1
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Letessier TB, Mouillot D, Mannocci L, Jabour Christ H, Elamin EM, Elamin SM, Friedlander AM, Hearn A, Juhel JB, Kleiven AR, Moland E, Mouquet N, Nillos-Kleiven PJ, Sala E, Thompson CDH, Velez L, Vigliola L, Meeuwig JJ. Divergent responses of pelagic and benthic fish body-size structure to remoteness and protection from humans. Science 2024; 383:976-982. [PMID: 38422147 DOI: 10.1126/science.adi7562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 01/24/2024] [Indexed: 03/02/2024]
Abstract
Animal body-size variation influences multiple processes in marine ecosystems, but habitat heterogeneity has prevented a comprehensive assessment of size across pelagic (midwater) and benthic (seabed) systems along anthropic gradients. In this work, we derive fish size indicators from 17,411 stereo baited-video deployments to test for differences between pelagic and benthic responses to remoteness from human pressures and effectiveness of marine protected areas (MPAs). From records of 823,849 individual fish, we report divergent responses between systems, with pelagic size structure more profoundly eroded near human markets than benthic size structure, signifying greater vulnerability of pelagic systems to human pressure. Effective protection of benthic size structure can be achieved through MPAs placed near markets, thereby contributing to benthic habitat restoration and the recovery of associated fishes. By contrast, recovery of the world's largest and most endangered fishes in pelagic systems requires the creation of highly protected areas in remote locations, including on the High Seas, where protection efforts lag.
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Affiliation(s)
- Tom B Letessier
- CESAB - FRB, Montpellier, France
- Institute of Zoology, Zoological Society of London, Regent's Park, London, UK
- Marine Futures Lab, School of Biological Sciences, University of Western Australia, Perth, WA, Australia
| | - David Mouillot
- MARBEC, Université de Montpellier, CNRS, Ifremer, IRD, Montpellier, France
| | - Laura Mannocci
- CESAB - FRB, Montpellier, France
- MARBEC, Université de Montpellier, CNRS, Ifremer, IRD, Montpellier, France
| | - Hanna Jabour Christ
- Marine Futures Lab, School of Biological Sciences, University of Western Australia, Perth, WA, Australia
| | | | - Sheikheldin Mohamed Elamin
- Faculty of Marine Science and Fisheries, Red Sea State University, P.O. Box 24, Port Sudan, Red Sea State, Sudan
| | - Alan M Friedlander
- National Geographic Society, Washington, DC 20036, USA
- Hawai'i Institute of Marine Biology, University of Hawai'i, Kāne'ohe, Hawai'i, USA
| | - Alex Hearn
- Galapagos Science Center, Universidad San Francisco de Quito, Quito, Ecuador
- MigraMar, Olema, CA, USA
| | - Jean-Baptiste Juhel
- ENTROPIE, Institut de Recherche pour le Développement, IRD-UR-UNC-IFREMER-CNRS, Centre IRD de Nouméa, Nouméa Cedex, New-Caledonia, France
| | - Alf Ring Kleiven
- Institute of Marine Research, Nye Flødevigveien 20, 4817 His, Norway
| | - Even Moland
- Institute of Marine Research, Nye Flødevigveien 20, 4817 His, Norway
- Centre for Coastal Research (CCR), Department of Natural Sciences, University of Agder, P.O. Box 422, N-4604 Kristiansand, Norway
| | - Nicolas Mouquet
- CESAB - FRB, Montpellier, France
- MARBEC, Université de Montpellier, CNRS, Ifremer, IRD, Montpellier, France
| | | | - Enric Sala
- National Geographic Society, Washington, DC 20036, USA
| | - Christopher D H Thompson
- Marine Futures Lab, School of Biological Sciences, University of Western Australia, Perth, WA, Australia
| | - Laure Velez
- MARBEC, Université de Montpellier, CNRS, Ifremer, IRD, Montpellier, France
| | - Laurent Vigliola
- ENTROPIE, Institut de Recherche pour le Développement, IRD-UR-UNC-IFREMER-CNRS, Centre IRD de Nouméa, Nouméa Cedex, New-Caledonia, France
| | - Jessica J Meeuwig
- Marine Futures Lab, School of Biological Sciences, University of Western Australia, Perth, WA, Australia
- Oceans Institute, University of Western Australia, Perth, WA, Australia
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2
