Impacts of marine pests



European fan worm smothering the seabed

Damage to the marine environment
Some pests like European fan worm form a 'carpet' on the seabed, smothering native species for food and space and altering the marine habitat to suit themselves.

   Image courtesy of CSIRO Marine & Atmospheric Research

northern Pacific seastar

Deplete fishing grounds & aquaculture stock
Some pests, like the northern Pacific seastar shown here, prey on native species depleting aquaculture and fishery operations.

   Image courtesy of Aquenal Pty Ltd

Chinese mitten crab covering shore

Reduce the attractiveness of coastal areas
Some pests may infest the shoreline to such an extent that the area becomes unattractive and its value as an amenity is reduced. This image shows a shoreline infested with Chinese mitten crab. This crab burrows into the shore causing erosion. It can also damage fishing gear and affect aquaculture operations.  It also hosts liver fluke which is harmful to human health.

   Image courtesy of S Gollasch

Asian green mussel infestation on power plant infrastructure

Damage marine and industrial infrastructure
Some pests will encrust structures such as jetties and marinas, long lines used in aquaculture or industrial water intake pipes. This image shows Asian green mussels smothering infrastructure associated with an underground power plant in the USA.

   Image courtesy of Chris Gazinski, Mote Marine Laboratory

Outboard motor covered with Asian green mussels

Damage engines and propellers
Marine pests can damage engines by clogging cooling water intakes resulting in engine overheating.  After being submerged for six weeks, this boat's propeller was completely covered by Asian green mussels.

   Image courtesy of John Koek, Mote Marine Laboratory

Yacht with heavy biofouling

Reduce vessel performance 
The build up of up of marine biofouling on vessel hulls slows down the vessel and increases fuel consumption.  The antifouling coating of this yacht is at the end of its effective life and biofouling has accumulated to a level where the yacht may inadvertently be harbouring marine pests.

   Image courtesy of Bayview Slipway Marine Services

Cause human poisoning 
Some pests are microscopic organisms that in high levels are toxic to humans. Shellfish feed by filtering such organisms from the water and can accumulate them in high levels when the right conditions exist. This has a double effect, creating human health issues as well as causing the affected shellfish beds to be closed down and loss of income for the operator.