Extensive aquaculture (Natura, WFD, MSFD….)

Understand how environmental assessment, habitat research, bird monitoring, and Natura 2000 screening inform extensive aquaculture licensing.

Environmental assessment at the licensing stage

All aquaculture activities are subject to environmental assessment at the licensing stage. For extensive operations, this primarily takes place through the Natura 2000 Appropriate Assessment process under the Habitats Directive and Birds Directive. Compliance with the Water Framework Directive is also considered.

Flowchart of the application, environmental assessment, consultation and ministerial decision process for extensive shellfish and seaweed aquaculture.

Habitat studies

We have commissioned surveys and research on interactions between habitats and extensive shellfish culture to inform aquaculture assessments.

The IQI is suitable for assessing ES in Irish intertidal environments.
The IQI has potential as a tool for managing intertidal oyster cultivation.
Cultivation activities at access routes had a significant negative impact on ES.
The IQI has potential for assessing habitat conservation status in Natura 2000 sites.

Feral Pacific oysters around Ireland

A national survey assessed 171 intertidal sites during 2024–2025, building on earlier surveys of feral Pacific oysters (Magallana gigas).

Results show that feral Pacific oysters are now widely established around the Irish coast. Abundance has increased, with a notable concentration along the western seaboard.

Oyster farms were associated with a higher likelihood of occurrence. However, environmental conditions, natural dispersal processes, and suitable settlement habitats appear to have a stronger influence on the distribution of feral populations.

Oysters were most commonly recorded on hard substrates such as boulders and artificial structures. Localised clusters indicate the presence of established source populations.

Comparison with earlier surveys shows a clear expansion in spatial distribution and population density over time, although some areas experienced localised declines.

The findings provide an updated baseline for understanding the spread of M. gigas in Ireland. Further information on the proliferation of Pacific oysters around the coast of Ireland is available in the Marine Institute repository.

Rows of raised shellfish-growing bags across an intertidal shore, with mountains and low cloud in the background.

Bird studies

Ongoing monitoring and research inform our advice on interactions between aquaculture activities and birds. Studies have tracked overwintering bird use of Special Protection Areas over several years to identify trends and the effects of intertidal aquaculture practices.

Protecting sensitive marine areas

Natura 2000 sites form a network of protected areas across the European Union. They protect important wildlife, habitats, and biodiversity.

protected habitats
sensitive species
the overall health of the site

Birds Directive link

This statutory instrument is linked in relation to the Birds Directive and environmental assessment for extensive aquaculture licensing.

Extensive aquaculture

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