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Kanzler L, Perthame B, Sarels B. Structured model conserving biomass for the size-spectrum evolution in aquatic ecosystems. J Math Biol 2024; 88:26. [PMID: 38324076 DOI: 10.1007/s00285-023-02043-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 12/13/2023] [Accepted: 12/27/2023] [Indexed: 02/08/2024]
Abstract
Mathematical modelling of the evolution of the size-spectrum dynamics in aquatic ecosystems was discovered to be a powerful tool to have a deeper insight into impacts of human- and environmental driven changes on the marine ecosystem. In this article we propose to investigate such dynamics by formulating and investigating a suitable model. The underlying process for these dynamics is given by predation events, causing both growth and death of individuals, while keeping the total biomass within the ecosystem constant. The main governing equation investigated is deterministic and non-local of quadratic type, coming from binary interactions. Predation is assumed to strongly depend on the ratio between a predator and its prey, which is distributed around a preferred feeding preference value. Existence of solutions is shown in dependence of the choice of the feeding preference function as well as the choice of the search exponent, a constant influencing the average volume in water an individual has to search until it finds prey. The equation admits a trivial steady state representing a died out ecosystem, as well as-depending on the parameter-regime-steady states with gaps in the size spectrum, giving evidence to the well known cascade effect. The question of stability of these equilibria is considered, showing convergence to the trivial steady state in a certain range of parameters. These analytical observations are underlined by numerical simulations, with additionally exhibiting convergence to the non-trivial equilibrium for specific ranges of parameters.
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Affiliation(s)
- L Kanzler
- CEREMADE, Université Paris Dauphine, Place du Maréchal de Lattre de Tassigny, 75775, Paris Cedex 16, France.
| | - B Perthame
- Sorbonne Université, CNRS, Université de Paris Cité, Inria, Laboratoire Jacques-Louis Lions, 75005, Paris, France
| | - B Sarels
- Sorbonne Université, CNRS, Université de Paris Cité, Laboratoire Jacques-Louis Lions, 75005, Paris, France
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3
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Atkinson A, Rossberg AG, Gaedke U, Sprules G, Heneghan RF, Batziakas S, Grigoratou M, Fileman E, Schmidt K, Frangoulis C. Steeper size spectra with decreasing phytoplankton biomass indicate strong trophic amplification and future fish declines. Nat Commun 2024; 15:381. [PMID: 38195697 PMCID: PMC10776571 DOI: 10.1038/s41467-023-44406-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 12/12/2023] [Indexed: 01/11/2024] Open
Abstract
Under climate change, model ensembles suggest that declines in phytoplankton biomass amplify into greater reductions at higher trophic levels, with serious implications for fisheries and carbon storage. However, the extent and mechanisms of this trophic amplification vary greatly among models, and validation is problematic. In situ size spectra offer a novel alternative, comparing biomass of small and larger organisms to quantify the net efficiency of energy transfer through natural food webs that are already challenged with multiple climate change stressors. Our global compilation of pelagic size spectrum slopes supports trophic amplification empirically, independently from model simulations. Thus, even a modest (16%) decline in phytoplankton this century would magnify into a 38% decline in supportable biomass of fish within the intensively-fished mid-latitude ocean. We also show that this amplification stems not from thermal controls on consumers, but mainly from temperature or nutrient controls that structure the phytoplankton baseline of the food web. The lack of evidence for direct thermal effects on size structure contrasts with most current thinking, based often on more acute stress experiments or shorter-timescale responses. Our synthesis of size spectra integrates these short-term dynamics, revealing the net efficiency of food webs acclimating and adapting to climatic stressors.
