Preliminary estimates of the abundance and fidelity of dolphins associating with a demersal trawl fishery
Abstract The incidental capture of wildlife in fishing gear presents a global conservation challenge. As a baseline to inform assessments of the impact of bycatch on bottlenose dolphins (Tursiops truncatus) interacting with an Australian trawl fishery, we conducted an aerial survey to estimate dolph...
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Nature Portfolio
2017-07-01
|
| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-017-05189-0 |
| _version_ | 1818344350158946304 |
|---|---|
| author | Simon J. Allen Kenneth H. Pollock Phil J. Bouchet Halina T. Kobryn Deirdre B. McElligott Krista E. Nicholson Joshua N. Smith Neil R. Loneragan |
| author_facet | Simon J. Allen Kenneth H. Pollock Phil J. Bouchet Halina T. Kobryn Deirdre B. McElligott Krista E. Nicholson Joshua N. Smith Neil R. Loneragan |
| author_sort | Simon J. Allen |
| collection | DOAJ |
| description | Abstract The incidental capture of wildlife in fishing gear presents a global conservation challenge. As a baseline to inform assessments of the impact of bycatch on bottlenose dolphins (Tursiops truncatus) interacting with an Australian trawl fishery, we conducted an aerial survey to estimate dolphin abundance across the fishery. Concurrently, we carried out boat-based dolphin photo-identification to assess short-term fidelity to foraging around trawlers, and used photographic and genetic data to infer longer-term fidelity to the fishery. We estimated abundance at ≈ 2,300 dolphins (95% CI = 1,247–4,214) over the ≈ 25,880-km2 fishery. Mark-recapture estimates yielded 226 (SE = 38.5) dolphins associating with one trawler and some individuals photographed up to seven times over 12 capture periods. Moreover, photographic and genetic re-sampling over three years confirmed that some individuals show long-term fidelity to trawler-associated foraging. Our study presents the first abundance estimate for any Australian pelagic dolphin community and documents individuals associating with trawlers over days, months and years. Without trend data or correction factors for dolphin availability, the impact of bycatch on this dolphin population’s conservation status remains unknown. These results should be taken into account by management agencies assessing the impact of fisheries-related mortality on this protected species. |
| first_indexed | 2024-12-13T16:45:05Z |
| format | Article |
| id | doaj.art-1634523ebfb34b2dbac6ef9773b465f9 |
| institution | Directory Open Access Journal |
| issn | 2045-2322 |
| language | English |
| last_indexed | 2024-12-13T16:45:05Z |
| publishDate | 2017-07-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj.art-1634523ebfb34b2dbac6ef9773b465f92022-12-21T23:38:11ZengNature PortfolioScientific Reports2045-23222017-07-017111110.1038/s41598-017-05189-0Preliminary estimates of the abundance and fidelity of dolphins associating with a demersal trawl fisherySimon J. Allen0Kenneth H. Pollock1Phil J. Bouchet2Halina T. Kobryn3Deirdre B. McElligott4Krista E. Nicholson5Joshua N. Smith6Neil R. Loneragan7School of Veterinary and Life Sciences, Murdoch UniversityDepartment of Applied Ecology, North Carolina State UniversitySchool of Biological Sciences and Oceans Institute, University of Western AustraliaSchool of Veterinary and Life Sciences, Murdoch UniversityDaithi O’Murchu Marine Research Station, GearhiesSchool of Veterinary and Life Sciences, Murdoch UniversitySchool of Veterinary and Life Sciences, Murdoch UniversitySchool of Veterinary and Life Sciences, Murdoch UniversityAbstract The incidental capture of wildlife in fishing gear presents a global conservation challenge. As a baseline to inform assessments of the impact of bycatch on bottlenose dolphins (Tursiops truncatus) interacting with an Australian trawl fishery, we conducted an aerial survey to estimate dolphin abundance across the fishery. Concurrently, we carried out boat-based dolphin photo-identification to assess short-term fidelity to foraging around trawlers, and used photographic and genetic data to infer longer-term fidelity to the fishery. We estimated abundance at ≈ 2,300 dolphins (95% CI = 1,247–4,214) over the ≈ 25,880-km2 fishery. Mark-recapture estimates yielded 226 (SE = 38.5) dolphins associating with one trawler and some individuals photographed up to seven times over 12 capture periods. Moreover, photographic and genetic re-sampling over three years confirmed that some individuals show long-term fidelity to trawler-associated foraging. Our study presents the first abundance estimate for any Australian pelagic dolphin community and documents individuals associating with trawlers over days, months and years. Without trend data or correction factors for dolphin availability, the impact of bycatch on this dolphin population’s conservation status remains unknown. These results should be taken into account by management agencies assessing the impact of fisheries-related mortality on this protected species.https://doi.org/10.1038/s41598-017-05189-0 |
| spellingShingle | Simon J. Allen Kenneth H. Pollock Phil J. Bouchet Halina T. Kobryn Deirdre B. McElligott Krista E. Nicholson Joshua N. Smith Neil R. Loneragan Preliminary estimates of the abundance and fidelity of dolphins associating with a demersal trawl fishery Scientific Reports |
| title | Preliminary estimates of the abundance and fidelity of dolphins associating with a demersal trawl fishery |
| title_full | Preliminary estimates of the abundance and fidelity of dolphins associating with a demersal trawl fishery |
| title_fullStr | Preliminary estimates of the abundance and fidelity of dolphins associating with a demersal trawl fishery |
| title_full_unstemmed | Preliminary estimates of the abundance and fidelity of dolphins associating with a demersal trawl fishery |
| title_short | Preliminary estimates of the abundance and fidelity of dolphins associating with a demersal trawl fishery |
| title_sort | preliminary estimates of the abundance and fidelity of dolphins associating with a demersal trawl fishery |
| url | https://doi.org/10.1038/s41598-017-05189-0 |
| work_keys_str_mv | AT simonjallen preliminaryestimatesoftheabundanceandfidelityofdolphinsassociatingwithademersaltrawlfishery AT kennethhpollock preliminaryestimatesoftheabundanceandfidelityofdolphinsassociatingwithademersaltrawlfishery AT philjbouchet preliminaryestimatesoftheabundanceandfidelityofdolphinsassociatingwithademersaltrawlfishery AT halinatkobryn preliminaryestimatesoftheabundanceandfidelityofdolphinsassociatingwithademersaltrawlfishery AT deirdrebmcelligott preliminaryestimatesoftheabundanceandfidelityofdolphinsassociatingwithademersaltrawlfishery AT kristaenicholson preliminaryestimatesoftheabundanceandfidelityofdolphinsassociatingwithademersaltrawlfishery AT joshuansmith preliminaryestimatesoftheabundanceandfidelityofdolphinsassociatingwithademersaltrawlfishery AT neilrloneragan preliminaryestimatesoftheabundanceandfidelityofdolphinsassociatingwithademersaltrawlfishery |