The distribution, movements and abundance of highly mobile marine species such as bottlenose dolphins Tursiops truncatus are best studied at large spatial scales, but previous research effort has generally been focused on relatively small areas, occupied by populations with high site fidelity. We aimed to characterize the distribution, movements and abundance of bottlenose dolphins around the coasts of Scotland, exploring how data from multiple sources could be integrated to build a broader‐scale picture of their ecology. We reviewed existing historical data, integrated data from ongoing studies and developed new collaborative studies to describe distribution patterns. We adopted a Bayesian multi‐site mark‐recapture model to estimate abundance of bottlenose dolphins throughout Scottish coastal waters and quantified movements of individuals between study areas. The majority of sightings of bottlenose dolphins around the Scottish coastline are concentrated on the east and west coasts, but records are rare before the 1990s. Dedicated photo‐identification studies in 2006 and 2007 were used to estimate the size of two resident populations: one on the east coast from the Moray Firth to Fife, population estimate 195 [95% highest posterior density intervals (HPDI): 162–253] and the second in the Hebrides, population estimate 45 (95% HPDI: 33–66). Interaction parameters demonstrated that the dolphins off the east coast of Scotland are highly mobile, whereas those off the west coast form two discrete communities. We provide the first comprehensive assessment of the abundance of bottlenose dolphins in the inshore waters of Scotland. The combination of dedicated photo‐identification studies and opportunistic sightings suggest that a relatively small number of bottlenose dolphins (200–300 individuals) occur regularly in Scottish coastal waters. On both east and west coasts, re‐sightings of identifiable individuals indicate that the animals have been using these coastal areas since studies began.

This study presents the first comprehensive genetic analyses of common bottlenose dolphin (Tursiops truncatus) based on mitochondrial DNA and microsatellite loci in the Wider Caribbean. Live captures of bottlenose dolphins have been occurring since the turn of the 20th century in Wider Caribbean waters where little is known about their population structure and genetic diversity. In this study, blood or tissue samples were obtained from stranded or captive dolphins from nine geographic regions. One hundred fifty-eight sequences of the mitochondrial DNA control region and nine microsatellite loci were analyzed and compared with previously published sequences. This study revealed the presence of 'inshore' ecotype and 'worldwide distributed form' haplotypes of bottlenose dolphins in Wider Caribbean waters. At the mitochondrial level, genetic differentiation between these two groups was significant (FST = 0.805, P < 0.001). Analyses of mitochondrial DNA sequences at a wider geographic level revealed three genetically differentiated (FST = 0.254, FST = 0.590, P < 0.001) population units: Puerto Rico, Cuba/Colombia/Bahamas/Mexico, and Honduras. There was evidence of low female-mediated gene flow among these population units (Nmf = 1.46). Microsatellite analyses identified four somewhat different population units: Honduras/Colombia/Puerto Rico, Bahamas, Cuba and Mexico. The presence of 'worldwide distributed form' and 'inshore' ecotype haplotypes in particular population units, may be causing differences in the population structure pattern showed by each molecular marker. Decreased observed heterozygosity and three loci out of the Hardy-Weinberg equilibrium were found in the Honduras/Colombia/Puerto Rico population unit suggesting a Wahlund effect. The genetic differentiation and divergence between the two forms identified in this study must be taken into consideration for captive programs that aim to reproduce bottlenose dolphins from this region. Although genetic diversity at the mitochondrial and microsatellite level in these dolphins seems to be relatively high, additional demographic and abundance data must be obtained before more captures are allowed. Animal Conservation. Print ISSN 1367-9430 Animal Conservation 15 (2012) 95-112 Phylogeography of bottlenose dolphins in the Caribbean S. Caballero et al. 96 Animal Conservation 15 (2012) 95-112 Animal Conservation 15 (2012) 95-112

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The population genetic structure of 251 bonnethead sharks, Sphyrna tiburo, from estuarine and nearshore ocean waters of the Western North Atlantic Ocean (WNA), was assessed using sequences of the mitochondrial DNA-control region. Highly significant genetic differences were observed among bonnetheads from 3 WNA regions; Atlantic coast of Florida, Gulf coast of Florida, and southwestern Gulf of Mexico (analysis of molecular variance, ΦCT = 0.137; P=0.001). Within the Gulf coast of Florida region, small but significant genetic differences were observed between bonnetheads from neighboring estuaries. These overall patterns were consistent with known latitudinal and inshore-offshore movements that occur seasonally for this species within US waters, and with the residency patterns and high site fidelity to feeding/nursery grounds reported in estuaries along the Atlantic coast of Florida and South Carolina. Historical demography also supported the occurrence of past population expansions occurring during Pleistocene glacial-interglacial cycles that caused drastic reductions in bonnethead population size, as a consequence of the eustatic processes that affected the Florida peninsula. This is the first population genetics study for bonnetheads to report genetic divergence among core abundance areas in US and Mexican waters of the WNA. These results, coupled with recent advances in knowledge regarding regional differences in life-history parameters of this species, are critical for defining management units to guide future management strategies for bonnetheads within US waters and across international boundaries into Mexico.