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Affiliation(s)
- Angus Atkinson
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, PL13DH, UK.
| | - Axel G Rossberg
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Ursula Gaedke
- Institute of Biochemistry and Biology, University of Potsdam, 14469, Potsdam, Germany
| | - Gary Sprules
- Department of Biology, University of Toronto Mississauga, 3359 Mississauga Rd. N., Mississauga, ON, L5L 1C6, Canada
| | - Ryan F Heneghan
- School of Mathematical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Stratos Batziakas
- Hellenic Centre for Marine Research, Former U.S. Base at Gournes, P.O. Box 2214, Heraklion GR-71003, Crete, Greece
| | | | - Elaine Fileman
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, PL13DH, UK
| | - Katrin Schmidt
- University of Plymouth, School of Geography, Earth and Environmental Sciences, Plymouth, PL4 8AA, UK
| | - Constantin Frangoulis
- Hellenic Centre for Marine Research, Former U.S. Base at Gournes, P.O. Box 2214, Heraklion GR-71003, Crete, Greece
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4
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Gutiérrez Al‐Khudhairy OU, Rossberg AG. Evolution of prudent predation in complex food webs. Ecol Lett 2022; 25:1055-1074. [PMID: 35229972 PMCID: PMC9540554 DOI: 10.1111/ele.13979] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 11/03/2021] [Accepted: 12/17/2021] [Indexed: 01/09/2023]
Abstract
Prudent predators catch sufficient prey to sustain their populations but not as much as to undermine their populations' survival. The idea that predators evolve to be prudent has been dismissed in the 1970s, but the arguments invoked then are untenable in the light of modern evolution theory. The evolution of prudent predation has repeatedly been demonstrated in two-species predator-prey metacommunity models. However, the vigorous population fluctuations that these models predict are not widely observed. Here we show that in complex model food webs prudent predation evolves as a result of consumer-mediated ('apparent') competitive exclusion of resources, which disadvantages aggressive consumers and does not generate such fluctuations. We make testable predictions for empirical signatures of this mechanism and its outcomes. Then we discuss how these predictions are borne out across freshwater, marine and terrestrial ecosystems. Demonstrating explanatory power of evolved prudent predation well beyond the question of predator-prey coexistence, the predicted signatures explain unexpected declines of invasive alien species, the shape of stock-recruitment relations of fish, and the clearance rates of pelagic consumers across the latitudinal gradient and 15 orders of magnitude in body mass. Specific research to further test this theory is proposed.
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Affiliation(s)
| | - Axel G. Rossberg
- School of Biological and Behavioural SciencesQueen Mary University of LondonLondonUK
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5
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García-Oliva O, Hantzsche FM, Boersma M, Wirtz KW. Phytoplankton and particle size spectra indicate intense mixotrophic dinoflagellates grazing from summer to winter. JOURNAL OF PLANKTON RESEARCH 2022; 44:224-240. [PMID: 35356359 PMCID: PMC8962713 DOI: 10.1093/plankt/fbac013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 02/10/2021] [Indexed: 06/14/2023]
Abstract
Mixotrophic dinoflagellates (MTD) are a diverse group of organisms often responsible for the formation of harmful algal blooms. However, the development of dinoflagellate blooms and their effects on the plankton community are still not well explored. Here we relate the species succession of MTD with parallel changes of phytoplankton size spectra during periods of MTD dominance. We used FlowCAM analysis to acquire size spectra in the range 2-200 μm every one or two weeks from July to December 2007 at Helgoland Roads (Southern North Sea). Most size spectra of dinoflagellates were bimodal, whereas for other groups, e.g. diatoms and autotrophic flagellates, the spectra were unimodal, which indicates different resource use strategies of autotrophs and mixotrophs. The biomass lost in the size spectrum correlates with the potential grazing pressure of MTD. Based on size-based analysis of trophic linkages, we suggest that mixotrophy, including detritivory, drives species succession and facilitates the formation of bimodal size spectra. Bimodality in particular indicates niche differentiation through grazing of large MTD on smaller MTD. Phagotrophy of larger MTD may exceed one of the smaller MTD since larger prey was more abundant than smaller prey. Under strong light limitation, a usually overlooked refuge strategy may derive from detritivory. The critical role of trophic links of MTD as a central component of the plankton community may guide future observational and theoretical research.
