Britain's booming whale-watching industry is being threatened by global warming, just as interest in the leviathans has reached unprecedented levels after last weekend's attempt to rescue one in the Thames.
Whale-watching has soared to a £10m industry, with some Hebridean villages boasting more people who depend on the cetaceans than fishermen.
Conservationists expect that the surge of public interest sparked by the dramatic bid to save the northern bottlenose whale in London will give the industry an unprecedented boost.
But those who seek to follow up their new fascination may be hard-pressed to find whales to watch. The Hebridean Whale and Dolphin Trust says that "very few" minke whales, the main species in the area, were reported off the west coast during August and September last year. During those two months - normally the peak of the whale-watching season - there were only 20 sightings, the trust says.
Scientists believe that some dolphins may also be imperilled by the warmer seas. They blame a shortage of sand eels, on which whales feed. Over recent years, populations of the lance-like silvery fish have plummeted, as the plankton on which they feed have been driven hundreds of miles to the north by warmer seas.
This has caused a catastrophic drop in numbers of seabirds, which also eat the fish, as first reported in The Independent on Sunday two years ago. This Christmas the shortage even denied Outer Hebrides islanders their traditional feast of "guga" - boiled baby gannet.
The Whale and Dolphin Conservation Society believes that climate change is also pushing the highly endangered North Atlantic right whale - a much rarer visitor to Scotland - to extinction by disrupting food supplies. And the society says that changes in water temperature may drive white-beaked dolphins and northern bottlenose whales, such as the one stranded in the Thames last week, away from British waters.
Tests on the London whale have left the cause of its decision to swim up the Thames shrouded in mystery. They have failed to establish for certain whether it was confused by noises from naval sonar or sesimic operations by the oil industry.
Giants of the sea: Where to see whales in the UK
NORTHERN ISLES: Regularly visited by orcas, minke whales, Atlantic white-sided and white-beaked dolphins, as well as harbour porpoises.
MORAY FIRTH: Home to the North Sea's only resident population of bottlenose dolphins.
ISLE OF MULL: A great place to see minke whales, harbour porpoises, Risso's dolphins, common dolphins and sometimes orcas, basking sharks, seals and otters.
WEST COUNTRY: Bempton Cliffs, Weymouth Bay, Dorset; Falmouth, Penzance, Porthleven, Seal Island, Cornwall; Dartmouth, Torbay, Devon for bottlenose dolphins and harbour porpoises.
ISLES OF SCILLY: Bottlenose and common dolphins, harbour porpoises and basking sharks.
CARDIGAN BAY: Home to more than 130 bottlenose dolphins, as well as harbour porpoises, local seabird colonies and grey seals.
PEMBROKESHIRE COAST: Good bet for common and bottlenose dolphins, minke whales, grey seals, harbour porpoises and orcas.Reuse content