151
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Werry JM, Sumpton W, Otway NM, Lee SY, Haig JA, Mayer DG. Rainfall and sea surface temperature: key drivers for occurrence of bull shark, Carcharhinus leucas, in beach areas. Glob Ecol Conserv 2018. [DOI: 10.1016/j.gecco.2018.e00430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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152
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Raby GD, Sundin J, Jutfelt F, Cooke SJ, Clark TD. Exposure to elevated carbon dioxide does not impair short-term swimming behaviour or shelter-seeking in a predatory coral-reef fish. JOURNAL OF FISH BIOLOGY 2018; 93:138-142. [PMID: 29931691 DOI: 10.1111/jfb.13728] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 04/22/2018] [Indexed: 06/08/2023]
Abstract
Adult bluespotted rockcod Cephalopholis cyanostigma, a coral-reef grouper, were acclimated to either ambient (mean ± s.d. 406 ± 21 μatm; 1 atmos = 101325 Pa) or high pCO2 (945 ± 116 μatm) conditions in a laboratory for 8-9 days, then released at the water surface directly above a reef (depth c. 5 m) and followed on video camera (for 191 ± 21 s) by scuba divers until they sought cover in the reef. No differences were detected between groups in any of the six measured variables, which included the time fish spent immobile after release, tail beat frequency during swimming and the time required to locate and enter the protective shelter of the reef.
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Affiliation(s)
- Graham D Raby
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, Canada
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, Canada
| | - Josefin Sundin
- Department of Neuroscience, Uppsala University, Uppsala, Sweden
| | - Fredrik Jutfelt
- Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Steven J Cooke
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, Canada
| | - Timothy D Clark
- School of Life and Environmental Sciences, Deakin University, Geelong, Australia
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153
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Housiaux JA, Hepburn CD, Rayment WJ. Seasonal variation in occurrence of the sevengill shark, Notorynchus cepedianus, in two inshore habitats of southern New Zealand. NEW ZEALAND JOURNAL OF ZOOLOGY 2018. [DOI: 10.1080/03014223.2018.1482930] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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154
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Santos CC, Coelho R. Migrations and habitat use of the smooth hammerhead shark (Sphyrna zygaena) in the Atlantic Ocean. PLoS One 2018; 13:e0198664. [PMID: 29874297 PMCID: PMC5991395 DOI: 10.1371/journal.pone.0198664] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 05/23/2018] [Indexed: 11/18/2022] Open
Abstract
The smooth hammerhead shark, Sphyrna zygaena, is a cosmopolitan semipelagic shark captured as bycatch in pelagic oceanic fisheries, especially pelagic longlines targeting swordfish and/or tunas. From 2012 to 2016, eight smooth hammerheads were tagged with Pop-up Satellite Archival Tags in the inter-tropical region of the Northeast Atlantic Ocean, with successful transmissions received from seven tags (total of 319 tracking days). Results confirmed the smooth hammerhead is a highly mobile species, as the longest migration ever documented for this species (> 6600 km) was recorded. An absence of a diel vertical movement behavior was noted, with the sharks spending most of their time at surface waters (0–50 m) above 23°C. The operating depth of the pelagic longline gear was measured with Minilog Temperature and Depth Recorders, and the overlap with the species vertical distribution was calculated. The overlap is taking place mainly during the night and is higher for juveniles (~40% of overlap time). The novel information presented can now be used to contribute to the provision of sustainable management tools and serve as input for Ecological Risk Assessments for smooth hammerheads caught in Atlantic pelagic longline fisheries.
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Affiliation(s)
- Catarina C. Santos
- Portuguese Institute for the Ocean and Atmosphere, I.P., Olhão, Portugal
- * E-mail:
| | - Rui Coelho
- Portuguese Institute for the Ocean and Atmosphere, I.P., Olhão, Portugal
- Center of Marine Sciences (CCMAR), University of Algarve, Faro, Portugal
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155
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Bailleul D, Mackenzie A, Sacchi O, Poisson F, Bierne N, Arnaud‐Haond S. Large-scale genetic panmixia in the blue shark ( Prionace glauca): A single worldwide population, or a genetic lag-time effect of the "grey zone" of differentiation? Evol Appl 2018; 11:614-630. [PMID: 29875806 PMCID: PMC5978958 DOI: 10.1111/eva.12591] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 12/12/2017] [Indexed: 12/31/2022] Open
Abstract
The blue shark Prionace glauca, among the most common and widely studied pelagic sharks, is a top predator, exhibiting the widest distribution range. However, little is known about its population structure and spatial dynamics. With an estimated removal of 10-20 million individuals per year by fisheries, the species is classified as "Near Threatened" by International Union for Conservation of Nature. We lack the knowledge to forecast the long-term consequences of such a huge removal on this top predator itself and on its trophic network. The genetic analysis of more than 200 samples collected at broad scale (from Mediterranean Sea, North Atlantic and Pacific Oceans) using mtDNA and nine microsatellite markers allowed to detect signatures of genetic bottlenecks but a nearly complete genetic homogeneity across the entire studied range. This apparent panmixia could be explained by a genetic lag-time effect illustrated by simulations of demographic changes that were not detectable through standard genetic analysis before a long transitional phase here introduced as the "population grey zone." The results presented here can thus encompass distinct explanatory scenarios spanning from a single demographic population to several independent populations. This limitation prevents the genetic-based delineation of stocks and thus the ability to anticipate the consequences of severe depletions at all scales. More information is required for the conservation of population(s) and management of stocks, which may be provided by large-scale sampling not only of individuals worldwide, but also of loci genomewide.
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Affiliation(s)
- Diane Bailleul
- IFREMER, UMR MARBEC, Station de SèteSèteFrance
- OREME – Station MarineUniversité MontpellierSèteFrance
| | - Alicia Mackenzie
- IFREMER, UMR MARBEC, Station de SèteSèteFrance
- OREME – Station MarineUniversité MontpellierSèteFrance
| | - Olivier Sacchi
- IFREMER, UMR MARBEC, Station de SèteSèteFrance
- OREME – Station MarineUniversité MontpellierSèteFrance
| | | | - Nicolas Bierne
- OREME – Station MarineUniversité MontpellierSèteFrance
- CNRS, Institut des Sciences de l'EvolutionUniversité MontpellierMontpellierFrance
| | - Sophie Arnaud‐Haond
- IFREMER, UMR MARBEC, Station de SèteSèteFrance
- OREME – Station MarineUniversité MontpellierSèteFrance
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156
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Páez-Rosas D, Insuasti-Zarate P, Riofrío-Lazo M, Galván-Magaña F. Feeding behavior and trophic interaction of three shark species in the Galapagos Marine Reserve. PeerJ 2018; 6:e4818. [PMID: 29844971 PMCID: PMC5971838 DOI: 10.7717/peerj.4818] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 05/01/2018] [Indexed: 11/25/2022] Open
Abstract
There is great concern about the future of sharks in Ecuador because of the lack of biological knowledge of most species that inhabit the region. This paper analyzes the feeding behavior of the pelagic thresher shark (Alopias pelagicus), the blue shark (Prionace glauca) and the silky shark (Carcharhinus falciformis) through the use of stable isotopes of carbon and nitrogen (δ13C and δ15N), with the aim of determining the degree of interaction between these species in the Galapagos Marine Reserve. No interspecific differences were found in use of oceanic vs. inshore feeding areas (δ13C: Kruskal–Wallis test, p = 0.09). The position in the hierarchy of the food web where A. pelagicus feeds differed from that of the other species (δ15N: Kruskal–Wallis test, p = 0.01). There were no significant differences in δ13C and δ15N values between males and females of the three species (Student’s t-test, p > 0.05), which suggests that both sexes have a similar feeding behavior. A specialist strategy was observed in P. glauca (trophic niche breadth TNB = 0.69), while the other species were found to be generalist (A. pelagicus TNB = 1.50 and C. falciformis TNB = 1.09). The estimated trophic level (TL) varied between the three species. C. falciformis occupied the highest trophic level (TL = 4.4), making it a quaternary predator in the region. The results of this study coincide with the identified behavior in these predators in other areas of the tropical Pacific (Colombia and Mexico), and suggest a pelagic foraging strategy with differential consumption of prey between the three species. These ecological aspects can provide timely information when implementing in conservation measures for these shark species in the Tropical Pacific and Galapagos Marine Reserve.
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Affiliation(s)
- Diego Páez-Rosas
- Galapagos Science Center, Universidad San Francisco de Quito, Galápagos, Ecuador.,Unidad Técnica San Cristóbal, Dirección del Parque Nacional Galápagos, Galápagos, Ecuador
| | - Paul Insuasti-Zarate
- Programa de Maestría en Manejo Sustentable de Biorecursos y Medio Ambiente, Universidad de Guayaquil, Guayaquil, Ecuador
| | - Marjorie Riofrío-Lazo
- Galapagos Science Center, Universidad San Francisco de Quito, Galápagos, Ecuador.,Centro Interdisciplinario de Ciencias Marinas, Instituto Politécnico Nacional, La Paz, México
| | - Felipe Galván-Magaña
- Centro Interdisciplinario de Ciencias Marinas, Instituto Politécnico Nacional, La Paz, México
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157
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Mäkinen J, Vanhatalo J. Hierarchical Bayesian model reveals the distributional shifts of Arctic marine mammals. DIVERS DISTRIB 2018. [DOI: 10.1111/ddi.12776] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Affiliation(s)
- Jussi Mäkinen
- Organismal and Evolutionary Biology Research Program; Faculty of Biological and Environmental Sciences; University of Helsinki; Helsinki Finland
| | - Jarno Vanhatalo
- Organismal and Evolutionary Biology Research Program; Faculty of Biological and Environmental Sciences; University of Helsinki; Helsinki Finland
- Department of Mathematics and Statistics; Faculty of Science; University of Helsinki; Helsinki Finland
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158
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Artisanal shark fishing in Milne Bay Province, Papua New Guinea: biomass estimation from genetically identified shark and ray fins. Sci Rep 2018; 8:6693. [PMID: 29703988 PMCID: PMC5923204 DOI: 10.1038/s41598-018-25101-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 04/13/2018] [Indexed: 11/08/2022] Open
Abstract
Our study is the first detailed examination of species composition using DNA COI barcoding of elasmobranchs from an artisanal fishery of Papua New Guinea. The study is the first in the region to provide biomass estimates based on species confirmation following examination of dried fins. Over 20 species of elasmobranchs were identified from 623 fins from the artisanal fishery in Milne Bay Province of PNG, with Carcharhinus amblyrhynchos and Carcharhinus melanopterus the most abundant species in the catches. Of concern, 21% of fins examined were from IUCN listed threatened species (Vulnerable or Endangered) with 8% of fins from the Endangered scalloped hammerhead (Sphyrna lewini). Following species identifications and use of species-specific length and weight extrapolations, we estimated over 9 t of elasmobranchs contributed to the fin batch. Importantly, the vast majority of the elasmobranchs in this batch were from immature animals. Genetic identification has an important role to play in the ongoing sustainable management of elasmobranchs in artisanal fisheries in PNG and more widely. However in the absence of ongoing genetic testing, recording the species (if known) at the time of catch is more achievable and would provide more robust data for fisheries managers in PNG over the longer term.