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Affiliation(s)
| | - Florian M Hantzsche
- Institute of Coastal Systems - Analysis and Modeling, Helmholtz-Zentrum Hereon, Max-Planck-straße 1, Geesthacht 21502, Germany
- Alfred-Wegener-Institute Helmholtz-Zentrum für Polar- und Meeresforschung, Biologischen Anstalt Helgoland, Helgoland 27483, Germany
| | - Maarten Boersma
- Alfred-Wegener-Institute Helmholtz-Zentrum für Polar- und Meeresforschung, Biologischen Anstalt Helgoland, Helgoland 27483, Germany
- FB2, University of Bremen, Leobener-Straße, Bremen 28359, Germany
| | - Kai W Wirtz
- Institute of Coastal Systems - Analysis and Modeling, Helmholtz-Zentrum Hereon, Max-Planck-straße 1, Geesthacht 21502, Germany
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6
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Baumgartner MT, Bianco Faria LD. The sensitivity of complex dynamic food webs to the loss of top omnivores. J Theor Biol 2022; 538:111027. [DOI: 10.1016/j.jtbi.2022.111027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 01/10/2022] [Accepted: 01/14/2022] [Indexed: 12/12/2022]
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7
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Benoit DM, Giacomini HC, Chu C, Jackson DA. Identifying influential parameters of a multi-species fish size spectrum model for a northern temperate lake through sensitivity analyses. Ecol Modell 2021. [DOI: 10.1016/j.ecolmodel.2021.109740] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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8
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Heather FJ, Stuart-Smith RD, Blanchard JL, Fraser KM, Edgar GJ. Reef communities show predictable undulations in linear abundance size spectra from copepods to sharks. Ecol Lett 2021; 24:2146-2154. [PMID: 34291561 DOI: 10.1111/ele.13844] [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: 03/08/2021] [Revised: 06/02/2021] [Accepted: 06/10/2021] [Indexed: 01/29/2023]
Abstract
Among the more widely accepted general hypotheses in ecology is that community relationships between abundance and body size follow a log-linear size spectrum, from the smallest consumers to the largest predators (i.e. 'bacteria to whales'). Nevertheless, most studies only investigate small subsets of this spectrum, and note that extreme size classes in survey data deviate from linear expectations. In this study, we fit size spectra to field data from 45 rocky and coral reef sites along a 28° latitudinal gradient, comprising individuals from 0.125 mm to 2 m in body size. We found that 96% of the variation in abundance along this 'extended' size gradient was described by a single linear function across all sites. However, consistent 'wobbles' were also observed, with subtle peaks and troughs in abundance along the spectrum, which varied with sea temperature, as predicted by theory relating to trophic cascades.
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Affiliation(s)
- Freddie J Heather
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
| | - Rick D Stuart-Smith
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
| | - Julia L Blanchard
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
| | - Kate M Fraser
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
| | - Graham J Edgar
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
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9
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Perkins DM, Durance I, Jackson M, Jones JI, Lauridsen RB, Layer-Dobra K, Reiss J, Thompson MSA, Woodward G. Systematic variation in food web body-size structure linked to external subsidies. Biol Lett 2021; 17:20200798. [PMID: 33726566 DOI: 10.1098/rsbl.2020.0798] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The relationship between body mass (M) and size class abundance (N) depicts patterns of community structure and energy flow through food webs. While the general assumption is that M and N scale linearly (on log-log axes), nonlinearity is regularly observed in natural systems, and is theorized to be driven by nonlinear scaling of trophic level (TL) with M resulting in the rapid transfer of energy to consumers in certain size classes. We tested this hypothesis with data from 31 stream food webs. We predicted that allochthonous subsidies higher in the web results in nonlinear M-TL relationships and systematic abundance peaks in macroinvertebrate and fish size classes (latter containing salmonids), that exploit terrestrial plant material and terrestrial invertebrates, respectively. Indeed, both M-N and M-TL significantly deviated from linear relationships and the observed curvature in M-TL scaling was inversely related to that observed in M-N relationships. Systemic peaks in M-N, and troughs in M-TL occurred in size classes dominated by generalist invertebrates, and brown trout. Our study reveals how allochthonous resources entering high in the web systematically shape community size structure and demonstrates the relevance of a generalized metabolic scaling model for understanding patterns of energy transfer in energetically 'open' food webs.
