Seventy-eight harbour porpoises, Phocoena phocoena, (33 females, 45 males) were obtained from the summer (June-September) cod fishery incidental-by-catch in the Gulf of St. Lawrence, and examined for the presence of cranial sinus nematodes. This is the first quantitative and in-depth study of the distribution of Stenurus minor (Kuhn, 1829) Baylis and Daubney, 1925 in the cranium of by-caught harbour porpoises. Stenurus minor was present in the cranial sinuses of all adult porpoises ($>$1yr, n = 66, x = 2362, range 87-8920) and absent in all young-of-the-year ($<$1yr, n = 12). Only fifth-stage worms were observed and these were equally distributed between the right and left side ot the skull (mean intensity = 1158 and 1213 in the left and right side, respectively). Female S. minor were predominant (1:1.8 sex ratio). Mean intensity of S. minor was similar among all infected porpoises, suggesting an annual loss and recruitment of this parasite. Parasite load had no apparent effect on porpoise body condition (measured as % blubber weight of carcass). No gross lesions associated with the presence of numerous S. minor in the cranial sinuses, were observed. There was an inverse relationship between the intensity of S. minor and mean worm-length, suggestive of a "crowding effect". Mean worm-length in lightly infected porpoises was 17.8 $ pm$ 0.2 mm and 16.1 $ pm$ 0.2 mm in heavily infected animals. Possible life-cycles and modes of transmission are examined in light of our findings. The absence of S. minor in porpoises less than 1 year old suggests heteroxenous transmission of this parasite, via an intermediate host in the food chain. Transmammary and or transplacental transmission is unlikely.

No description available.

Thesis (Ph.D.)--Memorial University of Newfoundland, 2001. / Bibliography: leaves 279-295.

This thesis deals with archiving morphological data utilizing a three dimensional coordinate system. Morphological reference points are archived via rectangular position coordinates, rectangular position vectors, and spherical position vectors. The concepts of translation trajectories, translation vectors, and relative position vectors are developed. Analysis of three dimensional coordinate data utilizing translation trajectories and translation vectors is described. In order to test the methodology developed, the method is applied to an analysis of harbor porpoise, Phocoena phocoena L., skull morphology. (Key words: morphology, ontogenetic trajectories, allometry, position coordinates, position vectors, translation trajectories, translation vectors, relative position vectors, and harbor porpoise).

Thesis (M. Sc.), Memorial University of Newfoundland, 1998. / Bibliography: leaves 93-106.

The waters off the west coast of Scotland have one of the highest densities of harbour porpoise (Phocoena phocoena) in Europe. Harbour porpoise are listed under Annex II of the EU Habitats Directive, requiring the designation of Special Areas of Conservation (SACs) for the species’ protection and conservation. The main aim of this thesis is to identify habitat preferences for harbour porpoise, and key regions that embody these preferences, which could therefore be suitable as SACs; and to determine how harbour porpoise use these regions over time and space. Designed visual and acoustic line-transect surveys were conducted between 2003 and 2008. Generalised Estimating Equations (GEEs) were used to determine relationships between the relative density of harbour porpoise and temporally and spatially variable oceanographic covariates. Predictive models showed that depth, slope, distance to land and spring tidal range were all important in explaining porpoise distribution. There were also significant temporal variations in habitat use. However, whilst some variation was observed among years and months, consistent preferences for water depths between 50 and 150 m and highly sloped regions were observed across the temporal models. Predicted surfaces revealed a consistent inshore distribution for the species throughout the west coast of Scotland. Regional models revealed similar habitat preferences to the full-extent models, and indicated that the Small Isles and Sound of Jura were the most consistently important regions for harbour porpoise, and that these regions could be suitable as SACs. The impacts of seal scarers on distribution and habitat use were also investigated, and there were indications that these devices have the potential to displace harbour porpoise. These results should be considered in the assessment of sites for SAC designation, and in implementing appropriate conservation measures for harbour porpoise.

Harbour porpoise (Phocoena phocoena) are the most abundant cetacean in UK waters, and are likely to be affected by a variety of marine industries and activities. This research uses data collected by acoustic recorders (C-PODs) and aerial video surveys to investigate patterns in porpoise detection. The findings can be split into five key themes, and are used to support the development of spatial management and survey recommendations. 1. Porpoise detection changes based on time of day in different habitats, indicating possible differences in diel habitat use and highlighting potential issues with visual or video data collection methods for assessing distribution. 2. Porpoise exhibit seasonal shifts in detection, yet year-round data are often lacking, therefore seasonal changes in distribution are often unknown. 3. The highest proportions of buzzes (associated with foraging) are not detected in areas with the highest relative density of porpoise. I propose that porpoise use different foraging strategies in different habitats which are not equally detectable by acoustic recorders. 4. Porpoise distribution may be influenced by the distribution of perceived risk from predator / competitor species (dolphins). Temporal partitioning of sites may arise either from porpoise actively avoiding times when bottlenose dolphins are expected to be present, or from porpoise and bottlenose preferences for different environmental conditions. 5. The choice of spatial modelling method can influence the fine-scale predictions of areas with the highest density. Improving our understanding of top and mesopredator ecology is informative for management strategies. Each of the points raised above should be considered when determining management strategies to minimise the impact from fisheries, offshore developments and other industrial activities on harbour porpoise.

A prevalence of 76% and a mean intensity of 42.7 Anisakis simplex was found in harbour porpoises (Phocoena phocoena) (N = 78) by-caught in cod gill nets set by fishers from the Gaspe area in summer 1993. No young-of-the-year porpoises (N = 12) were infected. Prevalence and mean intensity among immature and adult porpoises as well as between sexes and length-classes were not significantly different. Anisakis simplex was present in the three stomach compartments of harbour porpoises. Adult stages were proportionately less abundant in the main and pyloric stomachs than the forestomach. