Page 140 - Alderney Regional Environmental Assessment of Renewable Energy: Environmental Report

Alderney Regional Environmental Assessment of Renewable Energy:
Environmental Report
Based on the current understanding of near-shore bottlenose dolphin population and
community structure the ASCOBANS / HELCOM small cetacean population structure workshop
advised that the following populations are each proposed as separate management units
(although it is quite possible that some areas have overlapping communities with different
movement patterns) (Evans and Teilmann, 2009):
ƒ NS-North Sea (Eastern Scotland from Caithness to the borders with England);
ƒ OH-Outer Hebrides (Island of Barra);
ƒ IH-Inner Hebrides;
ƒ IS-Irish Sea;
ƒ SHE-Shannon Estuary;
ƒ WEI-Western Ireland;
ƒ SE-Southern England;
ƒ NF- North France (Channel Islands and Normandy coast);
ƒ BR-Brittany coast and islands (West France);
ƒ SGA-Southern Galicia; and
ƒ SAE-Sado Estuary (Portugal).
Distribution and Abundance in the English Channel
Inshore populations of bottlenose dolphins are found along the French coast in the English
Channel (Reid et al. 2003; Kiszka et al. 2004). The largest population is found in the Gulf of St.
Malo and Cotentin coast. Small numbers are also recorded further East along the Normandy
coast (Kiszka et al. 2004).
Further west, about 35 individuals inhabit the area around the island of Ouessant and the
Archipelago of Molène, with a further 25 individuals around the island of Sein and Cape of
Sizun (Liret et al., 2006; Evans and Teilmann, 2009). These two groups appear to be relatively
isolated with the resident population of bottlenose dolphins around Ile de Sein staying within an
area not larger than 5 km2 and the population around the nearby Molene archipelago using a
range of about 70 km2 (Liret et al. 1996; Liret et al. 2001). Scattered sightings occur south to the
Bay of Biscay, with regular groups along the coasts of Cantabria and Asturias, but no population
estimates are available (Evans and Teilmann, 2009).
A small population of bottlenose dolphin has also been documented to be wide-ranging but
resident to the coast of South West England since the early 1990 (Clark et al. 2010; Marine
Connection & The Wildlife Trusts, 2007).
Comparisons of images of recognisable individuals have shown no evidence for interchange
between bottlenose dolphins between the southern coasts (Normandy and the Channel Islands)
and the northern coasts of the English Channel (South coast of England) (Liret et al., 1998; Evans
and Teilmann, 2009).
Distribution and Abundance Around the Channel Islands and Cotentin Coast
The bottlenose dolphin population found along the Cotentin coast and Channel Islands is
thought to number approximately 387 (95% CI 304-480). The population is considered to be
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