Antifoul and Invasive Species
Whilst antifouling does a great job of keeping our hulls clean, and even has some environmental benefits such as improving fuel efficiency and preventing the spread of invasive non-native species, it is toxic to aquatic life. Since the banning of TBT in 1987, most antifouls are now copper or zinc based. Some of the compounds found in these antifouls can accumulate in marine organisms, and can find their way into marine wildlife further up the food chain.
The majority of copper in antifouling enters the marine environment through leaching. However concentrated amounts do enter the marine environment during the removal of antifouling paint, which occurs mostly by water blasting or mechanical scraping, and can form concentrated deposits in the sediments around marinas and in river beds.
Boat owners can play a vital role in preventing concentrated scrapings from entering the water by choosing a marine facility that uses a washdown system that captures run off and by following our best practice advice.
Invasive Non-Native Species
There are currently over 70 varieties of marine non-native species in UK waters. Whilst some of these species live quite happily alongside our native species, some are invasive and have the ability to disrupt natural ecology. Invasive non-native species may smother structures and ecosystems, block vital water intakes and interfere with fishery and aquacultures operations.
Of particular concern to the UK boater is Didemnum vexillum or Carpet Sea Squirt to give its common name. As the name suggests, this animal can grow in carpet like layers. It can be found on hard structures such as pilings, moorings, ropes, chains, gravel sea beds and even ship hulls. It can even overgrow other organisms such as other sea squirt varieties, sponges, seaweeds and scallops, mussels and oysters. Where these colonies occur on the seabed, they can act as a barrier between fish and their food on the seabed.
Invasive non-native species often arrive in the ballast or bilge water of tankers and ships. But they can also hitch a ride on your boat's hull, propeller, anchor or chain and you could be unknowingly transporting them to another location.