoscale oceanographic fronts as physical drivers of foraging habitat selection in northern gannets Morus bassanus. We tracked 66 breeding gannets from a Celtic Sea colony over 2 years and used residence time to identify area-restricted search (ARS) behaviour. Composite front maps identified thermal and chlorophyll-a mesoscale fronts at two different temporal scales-(i) contemporaneous fronts and (ii) seasonally persistent frontal zones. Using generalized additive models (GAMs), with generalized estimating equations (GEE-GAMs) to account for serial autocorrelation in tracking data, we found that gannets do not adjust their behaviour in response to contemporaneous fronts. However, ARS was more likely to occur within spatially predictable, seasonally persistent frontal zones (GAMs). Our results provide proof of concept that composite front mapping is a useful tool for studying the influence of oceanographic features on animal movements. Moreover, we highlight that frontal persistence is a crucial element of the formation of pelagic foraging hotspots for mobile marine vertebrates.
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Affiliation(s)
- Kylie L Scales
- Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, UK
| | - Peter I Miller
- Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, UK
| | - Clare B Embling
- Marine Biology and Ecology Research Centre, Plymouth University, Plymouth PL4 8AA, UK
| | - Simon N Ingram
- Marine Biology and Ecology Research Centre, Plymouth University, Plymouth PL4 8AA, UK
| | - Enrico Pirotta
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
| | - Stephen C Votier
- Environment and Sustainability Institute, University of Exeter, Penryn TR10 9EZ, UK
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40
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Briseño-Avena C, Roberts PL, Franks PJ, Jaffe JS. ZOOPS- O2: A broadband echosounder with coordinated stereo optical imaging for observing plankton in situ. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.mio.2015.07.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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41
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Miller PI, Scales KL, Ingram SN, Southall EJ, Sims DW. Basking sharks and oceanographic fronts: quantifying associations in the north‐east Atlantic. Funct Ecol 2015. [DOI: 10.1111/1365-2435.12423] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Peter I. Miller
- Plymouth Marine Laboratory Prospect Place Plymouth PL1 3DH UK
| | - Kylie L. Scales
- Plymouth Marine Laboratory Prospect Place Plymouth PL1 3DH UK
- Institute of Marine Sciences University of California Santa Cruz CA 95064 USA
| | - Simon N. Ingram
- Marine Biology and Ecology Research Centre Plymouth University Plymouth PL4 8AA UK
| | - Emily J. Southall
- The Laboratory Marine Biological Association of the United Kingdom Citadel Hill Plymouth PL1 2PB UK
| | - David W. Sims
- The Laboratory Marine Biological Association of the United Kingdom Citadel Hill Plymouth PL1 2PB UK
- Ocean and Earth Science National Oceanography Centre Southampton Waterfront Campus University of Southampton Southampton SO14 3ZH UK
- Centre for Biological Sciences Building 85 Highfield Campus University of Southampton Southampton SO17 1BJ UK
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42
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Fossette S, Gleiss A, Chalumeau J, Bastian T, Armstrong C, Vandenabeele S, Karpytchev M, Hays G. Current-Oriented Swimming by Jellyfish and Its Role in Bloom Maintenance. Curr Biol 2015; 25:342-347. [DOI: 10.1016/j.cub.2014.11.050] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 10/27/2014] [Accepted: 11/19/2014] [Indexed: 11/16/2022]
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43
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Frada MJ, Schatz D, Farstey V, Ossolinski JE, Sabanay H, Ben-Dor S, Koren I, Vardi A. Zooplankton may serve as transmission vectors for viruses infecting algal blooms in the ocean. Curr Biol 2014; 24:2592-7. [PMID: 25438947 DOI: 10.1016/j.cub.2014.09.031] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 09/11/2014] [Accepted: 09/11/2014] [Indexed: 11/17/2022]
Abstract
Marine viruses are recognized as a major driving force regulating phytoplankton community composition and nutrient cycling in the oceans. Yet, little is known about mechanisms that influence viral dispersal in aquatic systems, other than physical processes, and that lead to the rapid demise of large-scale algal blooms in the oceans. Here, we show that copepods, abundant migrating crustaceans that graze on phytoplankton, as well as other zooplankton can accumulate and mediate the transmission of viruses infecting Emiliania huxleyi, a bloom-forming coccolithophore that plays an important role in the carbon cycle. We detected by PCR that >80% of copepods collected during a North Atlantic E. huxleyi bloom carried E. huxleyi virus (EhV) DNA. We demonstrated by isolating a new infectious EhV strain from a copepod microbiome that these viruses are infectious. We further showed that EhVs can accumulate in high titers within zooplankton guts during feeding or can be adsorbed to their surface. Subsequently, EhV can be dispersed by detachment or via viral-dense fecal pellets over a period of 1 day postfeeding on EhV-infected algal cells, readily infecting new host populations. Intriguingly, the passage through zooplankton guts prolonged EhV's half-life of infectivity by 35%, relative to free virions in seawater, potentially enhancing viral transmission. We propose that zooplankton, swimming through topographically adjacent phytoplankton micropatches and migrating daily over large areas across physically separated water masses, can serve as viral vectors, boosting host-virus contact rates and potentially accelerating the demise of large-scale phytoplankton blooms.
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Affiliation(s)
- Miguel José Frada
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Daniella Schatz
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Viviana Farstey
- The Interuniversity Institute for Marine Sciences, H. Steinitz Marine Biology Laboratory, Eilat 88103, Israel
| | - Justin E Ossolinski
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - Helena Sabanay
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Shifra Ben-Dor
- Department of Biological Services, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Ilan Koren
- Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Assaf Vardi
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 76100, Israel.
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44
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Scales KL, Miller PI, Hawkes LA, Ingram SN, Sims DW, Votier SC. REVIEW: On the Front Line: frontal zones as priority at-sea conservation areas for mobile marine vertebrates. J Appl Ecol 2014. [DOI: 10.1111/1365-2664.12330] [Citation(s) in RCA: 135] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kylie L. Scales
- Plymouth Marine Laboratory; Prospect Place Plymouth PL1 3DH UK
| | - Peter I. Miller
- Plymouth Marine Laboratory; Prospect Place Plymouth PL1 3DH UK
| | - Lucy A. Hawkes
- Environment and Sustainability Institute; University of Exeter; Cornwall Campus Penryn TR10 9EZ UK
| | - Simon N. Ingram
- Centre for Marine and Coastal Policy Research; Plymouth University; Plymouth PL4 8AA UK
| | - David W. Sims
- Marine Biological Association of the United Kingdom; The Laboratory; Citadel Hill Plymouth PL1 2PB UK
- Ocean and Earth Science; University of Southampton; Waterfront Campus Southampton SO14 3ZH UK
| | - Stephen C. Votier
- Environment and Sustainability Institute; University of Exeter; Cornwall Campus Penryn TR10 9EZ UK
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45
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Abstract
Highly advective upwelling systems along the western margins of continents are widely believed to transport larvae far offshore in surface currents resulting in larval wastage, limited recruitment, and increased population connectivity. However, suites of larval behaviors effectively mediate interspecific differences in the extent of cross-shelf migrations between nearshore adult habitats and offshore larval habitats. Interspecific differences in behavior determining whether larvae complete development in estuaries or migrate to the continental shelf are evident in large estuaries, but they sometimes may be disrupted by turbulent tidal flow or the absence of a low-salinity cue in shallow, low-flow estuaries, which are widespread in upwelling systems. Larvae of most species on the continental shelf complete development in the coastal boundary layer of reduced flow, whereas other species migrate to the mid- or outer shelf depending on how much time is spent in surface currents. These migrations are maintained across latitudinal differences in the strength and persistence of upwelling, in upwelling jets at headlands, over upwelling-relaxation cycles, and among years of varying upwelling intensity. Incorporating larval behaviors into numerical models demonstrates that larvae recruit closer to home and in higher numbers than when larvae disperse passively or remain in surface currents.
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46
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Zarubin M, Farstey V, Wold A, Falk-Petersen S, Genin A. Intraspecific differences in lipid content of calanoid copepods across fine-scale depth ranges within the photic layer. PLoS One 2014; 9:e92935. [PMID: 24667529 PMCID: PMC3965483 DOI: 10.1371/journal.pone.0092935] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 02/26/2014] [Indexed: 11/18/2022] Open
Abstract
Copepods are among the most abundant and diverse groups of mesozooplankton in the world's oceans. Each species has a certain depth range within which different individuals (of the same life stage and sex) are found. Lipids are accumulated in many calanoid copepods for energy storage and reproduction. Lipid content in some species increases with depth, however studies so far focused mostly on temperate and high-latitude seasonal vertically migrating copepods and compared lipid contents among individuals either from coarse layers or between diapausing, deep-dwelling copepods and individuals found in the photic, near-surface layer. Here we examined whether lipid contents of individual calanoid copepods of the same species, life stage/sex differ between finer depth layers within the upper water column of subtropical and Arctic seas. A total of 6 calanoid species were collected from samples taken at precise depths within the photic layer in both cold eutrophic and warm oligotrophic environments using SCUBA diving, MOCNESS and Multinet. Measurements of lipid content were obtained from digitized photographs of the collected individuals. The results revealed significant differences in lipid content across depth differences as small as 12–15 meters for Mecynocera clausi C5 and Ctenocalanus vanus C5 (Red Sea), Clausocalanus furcatus males and two clausocalanid C5s (Mediterranean Sea), and Calanus glacialis C5 (Arctic). We suggest two possible explanations for the differences in lipid content with depth on such a fine scale: predator avoidance and buoyancy.
