Thesis
Population dynamics and spatial distribution of two commercially important species of sea cucumber, Parastichopus californicus and Parastichopus leukothele, in deep central California waters
Washington State University
Master of Science (MS), Washington State University
2011
Handle:
https://hdl.handle.net/2376/103010
Abstract
Sea cucumbers are fished around the world. Along the west coast of the U.S., Parastichopus californicus is the primary species targeted in both trawl and SCUBA dive fisheries; Parastichopus leukothele is also likely collected in trawls. As most fishery stock assessments target shallow populations of sea cucumbers, deeper populations often go unmonitored. The purpose of this study was to identify the spatial distribution and dynamics of the continental shelf and slope (25-365m) populations of P. californicus and P. leukothele in central California (Monterey Bay to Big Sur). From September-November 2007, 174 dives were conducted using the occupied submersible Delta from 25 to 365m. Using the video transects recorded during these dives, individual sea cucumbers of these species were identified and sized, and habitat was classified by substrate type. In total, 864 P. californicus and 478 P. leukothele, ranging in size from 10-45cm and 5-35cm respectively, were identified on transects. P. californicus was found from 25-248m (average=77m) depths and had an overall density of 57 cucumbers/hectare. P. leukothele was found from 99-317m (average=211m) depths with anoverall density of 34 cucumbers/hectare. Both species varied significantly in density by depth, habitat type, and site. P. californicus was found in the highest densities at Portuguese Ledge and in depths from 50-100m; P. leukothele was densest at Soquel Canyon and from 200-250m. Both species were most abundant on hard substrates. In general, P. californicus was most strongly associated with the continental shelf environment while P. leukothele was more associated with the slope. Results from this study provide a fishery-independent analysis of understudied continental shelf and slope sea cucumber populations that may be helpful in the management of these species.
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Details
- Title
- Population dynamics and spatial distribution of two commercially important species of sea cucumber, Parastichopus californicus and Parastichopus leukothele, in deep central California waters
- Creators
- Jennifer M. Blaine
- Contributors
- Brian N. Tissot (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Environment, School of the (CAHNRS)
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; Pullman, Wash. :
- Identifiers
- 99900525196301842
- Language
- English
- Resource Type
- Thesis