How Nelson Marina keeps marine pests at bay
Each boat movement both in and out of a marina presents a marine biosecurity risk. But with positive support from boat owners, and an end-to-end marine biosecurity program, that risk is now significantly reduced at Nelson Marina in New Zealand’s South Island.
Nelson Marina and its boaties have a lot to protect from invasive marine pests. The city is a maritime hub adjacent to New Zealand’s largest fishing port. The local marine aquaculture industry produces more than 70,000 tonnes of salmon and mussels a year. And it’s close to the Queen Charlotte and Abel Tasman which are natural treasures, also contributing more than $50,000 million a year to the local economy.
More than 3,500 recreational boats arrive in the region each year, and a large proportion of those arrive at Nelson Marina. It is also home to 600 boats.
Therefore the marina’s marine biosecurity program is proactive, thorough and world-class, designed to both protect the marina from new incoming marine pest infestations, and also to ensure its customers don’t accidentally transport marine pests when they leave.
Nelson Marina is unfortunately home to some marine pests: It is known to have established populations of Clubbed Tunicate (Styela clava), Wakame (Undaria pinnatifida) and Clavelina lepadiformis. It is a close watch out for any signs off Mediterranean fanworm (Sabella spallanzanii) and it’s concerned about the possible arrival of Australian Droplet Tunicate (Eudistoma elongatum) and Pyura, which are species established in the North Island.
The marina itself has 600 berths, totalling a whopping 9,900 lineal metres of hulls and floating structures, plus 180 piles - all of which are appealing habitat to marine pests.
The program includes regular surveillance of these structures and hulls. The marina commissions dive teams, and has also invested in an underwater drone which with floodlights, a 4k resolution, and a claw for taking samples, is able to supplement the dive work for surveillance.
While international arrivals are managed by the Ministry for Primary Industries and undergo a vigorous process to ensure they do not present risk, the marina team has a robust procedure for arrivals from locations within New Zealand.
The team uses the global ship tracking service Marine Traffic to see where the boat has been, and to determine its risk profile. Each arrival (including returning customers who have been away cruising), also completes a Risk Screening Application online. This tool was developed by local biosecurity specialist company Salt Ecology and uses a risk matrix to determine if the boat needs an underwater inspection or a haulout, where the boat is checked and cleaned, with all bio-fouling disposed of safely.
For boats that are unsuitable to be hauled out using Nelson Marina’s 44 tonne travelift, a Fabdock owned by the Top of the South Marine Biosecurity Partnership enables the boat to be wrapped and treated within its berth.
Once this is complete the boat is provided with a letter of certification, confirming that it has been checked and cleaned and is safe to travel to another destination. The letter also includes details of its most recent antifouling application.
Despite an extensive education program to help ensure boat owners and operators are aware of the consequences of carrying marine pests, one problem for the marina is a small proportion of heavily fouled boats. These are often unused, and like for other marinas in New Zealand, are a challenge to address.
With just 14 spaces available on its hard stand at any one time, Nelson Marina has introduced heavily discounted half-hour haulout sessions as one way of removing barriers to cleaning. This ensures that boat owners can receive a more affordable ‘lift and wash’, and uptake has been excellent. A bigger travelift and more hardstand space is in the pipeline.
‘It’s a constant battle but it’s extremely important,” says marina manager Nigel Skeggs. “We value the partnerships we have. We can’t do it alone.”