Ten years after the Thames whale, how are Britain鈥檚 sea mammals faring?
This article by , Honorary Senior Lecturer, was originally published on . Read the .
The British Isles are blessed with a wide variety of sea mammals, with records showing 29 species of whales, porpoises and dolphins and seven species of seals in its waters. But only some of these are regular inhabitants, and when the more unusual species make an appearance it can cause considerable public interest 鈥� as happened ten years ago when a northern bottlenose whale, normally found in the deep Atlantic, instead in front of the Houses of Parliament and tens of thousands of fascinated onlookers.
While few in the city can have been unaware of what was unfolding in the river, attempts to rescue the whale failed, and . The whale, far from its normal habitat, had probably entered the North Sea in pursuit of squid, its principal prey, before becoming lost and, hungry and disoriented, ended up in the Thames Estuary. A from the Zoological Society of London found the cause of death to be a combination of dehydration, physiological stress, cardiovascular collapse and multiple organ failure induced by the stress of repeated strandings and the attempted rescue.
In truth, the tale of the Thames whale says more about human behaviour than whales themselves. But a decade on, it鈥檚 interesting to reflect on what we know about the changing fortunes of the remarkable creatures that live in Britain鈥檚 waters.
Cetaceans 鈥� whales, dolphins and porpoise
Minke whale lunging through a large shoal of sprat in the Inner Hebrides.: Photo: Peter EvansOf the 29 cetacean species recorded around Britain, 15 are regular inhabitants. But we know very little about all but the most common species. Some species such as fin and , among the principal targets of the early 20th century whaling industry, show signs of recovery, with a marked increase in sightings.
, which are still taken in Norwegian waters but in smaller numbers, also show signs of population growth since the