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159
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Ferretti F, Curnick D, Liu K, Romanov EV, Block BA. Shark baselines and the conservation role of remote coral reef ecosystems. SCIENCE ADVANCES 2018; 4:eaaq0333. [PMID: 29532033 PMCID: PMC5842041 DOI: 10.1126/sciadv.aaq0333] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Scientific monitoring has recorded only a recent fraction of the oceans' alteration history. This biases our understanding of marine ecosystems. Remote coral reef ecosystems are often considered pristine because of high shark abundance. However, given the long history and global nature of fishing, sharks' vulnerability, and the ecological consequences of shark declines, these states may not be natural. In the Chagos archipelago, one of the remotest coral reef systems on the planet, protected by a very large marine reserve, we integrated disparate fisheries and scientific survey data to reconstruct baselines and long-term population trajectories of two dominant sharks. In 2012, we estimated 571,310 gray reef and 31,693 silvertip sharks, about 79 and 7% of their baseline levels. These species were exploited longer and more intensively than previously thought and responded to fishing and protection with variable and compensatory population trajectories. Our approach highlights the value of integrative and historical analyses to evaluate large marine ecosystems currently considered pristine.
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Affiliation(s)
- Francesco Ferretti
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
- Corresponding author.
| | - David Curnick
- Institute of Zoology, Zoological Society of London, Outer Circle, Regent’s Park, London NW1 4RY, UK
| | - Keli Liu
- Department of Statistics, Stanford University, Stanford, CA 94305, USA
| | - Evgeny V. Romanov
- Centre technique d’appui à la pêche réunionnaise (CAP RUN), 97420 Le Port, Île de la Réunion, France
| | - Barbara A. Block
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
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160
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Kolmann MA, Dean Grubbs R, Huber DR, Fisher R, Lovejoy NR, Erickson GM. Intraspecific variation in feeding mechanics and bite force in durophagous stingrays. J Zool (1987) 2018. [DOI: 10.1111/jzo.12530] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- M. A. Kolmann
- Friday Harbor Laboratories; University of Washington; Friday Harbor WA USA
| | - R. Dean Grubbs
- Florida State University Coastal and Marine Laboratory; Tallahassee FL USA
| | - D. R. Huber
- Department of Biology; University of Tampa; Tampa FL USA
| | - R. Fisher
- Marine Advisory Services; Virginia Institute of Marine Science; Gloucester Point VA USA
| | - N. R. Lovejoy
- Department of Biological Science; University of Toronto Scarborough; Toronto ON Canada
| | - G. M. Erickson
- Department of Biological Science; Florida State University; Tallahassee FL USA
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161
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Tomašových A, Kidwell SM. Nineteenth-century collapse of a benthic marine ecosystem on the open continental shelf. Proc Biol Sci 2018; 284:rspb.2017.0328. [PMID: 28592668 DOI: 10.1098/rspb.2017.0328] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 05/12/2017] [Indexed: 11/12/2022] Open
Abstract
The soft-sediment seafloor of the open continental shelf is among the least-known biomes on Earth, despite its high diversity and importance to fisheries and biogeochemical cycling. Abundant dead shells of epifaunal suspension-feeding terebratulid brachiopods (Laqueus) and scallops on the now-muddy mainland continental shelf of southern California reveal the recent, previously unsuspected extirpation of an extensive offshore shell-gravel ecosystem, evidently driven by anthropogenic siltation. Living populations of attached epifauna, which formerly existed in a middle- and outer-shelf mosaic with patches of trophically diverse muds, are restricted today to rocky seafloor along the shelf edge and to the sandier shelves of offshore islands. Geological age-dating of 190 dead brachiopod shells shows that (i) no shells have been produced on the mainland shelf within the last 100 years, (ii) their shell production declined steeply during the nineteenth century, and (iii) they had formerly been present continuously for at least 4 kyr. This loss, sufficiently rapid (less than or equal to 100 years) and thorough to represent an ecosystem collapse, coincides with intensification of alluvial-plain land use in the nineteenth century, particularly livestock grazing. Extirpation was complete by the start of twentieth-century urbanization, warming, bottom fishing and scientific surveys. The loss of this filter-feeding fauna and the new spatial homogeneity and dominance of deposit- and detritus-feeders would have altered ecosystem functioning by reducing habitat heterogeneity and seawater filtering. This discovery, attesting to the power of this geological approach to recent ecological transitions, also strongly increases the spatial scope attributable to the negative effects of siltation, and suggests that it has been under-recognized on continental shelves elsewhere as a legacy of coastal land use.
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Affiliation(s)
- Adam Tomašových
- Earth Science Institute, Slovak Academy of Sciences, Dúbravská cesta 9, 84005 Bratislava, Slovakia
| | - Susan M Kidwell
- Department of Geophysical Sciences, University of Chicago, Chicago, IL 60637, USA
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162
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A global perspective on the trophic geography of sharks. Nat Ecol Evol 2018; 2:299-305. [DOI: 10.1038/s41559-017-0432-z] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 11/28/2017] [Indexed: 11/09/2022]
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163
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Hempson TN, Graham NAJ, MacNeil MA, Bodin N, Wilson SK. Regime shifts shorten food chains for mesopredators with potential sublethal effects. Funct Ecol 2018. [DOI: 10.1111/1365-2435.13012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Tessa N. Hempson
- ARC Centre of Excellence for Coral Reef Studies James Cook University Townsville Queensland Australia
| | - Nicholas A. J. Graham
- ARC Centre of Excellence for Coral Reef Studies James Cook University Townsville Queensland Australia
- Lancaster Environment Centre Lancaster University Lancaster UK
| | - M. Aaron MacNeil
- ARC Centre of Excellence for Coral Reef Studies James Cook University Townsville Queensland Australia
- Department of Biology Ocean Frontier Institute Dalhousie University Halifax Nova Scotia Canada
| | - Nathalie Bodin
- Research Institute for Sustainable Development (IRD) MARine Biodiversity Exploitation and Conservation Unit Victoria Mahé, Seychelles
- Seychelles Fishing Authority (SFA) Victoria Mahé, Seychelles
| | - Shaun K. Wilson
- Marine Science Program Department of Biodiversity, Conservation and Attractions Kensington Perth WA Australia
- Oceans Institute University of Western Australia Crawley WA Australia
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164
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Snyder BF, Ruyle LE. The abolition of war as a goal of environmental policy. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 605-606:347-356. [PMID: 28668746 DOI: 10.1016/j.scitotenv.2017.06.223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 06/14/2017] [Accepted: 06/25/2017] [Indexed: 06/07/2023]
Abstract
Since the 1950s, select military and political leaders have had the capacity to kill all or nearly all human life on Earth. The number of people entrusted with this power grows each year through proliferation and the rise of new political leaders. If humans continue to maintain and develop nuclear weapons, it is highly probable that a nuclear exchange will occur again at some point in the future. This nuclear exchange may or may not annihilate the human species, but it will cause catastrophic effects on the biosphere. The international community has attempted to resolve this existential problem via treaties that control and potentially eliminate nuclear weapons, however, these treaties target only nuclear weapons, leaving the use of war as a normalized means for settling conflict. As long as war exists as a probable future, nations will be under pressure to develop more powerful weapons. Thus, we argue that the elimination of nuclear weapons alone is not a stable, long-term strategy. A far more secure strategy would be the elimination of war as a means of settling international disputes. Therefore, those concerned about environmental sustainability or the survival of the biosphere should work to abolish war.
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Affiliation(s)
- Brian F Snyder
- Department of Environmental Science, Louisiana State University, United States.
| | - Leslie E Ruyle
- Center on Conflict and Development, Texas A&M University, United States.
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165
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Cantoni E, Mills Flemming J, Welsh AH. A random-effects hurdle model for predicting bycatch of endangered marine species. Ann Appl Stat 2017. [DOI: 10.1214/17-aoas1074] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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166
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Akhilesh KV, Purushottama GB, Kizhakudan SJ. Biological observations on the broadfin shark Lamiopsis temminckii (Carcharhiniformes: Carcharhinidae). JOURNAL OF FISH BIOLOGY 2017; 91:1721-1729. [PMID: 29034466 DOI: 10.1111/jfb.13474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 08/22/2017] [Indexed: 06/07/2023]
Abstract
Biological information was collected from 214 individuals of the broadfin shark Lamiopsis temminckii measuring 418 to 1782 mm total length, LT . Size at maturity (L50 ) for females and males was estimated at 1430 and 1368 mm LT , respectively, while mature and gravid females were observed from 1350 mm LT with litter sizes 2-8 and size at birth 418-650 mm LT . Analysis of stomach contents revealed a variety of prey, primarily crustaceans (54·0%), teleosts (42·7%) and cephalopods.
