MEPS 404:249-258 (2010)  -  DOI:

Movement patterns and nursery habitat of juvenile thresher sharks Alopias vulpinus in the Southern California Bight

D. Cartamil1,*, N. C. Wegner1, D. Kacev2, N. Ben-aderet3, S. Kohin4, J. B. Graham1

1Marine Biology Research Division, Scripps Institution of Oceanography, University of California, San Diego,
9500 Gilman Dr., La Jolla, California 92093-0204, USA
2Biology Department, San Diego State University, 5500 Campanile Dr., San Diego, California 92182, USA
3Inter-University Institute for Marine Sciences in Eilat, PO Box 469, Eilat 88103, Israel
4Southwest Fisheries Science Center, National Marine Fisheries Service, La Jolla, California 92037,

ABSTRACT: We investigated the potential use of open coastal habitat over the continental shelf as a nursery area for the common thresher shark Alopias vulpinus. Seven juvenile threshers were tracked using acoustic telemetry to determine their movement patterns and nursery habitat in the Southern California Bight (SCB). Tracked sharks occupied waters over the continental shelf 87% of the time. These waters had an average (± SD) sea surface temperature of 18.8 ± 1.6°C and chlorophyll concentrations that were an order of magnitude higher than in adjacent waters offshore of the continental shelf. Tracked sharks had a mean rate of movement of 1.63 ± 0.56 km h–1, and some sharks exhibited high site fidelity. The vertical distribution of juvenile threshers was generally limited to the upper 20 m of the water, and most sharks showed diel depth distribution patterns, with daytime depths significantly greater than nighttime depths. An analysis of SCB commercial fishery observer data confirms that juvenile common threshers are most frequently captured over the continental shelf. This region appears to provide juvenile threshers with ample food resources and reduced predation risk relative to adult habitat, and partially satisfies more quantitative nursery area criteria recently established in the literature.

KEY WORDS: Acoustic telemetry · Shark nursery area · Southern California Bight · Thresher shark · Alopias vulpinus

Full text in pdf format 
Cite this article as: Cartamil D, Wegner NC, Kacev D, Ben-aderet N, Kohin S, Graham JB (2010) Movement patterns and nursery habitat of juvenile thresher sharks Alopias vulpinus in the Southern California Bight. Mar Ecol Prog Ser 404:249-258.

Export citation
Mail this link - Contents Mailing Lists - RSS
- -