The world’s biggest single colony of Balearic shearwaters live in a remote cave on the island of Mallorca.

Decline could be avoided with a simple technique

Europe’s most endangered seabird, the Balearic shearwater, is ‘on the road to extinction’, according to a new study.

Experts estimate the global population of Balearic shearwaters is fewer than 30,000 and could be extinct within 60 years.

But now, research published in the Journal of Applied Ecology shows that their decline could be avoided with a simple technique - setting fishing lines at night when the bird does not hunt.

The research team used modern techniques to model the sustainability of the current population of Balearic shearwaters.

Estimates of survival from the world’s biggest single colony, a remote cave on Mallorca, show that it is well below what is needed to maintain population growth or stability.

According to co-author Professor Tim Guilford, setting fishing gear at night when the bird does not dive ‘could make a massive difference’.

“Fishermen do not want to catch seabirds on their lines or in their nets, but shearwaters can be persistent scavengers,” he said.

“Indeed, the researchers estimate that the recent ban on discard waste in the Mediterranean will actually increase the risk to the Balearic shearwater population by reproducing reproductive success at least in the short term.

“However this effect turns out to be much less important than the effect of by catch on adult survival. Indeed the models suggest that extinction is inevitable unless by catch is eliminated or greatly reduced.

“By tracking shearwaters with miniature on-board dive loggers, the team has shown that there is a technically simple solution - the setting of demersal long-lines at night. Now it is up to the politicians to decide.”

Image (C) Wikimedia Commons/Marcabrera