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Affiliation(s)
- K V Akhilesh
- ICAR-Central Marine Fisheries Research Institute, P.B.No.1603, Ernakulam North, P.O., Kochi 682 018, Kerala, India
| | - G B Purushottama
- ICAR-Central Marine Fisheries Research Institute, P.B.No.1603, Ernakulam North, P.O., Kochi 682 018, Kerala, India
| | - S J Kizhakudan
- ICAR-Central Marine Fisheries Research Institute, P.B.No.1603, Ernakulam North, P.O., Kochi 682 018, Kerala, India
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167
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European catfish (Silurus glanis) as a freshwater apex predator drives ecosystem via its diet adaptability. Sci Rep 2017; 7:15970. [PMID: 29162872 PMCID: PMC5698325 DOI: 10.1038/s41598-017-16169-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 11/08/2017] [Indexed: 11/27/2022] Open
Abstract
Apex predators play a key role in ecosystem stability across environments but their numbers in general are decreasing. By contrast, European catfish (Silurus glanis), the European freshwater apex predator, is on the increase. However, studies concerning apex predators in freshwaters are scarce in comparison to those in terrestrial and marine ecosystems. The present study combines stomach content and stable isotope analyses with diet preferences of catfish to reveal its impact on the ecosystem since stocking. Catfish niche width is extremely wide in comparison to the typical model predator, Northern pike (Esox lucius). Catfish and pike have different individual dietary specialization that results in different functional roles in coupling or compartmentalizing distinct food webs. The role of both species in the ecosystem is irreplaceable due to multiple predator effects. The impact of catfish is apparent across the entire aquatic ecosystem, but herbivores are the most affected ecological group. The key feature of catfish, and probably a common feature of apex predators in general, is utilization of several dietary strategies by individuals within a population: long-term generalism or specialization and also short-term specialization. Catfish, similar to other large-bodied apex predators, have two typical features: enormous generalism and adaptability to new prey sources.
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168
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Boeckman KR, Whiteman HH. Predators Lack Complementarity in a Degraded Stream. COPEIA 2017. [DOI: 10.1643/ce-16-574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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169
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Larson SE, Lowry D. Introduction to Northeast Pacific Shark Biology, Research, and Conservation, Part B. ADVANCES IN MARINE BIOLOGY 2017; 78:1-8. [PMID: 29056140 DOI: 10.1016/bs.amb.2017.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Sharks are iconic, sometimes apex, predators found in every ocean. Because of their ecological role as predators and concern over the stability of their populations, there has been an increasing amount of work focused on shark conservation around the world in recent decades. The populations of sharks that reside in the Northeast Pacific (NEP) Ocean bordering the west coast of the United States reside in one of the most economically and ecologically important oceanic regions in the world. Volume 78 of Advances in Marine Biology (AMB) is a companion to Volume 77, which focused primarily on NEP shark biodiversity, organismal biology, and ecology. Volume 78 highlights fisheries and the conservation implications of fisheries management; shark population modelling and the conservation impacts of these models given that many life history metrics of NEP sharks necessary to accurately run these models are still unknown; the value of captive sharks to the biology, outreach, and conservation of NEP sharks; and the conservation value of citizen science and shark ecotourism. Together these volumes encapsulate the current state of the knowledge for sharks in the NEP and lay the foundation for protecting, managing, and learning from these species in the face evolving natural conditions and societal opinions.
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Affiliation(s)
| | - Dayv Lowry
- Washington Department of Fish and Wildlife, Marine Fish Science Unit, Olympia, WA, United States
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170
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Amaral CRL, Pereira F, Silva DA, Amorim A, de Carvalho EF. The mitogenomic phylogeny of the Elasmobranchii (Chondrichthyes). Mitochondrial DNA A DNA Mapp Seq Anal 2017; 29:867-878. [DOI: 10.1080/24701394.2017.1376052] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Cesar R. L. Amaral
- Departamento de Ecologia, Laboratório de Diagnósticos por DNA, Instituto de Biologia Roberto Alcântara Gomes, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Filipe Pereira
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Porto, Portugal
| | - Dayse A. Silva
- Departamento de Ecologia, Laboratório de Diagnósticos por DNA, Instituto de Biologia Roberto Alcântara Gomes, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil
| | - António Amorim
- i3S – Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- Instituto de Patologia e Imunologia Molecular da Universidade do Porto (IPATIMUP), Porto, Portugal
- Faculdade de Ciências, Universidade do Porto, Porto, Portugal
| | - Elizeu F. de Carvalho
- Departamento de Ecologia, Laboratório de Diagnósticos por DNA, Instituto de Biologia Roberto Alcântara Gomes, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil
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171
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Tiger sharks can connect equatorial habitats and fisheries across the Atlantic Ocean basin. PLoS One 2017; 12:e0184763. [PMID: 28926627 PMCID: PMC5604974 DOI: 10.1371/journal.pone.0184763] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 08/30/2017] [Indexed: 12/02/2022] Open
Abstract
Increasing our knowledge about the spatial ecology of apex predators and their interactions with diverse habitats and fisheries is necessary for understanding the trophic mechanisms that underlie several aspects of marine ecosystem dynamics and for guiding informed management policies. A preliminary assessment of tiger shark (Galeocerdo cuvier) population structure off the oceanic insular system of Fernando de Noronha (FEN) and the large-scale movements performed by this species in the equatorial Atlantic Ocean was conducted using longline and handline fishing gear and satellite telemetry. A total of 25 sharks measuring 175–372 cm in total length (TL) were sampled. Most sharks were likely immature females ranging between 200 and 260 cm TL, with few individuals < 200 cm TL being caught. This contrasts greatly with the tiger shark size-distribution previously reported for coastal waters off the Brazilian mainland, where most individuals measured < 200 cm TL. Also, the movements of 8 individuals measuring 202–310 cm TL were assessed with satellite transmitters for a combined total of 757 days (mean = 94.6 days∙shark-1; SD = 65.6). These sharks exhibited a considerable variability in their horizontal movements, with three sharks showing a mostly resident behavior around FEN during the extent of the respective tracks, two sharks traveling west to the South American continent, and two sharks moving mostly along the middle of the oceanic basin, one of which ending up in the northern hemisphere. Moreover, one shark traveled east to the African continent, where it was eventually caught by fishers from Ivory Coast in less than 474 days at liberty. The present results suggest that young tiger sharks measuring < 200 cm TL make little use of insular oceanic habitats from the western South Atlantic Ocean, which agrees with a previously-hypothesized ontogenetic habitat shift from coastal to oceanic habitats experienced by juveniles of this species in this region. In addition, this study adds evidence that tiger sharks are able to connect marine trophic webs from the neritic provinces of the eastern and western margins of the Atlantic Ocean across the equatorial basin and that they may experience mortality induced by remote fisheries. All this information is extremely relevant for understanding the energetic balance of marine ecosystems as much as the exposure of this species to fishing pressure in this yet poorly-known region.
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172
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Lopes PFM, Mendes L, Fonseca V, Villasante S. Tourism as a driver of conflicts and changes in fisheries value chains in Marine Protected Areas. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2017; 200:123-134. [PMID: 28575780 DOI: 10.1016/j.jenvman.2017.05.080] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Revised: 05/17/2017] [Accepted: 05/26/2017] [Indexed: 06/07/2023]
Abstract
Although critical tools for protecting ocean habitats, Marine Protected Areas (MPAs) are sometimes challenged for social impacts and conflicts they may generate. Some conflicts have an economic base, which, once understood, can be used to resolve associated socioenvironmental problems. We addressed how the fish trade in an MPA that combines no-take zones and tourist or resident zones creates incentives for increased fisheries. We performed a value chain analysis following the fish supply and trade through interviews that assessed consumer demand and preference. The results showed a simple and closed value chain driven by tourism (70% of the consumption). Both tourists and local consumers preferred high trophic level species (predators), but the former preferred large pelagics (tuna and dolphinfish) and the latter preferred reef species (barracuda and snapper). Pelagic predators are caught with fresh sardines, which are sometimes located only in the no-take zone. Pelagic species are mainly served as fillet, and the leftover fish parts end up as waste, an issue that, if properly addressed, can help reduce fishing pressure. Whereas some of the target species may be sustainable (e.g., dolphinfish), others are more vulnerable (e.g., wahoo) and should not be intensively fished. We advise setting stricter limits to the number of tourists visiting MPAs, according to their own capacity and peculiarities, in order to avoid conflicts with conservations goals through incentives for increased resource use.
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Affiliation(s)
- P F M Lopes
- Department of Ecology, Federal University of Rio Grande do Norte, Natal, Brazil; Fisheries and Food Institute, Santos, SP, Brazil; Fishing Ecology, Management and Economics (FEME), Natal, Brazil.
| | - L Mendes
- Department of Ecology, Federal University of Rio Grande do Norte, Natal, Brazil
| | - V Fonseca
- Graduate Program in Ecology, Federal University of Rio Grande do Norte, Natal, Brazil
| | - S Villasante
- Faculty of Political and Social Sciences, University of Santiago de Compostela, A Coruña, Spain
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173
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Yokoi H, Ijima H, Ohshimo S, Yokawa K. Impact of biology knowledge on the conservation and management of large pelagic sharks. Sci Rep 2017; 7:10619. [PMID: 28878365 PMCID: PMC5587552 DOI: 10.1038/s41598-017-09427-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 07/27/2017] [Indexed: 11/22/2022] Open
Abstract
Population growth rate, which depends on several biological parameters, is valuable information for the conservation and management of pelagic sharks, such as blue and shortfin mako sharks. However, reported biological parameters for estimating the population growth rates of these sharks differ by sex and display large variability. To estimate the appropriate population growth rate and clarify relationships between growth rate and relevant biological parameters, we developed a two-sex age-structured matrix population model and estimated the population growth rate using combinations of biological parameters. We addressed elasticity analysis and clarified the population growth rate sensitivity. For the blue shark, the estimated median population growth rate was 0.384 with a range of minimum and maximum values of 0.195–0.533, whereas those values of the shortfin mako shark were 0.102 and 0.007–0.318, respectively. The maturity age of male sharks had the largest impact for blue sharks, whereas that of female sharks had the largest impact for shortfin mako sharks. Hypotheses for the survival process of sharks also had a large impact on the population growth rate estimation. Both shark maturity age and survival rate were based on ageing validation data, indicating the importance of validating the quality of these data for the conservation and management of large pelagic sharks.
