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Yang S, Jin Y, Li S, Liu Z. Integrated approaches for comprehensive cetacean research and conservation in the East China Sea. MARINE POLLUTION BULLETIN 2024; 206:116789. [PMID: 39094284 DOI: 10.1016/j.marpolbul.2024.116789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 04/30/2024] [Accepted: 07/27/2024] [Indexed: 08/04/2024]
Abstract
This study thoroughly examines three cetacean monitoring methods and assessing their advantages and limitations, establishing a foundational basis for comprehensive information on composition, distribution, and behavior. While real-time and non-invasive, visual surveys favor surface-active cetaceans and are weather-dependent. Local ecological knowledge supplements insights into group behavior. Environmental DNA (eDNA) analysis efficiently detects species like the narrow-ridged finless porpoise (Neophocaena asiaeorientalis) and common bottlenose dolphin (Tursiops truncatus), offering non-invasive, and spatially adept monitoring. Furthermore, eDNA provides prey species information, revealing the narrow-ridged finless porpoise's winter migration to deeper waters due to prey distribution. The study identifies prevalent prey species, like the Japanese Anchovy (Engraulis japonicus) and Osbeck's grenadier anchovy (Coilia mystus), offering insights into the porpoise's feeding ecology and adaptation to changing prey availability in winter. This study systematically compares diverse methodologies employed in cetacean surveys, thereby yielding a comprehensive understanding of cetacean distribution, behavior, and feeding ecology.
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Affiliation(s)
- Shaobo Yang
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China; College of Marine Sciences of Shanghai Ocean University, Shanghai 201306, China
| | - Yan Jin
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China; Key Laboratory of East China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture and Rural Affairs, Shanghai 200090, China
| | - Shengfa Li
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China; Key Laboratory of East China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture and Rural Affairs, Shanghai 200090, China
| | - Zunlei Liu
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China; Key Laboratory of East China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture and Rural Affairs, Shanghai 200090, China.
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2
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Drackett L, Dragićević S. Suitability Analysis of Acoustic Refugia for Endangered Killer Whales (Orcinus orca) Using the GIS-based Logic Scoring of Preference Method. ENVIRONMENTAL MANAGEMENT 2021; 68:262-278. [PMID: 34019115 DOI: 10.1007/s00267-021-01481-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 05/03/2021] [Indexed: 06/12/2023]
Abstract
An emerging priority in marine noise pollution research is identifying marine "acoustic refugia" where noise levels are relatively low and good-quality habitat is available to acoustically sensitive species. The endangered Southern Resident population of killer whales (Orcinus orca) that inhabits the transboundary Salish Sea in Canada and the USA are affected by noise pollution. Geographic Information Systems (GIS) and spatial multicriteria evaluation (MCE) methods have been used to operationalize suitability analysis in ecology and conservation for site selection problems. However, commonly used methods lack the ability to represent complex logical relationships between input criteria. Therefore, the objective of this study is to apply a more advanced MCE method, known as Logic Scoring of Preference (LSP), to identify acoustic refugia for killer whales in the Salish Sea. This GIS-based LSP-MCE approach considers multiple input criteria by combining input data representing killer whale habitat requirements with noise pollution and other factors to identify suitable acoustic refugia. The results indicate the locations of suitable acoustic refugia and how they are affected by noise pollution from marine vessels in three scenarios developed to represent different levels of vessel traffic. Identifying acoustic refugia can contribute to efforts to reduce the effect of marine noise pollution on killer whale populations by highlighting high-priority areas in which to implement policies such as traffic-limiting measures or marine protected areas. Moreover, the proposed LSP-MCE procedure combines criteria in a stepwise manner that can support environmental management decision-making processes and can be applied to other marine suitability analysis contexts.
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Affiliation(s)
- Logan Drackett
- Spatial Analysis and Modeling Laboratory, Department of Geography, Simon Fraser University, Burnaby, BC, Canada
| | - Suzana Dragićević
- Spatial Analysis and Modeling Laboratory, Department of Geography, Simon Fraser University, Burnaby, BC, Canada.
