Post-disturbance haulout behaviour of harbour seals
Abstract
1. The impact of anthropogenic activity associated with marine renewable developments on harbour seals (Phoca vitulina) was investigated using controlled disturbance trials. 2. Hauled‐out seals were approached by boat until all seals had entered the water, and this was repeated approximately every 3 days (weather permitting). The time taken for seal counts to return to pre‐disturbance levels was determined by monitoring haulout sites using time‐lapse photography. 3. Mean post‐disturbance counts of hauled‐out seals returned to 52% (95% confidence interval [CI] 35–69%) of pre‐disturbance counts within 30 min. However, mean counts only returned to 94% (95% CI 55–132%) of pre‐disturbance counts after 4 hr. 4. Eight seals were tagged with Global Positioning System phone tags to provide information on haulout location and at‐sea movements, allowing investigation of how disturbance may influence haulout site choice and seal distribution. 5. Telemetry‐tagged seals displayed a high degree of haulout site fidelity. Disturbance trials did not have a significant effect on the probability of seals moving to a different haulout site. 6. When seals hauled out again within the same low‐tide period after disturbance trials, the proportion of time spent hauled out was high, indicating that when seals are motivated to haul out they will do so despite past disturbance. Motivation to haul out more on disturbance trial days was not linked to a cyclic pattern of hauling out more over consecutive low‐tide periods. 7. As there was no large‐scale redistribution after disturbance, we suggest that monitoring effort to determine the effects of short‐term increases in levels of disturbance caused by boat activity can be spatially localized. However, where disturbance is likely to be longer term or impact on important haulout sites for breeding and/or moulting, monitoring may be required over a larger geographical area.
Citation
Paterson , W D , Russell , D J F , Wu , G-M , McConnell , B , Currie , J I , McCafferty , D J & Thompson , D 2019 , ' Post-disturbance haulout behaviour of harbour seals ' , Aquatic Conservation: Marine and Freshwater Ecosystems , vol. 29 , no. S1 , pp. 144-156 . https://doi.org/10.1002/aqc.3092
Publication
Aquatic Conservation: Marine and Freshwater Ecosystems
Status
Peer reviewed
ISSN
1052-7613Type
Journal article
Rights
Copyright © 2019 John Wiley & Sons, Ltd. This work has been made available online in accordance with publisher policies or with permission. Permission for further reuse of this content should be sought from the publisher or the rights holder. This is the author created accepted manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at https://doi.org/10.1002/aqc.3092
Description
This study was funded by Scottish Natural Heritage, Marine Scotland and The Marine Alliance for Science and Technology for Scotland (MASTS).Collections
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