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Affiliation(s)
- Hiroki Yokoi
- National Research Institute of Far Seas Fisheries, Japan Fisheries Research and Education Agency; 5-7-1 Orido Shimizu, Shizuoka city, Japan
| | - Hirotaka Ijima
- National Research Institute of Far Seas Fisheries, Japan Fisheries Research and Education Agency; 5-7-1 Orido Shimizu, Shizuoka city, Japan.
| | - Seiji Ohshimo
- National Research Institute of Far Seas Fisheries, Japan Fisheries Research and Education Agency; 5-7-1 Orido Shimizu, Shizuoka city, Japan
| | - Kotaro Yokawa
- National Research Institute of Far Seas Fisheries, Japan Fisheries Research and Education Agency; 5-7-1 Orido Shimizu, Shizuoka city, Japan
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174
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Mlynarek JJ, Moffat CE, Edwards S, Einfeldt AL, Heustis A, Johns R, MacDonnell M, Pureswaran DS, Quiring DT, Shibel Z, Heard SB. Enemy escape: A general phenomenon in a fragmented literature? Facets (Ott) 2017. [DOI: 10.1139/facets-2017-0041] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Many populations are thought to be regulated, in part, by their natural enemies. If so, disruption of this regulation should allow rapid population growth. Such “enemy escape” may occur in a variety of circumstances, including invasion, natural range expansion, range edges, suppression of enemy populations, host shifting, phenological changes, and defensive innovation. Periods of relaxed enemy pressure also occur in, and may drive, population oscillations and outbreaks. We draw attention to similarities among circumstances of enemy escape and build a general conceptual framework for the phenomenon. Although these circumstances share common mechanisms and depend on common assumptions, enemy escape can involve dynamics operating on very different temporal and spatial scales. In particular, the duration of enemy escape is rarely considered but will likely vary among circumstances. Enemy escape can have important evolutionary consequences including increasing competitive ability, spurring diversification, or triggering enemy counteradaptation. These evolutionary consequences have been considered for plant–herbivore interactions and invasions but largely neglected for other circumstances of enemy escape. We aim to unite the fragmented literature, which we argue has impeded progress in building a broader understanding of the eco-evolutionary dynamics of enemy escape.
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Affiliation(s)
- Julia J. Mlynarek
- Department of Biology, University of New Brunswick, P.O. Box 4400, Fredericton, NB E3B 5A3, Canada
| | - Chandra E. Moffat
- Department of Biology, University of New Brunswick, P.O. Box 4400, Fredericton, NB E3B 5A3, Canada
| | - Sara Edwards
- Population Ecology Group, Faculty of Forestry & Environmental Management, University of New Brunswick, P.O. Box 4400, Fredericton, NB E3B 5A3, Canada
| | - Anthony L. Einfeldt
- Department of Biology, University of New Brunswick, P.O. Box 4400, Fredericton, NB E3B 5A3, Canada
| | - Allyson Heustis
- Department of Biology, University of New Brunswick, P.O. Box 4400, Fredericton, NB E3B 5A3, Canada
- Forest Insect Ecology, Atlantic Forestry Centre, 1350 Regent Street, P.O. Box 4000, Fredericton, NB E3B 5P7, Canada
| | - Rob Johns
- Forest Insect Ecology, Atlantic Forestry Centre, 1350 Regent Street, P.O. Box 4000, Fredericton, NB E3B 5P7, Canada
| | - Mallory MacDonnell
- Department of Biology, University of New Brunswick, P.O. Box 4400, Fredericton, NB E3B 5A3, Canada
| | - Deepa S. Pureswaran
- Forest Insect Ecology, Laurentian Forestry Centre, 1055 Du PEPS Street, P.O. Box 10380, Québec, QC G1V 4C7, Canada
| | - Dan T. Quiring
- Population Ecology Group, Faculty of Forestry & Environmental Management, University of New Brunswick, P.O. Box 4400, Fredericton, NB E3B 5A3, Canada
| | - Zoryana Shibel
- Department of Biology, University of New Brunswick, P.O. Box 4400, Fredericton, NB E3B 5A3, Canada
| | - Stephen B. Heard
- Department of Biology, University of New Brunswick, P.O. Box 4400, Fredericton, NB E3B 5A3, Canada
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175
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Bizzarro JJ, Carlisle AB, Smith WD, Cortés E. Diet Composition and Trophic Ecology of Northeast Pacific Ocean Sharks. ADVANCES IN MARINE BIOLOGY 2017; 77:111-148. [PMID: 28882212 DOI: 10.1016/bs.amb.2017.06.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Although there is a general perception of sharks as large pelagic, apex predators, most sharks are smaller, meso- and upper-trophic level predators that are associated with the seafloor. Among 73 shark species documented in the eastern North Pacific (ENP), less than half reach maximum lengths >200cm, and 78% occur in demersal or benthic regions of the continental shelf or slope. Most small (≤200cm) species (e.g., houndsharks) and demersal, nearshore juveniles of larger species (e.g., requiem sharks) consume small teleosts and decapod crustaceans, whereas large species in pelagic coastal and oceanic environments feed on large teleosts and squids. Several large, pelagic apex predator species occur in the ENP, but the largest species (i.e., Basking Shark, Whale Shark) consume zooplankton or small nekton. Size-based dietary variability is substantial for many species, and segregation of juvenile and adult foraging habitats also is common (e.g., Horn Shark, Shortfin Mako). Temporal dietary differences are most pronounced for temperate, nearshore species with wide size ranges, and least pronounced for smaller species in extreme latitudes and deep-water regions. Sympatric sharks often occupy various trophic positions, with resource overlap differing by space and time and some sharks serving as prey to other species. Most coastal species remain in the same general region over time and feed opportunistically on variable prey inputs (e.g., season migrations, spawning, or recruitment events), whereas pelagic, oceanic species actively seek hot spots of prey abundance that are spatiotemporally variable. The influence of sharks on ecosystem structure and regulation has been downplayed compared to that of large teleosts species with higher per capita consumption rates (e.g., tunas, billfishes). However, sharks also exert indirect influences on prey populations by causing behavioural changes that may result in restricted ranges and reduced fitness. Except for food web modelling efforts in Alaskan waters, the trophic impacts of sharks are poorly incorporated into current ecosystem approaches to fisheries management in the NEP.
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Affiliation(s)
| | - Aaron B Carlisle
- Hopkins Marine Station of Stanford University, Pacific Grove, CA, United States
| | - Wade D Smith
- University of British Columbia, Institute for the Oceans and Fisheries, Vancouver, BC, Canada
| | - Enric Cortés
- National Marine Fisheries Service, Southeast Fisheries Science Center, Panama City Laboratory, FL, United States
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176
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Lowry D, Larson SE. Introduction to Northeast Pacific Shark Biology, Ecology, and Conservation. ADVANCES IN MARINE BIOLOGY 2017; 77:1-8. [PMID: 28882211 DOI: 10.1016/bs.amb.2017.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Sharks are iconic, sometimes apex, predators found in every ocean and, as a result, they have featured prominently in the mythology, history, and fisheries of diverse human cultures around the world. Because of their regional significance to fisheries and ecological role as predators, and as a result of concern over long-term stability of their populations, there has been an increasing amount of work focused on shark conservation in recent decades. This volume highlights the biodiversity and biological attributes of, and conservation efforts targeted at, populations of sharks that reside in the Northeast Pacific Ocean bordering the west coast of the United States and Canada, one of the most economically and ecologically important oceanic regions in the world. A companion volume addresses details of fisheries and ecotourism in the same region, as well as delving into the relationship between captive husbandry of sharks and education/outreach efforts aimed at fostering a conservation mindset in the public at large. Together, these volumes provide readers a detailed backdrop against which to consider their own actions, and those of resource managers, academics, and educators, as they relate to the long-term conservation of sharks and their relatives.
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Affiliation(s)
- Dayv Lowry
- Marine Fish Science Unit, Washington Department of Fish and Wildlife, Olympia, WA, United States.
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177
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Holmes BJ, Williams SM, Otway NM, Nielsen EE, Maher SL, Bennett MB, Ovenden JR. Population structure and connectivity of tiger sharks ( Galeocerdo cuvier) across the Indo-Pacific Ocean basin. ROYAL SOCIETY OPEN SCIENCE 2017; 4:170309. [PMID: 28791159 PMCID: PMC5541554 DOI: 10.1098/rsos.170309] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 05/25/2017] [Indexed: 05/15/2023]
Abstract
Population genetic structure using nine polymorphic nuclear microsatellite loci was assessed for the tiger shark (Galeocerdo cuvier) at seven locations across the Indo-Pacific, and one location in the southern Atlantic. Genetic analyses revealed considerable genetic structuring (FST > 0.14, p < 0.001) between all Indo-Pacific locations and Brazil. By contrast, no significant genetic differences were observed between locations from within the Pacific or Indian Oceans, identifying an apparent large, single Indo-Pacific population. A lack of differentiation between tiger sharks sampled in Hawaii and other Indo-Pacific locations identified herein is in contrast to an earlier global tiger shark nDNA study. The results of our power analysis provide evidence to suggest that the larger sample sizes used here negated any weak population subdivision observed previously. These results further highlight the need for cross-jurisdictional efforts to manage the sustainable exploitation of large migratory sharks like G. cuvier.