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3
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Bestley S, Ropert-Coudert Y, Bengtson Nash S, Brooks CM, Cotté C, Dewar M, Friedlaender AS, Jackson JA, Labrousse S, Lowther AD, McMahon CR, Phillips RA, Pistorius P, Puskic PS, Reis AODA, Reisinger RR, Santos M, Tarszisz E, Tixier P, Trathan PN, Wege M, Wienecke B. Marine Ecosystem Assessment for the Southern Ocean: Birds and Marine Mammals in a Changing Climate. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.566936] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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Tulloch VJD, Plagányi ÉE, Brown C, Richardson AJ, Matear R. Future recovery of baleen whales is imperiled by climate change. GLOBAL CHANGE BIOLOGY 2019; 25:1263-1281. [PMID: 30807685 PMCID: PMC6850638 DOI: 10.1111/gcb.14573] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Revised: 11/28/2018] [Accepted: 12/11/2018] [Indexed: 05/24/2023]
Abstract
Historical harvesting pushed many whale species to the brink of extinction. Although most Southern Hemisphere populations are slowly recovering, the influence of future climate change on their recovery remains unknown. We investigate the impacts of two anthropogenic pressures-historical commercial whaling and future climate change-on populations of baleen whales (blue, fin, humpback, Antarctic minke, southern right) and their prey (krill and copepods) in the Southern Ocean. We use a climate-biological coupled "Model of Intermediate Complexity for Ecosystem Assessments" (MICE) that links krill and whale population dynamics with climate change drivers, including changes in ocean temperature, primary productivity and sea ice. Models predict negative future impacts of climate change on krill and all whale species, although the magnitude of impacts on whales differs among populations. Despite initial recovery from historical whaling, models predict concerning declines under climate change, even local extinctions by 2100, for Pacific populations of blue, fin and southern right whales, and Atlantic/Indian fin and humpback whales. Predicted declines were a consequence of reduced prey (copepods/krill) from warming and increasing interspecific competition between whale species. We model whale population recovery under an alternative scenario whereby whales adapt their migratory patterns to accommodate changing sea ice in the Antarctic and a shifting prey base. Plasticity in range size and migration was predicted to improve recovery for ice-associated blue and minke whales. Our study highlights the need for ongoing protection to help depleted whale populations recover, as well as local management to ensure the krill prey base remains viable, but this may have limited success without immediate action to reduce emissions.
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Affiliation(s)
- Vivitskaia J. D. Tulloch
- ARC Centre of Excellence in Environmental DecisionsUniversity of QueenslandSt Lucia, BrisbaneQLDAustralia
- CSIRO Oceans and Atmosphere, Queensland BioSciences Precinct (QBP)St Lucia, BrisbaneQLDAustralia
| | - Éva E. Plagányi
- CSIRO Oceans and Atmosphere, Queensland BioSciences Precinct (QBP)St Lucia, BrisbaneQLDAustralia
| | | | - Anthony J. Richardson
- CSIRO Oceans and Atmosphere, Queensland BioSciences Precinct (QBP)St Lucia, BrisbaneQLDAustralia
- Centre for Applications in Natural Resource Mathematics, School of Mathematics and PhysicsThe University of QueenslandSt LuciaQLDAustralia
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Thorne LH, Baird RW, Webster DL, Stepanuk JE, Read AJ. Predicting fisheries bycatch: A case study and field test for pilot whales in a pelagic longline fishery. DIVERS DISTRIB 2019. [DOI: 10.1111/ddi.12912] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
- Lesley H. Thorne
- School of Marine and Atmospheric Sciences Stony Brook University Stony Brook New York
| | | | | | - Julia E. Stepanuk
- School of Marine and Atmospheric Sciences Stony Brook University Stony Brook New York
| | - Andrew J. Read
- Division of Marine Science and Conservation, Nicholas School of the Environment Duke University Beaufort North Carolina
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Commercial fishing patterns influence odontocete whale-longline interactions in the Southern Ocean. Sci Rep 2019; 9:1904. [PMID: 30760725 PMCID: PMC6374415 DOI: 10.1038/s41598-018-36389-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 11/19/2018] [Indexed: 11/12/2022] Open
Abstract
The emergence of longline fishing around the world has been concomitant with an increase in depredation-interactions by odontocete whales (removal of fish caught on hooks), resulting in substantial socio-economic and ecological impacts. The extent, trends and underlying mechanisms driving these interactions remain poorly known. Using long-term (2003–2017) datasets from seven major Patagonian toothfish (Dissostichus eleginoides) longline fisheries, this study assessed the levels and inter-annual trends of sperm whale (Physeter macrocephalus) and/or killer whale (Orcinus orca) interactions as proportions of fishing time (days) and fishing area (spatial cells). The role of fishing patterns in explaining between-fisheries variations of probabilities of odontocete interactions was investigated. While interaction levels remained globally stable since the early 2000s, they varied greatly between fisheries from 0 to >50% of the fishing days and area. Interaction probabilities were influenced by the seasonal concentration of fishing effort, size of fishing areas, density of vessels, their mobility and the depth at which they operated. The results suggest that between-fisheries variations of interaction probabilities are largely explained by the extent to which vessels provide whales with opportunities for interactions. Determining the natural distribution of whales will, therefore, allow fishers to implement better strategies of spatio-temporal avoidance of depredation.
