For anyone who lived beside the Irish coastline in the 1950s and 1960s there were more than occasional sightings of the enormous basking shark.
Knowing its preference for plankton rather than human flesh, spectators reacted with awe rather than Jaws-like terror when its dorsal fin was seen lurking on or near the surface of inshore waters, swimming slowly by with its large mouth wide open.
It may be related to the great white shark, but its teeth are so small it could not muster a nibble. Its length (running to 30 ft) and weight (up to 7 tonnes) make, however, for a very powerful species. If frightened or disturbed, especially if in pairs and courting, they can dive abruptly with the possibility of destabilising a nearby small leisure or fishing boat. They are also known to lash out with their tails if surprised.
The reduced number of sightings (until recently) may be cause for worry about this majestic species. But they are migratory and can disappear for long periods. They are believed to move to warmer or deeper waters during the winter.
But the lack of global management and recording of their activities are a definite cause for worry. Factor in continuing high demand for basking sharks in Asia, notably for shark fin soup, and the species may be imperilled, coming as it does after decades of over-fishing. They have slow growth and late maturity and produce small numbers of young after a long pregnancy.
Prompted by a number of conservation and animal welfare groups including the International Fund for Animal Welfare (IFAW), Britain has proposed the listing of the basking shark within an appendix of the Convention on International Trade in Endangered Species known as CITES.
Some 150 countries have joined CITES and agreed to ban commercial trade in an agreed list of endangered species but, more significantly for the basking shark, it also regulates and monitors trade in other species that might become endangered (listed in Appendix II). This would be the first listing of a marine fish and as such clearly sets a precedent.
The species is particularly sensitive to overexploitation. "They clearly have great difficulty in recovering from any serious decline as witnessed off the coast of Ireland," said the IFAW EU director, Ms Lesley O'Donnell.
Moreover, it would be a landmark decision for the survival of our much-depleted ocean life, she said. The UK has already put in place protection within its waters under the terms of its wildlife legislation, but Ireland is in a curious position. It is a signatory to CITES but has not yet ratified the convention. as a result, the EU has a block vote of only 14."
Fortunately, it looks as if the Republic will do so shortly, said Mr Simon Pope of IFAW UK, and then another piece in the protection jigsaw will fall into place. "There is protection in British waters but they're migratory. When they leave UK waters that protection ends."
Though high basking-shark fin prices encourage fishing activity, most "targeted basking-shark fisheries" have ceased as a result of stock collapse or legal protection.
But finning is believed to be happening: large fins are removed and bodies dumped at sea when the sharks are caught accidentally, Mr Pope warned.
This, he added, was facilitated by the lack of management, a shortcoming ruthlessly exposed by the whaling practices of some countries. "If there is no proper management, there are no proper records. We are not saying: stop the trade completely. All we are saying is: let's have a proper policy with some science attached. At present, unregulated trade is causing conservationists grave concern."
Ironically, Irish records of numbers of basking sharks landed in Achill Island Fishery between 1948 and 1976 tell a graphic story. In the 1950s the numbers often exceeded 1,500 a year. By 1962 it was less than 100 and never exceeded that figure again.
Yet there are indications that basking sharks are returning in large numbers to UK and Irish waters of late; possibly due to global warming. Knowing something of their past, Mr Pope said, this should not be interpreted as an increase in their number.
Basking Shark Watch can be contacted at: www.mcsuk.mcmail.com