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Affiliation(s)
- Bonnie J. Holmes
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland 4072Australia
- Molecular Fisheries Laboratory, The University of Queensland, St Lucia, Queensland 4072Australia
| | - Samuel M. Williams
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland 4072Australia
- Molecular Fisheries Laboratory, The University of Queensland, St Lucia, Queensland 4072Australia
| | - Nicholas M. Otway
- New South Wales Department of Primary Industries, Port Stephens Fisheries Institute, Taylors Beach, New South Wales 2316, Australia
| | - Einar E. Nielsen
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland 4072Australia
- National Institute of Aquatic Resources, Technical University of Denmark, Vejlsøvej 39, 8600 Silkeborg, Denmark
| | - Safia L. Maher
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland 4072Australia
- Molecular Fisheries Laboratory, The University of Queensland, St Lucia, Queensland 4072Australia
| | - Mike B. Bennett
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland 4072Australia
| | - Jennifer R. Ovenden
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland 4072Australia
- Molecular Fisheries Laboratory, The University of Queensland, St Lucia, Queensland 4072Australia
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178
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An Assessment of Mobile Predator Populations along Shallow and Mesophotic Depth Gradients in the Hawaiian Archipelago. Sci Rep 2017. [PMID: 28634373 PMCID: PMC5478628 DOI: 10.1038/s41598-017-03568-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Large-bodied coral reef roving predators (sharks, jacks, snappers) are largely considered to be depleted around human population centers. In the Hawaiian Archipelago, supporting evidence is primarily derived from underwater visual censuses in shallow waters (≤30 m). However, while many roving predators are present or potentially more abundant in deeper strata (30–100 m+), distributional information remains sparse. To partially fill that knowledge gap, we conducted surveys in the remote Northwestern Hawaiian Islands (NWHI) and populated Main Hawaiian Islands (MHI) from 2012–2014 using baited remote underwater stereo-video. Surveys between 0–100 m found considerable roving predator community dissimilarities between regions, marked conspicuous changes in species abundances with increasing depth, and largely corroborated patterns documented during shallow water underwater visual censuses, with up to an order of magnitude more jacks and five times more sharks sampled in the NWHI compared to the MHI. Additionally, several species were significantly more abundant and larger in mesophotic versus shallow depths, which remains particularly suggestive of deep-water refugia effects in the MHI. Stereo-video extends the depth range of current roving predator surveys in a more robust manner than was previously available, and appears to be well-suited for large-scale roving predator work in the Hawaiian Archipelago.
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179
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Tromeur E, Loeuille N. Balancing yield with resilience and conservation objectives in harvested predator-prey communities. OIKOS 2017. [DOI: 10.1111/oik.03985] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Eric Tromeur
- Sorbonne Univ., UPMC Univ Paris 06, Univ Paris Diderot, Univ Paris-Est Créteil, CNRS, INRA, IRD, Inst. of Ecology and Environmental Sciences of Paris (iEES Paris), 7 quai St Bernard, FR-75252; Paris France
- AgroParisTech, Univ Paris-Saclay; Paris France
| | - Nicolas Loeuille
- Sorbonne Univ., UPMC Univ Paris 06, Univ Paris Diderot, Univ Paris-Est Créteil, CNRS, INRA, IRD, Inst. of Ecology and Environmental Sciences of Paris (iEES Paris), 7 quai St Bernard, FR-75252; Paris France
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180
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Dicken ML, Hussey NE, Christiansen HM, Smale MJ, Nkabi N, Cliff G, Wintner SP. Diet and trophic ecology of the tiger shark (Galeocerdo cuvier) from South African waters. PLoS One 2017; 12:e0177897. [PMID: 28594833 PMCID: PMC5464543 DOI: 10.1371/journal.pone.0177897] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 05/04/2017] [Indexed: 11/18/2022] Open
Abstract
Knowledge of the diet and trophic ecology of apex predators is key for the implementation of effective ecosystem as well as species-based management initiatives. Using a combination of stomach content data and stable isotope analysis (δ15N and δ13C) the current study provides information on size-based and sex-specific variations in diet, trophic position (TP) and foraging habitat of tiger sharks (Galeocerdo cuvier) caught in the KwaZulu-Natal Sharks Board bather protection program. This study presents the longest time-series and most detailed analysis of stomach content data for G. cuvier worldwide. Prey identified from 628 non-empty stomachs revealed a size-based shift in diet. Reptiles, birds, mysticetes, and large shark species increased in dietary importance with G. cuvier size, concomitant with a decrease in smaller prey such as batoids and teleosts. Seasonal and decadal shifts in diet driven primarily by changes in the importance of elasmobranchs and mammal (cetacean) prey were recorded for medium sized (150-220 cm) G. cuvier. Both stomach content and stable isotope analysis indicated that G. cuvier is a generalist feeder at the population level. Size-based δ13C profiles indicated a movement to offshore foraging habitats by larger G. cuvier. Calculated TP varied by method ranging from 4.0 to 5.0 (TPSCA for stomach contents) and from 3.6 to 4.5 (TPscaled and TPadditive for δ15N). Large (> 220 cm) G. cuvier did not feed at discrete trophic levels, but rather throughout the food web. These data provide key information on the ecological role of G. cuvier to improve the accuracy of regional food web modelling. This will enable a better understanding of the ecological impacts related to changes in the abundance of this predator.
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Affiliation(s)
- Matthew L. Dicken
- KwaZulu-Natal Sharks Board, Umhlanga Rocks, South Africa
- Department of Zoology and Entomology, University of Fort Hare, Alice. South Africa
- * E-mail:
| | - Nigel E. Hussey
- University of Windsor–Biological Sciences, Windsor, Ontario, Canada
| | | | - Malcolm J. Smale
- Department of Zoology, Nelson Mandela Metropolitan University, Port Elizabeth, South Africa
- Port Elizabeth Museum, Humewood, Port Elizabeth, South Africa
| | - Nomfundo Nkabi
- KwaZulu-Natal Sharks Board, Umhlanga Rocks, South Africa
| | - Geremy Cliff
- KwaZulu-Natal Sharks Board, Umhlanga Rocks, South Africa
- Biomedical Resource Unit, University of KwaZulu-Natal, Durban South Africa
| | - Sabine P. Wintner
- KwaZulu-Natal Sharks Board, Umhlanga Rocks, South Africa
- Biomedical Resource Unit, University of KwaZulu-Natal, Durban South Africa
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181
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McQuiston AD, Crawford C, Schoepf UJ, Varga-Szemes A, Canstein C, Renker M, De Cecco CN, Baumann S, Naylor GJP. Segmentations of the cartilaginous skeletons of chondrichthyan fishes by the use of state-of-the-art computed tomography. World J Radiol 2017; 9:191-198. [PMID: 28529682 PMCID: PMC5415888 DOI: 10.4329/wjr.v9.i4.191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 10/15/2016] [Accepted: 12/14/2016] [Indexed: 02/06/2023] Open
Abstract
AIM To apply dual-source multidetector computed tomography (DSCT) scanning technology in conjunction with computationally assisted segmentation in order to explore and document skeletal variation that has occurred over the course of evolution.
METHODS We examined 4 divergent species of elasmobranchs with high-resolution 3rd generation DSCT. The formalin prepared species examined were: Aptychotrema vincentiana, Mitsukurina owstoni, Negaprion brevirostris and Dactylobatus armatus.
RESULTS All three structures of the hyoid arch (hyomandibular, ceratohyal, and basihyal) were clearly visible whereas in the two batoids, the hyomandibular was the prominent feature, the ceratohyal was not visible and the basihyal was more reduced and closer to the gill arches. The general shape of the puboischiadic bar, or pelvic girdle, illustrated a closer relationship between the two sharks and the two batoids than between the two groups.
CONCLUSION In exquisite detail, DSCT imaging revealed important morphological variations in various common structures in the four elasmobranch specimens studied, providing insights into their evolutionary diversification.
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182
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Witman JD, Smith F, Novak M. Experimental demonstration of a trophic cascade in the Galápagos rocky subtidal: Effects of consumer identity and behavior. PLoS One 2017; 12:e0175705. [PMID: 28430794 PMCID: PMC5400256 DOI: 10.1371/journal.pone.0175705] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 03/30/2017] [Indexed: 11/18/2022] Open
Abstract
In diverse tropical webs, trophic cascades are presumed to be rare, as species interactions may dampen top-down control and reduce their prevalence. To test this hypothesis, we used an open experimental design in the Galápagos rocky subtidal that enabled a diverse guild of fish species, in the presence of each other and top predators (sea lions and sharks), to attack two species of sea urchins grazing on benthic algae. Time-lapse photography of experiments on natural and experimental substrates revealed strong species identity effects: only two predator species–blunthead triggerfish (Pseudobalistes naufragium) and finescale triggerfish (Balistes polylepis)–drove a diurnal trophic cascade extending to algae, and they preferred large pencil urchins (Eucidaris galapagensis) over green urchins (Lytechinus semituberculatus). Triggerfish predation effects were strong, causing a 24-fold reduction of pencil urchin densities during the initial 21 hours of a trophic cascade experiment. A trophic cascade was demonstrated for pencil urchins, but not for green urchins, by significantly higher percent cover of urchin-grazed algae in cages that excluded predatory fish than in predator access (fence) treatments. Pencil urchins were more abundant at night when triggerfish were absent, suggesting that this species persists by exploiting a nocturnal predation refuge. Time-series of pencil urchin survivorship further demonstrated per capita interference effects of hogfish and top predators. These interference effects respectively weakened and extended the trophic cascade to a fourth trophic level through behavioral modifications of the triggerfish-urchin interaction. We conclude that interference behaviors capable of modifying interaction strength warrant greater attention as mechanisms for altering top-down control, particularly in speciose food webs.