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Affiliation(s)
- Daniel M Perkins
- Department of Life Sciences, Whitelands College, University of Roehampton, London SW15 4JD, UK
| | - Isabelle Durance
- Cardiff Water Research Institute, Cardiff School of Biosciences, Cardiff University, PO Box 915, Cardiff CF10 3TL, UK
| | | | - J Iwan Jones
- School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4NS, UK.,Centre for Ecology and Hydrology, Wallingford OX10 8BB, UK
| | - Rasmus B Lauridsen
- School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4NS, UK.,Game and Wildlife Conservation Trust, Salmon and Trout Research Centre, Wareham, Dorset BH20 6BB, UK
| | - Katrin Layer-Dobra
- Grand Challenges in Ecosystems and the Environment, Department of Life Sciences, Imperial College London, Silwood Park Campus SL5 7PY, UK
| | - Julia Reiss
- Department of Life Sciences, Whitelands College, University of Roehampton, London SW15 4JD, UK
| | - Murray S A Thompson
- Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory, Pakefield Road, Lowestoft, Suffolk NR33 0HT, UK
| | - Guy Woodward
- Grand Challenges in Ecosystems and the Environment, Department of Life Sciences, Imperial College London, Silwood Park Campus SL5 7PY, UK
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10
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Galiana N, Arnoldi JF, Barbier M, Acloque A, de Mazancourt C, Loreau M. Can biomass distribution across trophic levels predict trophic cascades? Ecol Lett 2020; 24:464-476. [PMID: 33314592 DOI: 10.1111/ele.13658] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 11/14/2020] [Indexed: 11/30/2022]
Abstract
The biomass distribution across trophic levels (biomass pyramid) and cascading responses to perturbations (trophic cascades) are archetypal representatives of the interconnected set of static and dynamical properties of food chains. A vast literature has explored their respective ecological drivers, sometimes generating correlations between them. Here we instead reveal a fundamental connection: both pyramids and cascades reflect the dynamical sensitivity of the food chain to changes in species intrinsic rates. We deduce a direct relationship between cascades and pyramids, modulated by what we call trophic dissipation - a synthetic concept that encodes the contribution of top-down propagation of consumer losses in the biomass pyramid. Predictable across-ecosystem patterns emerge when systems are in similar regimes of trophic dissipation. Data from 31 aquatic mesocosm experiments demonstrate how our approach can reveal the causal mechanisms linking trophic cascades and biomass distributions, thus providing a road map to deduce reliable predictions from empirical patterns.
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Affiliation(s)
- Núria Galiana
- Theoretical and Experimental Ecology Station, CNRS, Moulis, 09200, France
| | - Jean-François Arnoldi
- Zoology Department, School of Natural Sciences, Trinity College Dublin, The University of Dublin, Ireland
| | - Matthieu Barbier
- Theoretical and Experimental Ecology Station, CNRS, Moulis, 09200, France
| | - Amandine Acloque
- Theoretical and Experimental Ecology Station, CNRS, Moulis, 09200, France
| | | | - Michel Loreau
- Theoretical and Experimental Ecology Station, CNRS, Moulis, 09200, France
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11
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Woodson CB, Schramski JR, Joye SB. Food web complexity weakens size-based constraints on the pyramids of life. Proc Biol Sci 2020; 287:20201500. [PMID: 32900320 DOI: 10.1098/rspb.2020.1500] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Marine ecosystems are generally expected to have bottom-heavy trophic structure (more plants than animals) due to size-based constraints arising from increased metabolic requirements and inefficient energy transfer. However, size-based (allometric) approaches are often limited to confined trophic-level windows where energy transfer is predicted by size alone and are constrained to a balance between bottom-up and top-down control at steady state. In real food webs, energy flow is more complex and imbalances in top-down and bottom-up processes can also shape trophic structure. We expand the size-based theory to account for complex food webs and show that moderate levels of food web connectance allow for inverted trophic structure more often than predicted, especially in marine ecosystems. Trophic structure inversion occurs due to the incorporation of complex energy pathways and top-down effects on ecosystems. Our results suggest that marine ecosystems should be top-heavy, and observed bottom-heavy trophic structure may be a result of human defaunation of the ocean that has been more extreme than presently recognized.
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Affiliation(s)
- C B Woodson
- School of Environmental, Civil, Agricultural and Mechanical Engineering, University of Georgia, Athens, GA 30602, USA
| | - J R Schramski
- School of Environmental, Civil, Agricultural and Mechanical Engineering, University of Georgia, Athens, GA 30602, USA
| | - S B Joye
- Department of Marine Sciences, University of Georgia, Athens, GA 30602, USA
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