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Toothed whale and shark depredation indicators: A case study from the Reunion Island and Seychelles pelagic longline fisheries. PLoS One 2018; 13:e0202037. [PMID: 30096170 PMCID: PMC6086455 DOI: 10.1371/journal.pone.0202037] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 07/26/2018] [Indexed: 11/19/2022] Open
Abstract
Depredation in marine ecosystems is defined as the damage or removal of fish or bait from fishing gear by predators. Depredation raises concerns about the conservation of species involved, fisheries yield and profitability, and reference points based on stock assessment of depredated species. Therefore, the development of accurate indicators to assess the impact of depredation is needed. Both the Reunion Island and the Seychelles archipelago pelagic longline fisheries targeting swordfish (Xiphias gladius) and tuna (Thunnus spp.) are affected by depredation from toothed whales and pelagic sharks. In this study, we used fishery data collected between 2004 and 2015 to propose depredation indicators and to assess depredation levels in both fisheries. For both fisheries, the interaction rate (depredation occurrence) was significantly higher for shark compared to toothed whale depredation. However, when depredation occurred, toothed whale depredation impact was significantly higher than shark depredation impact, with higher depredation per unit effort (number of fish depredated per 1000 hooks) and damage rate (proportion of fish depredated per depredated set). The gross depredation rate in the Seychelles was 18.3%. A slight increase of the gross depredation rate was observed for the Reunion Island longline fleet from 2011 (4.1% in 2007-2010 and 4.4% in 2011-2015). Economic losses due to depredation were estimated by using these indicators and published official statistics. A loss of 0.09 EUR/hook due to depredation was estimated for the Reunion Island longline fleet, and 0.86 EUR/hook for the Seychelles. These results suggest a southward decreasing toothed whale and shark depredation gradient in the southwest Indian Ocean. Seychelles depredation levels are among the highest observed in the world revealing this area as a "hotspot" of interaction between pelagic longline fisheries and toothed whales. This study also highlights the need for a set of depredation indicators to allow for a global comparison of depredation rates among various fishing grounds worldwide.
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Tixier P, Lea MA, Hindell MA, Guinet C, Gasco N, Duhamel G, Arnould JPY. Killer whale ( Orcinus orca) interactions with blue-eye trevalla ( Hyperoglyphe antarctica) longline fisheries. PeerJ 2018; 6:e5306. [PMID: 30123694 PMCID: PMC6087417 DOI: 10.7717/peerj.5306] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 07/03/2018] [Indexed: 11/20/2022] Open
Abstract
Over the past five decades, marine mammal interactions with fisheries have become a major human-wildlife conflict globally. The emergence of longline fishing is concomitant with the development of depredation-type interactions i.e., marine mammals feeding on fish caught on hooks. The killer whale (Orcinus orca) is one of the species most involved in depredation on longline fisheries. The issue was first reported in high latitudes but, with increasing expansion of this fishing method, other fisheries have begun to experience interactions. The present study investigated killer whale interactions with two geographically isolated blue-eye trevalla (Hyperoglyphe antarctica) fisheries operating in temperate waters off Amsterdam/St. Paul Islands (Indian Ocean) and south-eastern Australia. These two fisheries differ in the fishing technique used (vertical vs. demersal longlines), effort, catch, fleet size and fishing area size. Using 7-year (2010–16) long fishing and observation datasets, this study estimated the levels of killer whale interactions and examined the influence of spatio-temporal and operational variables on the probability of vessels to experience interactions. Killer whales interactions occurred during 58.4% and 21.2% of all fishing days, and over 94% and 47.4% of the fishing area for both fisheries, respectively. In south-eastern Australia, the probability of occurrence of killer whale interactions during fishing days varied seasonally with a decrease in spring, increased with the daily fishing effort and decreased with the distance travelled by the vessel between fishing days. In Amsterdam/St. Paul, this probability was only influenced by latitude, with an increase in the southern part of the area. Together, these findings document two previously unreported cases of high killer whale depredation, and provide insights on ways to avoid the issue. The study also emphasizes the need to further examine the local characteristics of fisheries and the ecology of local depredating killer whale populations in as important drivers of depredation.
