Pest check reveals many dirty hulls

21:06, May 14 2014
WORRYING SIGHT: Marlborough boat owners are being asked to ensure their hulls are clean to prevent the spread of marine pests. This boat, moored in Waikawa Bay, was found to be very heavily ‘‘fouled’’, during checks for Mediterranean fanworm.

Marlborough boaties are being urged to keep their boats clean in order to prevent the spread of marine pests, despite the region receiving the all-clear for Mediterranean fanworm.

The Marlborough District Council has just completed an operation checking for the pest, also known as Sabella, in conjunction with the Ministry for Primary Industries.

Council response manager Jono Underwood said a thorough search was completed, checking all moorings and vessels, as well as the sea floor around the moorings in a large area in which a number of fanworms were found on the bottom of a heavily fouled yacht moored in Waikawa Bay in February.

Boats moored in high-risk areas of the Waikawa Marina were also checked.

"We were very pleased to find no further sign on fanworm, although we did find and remove six individual Styela clava sea squirts which are a marine pest," Underwood said.

Following the first Marlborough detection of Styela in Picton Marina last year, the council, Ministry for Primary Industries, Port Marlborough and the Marine Farming Association had developed a long-term management plan to deal with the pest.


"The results are looking promising for the suppression of Styela population in the marina. However, continued work is needed to manage the pest and minimise the chance of spread from Picton and now Waikawa to other parts of the Marlborough Sounds."

Ministry senior adviser Kathy Walls said the main way pests such as the fanworm and Styela are spread to new locations was as fouling growth on the bottom of boats.

Fouling is the growth of marine life on immersed surfaces, such as boat hulls.

"In this most recent check for the fanworm in Waikawa, we were dismayed to observe how heavily fouled a large number of the vessels were.

"Some of the vessels observed had fouling that was very obvious even from above the waterline. Boats in this condition are able to transport the fouling species to new locations," Walls said.

Of concern were areas of high environmental or commercial value, and both the ministry and council encouraged owners of moored boats to regularly clean their hulls and keep their antifouling paint in effective condition, she said.

The Marlborough Express