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SDWF publish study on abundance estimates of the Shannon Dolphins.
A recent paper in Aquatic Mammals suggests the Shannon dolphin population is stable.
European Union Member States are obliged to designate SACs for bottlenose dolphins to protect important habitats. The Lower River Shannon is the only cSAC in Ireland for this species.
Using a technique called photo-identification bottlenose dolphins were photographed on 12 transects from July to October 2010. A cumulative total of 273 bottlenose dolphins were photographed during the 12 transects, and from these a total of 116 individual animals were identified.
The estimated abundance of marked individuals was elevated depending on the estimated proportion of marked individuals in the population to give a final estimate of 107 ± 12, CV = 0.12 (95% CI = 83 to 131). Previous abundance estimates for bottlenose dolphins in the Lower River Shannon cSAC ranged from 114 in 2008 to 140 in 2006; the present estimate was within this range and also within the 95% Confidence Intervals for all surveys carried out to date. This suggests that, within the power of the survey technique, the population of bottlenose dolphins in the Lower River Shannon cSAC is relatively stable.
The survey was funded by the Department of Arts, Heritage and the Gaeltacht.
A copy of the report can be downloaded from Download document
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Soundwaves
Special Area of Conservation (SAC)
Threats
Monitoring
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