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Affiliation(s)
- Paul Tixier
- School of Life and Environmental Sciences (Burwood Campus), Deakin University, Geelong, Victoria, Australia
| | - Mary-Anne Lea
- Ecology and Biodiversity Centre, Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia
| | - Mark A Hindell
- Ecology and Biodiversity Centre, Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia
| | - Christophe Guinet
- Centre d'Etudes Biologiques de Chizé (CEBC), UMR 7372 Université de La Rochelle-CNRS, Villiers-en-Bois, France
| | - Nicolas Gasco
- Département Adaptations du vivant, UMR BOREA, Museum national d'Histoire naturelle, Paris, France
| | - Guy Duhamel
- Département Adaptations du vivant, UMR BOREA, Museum national d'Histoire naturelle, Paris, France
| | - John P Y Arnould
- School of Life and Environmental Sciences (Burwood Campus), Deakin University, Geelong, Victoria, Australia
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van den Hoff J, Kilpatrick R, Welsford D. Southern elephant seals (Mirounga leonina Linn.) depredate toothfish longlines in the midnight zone. PLoS One 2017; 12:e0172396. [PMID: 28234988 PMCID: PMC5325274 DOI: 10.1371/journal.pone.0172396] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 02/03/2017] [Indexed: 11/19/2022] Open
Abstract
Humans have devised fishing technologies that compete with marine predators for fish resources world-wide. One such fishery for the Patagonian toothfish (Dissostichus eleginoides) has developed interactions with a range of predators, some of which are marine mammals capable of diving to extreme depths for extended periods. A deep-sea camera system deployed within a toothfish fishery operating in the Southern Ocean acquired the first-ever video footage of an extreme-diver, the southern elephant seal (Mirounga leonina), depredating catch from longlines set at depths in excess of 1000m. The interactions recorded were non-lethal, however independent fisheries observer reports confirm elephant seal-longline interactions can be lethal. The seals behaviour of depredating catch at depth during the line soak-period differs to other surface-breathing species and thus presents a unique challenge to mitigate their by-catch. Deployments of deep-sea cameras on exploratory fishing gear prior to licencing and permit approvals would gather valuable information regarding the nature of interactions between deep diving/dwelling marine species and longline fisheries operating at bathypelagic depths. Furthermore, the positive identification by sex and age class of species interacting with commercial fisheries would assist in formulating management plans and mitigation strategies founded on species-specific life-history strategies.
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Affiliation(s)
- John van den Hoff
- Australian Antarctic Division, Kingston, Tasmania, Australia
- * E-mail:
| | | | - Dirk Welsford
- Australian Antarctic Division, Kingston, Tasmania, Australia
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Söffker M, Trathan P, Clark J, Collins MA, Belchier M, Scott R. The impact of predation by marine mammals on patagonian toothfish longline fisheries. PLoS One 2015; 10:e0118113. [PMID: 25738698 PMCID: PMC4349812 DOI: 10.1371/journal.pone.0118113] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 01/07/2015] [Indexed: 11/26/2022] Open
Abstract
Predatory interaction of marine mammals with longline fisheries is observed globally, leading to partial or complete loss of the catch and in some parts of the world to considerable financial loss. Depredation can also create additional unrecorded fishing mortality of a stock and has the potential to introduce bias to stock assessments. Here we aim to characterise depredation in the Patagonian toothfish (Dissostichus eleginoides) fishery around South Georgia focusing on the spatio-temporal component of these interactions. Antarctic fur seals (Arctocephalus gazella), sperm whales (Physeter macrocephalus), and orcas (Orcinus orca) frequently feed on fish hooked on longlines around South Georgia. A third of longlines encounter sperm whales, but loss of catch due to sperm whales is insignificant when compared to that due to orcas, which interact with only 5% of longlines but can take more than half of the catch in some cases. Orca depredation around South Georgia is spatially limited and focused in areas of putative migration routes, and the impact is compounded as a result of the fishery also concentrating in those areas at those times. Understanding the seasonal behaviour of orcas and the spatial and temporal distribution of "depredation hot spots" can reduce marine mammal interactions, will improve assessment and management of the stock and contribute to increased operational efficiency of the fishery. Such information is valuable in the effort to resolve the human-mammal conflict for resources.
