Calls to prevent the spread of alien species
Researchers into the spread of invasive species in the Mediterranean are calling for tighter controls on biofouling. The study, published in the Journal of Applied Ecology, is recommending that all incoming yachts from a different country are screened at the marina of entry for alien species and professionally cleaned if necessary. Routine monitoring for invasive species should also be carried out by boat and marina owners, and pontoons should be regularly cleaned, it said.
This is the first study in the Mediterranean to combine boat and marina sampling data with crew surveys to better understand the role boats play in spreading alien species.
The researchers from the University of Pavia in Italy surveyed 601 boats owners and sampled their vessel’s hulls for invasive species in 25 marinas across the Mediterranean.
Lead author of the study, Aylin Ulman, said biofouling was not regulated in the Mediterranean and this needed to change. ‘Boats which have visited Eastern Mediterranean marinas had an especially high risk of spreading alien species due to the proximity to the Suez Canal, where most alien species enter the Mediterranean,’ she said.
‘Biofouling is a major vector for the spread of marine alien species in the Mediterranean and needs regulation. To inhibit further spreading, marine pontoons should be cleaned regularly, and incoming vessels to marinas should be screened.’
Researchers found that even boats that had been professionally cleaned were still harbouring alien species, as biofouling had been missed on areas such as ladders and propellers. Snorkeling or using a camera on a pole were suggested for screening.
While some Mediterranean sailors support the idea of limiting the spread of invasive species, others consider it an ‘impossible’ task, especially as species can be carried by floating debris or by sealife like turtles.
A long-term cruiser in Greece, Vyv Cox said he believed few sailors would support an increased cost for screening, lift and relaunch and professional cleaning, which costs from €300 at his local marina. He added that many marinas do not have lifting out facilities, and that some cruisers avoid marinas.
‘I personally know many cruisers who never visit marinas. Some of them travel widely, from North Africa to the countries bordering the north of the Mediterranean and back again, always living on anchor,’ he said.
Global management of biofouling is currently under consideration by the International Maritime Organisation.