DATELINE: 14th February 2001

WARMER UK DIVING?
In late December, weathermen were claiming it could be the warmest December for 20 years. It's all part of the global warming debate, but could most British divers be diving all year round 50 years from now?
Weather and oceanic flow systems are inter-dependent, so could our warmer winter air temperatures also mean changing water temperatures and a warming of the cold-water Atlantic currents that make British diving in February and March such a brass-monkeys experience?
Judging by the movements of some marine creatures, the answer is yes.
Douglas Herdson, who is Information Officer at the National Marine Aquarium in Plymouth, told Divernet."We've had various creatures normally found further south turning up in summer months."
These include saddled bream, jacks, sunfish, tritons [a large whelk] and slipper lobsters, a small lobster without claws."
"We always expect a certain number of unusual creature movements, which do not have immense meaning in the overall scheme of things, but it is interesting that some these animals are now turning up in the winter, too."
Sunfish, for instance, have been periodically located in British waters for years, between July and September. It was "significant", said Herdson, that in 1999 two were recorded in January and one in March.
The number of summer sightings also seems to be increasing.
"We've had five tropical jacks [Britain's native species is the horse mackerel] reported in the past year, where one would expect a sighting maybe every three years," said Herdson. "And recordings of slipper lobsters, a Mediterranean species, have numbered three in the past two years, where previously it was very rare in Britain, with nine sightings in 200 years."
Herdson did however warn of the danger of jumping to conclusions on the basis of such minimal evidence; increased sightings could be explained by nothing more complicated than the existence of higher numbers of divers and fishermen doing the spotting and catching.

---