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Affiliation(s)
- Marta Söffker
- Centre for Environment, Fisheries & Aquaculture Science; Pakefield Rd, Lowestoft, United Kingdom
| | - Phil Trathan
- British Antarctic Survey; High Cross, Madingley Road, Cambridge, United Kingdom
| | - James Clark
- Marine Resources Assessment Group; 18 Queen Street, London, United Kingdom
| | - Martin A. Collins
- Government of South Georgia and the South Sandwich Islands; Ross Road, Stanley, Falkland Islands
| | - Mark Belchier
- British Antarctic Survey; High Cross, Madingley Road, Cambridge, United Kingdom
| | - Robert Scott
- Centre for Environment, Fisheries & Aquaculture Science; Pakefield Rd, Lowestoft, United Kingdom
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Adimey NM, Hudak CA, Powell JR, Bassos-Hull K, Foley A, Farmer NA, White L, Minch K. Fishery gear interactions from stranded bottlenose dolphins, Florida manatees and sea turtles in Florida, U.S.A. MARINE POLLUTION BULLETIN 2014; 81:103-115. [PMID: 24613263 DOI: 10.1016/j.marpolbul.2014.02.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 01/31/2014] [Accepted: 02/07/2014] [Indexed: 06/03/2023]
Abstract
Documenting the extent of fishery gear interactions is critical to wildlife conservation efforts, especially for reducing entanglements and ingestion. This study summarizes fishery gear interactions involving common bottlenose dolphins (Tursiops truncatus truncatus), Florida manatees (Trichechus manatus latirostris) and sea turtles: loggerhead (Caretta caretta), green turtle (Chelonia mydas), leatherback (Dermochelys coriacea), hawksbill (Eretmochelys imbricata), Kemp's ridley (Lepidochelys kempii), and olive ridley (Lepidochelys olivacea) stranding in Florida waters during 1997-2009. Fishery gear interactions for all species combined were 75.3% hook and line, 18.2% trap pot gear, 4.8% fishing nets, and 1.7% in multiple gears. Total reported fishery gear cases increased over time for dolphins (p<0.05), manatees (p<0.01), loggerheads (p<0.05) and green sea turtles (p<0.05). The proportion of net interaction strandings relative to total strandings for loggerhead sea turtles increased (p<0.05). Additionally, life stage and sex patterns were examined, fishery gear interaction hotspots were identified and generalized linear regression modeling was conducted.
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Affiliation(s)
- Nicole M Adimey
- U.S. Fish and Wildlife Service, 7915 Baymeadows Way, Suite 200, Jacksonville, FL 32256, USA.
| | - Christine A Hudak
- Right Whale Research Program, Center for Coastal Studies, Provincetown, MA 02657, USA.
| | - Jessica R Powell
- NOAA Fisheries, Southeast Regional Office, 263 13th Avenue South, St. Petersburg, FL 33701, USA.
| | - Kim Bassos-Hull
- Sarasota Dolphin Research Program, Chicago Zoological Society, c/o Mote Marine Laboratory, 1600 Ken Thompson Parkway, Sarasota, FL 34236, USA.
| | - Allen Foley
- Florida Fish and Wildlife Conservation Commission, Fish and Wildlife Research Institute, Jacksonville Field Laboratory, Jacksonville, FL 32218, USA.
| | - Nicholas A Farmer
- NOAA Fisheries, Southeast Regional Office, 263 13th Avenue South, St. Petersburg, FL 33701, USA.
| | - Linda White
- U.S. Fish and Wildlife Service, 7915 Baymeadows Way, Suite 200, Jacksonville, FL 32256, USA
| | - Karrie Minch
- Florida Fish and Wildlife Conservation Commission, Fish and Wildlife Research Institute, Sea Turtle Stranding and Salvage Network Indian River Field Lab, 1220 Prospect Ave, Suite 285, Melbourne, FL 32901, USA.
