An illicit artisanal fishery for North Pacific white sharks indicates frequent occurrence and high mortality in the Gulf of California
Abstract Large sharks shape ecosystems across their geographic ranges and have become a top research and conservation priority. Eastern North Pacific (ENP) white shark (Carcharodon carcharias) aggregations off the United States and Mexico are well described, but their population status is currently...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Wiley
2021-07-01
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| Series: | Conservation Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1111/conl.12796 |
| _version_ | 1819124695560093696 |
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| author | Daniel J. Madigan Natalie S. Arnoldi Nigel E. Hussey Aaron B. Carlisle |
| author_facet | Daniel J. Madigan Natalie S. Arnoldi Nigel E. Hussey Aaron B. Carlisle |
| author_sort | Daniel J. Madigan |
| collection | DOAJ |
| description | Abstract Large sharks shape ecosystems across their geographic ranges and have become a top research and conservation priority. Eastern North Pacific (ENP) white shark (Carcharodon carcharias) aggregations off the United States and Mexico are well described, but their population status is currently uncertain. Population assessments of ENP white sharks are complicated by migrations across international boundaries, vulnerability at aggregation sites, and undetermined mortality levels. While protective legislation exists both in the United States and Mexico, ongoing incidental and unreported catch may undermine assessments and management. Here, access to a clandestine artisanal fishery provides evidence for white shark abundance and mortality in the Gulf of California that has been underestimated by other methods (e.g., satellite telemetry, [by]catch data). Shark size estimates based on tooth measurements suggest abundance of both juvenile and mature sharks in the region, and updated population models indicate the potential for substantial impacts of this fishery on ENP population viability. The data here, fisher‐provided information, and anecdotal evidence suggest potentially high abundance at two specific regions, making directed future research efforts feasible in the Gulf. These data demonstrate that cryptic life histories and geopolitical boundaries can still limit fundamental understanding of megafauna distribution, necessitating international cooperation for both research and management. |
| first_indexed | 2024-12-22T07:28:20Z |
| format | Article |
| id | doaj.art-70dd10c68eda4ec3a577ed04f96fa0aa |
| institution | Directory Open Access Journal |
| issn | 1755-263X |
| language | English |
| last_indexed | 2024-12-22T07:28:20Z |
| publishDate | 2021-07-01 |
| publisher | Wiley |
| record_format | Article |
| series | Conservation Letters |
| spelling | doaj.art-70dd10c68eda4ec3a577ed04f96fa0aa2022-12-21T18:34:05ZengWileyConservation Letters1755-263X2021-07-01144n/an/a10.1111/conl.12796An illicit artisanal fishery for North Pacific white sharks indicates frequent occurrence and high mortality in the Gulf of CaliforniaDaniel J. Madigan0Natalie S. Arnoldi1Nigel E. Hussey2Aaron B. Carlisle3Department of Integrative Biology University of Windsor Windsor Ontario CanadaHopkins Marine Station Stanford University Pacific Grove California USADepartment of Integrative Biology University of Windsor Windsor Ontario CanadaSchool of Marine Science & Policy University of Delaware Lewes Delaware USAAbstract Large sharks shape ecosystems across their geographic ranges and have become a top research and conservation priority. Eastern North Pacific (ENP) white shark (Carcharodon carcharias) aggregations off the United States and Mexico are well described, but their population status is currently uncertain. Population assessments of ENP white sharks are complicated by migrations across international boundaries, vulnerability at aggregation sites, and undetermined mortality levels. While protective legislation exists both in the United States and Mexico, ongoing incidental and unreported catch may undermine assessments and management. Here, access to a clandestine artisanal fishery provides evidence for white shark abundance and mortality in the Gulf of California that has been underestimated by other methods (e.g., satellite telemetry, [by]catch data). Shark size estimates based on tooth measurements suggest abundance of both juvenile and mature sharks in the region, and updated population models indicate the potential for substantial impacts of this fishery on ENP population viability. The data here, fisher‐provided information, and anecdotal evidence suggest potentially high abundance at two specific regions, making directed future research efforts feasible in the Gulf. These data demonstrate that cryptic life histories and geopolitical boundaries can still limit fundamental understanding of megafauna distribution, necessitating international cooperation for both research and management.https://doi.org/10.1111/conl.12796Carcharodon carchariasconservationpopulation dynamicsSea of Cortez |
| spellingShingle | Daniel J. Madigan Natalie S. Arnoldi Nigel E. Hussey Aaron B. Carlisle An illicit artisanal fishery for North Pacific white sharks indicates frequent occurrence and high mortality in the Gulf of California Conservation Letters Carcharodon carcharias conservation population dynamics Sea of Cortez |
| title | An illicit artisanal fishery for North Pacific white sharks indicates frequent occurrence and high mortality in the Gulf of California |
| title_full | An illicit artisanal fishery for North Pacific white sharks indicates frequent occurrence and high mortality in the Gulf of California |
| title_fullStr | An illicit artisanal fishery for North Pacific white sharks indicates frequent occurrence and high mortality in the Gulf of California |
| title_full_unstemmed | An illicit artisanal fishery for North Pacific white sharks indicates frequent occurrence and high mortality in the Gulf of California |
| title_short | An illicit artisanal fishery for North Pacific white sharks indicates frequent occurrence and high mortality in the Gulf of California |
| title_sort | illicit artisanal fishery for north pacific white sharks indicates frequent occurrence and high mortality in the gulf of california |
| topic | Carcharodon carcharias conservation population dynamics Sea of Cortez |
| url | https://doi.org/10.1111/conl.12796 |
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