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Affiliation(s)
- Jon D. Witman
- Department of Ecology and Evolutionary Biology, Brown University, Providence, RI, United States of America
- * E-mail:
| | - Franz Smith
- Department of Ecology and Evolutionary Biology, Brown University, Providence, RI, United States of America
| | - Mark Novak
- Department of Integrative Biology, Oregon State University, Corvallis, OR, United States of America
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183
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Gaining insights into the ecological role of the New Zealand sole (Peltorhamphus novaezeelandiae) through parasites. J Helminthol 2017; 92:187-196. [PMID: 28424102 DOI: 10.1017/s0022149x17000323] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Despite the fact that tapeworms comprise the bulk of parasite communities of sharks in marine ecosystems, little is known about their life cycles and, more specifically, about the potential intermediate hosts they utilize as transmission routes. In the absence of morphological features required for specific identification of larval tapeworms from potential intermediate hosts, recent molecular advances have contributed to linking larval and adult parasites and, in some instances, uncovering unknown trophic links. Host-parasite checklists are often the first source of information consulted to assess the diversity and host specificity of parasites, and provide insights into parasite identification. However, these host-parasite checklists are only useful if they encompass the full spectrum of associations between hosts and parasites. A checklist of New Zealand fishes and their parasites has been published, but recent parasitological examinations of commercial fish species reveal that the checklist appears to be far from complete. We focused our current study on a comprehensive survey of macroparasites of a commercial species, the New Zealand sole (Peltorhamphus novaezeelandiae) off the coast of Otago, New Zealand. Specifically, we were expecting to recover marine tapeworms using sharks as their definitive hosts that are generally underreported in parasite surveys. The parasites recovered included tapeworms, flukes, round worms and thorny-headed worms. Surprisingly, a large proportion of the non-tapeworm parasites we recovered were not previously reported from this fish species. A discussion on the potential ecological roles played by this fish species in the transmission of parasites is included.
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184
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Thermal stratification drives movement of a coastal apex predator. Sci Rep 2017; 7:526. [PMID: 28373662 PMCID: PMC5428662 DOI: 10.1038/s41598-017-00576-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 03/03/2017] [Indexed: 12/22/2022] Open
Abstract
A characterization of the thermal ecology of fishes is needed to better understand changes in ecosystems and species distributions arising from global warming. The movement of wild animals during changing environmental conditions provides essential information to help predict the future thermal response of large marine predators. We used acoustic telemetry to monitor the vertical movement activity of the common dentex (Dentex dentex), a Mediterranean coastal predator, in relation to the oscillations of the seasonal thermocline during two summer periods in the Medes Islands marine reserve (NW Mediterranean Sea). During the summer stratification period, the common dentex presented a clear preference for the warm suprathermoclinal layer, and adjusted their vertical movements following the depth changes of the thermocline. The same preference was also observed during the night, when fish were less active. Due to this behaviour, we hypothesize that inter-annual thermal oscillations and the predicted lengthening of summer conditions will have a significant positive impact on the metabolic efficiency, activity levels, and population dynamics of this species, particularly in its northern limit of distribution. These changes in the dynamics of an ecosystem's keystone predator might cascade down to lower trophic levels, potentially re-defining the coastal fish communities of the future.
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185
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Houk P, Tilfas R, Luckymis M, Nedlic O, Ned B, Cuetos-Bueno J, McLean M. An applied framework to assess exploitation and guide management of coral-reef fisheries. Ecosphere 2017. [DOI: 10.1002/ecs2.1727] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Affiliation(s)
- Peter Houk
- UOG Station; University of Guam Marine Laboratory; Mangilao Guam 96923 USA
| | - Ronny Tilfas
- Kosrae State Fisheries Office; Lelu Kosrae, Federated States of Micronesia 96944
| | - Marston Luckymis
- Kosrae Conservation and Safety Organization; P.O. Box 1007 Lelu Kosrae, Federated States of Micronesia 96944
| | - Osamu Nedlic
- Kosrae Conservation and Safety Organization; P.O. Box 1007 Lelu Kosrae, Federated States of Micronesia 96944
| | - Bruno Ned
- Kosrae State Fisheries Office; Lelu Kosrae, Federated States of Micronesia 96944
| | | | - Matthew McLean
- UOG Station; University of Guam Marine Laboratory; Mangilao Guam 96923 USA
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186
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Breed GA, Matthews CJD, Marcoux M, Higdon JW, LeBlanc B, Petersen SD, Orr J, Reinhart NR, Ferguson SH. Sustained disruption of narwhal habitat use and behavior in the presence of Arctic killer whales. Proc Natl Acad Sci U S A 2017; 114:2628-2633. [PMID: 28223481 PMCID: PMC5347589 DOI: 10.1073/pnas.1611707114] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Although predators influence behavior of prey, analyses of electronic tracking data in marine environments rarely consider how predators affect the behavior of tracked animals. We collected an unprecedented dataset by synchronously tracking predator (killer whales, [Formula: see text] = 1; representing a family group) and prey (narwhal, [Formula: see text] = 7) via satellite telemetry in Admiralty Inlet, a large fjord in the Eastern Canadian Arctic. Analyzing the movement data with a switching-state space model and a series of mixed effects models, we show that the presence of killer whales strongly alters the behavior and distribution of narwhal. When killer whales were present (within about 100 km), narwhal moved closer to shore, where they were presumably less vulnerable. Under predation threat, narwhal movement patterns were more likely to be transiting, whereas in the absence of threat, more likely resident. Effects extended beyond discrete predatory events and persisted steadily for 10 d, the duration that killer whales remained in Admiralty Inlet. Our findings have two key consequences. First, given current reductions in sea ice and increases in Arctic killer whale sightings, killer whales have the potential to reshape Arctic marine mammal distributions and behavior. Second and of more general importance, predators have the potential to strongly affect movement behavior of tracked marine animals. Understanding predator effects may be as or more important than relating movement behavior to resource distribution or bottom-up drivers traditionally included in analyses of marine animal tracking data.
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Affiliation(s)
- Greg A Breed
- Institute of Arctic Biology, University of Alaska, Fairbanks, AK 99775;
| | - Cory J D Matthews
- Arctic Aquatic Research Division, Fisheries and Oceans Canada, Winnipeg, MB, Canada R3T 2N6
| | - Marianne Marcoux
- Arctic Aquatic Research Division, Fisheries and Oceans Canada, Winnipeg, MB, Canada R3T 2N6
| | - Jeff W Higdon
- Higdon Wildlife Consulting, Winnipeg, MB, Canada R3G 3C9
| | - Bernard LeBlanc
- Fisheries Management, Fisheries and Oceans Canada, Quebec, QC, Canada G1K 7Y7
| | | | - Jack Orr
- Arctic Aquatic Research Division, Fisheries and Oceans Canada, Winnipeg, MB, Canada R3T 2N6
| | - Natalie R Reinhart
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, Canada R3T 2N2
| | - Steven H Ferguson
- Arctic Aquatic Research Division, Fisheries and Oceans Canada, Winnipeg, MB, Canada R3T 2N6
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187
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Nevalainen M, Helle I, Vanhatalo J. Preparing for the unprecedented - Towards quantitative oil risk assessment in the Arctic marine areas. MARINE POLLUTION BULLETIN 2017; 114:90-101. [PMID: 27593852 DOI: 10.1016/j.marpolbul.2016.08.064] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 08/22/2016] [Accepted: 08/24/2016] [Indexed: 05/23/2023]
Abstract
The probability of major oil accidents in Arctic seas is increasing alongside with increasing maritime traffic. Hence, there is a growing need to understand the risks posed by oil spills to these unique and sensitive areas. So far these risks have mainly been acknowledged in terms of qualitative descriptions. We introduce a probabilistic framework, based on a general food web approach, to analyze ecological impacts of oil spills. We argue that the food web approach based on key functional groups is more appropriate for providing holistic view of the involved risks than assessments based on single species. We discuss the issues characteristic to the Arctic that need a special attention in risk assessment, and provide examples how to proceed towards quantitative risk estimates. The conceptual model presented in the paper helps to identify the most important risk factors and can be used as a template for more detailed risk assessments.
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Affiliation(s)
- Maisa Nevalainen
- Department of Environmental Sciences, University of Helsinki, P.O. Box 65, FI-00014 University of Helsinki, Finland.
| | - Inari Helle
- Department of Environmental Sciences, University of Helsinki, P.O. Box 65, FI-00014 University of Helsinki, Finland
| | - Jarno Vanhatalo
- Department of Mathematics and Statistics, University of Helsinki, P.O. Box 68, FI-00014 University of Helsinki, Finland; Department of Biosciences, University of Helsinki, P.O. Box 65, FI-00014 University of Helsinki, Finland
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188
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Uchoa M, O’Connell C, Goreau T. The effects of Biorock-associated electric fields on the Caribbean reef shark (Carcharhinus perezi) and the bull shark (Carcharhinus leucas). ANIM BIOL 2017. [DOI: 10.1163/15707563-00002531] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Healthy coral reefs are biologically diverse and provide vital ecosystem services. However, decreasing water quality and global warming are key contributors to coral reef decline, which poses substantial environmental threats. In response to this degradation, an innovative coral reef restoration technology, called Biorock, utilizes weak direct current electric fields to cause limestone deposition on conductive materials, inevitably inducing prolific coral reef growth. Although expediting coral growth, research on how the associated electric fields may impact the behavioural patterns of teleosts and/or organisms (i.e. elasmobranchs) possessing electroreception capabilities is lacking. Therefore, we studied the behavioural responses of two shark species, the bull shark (Carcharhinus leucas) and the Caribbean reef shark (Carcharhinus perezi) and multiple teleost species towards weak direct current electric fields in Bimini, Bahamas. Generalized linear mixed model analyses based on 90 trials illustrate that both the feeding and avoidance behaviors of C. leucas and C. perezi were significantly associated with treatment type, with the weak experimental electrode treatments resulting in the greatest quantity of avoidances and fewest feedings for both species. However, data analyses illustrate that teleost feeding behavior was not observably impacted by experimental treatments. Although the Biorock technology exhibits promise in coral reef restoration, the findings from this study illustrate a need for future large-scale studies assessing shark behavioral patterns around these devices, since the deterrence of apex predators may impact ecosystem balance.
