Article

 

CasaleHowMuchSeaTurtleBycatch.pdf Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/articles/g158bn71s

Descriptions

Attribute NameValues
Creator
Abstract
  • Mediterranean populations of loggerhead Caretta caretta and green sea turtles Chelonia mydas are subject to several anthropogenic threats, with documented mortality from incidental capture in fishing gear. However, how such mortalities actually affect the populations is uncertain without an estimate of population size. We derived a theoretical demographic structure for each species in the Mediterranean, assuming a stationary age distribution in a stable population with constant proportions of turtles in each life stage, using distributions of age-specific vital rates. We incorporated uncertainty into the main vital rate parameters to identify a likely order of magnitude of turtle abundance in different life stages. Through this approach, we aim to (1) provide a rough estimate of all population stage classes, particularly the juvenile classes that are most subject to fisheries interactions, (2) provide an estimate of reproductive life span, (3) identify and review the key demographic parameters, and (4) identify the priority gaps in our information in need of further investigation. The range of population abundance estimates from the models constructed with uncertainty (95% CI) was 0.81-3.38 million loggerheads and 0.26-2.21 million green turtles, Mediterranean-wide. When we calculated the potential biological removal for the segment of the population at risk of fisheries capture, our estimates were comparable to or lower than the estimated bycatch levels in fisheries. Although the model assumes a stable population and provides only a rough estimate of abundance, these results suggest that the current bycatch level should be regarded as unsustainable for Mediterranean turtle populations.
Keyword
Rights Statement
Additional Information
  • description.provenance : Made available in DSpace on 2016-03-08T15:35:00Z (GMT). No. of bitstreams: 3 license_rdf: 1370 bytes, checksum: cd1af5ab51bcc7a5280cf305303530e9 (MD5) CasaleHowMuchSeaTurtleBycatch.pdf: 1013904 bytes, checksum: c065cc04df80ddbcda6cfed0d7c46433 (MD5) CasaleHowMuchSeaTurtleBycatchSupplement.pdf: 428204 bytes, checksum: f948bfcbdf6a88d197cd577d4b035b2a (MD5) Previous issue date: 2016
  • description.provenance : Submitted by Patricia Black (patricia.black@oregonstate.edu) on 2016-03-08T15:34:32Z No. of bitstreams: 3 license_rdf: 1370 bytes, checksum: cd1af5ab51bcc7a5280cf305303530e9 (MD5) CasaleHowMuchSeaTurtleBycatch.pdf: 1013904 bytes, checksum: c065cc04df80ddbcda6cfed0d7c46433 (MD5) CasaleHowMuchSeaTurtleBycatchSupplement.pdf: 428204 bytes, checksum: f948bfcbdf6a88d197cd577d4b035b2a (MD5)
  • description.provenance : Approved for entry into archive by Patricia Black(patricia.black@oregonstate.edu) on 2016-03-08T15:35:00Z (GMT) No. of bitstreams: 3 license_rdf: 1370 bytes, checksum: cd1af5ab51bcc7a5280cf305303530e9 (MD5) CasaleHowMuchSeaTurtleBycatch.pdf: 1013904 bytes, checksum: c065cc04df80ddbcda6cfed0d7c46433 (MD5) CasaleHowMuchSeaTurtleBycatchSupplement.pdf: 428204 bytes, checksum: f948bfcbdf6a88d197cd577d4b035b2a (MD5)