Data from: Habitat-driven population structure of bottlenose dolphins, Tursiops truncatus, in the North-East Atlantic

Despite no obvious barrier to gene flow, historical environmental
processes and ecological specializations can lead to genetic
differentiation in highly mobile animals. Ecotypes emerged in several
large mammal species as a result of niche specializations and/or social
organization. In the North-West Atlantic, two distinct bottlenose dolphin
(Tursiops truncatus) ecotypes (i.e. ‘coastal’ and ‘pelagic’) have been
identified. Here, we investigated the genetic population structure of
North-East Atlantic (NEA) bottlenose dolphins on a large scale through the
analysis of 381 biopsy-sampled or stranded animals using 25
microsatellites and a 682-bp portion of the mitochondrial control region.
We shed light on the likely origin of stranded animals using a carcass
drift prediction model. We showed, for the first time, that coastal and
pelagic bottlenose dolphins were highly differentiated in the NEA.
Finer-scale population structure was found within the two groups. We
suggest that distinct founding events followed by parallel adaptation may
have occurred independently from a large Atlantic pelagic population in
the two sides of the basin. Divergence could be maintained by philopatry
possibly as a result of foraging specializations and social organization.
As coastal environments are under increasing anthropogenic pressures,
small and isolated populations might be at risk and require appropriate
conservation policies to preserve their habitats. While genetics can be a
powerful first step to delineate ecotypes in protected and difficult to
access taxa, ecotype distinction should be further documented through diet
studies and the examination of cranial skull features associated with
feeding.