The waters around the British Isles could soon be home to several new
species of mammals as a rising number of foreign visitors are being
reported around our coasts. Experts believe the rare sightings of
cetaceans from tropical climes could mean sea creatures are scouting for
new territories to settle as global warming takes effect on sea
temperatures.
Animals from the tropics, including the dwarf sperm
whale, the pygmy sperm whale, and the Fraser's dolphin have all made
recent appearances here, and the Cuvier's beaked whale, another
warm-water species, has been recorded increasingly regularly in the west
of Britain. The melon-headed whale, a squid-loving relative of the
killer whale, has been seen in the Channel, off the coast of Brittany.
Before too long we may see giants such as the 16-metre gray whale
nudging into deep water around Cornwall and into the Irish Sea.
"We
are now seeing a number of species far from home, and they probably
will continue to recur with increasing frequency," said Peter Evans,
director of the Sea Watch Foundation. "Several are normally found off
west Africa. For the moment they tend to be seen at times of year when
our sea temperatures are at their warmest. Whales
and dolphins can cope with a wide range of temperatures but their fish
and squid prey tend to be more constrained, and their ranges are
extending significantly northwards."
He said cetaceans would
follow their favourite food, and many species rare in colder waters just
a decade ago had moved into British seas. This autumn a dwarf sperm
whale was spotted in Mounts Bay, Cornwall, while a pygmy sperm whale,
its close relative, was found beached on Seil island, near Oban.
"They
were both very big surprises: they are rarely seen even where the
populations are known to exist," said Evans. "If the fish are extending
their range, as we know many are, then the whales and dolphins will
follow. Anchovies, for example, were really quite scarce in the North
Sea 10-20 years ago. Now they are widespread and may be why the common
dolphin is now a regular in the North Sea.
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