We are pleased to announce a new publication in Frontiers in Marine Science: Using Genome-Wide SNPs to Detect Structure in High-Diversity and Low-Divergence Populations of Severely Impacted Eastern Tropical Pacific Spinner (Stenella longirostris) and Pantropical Spotted Dolphins (S. attenuata).
Abstract: Millions of spinner (Stenella longirostris) and pantropical spotted dolphins (Stenella attenuata)
died since the 1960's as bycatch in tuna nets in the eastern tropical
Pacific Ocean. Despite three decades of protection, they show
little-to-no sign of recovery (although recent fisheries-independent
abundance estimates are not available). In efforts to establish
biologically meaningful management boundaries for recovery, endemic
subspecies and multiple stocks have been proposed. However, genetic
differentiation among most of these units has been difficult to
identify, possibly due to low statistical power stemming from large
historical abundances, ongoing gene flow, and recent divergence. We
tested for genetic structure at multiple hierarchical levels by
analyzing the largest dataset to date brought to bear on these
questions. Single nucleotide polymorphisms (SNPs) were collected from
nuclear DNA regions associated with the restriction enzyme site PstI
from 72 spinner dolphins and 58 pantropical spotted dolphins using
genotype-by-sequencing (GBS). Our results support the current subspecies
for both species and indicate stock-level separation for Tres Marias
spinner dolphins and the two offshore pantropical spotted dolphin stocks
in this area. Although bycatch has been reduced to a small fraction of
pre-protection levels, incidental mortality continues to impact these
populations. Our results are important for the ongoing management and
recovery of these highly-impacted pelagic dolphins in the eastern
tropical Pacific Ocean.
The article is online available as open access at: