The Net Effect? - Whale and Dolphin Conservation Society

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The Net Effect?
A WDCS report for Greenpeace
the British Isles during April (Evans 1992),
which coincides with the start of the peak
mating season (Desportes et al. 1993).
Long-finned pilot whales occur in temperate
and sub-Arctic regions, mainly in deep-water
habitat. Surveys in the northern and northeastern
North Atlantic in 1987 and 1989
indicate that their core range is deep water
south-west of the Faeroes and south and
west of Iceland. The species also occurs in
the Bay of Biscay south to the Iberian
Peninsula (Reid et al. 2003). Long-finned
pilot whales are recorded in high numbers
to the north of Scotland and south-east of
the Faeroes as well as along the continental
shelf edge from southern Ireland south to the
Bay of Biscay, with most records from waters
deeper than 200 m.
Although little seasonality has been observed
in their distribution, a peak of long-finned
pilot whale sightings has been reported in the
south-west English Channel and North Sea
between November and January, when pods
were frequently seen near vessels fishing for
mackerel (Evans 1980). The species’ distribution
has also been linked to its preferred prey
of squid. Other species recorded in its diet
include mid-water shoaling fish species such
as blue whiting and greater argentine, and
crustaceans (Reid et al. 2003).
2.7.2 Bycatch of long-finned
pilot whales
The incidental capture of long-finned pilot
whales has been recorded in a number of the
fisheries already described.
Records from the Dutch pelagic trawl fishery
for mackerel and horse mackerel during
1989-94 include the capture of nineteen
long-finned pilot whales off south-west
Ireland and a further five in other areas
(North Sea and Channel). Bycatches of longfinned
pilot whales constituted 12% of all
the recorded bycatch events in these fisheries,
the majority involving white-sided dolphins
(Couperus 1997a; see also 2.5.2).
The study of the Irish pair trawl fishery for
albacore tuna in 1999 recorded 8 pilot
whales caught (out of 145 cetaceans, mainly
common dolphins) during 313 hauls (BIM
2000; see also 2.3.2).
Two bycaught long-finned pilot whales were
handed in during the Spanish carcass
recovery scheme operated in 1998-99, out
of 17 retrieved animals (López et al. 2003).
Based on interview data from fishermen,
about 100 long-finned pilot whales were estimated
to be caught per year in Galician fisheries,
some 80% of these in gillnets. A few
were also reported as being bycaught in
Spanish trawl fisheries operating in Grand
Sole off south-west Ireland (see 2.3.2).