Data from: Genetic diversity of white sharks, Carcharodon carcharias, in the northwest Atlantic and southern Africa

The white shark, Carcharodon carcharias, is both one of the largest apex
predators in the world and among the most heavily protected marine fish.
Population genetic diversity is in part shaped by recent demographic
history and can thus provide information complementary to more traditional
population assessments, which are difficult to obtain for white sharks and
have at times been controversial. Here, we use the mitochondrial control
region and 14 nuclear-encoded microsatellite loci to assess white shark
genetic diversity in 2 regions: the Northwest Atlantic (NWA, N = 35) and
southern Africa (SA, N = 131). We find that these 2 regions harbor
genetically distinct white shark populations (Φ ST = 0.10, P <
0.00001; microsatellite F ST = 0.1057, P < 0.021). M-ratios were
low and indicative of a genetic bottleneck in the NWA (M-ratio = 0.71, P
< 0.004) but not SA (M-ratio = 0.85, P = 0.39). This is consistent
with other evidence showing a steep population decline occurring in the
mid to late 20th century in the NWA, whereas the SA population appears to
have been relatively stable. Estimates of effective population size ranged
from 22.6 to 66.3 (NWA) and 188 to 1998.3 (SA) and evidence of inbreeding
was found (primarily in NWA). Overall, our findings indicate that white
population dynamics within NWA and SA are determined more by intrinsic
reproduction than immigration and there is genetic evidence of a
population decline in the NWA, further justifying the strong domestic
protective measures that have been taken for this species in this region.
Our study also highlights how assessment of genetic diversity can
complement other sources of information to better understand the status of
threatened marine fish populations.