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Affiliation(s)
- Marcella P. Uchoa
- 1O’Seas Conservation Foundation, 3636 Waldo Ave, Apt 2B, Bronx, NY 10463, USA
| | - Craig P. O’Connell
- 1O’Seas Conservation Foundation, 3636 Waldo Ave, Apt 2B, Bronx, NY 10463, USA
| | - Thomas J. Goreau
- 2Global Coral Reef Alliance, 37 Pleasant St, Cambridge, MA 02139, USA
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189
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Marinsek GP, Viliod MCDL, Mari RDB. Ecomorphology of the digestive tract of the brazilian electric ray Narcine brasiliensis
(Olfers, 1831) (Torpediniformes: Narcinidae). ACTA ZOOL-STOCKHOLM 2016. [DOI: 10.1111/azo.12168] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Gabriela Pustiglione Marinsek
- Laboratory of Marine Animal Morphology; Bioscience Institute; São Paulo State University - UNESP; Coastal Campus, Praça Infante Dom Henrique, s/n°, Parque Bitaru São Vicente SP Brazil
| | - Marcela Coffacci de Lima Viliod
- Laboratory of Marine Animal Morphology; Bioscience Institute; São Paulo State University - UNESP; Coastal Campus, Praça Infante Dom Henrique, s/n°, Parque Bitaru São Vicente SP Brazil
| | - Renata de Britto Mari
- Laboratory of Marine Animal Morphology; Bioscience Institute; São Paulo State University - UNESP; Coastal Campus, Praça Infante Dom Henrique, s/n°, Parque Bitaru São Vicente SP Brazil
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190
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Young HS, McCauley DJ, Galetti M, Dirzo R. Patterns, Causes, and Consequences of Anthropocene Defaunation. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2016. [DOI: 10.1146/annurev-ecolsys-112414-054142] [Citation(s) in RCA: 233] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Anthropocene defaunation, the global extinction of faunal species and populations and the decline in abundance of individuals within populations, has been predominantly documented in terrestrial ecosystems, but indicators suggest defaunation has been more severe in freshwater ecosystems. Marine defaunation is in a more incipient stage, yet pronounced effects are already apparent and its rapid acceleration seems likely. Defaunation now impacts the planet's wildlife with profound cascading consequences, ranging from local to global coextinctions of interacting species to the loss of ecological services critical for humanity. Slowing defaunation will require aggressively reducing animal overexploitation and habitat destruction; mitigating climate disruption; and stabilizing the impacts of human population growth and uneven resource consumption. Given its omnipresence, defaunation should receive status of major global environmental change and should be addressed with the same urgency as deforestation, pollution, and climatic change. Global action is needed to prevent defaunation's current trajectory from catalyzing the planet's sixth major extinction.
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Affiliation(s)
- Hillary S. Young
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, California 93106
| | - Douglas J. McCauley
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, California 93106
| | - Mauro Galetti
- Departamento de Ecologia, Universidade Estadual Paulista (UNESP), 13506–900 Rio Claro, São Paulo, Brazil
| | - Rodolfo Dirzo
- Department of Biology, Stanford University, Stanford, California 94305
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191
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Bu H, Wang F, McShea WJ, Lu Z, Wang D, Li S. Spatial Co-Occurrence and Activity Patterns of Mesocarnivores in the Temperate Forests of Southwest China. PLoS One 2016; 11:e0164271. [PMID: 27723772 PMCID: PMC5056745 DOI: 10.1371/journal.pone.0164271] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 09/22/2016] [Indexed: 11/18/2022] Open
Abstract
Understanding the interactions between species and their coexistence mechanisms will help explain biodiversity maintenance and enable managers to make sound conservation decisions. Mesocarnivores are abundant and diverse mid-sized carnivores and can have profound impacts on the function, structure and dynamics of ecosystem after the extirpation of apex predators in many ecosystems. The moist temperate forests of Southwest China harbor a diverse community of mesocarnivores in the absence of apex predators. Sympatric species tend to partition limited resources along time, diet and space to facilitate coexistence. We determined the spatial and temporal patterns for five species of mesocarnivores. We used detection histories from a large camera-trap dataset collected from 2004-2015 with an extensive effort of 23,313 camera-days from 495 camera locations. The five mesocarnivore species included masked palm civet Paguma larvata, leopard cat Prionailurus bengalensis, hog badger Arctonyx collaris, yellow-throated marten Martes flavigula, and Siberian weasel Mustela sibirica. Only the masked palm civet and hog badger tended to avoid each other; while for other pairs of species, they occurred independently of each other, or no clear pattern observed. With regard to seasonal activity, yellow-throated marten was most active in winter, opposite the pattern observed for masked palm civet, leopard cat and hog badger. For diel activity, masked palm civet, leopard cat and hog badger were primarily nocturnal and crepuscular; yellow-throated marten was diurnal, and Siberian weasel had no clear pattern for most of the year (March to November), but was nocturnal in the winter (December to February). The seasonal shift of the Siberian weasel may be due to the high diet overlap among species in winter. Our results provided new facts and insights into this unique community of mesocarnivores of southwest China, and will facilitate future studies on the mechanism determining coexistence of animal species within complex system.
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Affiliation(s)
- Hongliang Bu
- School of Life Sciences, Peking University, Beijing, 100871, China
| | - Fang Wang
- Center for Systems Integration and Sustainability, Michigan State University, East Lansing, Michigan, 48823, United States of America
| | - William J. McShea
- Smithsonian Conservation Biology Institute, Front Royal, Virginia, 22630, United States of America
| | - Zhi Lu
- School of Life Sciences, Peking University, Beijing, 100871, China
| | - Dajun Wang
- School of Life Sciences, Peking University, Beijing, 100871, China
| | - Sheng Li
- School of Life Sciences, Peking University, Beijing, 100871, China
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192
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Adams GD, Flores D, Flores OG, Aarestrup K, Svendsen JC. Spatial ecology of blue shark and shortfin mako in southern Peru: local abundance, habitat preferences and implications for conservation. ENDANGER SPECIES RES 2016. [DOI: 10.3354/esr00744] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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193
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Siegenthaler A, Niemantsverdriet PRW, Laterveer M, Heitkönig IMA. Aversive responses of captive sandbar sharks Carcharhinus plumbeus to strong magnetic fields. JOURNAL OF FISH BIOLOGY 2016; 89:1603-1611. [PMID: 27323691 DOI: 10.1111/jfb.13064] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 05/11/2016] [Indexed: 06/06/2023]
Abstract
This experimental study focused on the possible deterrent effect of permanent magnets on adult sandbar sharks Carcharhinus plumbeus. Results showed that the presence of a magnetic field significantly reduced the number of approaches of conditioned C. plumbeus towards a target indicating that adult C. plumbeus can be deterred by strong magnetic fields. These data, therefore, confirm that the use of magnetic devices to reduce shark by-catch is a promising avenue.
