Guidance for Aquaculture

The ability of species to contaminate aquaculture equipment and stock species, foul the hull of boats and stow away in bilge water has and can continue to deliver non-native species to new areas where they can impact on the biodiversity and economy of the region.

The aquaculture sector has a role to play in preventing movement of invasive non-native species by  preventing the contamination of transported equipment and product, reducing fouling of vessels and equipment by use of an appropriate antifouling method (e.g. antifouling paint), removing fouling in a responsible manner where it cannot return to the environment, draining all water from the vessel/craft before transferring to another water body, preventing fouling of ropes and chains by drying them on a regular basis and not disposing of live material in the water.

Here are some guidelines that can be followed to reduce the spread of invasive species by aquaculture:

Invasive Species Hazard Analysis and Critical Control Points (HACCP): Aquaculture managers are encouraged to introduce a HACCP system to help identify risks, procedures to limit the opportunity of non target species transfer and the appropriate time to take action when moving aquaculture species and equipment.

Click to download the template HACCP system for Aquaculture:

Inspect – remove – dispose – report: Removing build up of plant and animal material from equipment or the hull of boats is effective at preventing further colonisation by invasive species. Prevent the spread of invasive species when moving equipment and culture material to a new area by always following these guidelines:

  • Check, clean and dry all parts of equipment, boats and trailer that come into contact with the water.
  • Remove any visible plant, fish, animal material and mud.
  • Use damp cloths and vacuum sanders to keep paint, debris, and cleaners out of the water.
  • Do not allow rinse water to return to the marine environment. Many organisms can remain viable even in small (sometimes microscopic) quantities.
  • Do not move fouled vessels or equipment from one area to another.
  • Keep good records of when equipment and boats are due to have antifouling renewed.
  • Report any organism you suspect may be a high risk species.
  • Watch out for hitchhikers on ropes and chains.

Remove unused equipment and stock: Equipment and seed stock should not be left in the environment if it is no longer used by the grower or the grower is no longer able to maintain the installation.

Biofouling control on aquaculture equipment: Biofouling can be a costly problem for the aquaculture sector. Uncontrolled biofouling on aquaculture infrastructure and stock leads to increased maintenance costs and production losses (low growth/poorer quality).

During the normal course of farming operations, naturally occurring biofouling including mussels; barnacles; marine plants; and other marine invertebrate animals can collect on culture equipment and on cultured species themselves. However, invasive species can also foul aquaculture equipment and species. These species can increase costs, reduce yields and also use the installation as a stepping stone to colonise natural ecosystems.

There are economic incentives for the sector to develop management practices that reduce the impact and requirement to discard non-target species on their product/s and equipment, while ensuring their site can be operated in a long-term sustainable manner. Actions include:

  • Minimise the potential for over settlement of non-target species by selecting sites and culture methods which avoid fouling in high densities.
  • Adopt operating and maintenance practices such as regular cleaning which reduce the potential for non-target species to become a significant factor.
  • If possible, facilitate probiotic control measures such as the polyculture of native sea urchins and other native grazers to reduce fouling impact.
  • Where biofouling must be washed or removed, attempt to reduce its impact and potential for colonisation on natural ecosystems by disposing of the debris in rubbish bins or onland composting. Remember that if fouling paints have been used, that debris must be disposed off at a licensed landfill site.

Ensure compliance with the ICES Code of Practice on the Introductions and Transfers of Marine Organisms 2005:

The ICES code aims to reduce the ecological, environmental, economic and genetic impacts associated with the transfer of species utilised in aquaculture activities. While Government is responsible for some of the actions in this code others lie solely with the aquaculture sector for implementation. Familiarise yourself with this code and its requirements for new species introductions and species already utilised in aquaculture.

Promotion of native species and biodiversity: Northern Ireland’s biodiversity has been put under pressure in recent years due to threats such as increased construction and development, intensive farming, inappropriate habitat management and the introduction of non-native species. Promoting native species will contribute to the efforts to halt the loss of biodiversity.

Related information

DAERA Fisheries

Under the Fisheries Act (Northern Ireland) 1966, Marine & Fisheries Division is responsible for the licensing of fish farms in Northern Ireland. This includes the granting of fish culture licences, shellfish fishery licences and marine fish fishery licences.

Bord Iascaigh Mhara

BIM is the Irish State agency with responsibility for developing the Irish Sea Fishing and Aquaculture industries.

Guides to Marine Invasive Species in Northern Ireland can be found below. More information on individual species can be found in the species accounts here

Full ID Guide to Marine Invasive Species in Northern Ireland


Working Version of Marine Invasive Species ID Guide in Northern Ireland



Invasive Species Northern Ireland

Invasive Species Northern Ireland