Show simple item record

dc.contributor.authorKanive, Paul E.
dc.contributor.authorRotella, Jay J.
dc.contributor.authorChapple, Taylor K.
dc.contributor.authorAnderson, Scot D.
dc.contributor.authorWhite, Timothy D.
dc.contributor.authorBlock, Barbara A.
dc.contributor.authorJorgensen, Salvador J.
dc.identifier.citationKanive, Paul E., Jay J. Rotella, Taylor K. Chapple, Scot D. Anderson, Timothy D. White, Barbara A. Block, and Salvador J. Jorgensen. “Estimates of Regional Annual Abundance and Population Growth Rates of White Sharks Off Central California.” Biological Conservation 257 (May 2021): 109104. doi:10.1016/j.biocon.2021.109104.en_US
dc.description.abstractDetermining population trends is critical for evaluating management actions and prioritizing species protections. In this study, we used empirical data to produce an estimate of the population trend for sub-adult and adult white sharks in central California. We used the unique dorsal fin morphology to build a mark-recapture data set in a modified Jolly-Seber model (POPAN formulation) to estimate annual abundance and then investigate population growth rates using parametric bootstrapping methods for sub-adult and adult sharks (males and females). For all demographic groups combined, we found equivocal evidence for a positive regional population growth (λ = 1.07 (95% CI = 0.91 to 1.23)). However, sex- and size-specific population growth rate estimates provided some evidence of population increases for reproductively mature males (λ = 1.06 (95% CI = 0.99 to 1.13)) and females (λ = 1.06 (95% CI = 0.95 to 1.17)). For sub-adult male and female white sharks, point estimates of λ were positive but uncertainty prevents strong inference (λ = 1.07 (95% CI = 0.85 to 1.29)) and (λ = 1.08 (95% CI = 0.88 to 1.28)), respectively. Our findings of a potential increase in reproductive-aged white sharks in central California may be a result of regional fluxes in density or attributed in part to current protection efforts and subsequent increase in abundance of pinnipeds as well as reduced gill-net fisheries mortality of juveniles. A trend estimate for the entire northeastern Pacific will require obtaining similar data across known aggregation areas along the west coast of North America.en_US
dc.rights© This published version is made available under the CC-BY 4.0 license.en_US
dc.titleEstimates of regional annual abundance and population growth rates of white sharks off central Californiaen_US
mus.citation.journaltitleBiological Conservationen_US
mus.relation.collegeCollege of Letters & Scienceen_US
mus.relation.universityMontana State University - Bozemanen_US

Files in this item


This item appears in the following Collection(s)

Show simple item record

© This published version is made available under the CC-BY 4.0 license.
Except where otherwise noted, this item's license is described as © This published version is made available under the CC-BY 4.0 license.

MSU uses DSpace software, copyright © 2002-2017  Duraspace. For library collections that are not accessible, we are committed to providing reasonable accommodations and timely access to users with disabilities. For assistance, please submit an accessibility request for library material.