In cases where human and wildlife are co-using the same geographical areas and resources, management issues often get complex and stakeholder conflicts are common. The Icelandic harbour seal (Phoca vitulina) population is rapidly decreasing, but direct culling of seals still occurs. At the same time seals are becoming an important resource due to increased interest in wildlife watching. Despite the complicated management situation, the Icelandic harbour seal population is one of the least studied pinniped populations in the world. Mapping the typical haul-out pattern is an important foundation for further studies. In paper I haul-out behaviour of harbour seals was investigated and a seasonal haul-out pattern was detected with the maximum number of seals hauling out during summer. A bimodal distribution curve was found during the summer time, suggesting that pupping period occurs in late May to early June, while moulting occurs in late July to early August. Tidal state, air-temperature and wind-speed affected the haul-out boots. Today, the main reason for culling harbour seals in Iceland is to reduce harbour seal predation on salmonids, despite limited knowledge on the effect of seal predation on salmonid populations and salmon angling. The diet of harbour seals that haul out in the estuary area of Bjargós and Ósar in NW-Iceland was therefore investigated using hard-part (paper II) and DNA metabarcoding analysis (paper III). Both methods showed that the main prey species were sand eels, flatfishes, gadoids, herring and capelin, while salmonids were not an important prey in this area. Based on these results, culling of harbour seals in the area is not likely to have a positive effect on salmonid angling. These results have crucial management implications, especially in the light of the severe decline in the Icelandic harbour seal population. Potential effects of seal watching tourism on the harbour seal population must also be considered in management plans. In paper IV, we investigated the effects of land based seal watching on seal behaviour and found that spatial distribution and vigilance was affected by tourists. Calm tourists behaviour had less effect, meaning that disturbance could be reduced if tourist behaviour is modified. In paper V, this line of investigation was followed by analysing knowledge transfer from academia to the tourist industry and a model was presented where a synergy effect of working interdisciplinary is hypothesised. Finally, in paper VI, the effect of signage on tourist behaviour was studied. Empirical testing showed that teleological information is more effective than ontological in terms of modifying general tourist behaviour. In this thesis, I present new knowledge on behaviour and diet of harbour seals, as well as new empirical findings on tourist behaviour in wildlife tourism settings. Further I explore interdisciplinary management approaches for seal watching tourism. The findings presented in this thesis have an important value within academic research in environmental-, life- and social sciences and the knowledge can be applied in several areas of harbour seal management in Iceland and elsewhere. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 6: Manuscript.</p>

Sequence variation was examined for the Zinc-finger Y (zfy) gene and the mitochondrial control region for two species of pinnipeds, the Steller sea lion (Eumetopias jubatus) and harbor seal (Phoca vitulina). The two species differ in aspects of their breeding strategies, dispersal, and life histories. Comparable stock sample sizes of males from each species were taken from localities that span at least one wellrecognized phylogeographic stock as defined by mtDNA markers. Variation in zfy, a strictly paternally inherited marker located on the Y chromosome, was low in both species. An interesting pattern of subdivision was found for zfy in harbor seals that was concordant with population subdivision for mtDNA. In Steller sea lions, no such concordant pattern was evident with only a single rare zfy variant being observed. One explanation for the different patterns observed is that dispersal is less in male harbor seals than in male Steller sea lions.

Typescript. Includes vita and abstract. Bibliography: Includes bibliographical references (leaves 84-90). Description: xiv, 90 leaves : ill. ; 29 cm.

This study investigated the abundance of harbour seals (Phoca vitulina) on inter-tidal sandbanks, mother-pup interactions as well as the impact of anthropogenic disturbance during breeding season. The abundance was a composite picture of harbour seals of different age and sex, and increased gradually towards peaks in June. Although the sandbank water inlet was the longest time emerged, mother-pup pairs and other seals hauled out more abundant on the other sandbanks, probably due to space availability, differences in sandbank structure and distance to human activity. Mothers and their offspring were found to be mostly inactive during haul out. Mothers initiated significantly more frequently interactions i.e. hauling out, entering water and suckling. Seals hauled out at sandbanks close to the dyke were most frequently disturbed by pedestrians. Important regarding the impact on the seals seemed to be the group size of pedestrians and the distance to the seals (on dyke or seaside of it), i.e. pedestrians seaside disturbed more seals. This applies also to the disturbance by marine activity, e.g. distance of seals to the engine boat. Jet fighters were shown to affect the highest mean number of seals per event. After anthropogenic disturbances separations of mother and offspring were not recorded, e.g. due to seals being in the water; however, the steep edges as result of the culvert at water inlet lead to a few separations. The most frequent behavioural response towards anthropogenic disturbance was commotion with a probably lower level of energy costs during the energy consuming lactation period.