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Affiliation(s)
- A Siegenthaler
- Wageningen University, Resource Ecology Group, Droevendaalsesteeg 3a, 6708 PB, Wageningen, the Netherlands
- Rotterdam Zoo, P. O. Box 532, 3000 AM, Rotterdam, the Netherlands
| | | | - M Laterveer
- Rotterdam Zoo, P. O. Box 532, 3000 AM, Rotterdam, the Netherlands
| | - I M A Heitkönig
- Wageningen University, Resource Ecology Group, Droevendaalsesteeg 3a, 6708 PB, Wageningen, the Netherlands
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194
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Barley SC, Meeuwig JJ. The Power and the Pitfalls of Large-scale, Unreplicated Natural Experiments. Ecosystems 2016. [DOI: 10.1007/s10021-016-0028-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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195
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Gilbert SL, Sivy KJ, Pozzanghera CB, DuBour A, Overduijn K, Smith MM, Zhou J, Little JM, Prugh LR. Socioeconomic Benefits of Large Carnivore Recolonization Through Reduced Wildlife‐Vehicle Collisions. Conserv Lett 2016. [DOI: 10.1111/conl.12280] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- Sophie L. Gilbert
- Department of Fish and Wildlife SciencesUniversity of Idaho Moscow ID 83844 USA
- Department of Biological Sciences University of Alberta Edmonton AB T6G0C5 Canada
- Department of Biology and WildlifeUniversity of Alaska Fairbanks Fairbanks AK 99775 USA
| | - Kelly J. Sivy
- Department of Biology and WildlifeUniversity of Alaska Fairbanks Fairbanks AK 99775 USA
| | - Casey B. Pozzanghera
- Department of Biology and WildlifeUniversity of Alaska Fairbanks Fairbanks AK 99775 USA
| | - Adam DuBour
- Department of Biology and WildlifeUniversity of Alaska Fairbanks Fairbanks AK 99775 USA
| | - Kelly Overduijn
- Department of Biology and WildlifeUniversity of Alaska Fairbanks Fairbanks AK 99775 USA
| | - Matthew M. Smith
- Department of Biology and WildlifeUniversity of Alaska Fairbanks Fairbanks AK 99775 USA
| | - Jiake Zhou
- Department of Biology and WildlifeUniversity of Alaska Fairbanks Fairbanks AK 99775 USA
| | - Joseph M. Little
- UAF School of ManagementUniversity of Alaska Fairbanks Fairbanks AK 99775 USA
| | - Laura R. Prugh
- Department of Biology and WildlifeUniversity of Alaska Fairbanks Fairbanks AK 99775 USA
- School of Environmental and Forest SciencesUniversity of Washington WA 98195 USA
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196
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Pistevos JCA, Nagelkerken I, Rossi T, Connell SD. Antagonistic effects of ocean acidification and warming on hunting sharks. OIKOS 2016. [DOI: 10.1111/oik.03182] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Jennifer C. A. Pistevos
- Darling Building, DX 650 418, Southern Seas Ecological Laboratories, School of Biological Sciences and The Environment Institute Univ. of Adelaide South Australia SA 5005 Australia
| | - Ivan Nagelkerken
- Darling Building, DX 650 418, Southern Seas Ecological Laboratories, School of Biological Sciences and The Environment Institute Univ. of Adelaide South Australia SA 5005 Australia
| | - Tullio Rossi
- Darling Building, DX 650 418, Southern Seas Ecological Laboratories, School of Biological Sciences and The Environment Institute Univ. of Adelaide South Australia SA 5005 Australia
| | - Sean D. Connell
- Darling Building, DX 650 418, Southern Seas Ecological Laboratories, School of Biological Sciences and The Environment Institute Univ. of Adelaide South Australia SA 5005 Australia
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197
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Bezerra NPA, Travassos P, Hazin FHV. Vulnerability to longline fisheries of three hammerhead shark Sphyrna species in the south-western and equatorial Atlantic Ocean. JOURNAL OF FISH BIOLOGY 2016; 89:1419-1433. [PMID: 27349350 DOI: 10.1111/jfb.13062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 05/18/2016] [Indexed: 06/06/2023]
Abstract
Catch and effort data from 29 418 longline sets from Brazilian tuna longline vessels operating in the south-western and equatorial Atlantic Ocean between 2004 and 2011 were analysed to investigate the distribution, catch rate and size of three species of hammerhead sharks (Sphyrna lewini, Sphyrna mokarran and Sphyrna zygaena). During that period, 6172 hammerhead sharks were caught. Among the elasmobranchs, the highest percentage of hammerhead sharks were caught in 2007, when they accounted for 3·90% of the group, while the lowest value of 0·40% was recorded in 2010. In general, the spatial distribution of the mean catch per unit effort (CPUE) by years and quarters showed a trend of higher catches near the equatorial region and in southern Brazil. The nominal mean CPUE was 0·12 Sphyrna spp. 1000(-1) hooks, with the highest value being recorded in 2007 (0·30 Sphyrna spp. 1000(-1) hooks). The standardized yearly CPUE estimated by a generalized linear model assuming a zero inflated negative binomial (ZINB) distribution were not much different from nominal values. Of the 205 sexed specimens, 117 were females and 88 were males, resulting in a sex ratio with a predominance of females (1·30:1·00), although not statistically significant. The total length of females ranged from 1200 to 2800 mm and of males from 1100 to 3100 mm. Juvenile hammerhead sharks represented 82 and 54% of the sexed female and male specimens, respectively.
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Affiliation(s)
- N P A Bezerra
- Department of Oceanography, Postgraduate Program in Oceanography, Federal University of Pernambuco, Recife, PE, Brazil
| | - P Travassos
- Department of Fisheries and Aquaculture, Federal Rural University of Pernambuco, Recife, PE, Brazil
| | - F H V Hazin
- Department of Fisheries and Aquaculture, Federal Rural University of Pernambuco, Recife, PE, Brazil
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198
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Terrazas-López R, Arreola-Mendoza L, Galván-Magaña F, Anguiano-Zamora M, Sujitha SB, Jonathan MP. Cadmium concentration in liver and muscle of silky shark (Carcharhinus falciformis) in the tip of Baja California south, México. MARINE POLLUTION BULLETIN 2016; 107:389-392. [PMID: 27016957 DOI: 10.1016/j.marpolbul.2016.03.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 03/12/2016] [Accepted: 03/16/2016] [Indexed: 06/05/2023]
Abstract
Cadmium concentrations were determined in the tissues of muscle and liver of Carcharhinus falciformis (silky shark) sampled in Todos Santos, Baja California South, Mexico. This is one of the main shark species for human consumption in Mexico. Results indicate that accumulation of Cd varied in both sexes, based on its metabolism, sex, maturity and other biological characteristics. High Cd values were observed in the liver of adults of male (529.61μgg(-1)) and female (457.43μgg(-1)), whereas, in muscular tissues it was low (0.37μgg(-1)) than the prescribed permissible limits for seafood (0.5μgg(-1)). Substantial correlations were observed between body length and Cd values in adults except young male due to faster growth rate and its metabolism. The study indicated the impact of environmental conditions in the accumulation of Cd and its risk to the food web structure in the marine environment and health hazard for humans.
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Affiliation(s)
- Rafael Terrazas-López
- Centro Interdisciplinario de Ciencias Marinas (CICIMAR), Instituto Politécnico Nacional (IPN), Avenida IPN, s/n Colonia Playa Polo de Santa Rita, C.P. 23096, La Paz, Baja California Sur, México
| | - Laura Arreola-Mendoza
- Centro Interdisciplinario de Investigaciones y Estudios sobre Medio Ambiente y Desarrollo (CIIEMAD), Instituto Politécnico Nacional (IPN), Calle 30 de Junio de 1520, Barrio la Laguna Ticomán, Del. Gustavo A. Madero, C.P.07340, Distrito Federal, México.
| | - Felipe Galván-Magaña
- Centro Interdisciplinario de Ciencias Marinas (CICIMAR), Instituto Politécnico Nacional (IPN), Avenida IPN, s/n Colonia Playa Polo de Santa Rita, C.P. 23096, La Paz, Baja California Sur, México
| | - Marlene Anguiano-Zamora
- Centro Interdisciplinario de Investigaciones y Estudios sobre Medio Ambiente y Desarrollo (CIIEMAD), Instituto Politécnico Nacional (IPN), Calle 30 de Junio de 1520, Barrio la Laguna Ticomán, Del. Gustavo A. Madero, C.P.07340, Distrito Federal, México
| | - S B Sujitha
- Centro Interdisciplinario de Investigaciones y Estudios sobre Medio Ambiente y Desarrollo (CIIEMAD), Instituto Politécnico Nacional (IPN), Calle 30 de Junio de 1520, Barrio la Laguna Ticomán, Del. Gustavo A. Madero, C.P.07340, Distrito Federal, México
| | - M P Jonathan
- Centro Interdisciplinario de Investigaciones y Estudios sobre Medio Ambiente y Desarrollo (CIIEMAD), Instituto Politécnico Nacional (IPN), Calle 30 de Junio de 1520, Barrio la Laguna Ticomán, Del. Gustavo A. Madero, C.P.07340, Distrito Federal, México
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199
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Worm B, Paine RT. Humans as a Hyperkeystone Species. Trends Ecol Evol 2016; 31:600-607. [PMID: 27312777 DOI: 10.1016/j.tree.2016.05.008] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 05/20/2016] [Accepted: 05/23/2016] [Indexed: 11/17/2022]
Abstract
Ecologists have identified numerous keystone species, defined as organisms that have outsized ecological impacts relative to their biomass. Here we identify human beings as a higher-order or 'hyperkeystone' species that drives complex interaction chains by affecting other keystone actors across different habitats. Strong indirect effects and a global reach further characterize these interactions and amplify the impacts of human activities on diverse ecosystems, from oceans to forests. We require better understanding of hyperkeystone interaction chains most urgently, especially for marine species and terrestrial large carnivores, which experience relatively higher exploitation rates than other species. This requires innovative approaches that integrate the study of human behavior with food-web theory, and which might provide surprising new insights into the complex ecology of our own species.
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Affiliation(s)
- Boris Worm
- Department of Biology, Dalhousie University, Halifax, NS B3H4R2, Canada.
| | - Robert T Paine
- Department of Biology, University of Washington, Seattle, WA 98195, USA
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200
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Salinas-de-León P, Acuña-Marrero D, Rastoin E, Friedlander AM, Donovan MK, Sala E. Largest global shark biomass found in the northern Galápagos Islands of Darwin and Wolf. PeerJ 2016; 4:e1911. [PMID: 27190701 PMCID: PMC4867720 DOI: 10.7717/peerj.1911] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 03/17/2016] [Indexed: 12/11/2022] Open
Abstract
Overfishing has dramatically depleted sharks and other large predatory fishes worldwide except for a few remote and/or well-protected areas. The islands of Darwin and Wolf in the far north of the Galapagos Marine Reserve (GMR) are known for their large shark abundance, making them a global scuba diving and conservation hotspot. Here we report quantitative estimates of fish abundance at Darwin and Wolf over two consecutive years using stereo-video surveys, which reveal the largest reef fish biomass ever reported (17.5 t [Formula: see text] on average), consisting largely of sharks. Despite this, the abundance of reef fishes around the GMR, such as groupers, has been severely reduced because of unsustainable fishing practices. Although Darwin and Wolf are within the GMR, they were not fully protected from fishing until March 2016. Given the ecological value and the economic importance of Darwin and Wolf for the dive tourism industry, the current protection should ensure the long-term conservation of this hotspot of unique global value.
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Affiliation(s)
- Pelayo Salinas-de-León
- Department of Marine Sciences, Charles Darwin Research Station , Puerto Ayora, Galapagos Islands , Ecuador
| | - David Acuña-Marrero
- Department of Marine Sciences, Charles Darwin Research Station , Puerto Ayora, Galapagos Islands , Ecuador
| | - Etienne Rastoin
- Department of Marine Sciences, Charles Darwin Research Station , Puerto Ayora, Galapagos Islands , Ecuador
| | - Alan M Friedlander
- Pristine Seas, National Geographic Society, Washington, D.C., USA; Fisheries Ecology Research Lab, University of Hawai'i at Manoa, Honolulu, HI, USA
| | - Mary K Donovan
- Fisheries Ecology Research Lab, University of Hawai'i at Manoa , Honolulu, HI , USA
| | - Enric Sala
- Pristine Seas, National Geographic Society , Washington, D.C. , USA
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