Pat Monaghan of Glasgow University said that all the evidence showed that sea birds were vastly better than fishermen at finding fish. Their movements, success in breeding and physical condition could provide valuable information about the state of the stocks.
"They could be a useful component of fisheries' management," she said. "For instance, we know hardly anything about sand eels [a small, very abundant fish near the base of the North Sea food webs]. The birds know infinitely more about them than us."
Professor Monaghan said that when the sand eels stocks collapsed around Shetland in the late 1980s and early 1990s, sea bird colonies which were being studied were severely affected.
When fish stocks are low, observation has shown that the birds have far less free time because they have to spend much longer periods fishing. In times of plenty, the parent on fishing duty - rather than being permanently with the egg and chick - can be seen hanging around the nest, resting for long periods.
Some birds will only give very local information; arctic terns, for instance, do not fish much more than two miles from their nests. But others, like the kittiwake, travel as far as 25 miles. "They're not flying around for fun," said the professor. "Flying and fishing costs them energy." The greater the food available, the less far they would fly.
She suggested that radio tracking devices, which showed how far and where sea birds travelled and also their body weight at the start of the breeding season, would give most information about the distribution and size of fish stocks.
"We could go into partnership with the sea birds to our mutual benefit," she said. "The birds could tell us more about the state of fish populations which would hopefully lead to better management of them. And that in turn would prevent the over fishing and stock collapses which kill birds and put fishermen out of work."Reuse content