La plasticité comportementale et les interactions entre organismes sont connues pour avoir une influence sur l’utilisation de l’espace, notamment la sélection de l’habitat de chasse. Dans l’Atlantique Nord-Est, les phoques gris et veaux marins vivent en sympatrie. Ces deux espèces sont réparties dans différentes colonies où les interactions entre organismes (liées à la taille de la colonie et à la présence simultanée ou non des deux espèces) ainsi que la disponibilité de l’habitat (et donc des proies) varient localement. L’objectif de cette thèse était d’étudier l’utilisation spatiale et la sélection d’habitat de chasse à l’échelle locale de ces deux espèces dans des situations contrastées de dynamique de colonies. Pour cela, plusieurs individus de différentes colonies situées en Irlande, en Écosse et en France ont été équipés de balises GPS/GSM. Les données récoltées ont permis de caractériser leurs trajets en mer ainsi que d’identifier les zones de chasse permettant par la suite la sélection d’habitat. Contrairement aux veaux marins, qui ont réalisé des déplacements restreints aux alentours des colonies, la plupart des phoques gris se sont déplacés entre différentes colonies. Ainsi, l’étude de la sélection d’habitat à l’échelle individuelle pour les individus se déplaçant entre différentes colonies a mis en évidence l’influence de la plasticité comportementale et suggéré celle de la personnalité de l’animal. A l’échelle de la colonie, chez les deux espèces, les résultats ont mis en évidence l’influence de la disponibilité de l’habitat (et indirectement de la disponibilité des proies) ainsi que des interactions intra-spécifiques (liée à l’effet de densité dépendance) sur l’utilisation spatiale et la sélection de l’habitat de chasse. Cependant, la sélection de l’habitat de chasse était principalement liée à la distance au reposoir et la bathymétrie. Ces deux paramètres sont liés aux caractères de chasseur à place centrale et benthique des phoques. Cette étude a également mis en évidence, pour les sites où les deux espèces étaient présentes, une certaine ségrégation spatiale et des différences de sélection d’habitat entre les deux espèces. / The behavioural plasticity and the interactions between organisms are known to influence foraging habitat selection and spatial usage. In the Northeast Atlantic, greyand harbour seals live in sympatry. These two species are spread into different colonies where interactions between organisms (linked to the colony size et and the presence of one or both species) and habitat availability (linked to the prey distribution) vary locally. The objective of this PhD was to study the spatial usage and foraging habitat selection of these two species at the local scale, in contrasted situations of population dynamics. Several individuals were tagged with GPS/GSM tags in different colonies located in Ireland, Scotland and France. Telemetry data was used to characterize the seals’ trips at sea and to identify their foraging areas in order to model foraging habitat selection. While harbour seals only performed trips restricted around their haulout sites, grey seals moved between colonies. Studying habitat selection at the individual scale, for individuals moving between colonies, highlighted the influence of behavioural plasticity and suggested the influence of individual personality. At the colony scale, for both species, results highlighted the influence of habitat availability (indirectly linked to prey availability) and intra-specific interactions (linked to density dependence effects) on spatial usage and foraging habitat selection. However, the foraging habitat selection was mainly explained by the distance from the last haulout and the bathymetry. These two parameters are linked to the central place forager and benthic feeder characteristics of the seals. Furthermore, this study also highlighted, for study sites where both species occur, a spatial segregation and differences in foraging habitat selection between grey and harbourseals.

The recovering harbor seal population along the Swedish west coast has coincided with declining cod stocks. Although the cod stocks were primarily depleted by intense fisheries, some stakeholders argue that reduced seal populations could have direct, positive effects on the cod stocks. The outbreaks of Phocine distemper virus (PDV) in 1988 and 2002 when up to 66% of the harbor seals along the Swedish west coast died, could be viewed as natural experiments allowing for assessment of any positive impacts of reduced mortality from seal predation on cod abundance. I quantified removal from seal predation and fishery landings and analyzed correlations to cod abundance of different length classes. Analyses were conducted for a longer time- series, 1979-2019, reaching back to when removal from fisheries was substantially larger than that from seal consumption. I also analyzed the data with a more recent perspective, 2003-2019, starting after the later PDV outbreak when seal predation relative landing sizes has increased. During this period, fishery discard data is available and included in the models. Methods include graphical presentation, multiple linear regression analyses, and to expand the existing data on seal diet, I collected diet samples of harbor seal feces from two haul-outs in Skagerrak. No statistically significant, negative correlations between seal predation and cod abundance were found in any data set, hence, I cannot support the idea of harbor seals having an impact on cod abundance. Also, the significant correlations between cod abundance and landings were all positive. I argue that culling of seals cannot be motivated as a strategy to help cod recover, as this would jeopardize the persistence of the seal population rather than assuring cod stability.