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de Bruyn PJN, Tosh CA, Terauds A. Killer whale ecotypes: is there a global model? Biol Rev Camb Philos Soc 2012; 88:62-80. [DOI: 10.1111/j.1469-185x.2012.00239.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Collins MA, Brickle P, Brown J, Belchier M. The Patagonian toothfish: biology, ecology and fishery. ADVANCES IN MARINE BIOLOGY 2010; 58:227-300. [PMID: 20959159 DOI: 10.1016/b978-0-12-381015-1.00004-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Patagonian toothfish (Dissostichus eleginoides) is a large notothenioid fish that supports valuable fisheries throughout the Southern Ocean. D. eleginoides are found on the southern shelves and slopes of South America and around the sub-Antarctic islands of the Southern Ocean. Patagonian toothfish are a long-lived species (>50 years), which initially grow rapidly on the shallow shelf areas, before undertaking an ontogenetic migration into deeper water. Although they are active predators and scavengers, there is no evidence of large-scale geographic migrations, and studies using genetics, biochemistry, parasite fauna and tagging indicate a high degree of isolation between populations in the Indian Ocean, South Georgia and the Patagonian Shelf. Patagonian toothfish spawn in deep water (ca. 1000 m) during the austral winter, producing pelagic eggs and larvae. Larvae switch to a demersal habitat at around 100 mm (1-year-old) and inhabit relatively shallow water (<300 m) until 6-7 years of age, when they begin a gradual migration into deeper water. As juveniles in shallow water, toothfish are primarily piscivorous, consuming the most abundant suitably sized local prey. With increasing size and habitat depth, the diet diversifies and includes more scavenging. Toothfish have weakly mineralised skeletons and a high fat content in muscle, which helps neutral buoyancy, but limits swimming capacity. Toothfish generally swim with labriform motion, but are capable of more rapid sub-carangiform swimming when startled. Toothfish were first caught as a by-catch (as juveniles) in shallow trawl fisheries, but following the development of deep water longlining, fisheries rapidly developed throughout the Southern Ocean. The initial rapid expansion of the fishery, which led to a peak of over 40,000 tonnes in reported landings in 1995, was accompanied by problems of bird by-catch and overexploitation as a consequence of illegal, unreported and unregulated fishing (IUU). These problems have now largely been addressed, but continued vigilance is required to ensure that the species is sustainably exploited and the ecosystem effects of the fisheries are minimised.
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Affiliation(s)
- Martin A Collins
- Government of South Georgia and the South Sandwich Islands, Government House, Stanley, Falkland Islands, FIQQ 1ZZ
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Sakamoto KQ, Takahashi A, Iwata T, Trathan PN. From the eye of the albatrosses: a bird-borne camera shows an association between albatrosses and a killer whale in the Southern Ocean. PLoS One 2009; 4:e7322. [PMID: 19809497 PMCID: PMC2752807 DOI: 10.1371/journal.pone.0007322] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2009] [Accepted: 09/12/2009] [Indexed: 11/19/2022] Open
Abstract
Albatrosses fly many hundreds of kilometers across the open ocean to find and feed upon their prey. Despite the growing number of studies concerning their foraging behaviour, relatively little is known about how albatrosses actually locate their prey. Here, we present our results from the first deployments of a combined animal-borne camera and depth data logger on free-ranging black-browed albatrosses (Thalassarche melanophrys). The still images recorded from these cameras showed that some albatrosses actively followed a killer whale (Orcinus orca), possibly to feed on food scraps left by this diving predator. The camera images together with the depth profiles showed that the birds dived only occasionally, but that they actively dived when other birds or the killer whale were present. This association with diving predators or other birds may partially explain how albatrosses find their prey more efficiently in the apparently ‘featureless’ ocean, with a minimal requirement for energetically costly diving or landing activities.
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Affiliation(s)
| | - Akinori Takahashi
- Department of Polar Science, The Graduate University for Advanced Studies, National Institute of Polar Research, Tachikawa, Tokyo, Japan
- * E-mail:
| | - Takashi Iwata
- Department of Polar Science, The Graduate University for Advanced Studies, National Institute of Polar Research, Tachikawa, Tokyo, Japan
| | - Philip N. Trathan
- British Antarctic Survey, Natural Environment Research Council, High Cross, Cambridge, United Kingdom
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