Page 95 - Alderney Regional Environmental Assessment of Renewable Energy: Environmental Report

Alderney Regional Environmental Assessment of Renewable Energy:
Environmental Report
In the wider study area, four ray species are commonly caught in Jersey waters: blonde ray
Raja brachyura, small-eyed ray Raja microocellata; thornback Raja clavata and undulate ray
Raja undulata. A tag and recapture study of small-eyed, blonde and undulate rays conducted
in Jersey showed that the majority of recaptured rays (17% of the total tagged) were caught
around Jersey (within 20 km of the original tag and release site), although some were taken
from Guernsey and Sark and two were caught along the French coast. The maximum distance
travelled by a recaptured skate was 61 km (blonde ray moving from St Aubin’s Bay on Jersey’s
south coast to the Bay of St-Brieuc (France). No recaptures were reported from outside the
Normano-Breton Gulf (Ellis et al., 2010). An acoustic tagging study conducted on a small
number of small-eyed and blonde rays captured within 500 m of Portelet Bay on the south
coast of Jersey suggested that the rays occasionally returned to the bay for short periods
during movements over a wider area although the study was not able to determine the range of
the rays’ movements when not present in the Bay (Morel et al., 2012).
Basking sharks Cetorhinus maximus have been recorded around Alderney within the 12 nm
limit (Bloomfield and Solandt, 2008), although the total number of sightings (between 1987 and
2006) is relatively low compared to the southwest of England. In the wider area, Brittany has
been described as a ‘hot-spot’ for surface sightings of basking sharks (OSPAR, 2009) and the
waters around the Channel Islands could form part of their migratory route as they travel from
Plymouth to waters off north-west Brittany (Sims et al., 2005 cited in ARE, 2011). The entrance
to the Casquets Traffic Separation Scheme in the English Channel (see Section 7.3.1) has
been reported to have ‘high basking shark activity’ (OSPAR, 2009). In 2004, an estimated 70
basking sharks were reported off the Hurd Deep (north of Alderney), 3-4 miles north-west of
Les Casquets lighthouse (GREC, 2011 and references therein).
Of the elasmobranch species recorded in the study area, tope, porbeagle, blue shark and
basking shark are UK BAP priority species.
Migratory Diadromous Fish
No information was found relating to the movements of migratory diadromous fish species in
and through Alderney waters. There are sites in the wider study area, on the French coast,
that are designated for such features, including Atlantic salmon, European brook, river and sea
lamprey and twaite and allis shad, and these are detailed in the Nature Conservation Section
(Section 5.6).
Spawning and Nursery Areas
The wider study area has been identified as a high intensity spawning ground for sole Solea
solea and plaice, a low intensity spawning ground for sole, sandeel Ammodytidea spp.,
mackerel, cod and horse mackerel Trachurus trachurus and a low intensity nursery ground for
undulate ray, anglerfish Lophius piscatorius and mackerel (Ellis et al., 2012). Of these species
mackerel, cod, ling, sole, horse mackerel and anglerfish are covered by the UK BAP
commercial marine fish grouped plan and undulate ray is a UK BAP priority species.
R/4001/7 71 R.2129