No description available.

It has been assumed that the considerable dispersal ability of many marine species would prevent genetic divergence in the absence of geographic isolation. However, recent work has shown that many marine species often develop differentiation among areas within their known dispersal range. This 'paradox' of marine divergence is particularly important among marine mammal species where behavior can restrict gene flow. To investigate genetic substructure within such a species, I used tissue samples collected from 63 stranded Pacific harbor seals (Phoca vitulina richardsi) in Washington and Oregon between 2006 and 2010 for population stock analysis. DNA was extracted from frozen tissues, and a 551 bp fragment of mtDNA control region sequence and eight microsatellite loci were amplified to investigate localized genetic structure. Minimum spanning network and haplotype frequency analyses of mtDNA sequences indicated that while haplotype lineages are not isolated within a sampling region, there is some evidence of regional differentiation. On the other hand, microsatellite data suggest a lack of substructure among the animals sampled, with only a weak signal of limited gene flow between Puget Sound and coastal areas. Biased dispersal among age classes was also suggested, with juveniles showing less differentiation among areas than adults. Regardless of the historical scenario which has led to this complex pattern of genetic structure in Pacific harbor seals across the Pacific Northwest, my results suggest higher levels of exchange among areas than previously suspected, and will have important consequences for future management considerations for these stocks.

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.

Understanding the movement behavior and foraging strategies of individuals across multiple spatial and temporal scales is essential not only for understanding the biological requirements of individuals but also for linking individual strategies to population level effects. Glacial fjords scattered throughout south-central and southeastern Alaska host some of the largest seasonal aggregations of harbor seals (Phoca vitulina richardii) in the world, and an estimated 15% of the harbor seal population in Alaska is found seasonally at these glacial ice sites. Over the last two decades, the number of harbor seals has declined at two of the primary glacial fjords, in Aialik Bay in south-central Alaska and in Glacier Bay in southeastern Alaska, thus raising concerns regarding the viability of seal populations in glacial fjord environments. From 2004-2009, the foraging ecology, diving behavior, and migration patterns of harbor seals from Glacier Bay National Park, Alaska were examined in relation to prey availability and oceanographic features in Glacier Bay and the surrounding regions of southeastern Alaska. Time-depth recorders, very high frequency transmitters, and satellite-linked transmitters were used to quantify the vertical and horizontal movement patterns of harbor seals in the marine environment. Specifically, (1) I characterized the diving behavior, foraging areas, and foraging strategies of female harbor seals from terrestrial and glacial ice sites relative to prey availability during the breeding season (May-June) in Glacier Bay, (2) I quantified the intra-population variation in at-sea post-breeding season (September-April) distribution and movement patterns of female harbor seals in relation to oceanographic features, (3) I quantified the post-breeding season migration patterns of female harbor seals relative to the boundaries of the marine protected area of Glacier Bay National Park, and (4) I characterized the use of the continental shelf region of the eastern Gulf of Alaska by female harbor seals from Glacier Bay, both as a foraging area and as a migratory corridor in relation to oceanographic features. During the breeding season, there was a substantial degree of intra-population variation in the diving behavior and foraging areas of juvenile and adult female seals from glacial ice and terrestrial sites in Glacier Bay. The presence of multiple diving strategies suggests that differences in the relative density and depth of prey fields in glacial ice and terrestrial habitats in addition to seal age and reproductive status may influence diving and foraging behavior of harbor seals. During the post-breeding season, juvenile and adult female harbor seals ranged extensively beyond the boundaries of the marine protected area of Glacier Bay National Park, throughout the northern inshore waters of southeastern Alaska and the continental shelf region of the eastern Gulf of Alaska between Cross Sound and Prince William Sound, Alaska (up to 900 kilometers away). Seals exhibited a relatively high degree of intra-population variation in their at-sea post-breeding season distribution patterns that may be a function of extrinsic factors such as oceanographic characteristics, which can influence prey availability as well as intrinsic factors including previous experience with foraging areas and seal condition and age. Use of the continental shelf region of the eastern Gulf of Alaska by harbor seals as a foraging area may be due to enhanced biological productivity which may be associated with ephemeral hydrographic and/or static bathymetric features. Despite extensive migrations of seals from Glacier Bay during the post-breeding season, there was a high degree of inter-annual site fidelity of seals to Glacier Bay the following breeding season after seals were captured. / Graduation date: 2012