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Measure the effectiveness of mitigation measures of managed activities (aquaculture) carried out in Natura sites – monitoring and baseline data collection.

This project was designed to measure the effectiveness of management or mitigation measures taken as part of aquaculture licencing decisions to reduce or minimise risk to conservation features. Such measures are likely to be of the form of, 1) licence conditions that place certain constraints on activities in certain areas or, 2) redrawing site boundaries.  The response of the conservation features to such measures will have to be considered.

This project continued to monitor the response of shorebirds to a reconfiguration of oyster trestles in Dungarvan Harbour SPA (commenced during 2016/2017 winter season). The reconfiguration of trestles allowed for a tidal break to allow shorebirds free movement up and down the shore. The tidal break provides for a single clear corridor of approximately 400 metres. This break is considered an exclusion zone with no shellfish culture activities permitted. For example, travel must avoid this area. Travel across this area will only be permitted across the top of the shore (i.e. in the high intertidal zone). The response of shorebirds, in particular Grey plover, to the creation of this exclusion zone will be monitored during 2018/19 as part of this project.

Surveys were carried out in Bannow Bay SPA to augment shorebird counts to provide greater confidence in the conclusions of the AA reports and subsequent management decisions.

Assessing the impact of aquaculture activity in Shannon Estuary and Wexford Harbour continued during 2019. Monitoring consists of assessing the interactions between bottom mussel dredging activity in Wexford Harbour and how it interacts with site use by the Greenland Whitefronted Geese at the North Slob portion of the SPA. Shannon Estuary monitoring consists of targeted counts of shorebirds in Poulnasherry Bay. Baseline winter low water shorebird counts data collection were required in Castlemaine Harbour SPA to identify sensitive/important bird habitat and areas. These data will be used to validate existing and facilitate future licencing decisions.

A broader survey of SPA sites designated for shorebirds was conducted to calculate annual trends to relate to aquaculture activities at the sites. This includes the acquisition of shorebird trend data from NPWS/Birdwatch and mapping of trestle cover (to reflect levels of activities). This study will help determine the relationship between broader trends in bird numbers with aquaculture activities to aid future planning of aquaculture activities. 


The project has a 4 year duration and runs between 2019 and 2022.

Project Outputs:

Monitoring of effectiveness of mitigation measures :

  1. Response of shorebirds to a reconfiguration of oyster trestles in Dungarvan Harbour SPA.
  2. Monitoring of shore birds in Bannow Bay SPA.
  3. Monitoring of targeted counts of shorebirds in Poulnasherry Bay as part of Shannon Estuary.
  4. Baseline low water bird counts in Castlemaine Harbour SPA (Winter 2019).
  5. SPA shorebird population trend analysis allied with site usage (trestle mapping). Production of report.

Reports for each monitoring site are produced annually in March. The reports outline the links between SPA site usage and population status of shorebird species to inform future licencing decisions.

Expected Benefit:

Validation of licensing decisions taken at sites to allow adaptive management of aquaculture in Natura sites.

Further Information:
Contact Francis O’Beirn, Marine Institute, Rinville, Oranmore, Co. Galway at
Project Cost - Actual
Project Cost - Projected:
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