Spatial ecology of marine top predators
MetadataShow full item record
Species distribution maps can provide important information to focus conservation efforts and enable spatial management of human activities. Two sympatric marine predators, grey seals (Halichoerus grypus) and harbour seals (Phoca vitulina), have overlapping ranges but contrasting population dynamics around the UK; whilst grey seals have generally increased, harbour seals have shown significant regional declines. A robust analytical methodology was developed to produce maps of grey and harbour seal usage estimates with corresponding uncertainty, and scales of spatial partitioning between the species were found. Throughout their range, both grey and harbour seals spend the majority of their time within 50 km of the coast. The scalability of the analytical approach was enhanced and environmental information to enable spatial predictions was included. The resultant maps have been applied to inform consent and licensing of marine renewable developments of wind farms and tidal turbines. For harbour seals around Orkney, northern Scotland, distance from haul out, proportion of sand in seabed sediment, and annual mean power were important predictors of space-use. Utilising seal usage maps, a framework was produced to allow shipping noise, an important marine anthropogenic stressor, to be explicitly incorporated into spatial planning. Potentially sensitive areas were identified through quantifying risk of exposure of shipping traffic to marine species. Individual noise exposure was predicted with associated uncertainty in an area with varying rates of co-occurrence. Across the UK, spatial overlap was highest within 50 km of the coast, close to seal haul outs. Areas identified with high risk of exposure included 11 Special Areas of Conservation (from a possible 25). Risk to harbour seal populations was highest, affecting half of all SACs associated with the species. For 20 of 28 animals in the acoustic exposure study, 95% CI for M-weighted cumulative Sound Exposure Levels had upper bounds above levels known to induce Temporary Threshold Shift. Predictions of broadband received sound pressure levels were underestimated on average by 0.7 dB re 1μPa (± 3.3). An analytical methodology was derived to allow ecological maps to be quantitatively compared. The Structural Similarity (SSIM) index was enhanced to incorporate uncertainty from underlying spatial models, and a software algorithm was developed to correct for internal edge effects so that loss of spatial information from the map comparison was limited. The application of the approach was demonstrated using a case study of sperm whales (Physeter macrocephalus, Linneaus 1758) in the Mediterranean Sea to identify areas where local-scale differences in space-use between groups and singleton whales occurred. SSIM is applicable to a broad range of spatial ecological data, providing a novel tool for map comparison.
Thesis, PhD Doctor of Philosophy
Attribution-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nd/4.0/
Except where otherwise noted within the work, this item's license for re-use is described as Attribution-NoDerivatives 4.0 International
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.
Showing items related by title, author, creator and subject.
Karlõševa, Aljona; Nõmmann, Sulev; Nõmmann, Tea; Urbel-Piirsalu, Evelin; Budziński, Wiktor; Czajkowski, Mikołaj; Hanley, Nicholas David (2016-03) - Journal articleThe drive to increase renewable electricity production in many parts of Europe has led to an increasing concentration of new wind energy sites at sea. This results in a range of environmental impacts which should be taken ...
Progress in marine geoconservation in Scotland’s seas : assessment of key interests and their contribution to Marine Protected Area network planning Gordon, John E.; Brooks, Anthony J.; Chaniotis, Peter D.; James, Ben D.; Kenyon, Neil H.; Leslie, Alick B.; Long, David; Rennie, Alistair F. (2016-12) - Journal articleGeoconservation in the marine environment has been largely overlooked, despite a wealth of accumulated information on marine geology and geomorphology and clear links between many terrestrial and marine features. As part ...
Aversiveness of sound in marine mammals : psycho-physiological basis, behavioural correlates and potential applications Götz, Thomas (University of St Andrews, 2008) - ThesisUnderstanding what psycho-physiological and behavioural factors influence aversiveness of sound in marine mammals is important for conservation and practical applications. The aim of this study was to determine predictors ...