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Affiliation(s)
- Margarita Zarubin
- The Interuniversity Institute for Marine Sciences, Eilat, Israel
- Department of Ecology, Evolution and Behavior, Silberman Institute of Life Sciences, the Hebrew University of Jerusalem, Jerusalem, Israel
- * E-mail:
| | - Viviana Farstey
- The Interuniversity Institute for Marine Sciences, Eilat, Israel
| | | | - Stig Falk-Petersen
- Akvaplan-niva, Fram Centre, Tromsø, Norway
- Department of Arctic and Marine Biology, Faculty of Biosciences, Fisheries and Economics, University of Tromsø, Tromsø, Norway
- Norwegian Polar Institute, Tromsø, Norway
| | - Amatzia Genin
- The Interuniversity Institute for Marine Sciences, Eilat, Israel
- Department of Ecology, Evolution and Behavior, Silberman Institute of Life Sciences, the Hebrew University of Jerusalem, Jerusalem, Israel
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47
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Prairie JC, Sutherland KR, Nickols KJ, Kaltenberg AM. Biophysical interactions in the plankton: A cross-scale review. ACTA ACUST UNITED AC 2012. [DOI: 10.1215/21573689-1964713] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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48
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Abstract
Summary
Plankton are small organisms that dwell in oceans, seas and bodies of fresh water. In this review, we discuss life in the plankton, which involves a balance between the behavioral capabilities of the organism and the characteristics and movement of the water that surrounds it. In order to consider this balance, we discuss how plankton interact with their environment across a range of scales – from the smallest viruses and bacteria to larger phytoplankton and zooplankton. We find that the larger scale distributions of plankton, observed in coastal waters, along continental shelves and in ocean basins, are highly dependent upon the smaller scale interactions between the individual organism and its environment. Further, we discuss how larger scale organism distributions may affect the transport and/or retention of plankton in the ocean environment. The research reviewed here provides a mechanistic understanding of how organism behavior in response to the physical environment produces planktonic aggregations, which has a direct impact on the way marine ecosystems function.
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Affiliation(s)
| | - C. Brock Woodson
- Environmental Fluid Mechanics Laboratory, Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305-4020, USA
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49
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Abstract
The motility of organisms is often directed in response to environmental stimuli. Rheotaxis is the directed movement resulting from fluid velocity gradients, long studied in fish, aquatic invertebrates, and spermatozoa. Using carefully controlled microfluidic flows, we show that rheotaxis also occurs in bacteria. Excellent quantitative agreement between experiments with Bacillus subtilis and a mathematical model reveals that bacterial rheotaxis is a purely physical phenomenon, in contrast to fish rheotaxis but in the same way as sperm rheotaxis. This previously unrecognized bacterial taxis results from a subtle interplay between velocity gradients and the helical shape of flagella, which together generate a torque that alters a bacterium's swimming direction. Because this torque is independent of the presence of a nearby surface, bacterial rheotaxis is not limited to the immediate neighborhood of liquid-solid interfaces, but also takes place in the bulk fluid. We predict that rheotaxis occurs in a wide range of bacterial habitats, from the natural environment to the human body, and can interfere with chemotaxis, suggesting that the fitness benefit conferred by bacterial motility may be sharply reduced in some hydrodynamic conditions.
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50
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Abstract
Mesoscale eddies stimulate biological production in the ocean, but knowledge of energy transfers to higher trophic levels within eddies remains fragmented and not quantified. Increasing the knowledge base is constrained by the inability of traditional sampling methods to adequately sample biological processes at the spatio-temporal scales at which they occur. By combining satellite and acoustic observations over spatial scales of 10 s of km horizontally and 100 s of m vertically, supported by hydrographical and biological sampling we show that anticyclonic eddies shape distribution and density of marine life from the surface to bathyal depths. Fish feed along density structures of eddies, demonstrating that eddies catalyze energy transfer across trophic levels. Eddies create attractive pelagic habitats, analogous to oases in the desert, for higher trophic level aquatic organisms through enhanced 3-D motion that accumulates and redistributes biomass, contributing to overall bioproduction in the ocean. Integrating multidisciplinary observation methodologies promoted a new understanding of biophysical interaction in mesoscale eddies. Our findings emphasize the impact of eddies on the patchiness of biomass in the sea and demonstrate that they provide rich feeding habitat for higher trophic marine life.
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