Publications

a first estimate of white shark, carcharodon carcharias, abundance off central california.	the decline of sharks in the global oceans underscores the need for careful assessment and monitoring of remaining populations. the northeastern pacific is the home range for a genetically distinct clade of white sharks (carcharodon carcharias). little is known about the conservation status of this demographically isolated population, concentrated seasonally at two discrete aggregation sites: central california (cca) and guadalupe island, mexico. we used photo-identification of dorsal fins in a ...	2011	21389017
ontogenetic and among-individual variation in foraging strategies of northeast pacific white sharks based on stable isotope analysis.	there is growing evidence for individuality in dietary preferences and foraging behaviors within populations of various species. this is especially important for apex predators, since they can potentially have wide dietary niches and a large impact on trophic dynamics within ecosystems. we evaluate the diet of an apex predator, the white shark (carcharodon carcharias), by measuring the stable carbon and nitrogen isotope composition of vertebral growth bands to create lifetime records for 15 indi ...	2012	23028766
evidence of maternal offloading of organic contaminants in white sharks (carcharodon carcharias).	organic contaminants were measured in young of the year (yoy) white sharks (carcharodon carcharias) incidentally caught in southern california between 2005 and 2012 (n = 20) and were found to be unexpectedly high considering the young age and dietary preferences of young white sharks, suggesting these levels may be due to exposure in utero. to assess the potential contributions of dietary exposure to the observed levels, a five-parameter bioaccumulation model was used to estimate the total loads ...	2013	23646154
a re-evaluation of the size of the white shark (carcharodon carcharias) population off california, usa.	white sharks are highly migratory and segregate by sex, age and size. unlike marine mammals, they neither surface to breathe nor frequent haul-out sites, hindering generation of abundance data required to estimate population size. a recent tag-recapture study used photographic identifications of white sharks at two aggregation sites to estimate abundance in "central california" at 219 mature and sub-adult individuals. they concluded this represented approximately one-half of the total abundance ...	2014	24932483
mitochondrial genetic structure and matrilineal origin of white sharks, carcharodon carcharias, in the northeastern pacific: implications for their conservation.	white sharks (carcharodon carcharias, ws henceforth) are globally and regionally threatened. understanding their patterns of abundance and connectivity, as they relate to habitat use, is central for delineating conservation units and identifying priority areas for conservation. we analyzed mitochondrial data to test the congruence between patterns of genetic connectivity and of individual movements in the northeastern pacific (nep) and to trace the matrilineal origin of immature ws from coastal ...	2015	26034138
a novel application of multi-event modeling to estimate class segregation in a highly migratory oceanic vertebrate.	spatial segregation of animals by class (i.e., maturity or sex) within a population due to differential rates of temporary emigration (te) from study sites can be an important life history feature to consider in population assessment and management. however, such rates are poorly known; new quantitative approaches to address these knowledge gaps are needed. we present a novel application of multi-event models that takes advantage of two sources of detections to differentiate temporary emigration ...	2016	27912002