Aquatic pests: marine and freshwater

Marine pests can be introduced and spread by hitching a ride in and on vessel systems and equipment such as ballast water systems, hulls, anchor chains, buoys, nets and fishing gear. 

Pests can also be introduced via the aquarium trade.

The Aquatic Biosecurity Unit monitors waterways and works to prevent pests being introduced.

Major pest threats

The following marine species are major threats to Northern Territory (NT) waters:

• Asian bag mussel
• Asian green mussel
• black-striped mussel.

These species are found overseas in countries frequently visited by boats that travel to the NT.

For more information go to the Australian Government's Keeping Marine Pests out of Australian Waters website. 

Impact of marine pests

Marine pests can have all of the following effects: 

• compete with native species for food and space
• dominate waterways by reproducing in large numbers - including hybridisation with native species and surviving in adverse and disturbed habitats
• alter and disturb natural habitats
• introduce diseases and parasites to native species
• foul the hulls and seawater systems of boats, which can reduce speed and increase fuel use
• clog cooling water intakes resulting in overheating and damage to boat motors
• cause considerable damage to structures and vessels.

How you can help prevent marine pests

If you find a marine pest in the NT you must report it. Read how to report aquatic pests.

Boat owners should also do all of the following:

• dislodge all plants and animals from your boat and gear 
• drain your trailer, boat and gear on land 
• dispose of unwanted bait on land 
• douse your trailer, boat and gear with fresh water 
• dry your trailer, boat and gear 
• maintain the anti-fouling on moored vessels.