LNTM 27-24 Invasive Species warning: Worm Wart Weed

We have been informed that the invasive species Worm Wart Weed (Gracilaria vermiculophylla) has been found in significant quantities at the head of the Kingsbridge Estuary.  This species comes from the Pacific, and has the potential to spread to the Dart, and form large mats which could smother our local species of plants, seaweeds and animals, and has the potential to fouls nets and propellers.  This weed can be spread by leisure craft – typically by fouling of larger vessels, or by fragments stuck to smaller paddle craft and similar vessels, trailers, boots, leisure equipment, etc.

The weed is described as being more brown than truly red to look at and ‘scraggerly’ along the surface of the mudflats, which is unusual in itself as most seaweeds can’t attach here.  Please see the below photo.

You are reminded to take particular care when bringing your boat to the Dart from Kingsbridge and other estuaries – either coming by sea, or launching a boat, canoe, paddleboard etc, or using equipment such as a boat trailer, anchor or even a crabbing net on the Dart that has been used in other waters, particularly Kingsbridge, within a two week period.  The advice remains:

Maintain your antifouling to avoid a boat that is kept afloat being fouled, and clean areas such as the prop, water inlets etc regularly

Check your equipment, boat, and clothing after leaving the water for mud, aquatic animals or plant material. Remove anything you find and leave it at the site.

Clean everything thoroughly as soon as you can, paying attention to areas that are damp or hard to access. Use hot water if possible.

Dry everything for as long as you can before using elsewhere as some invasive plants, seaweeds and animals can survive for over two weeks in damp conditions.

Whilst this message is specifically targeted at Worm Wart Weed, this is good advice whenever moving between any different water bodies, particularly of a similar type e.g. estuary.  Further advice and our Dart Harbour Biosecurity plan can be found on our website here: https://www.dartharbour.org/the-dart-estuary/environment/dart-harbour-marine-biosecurity-plan/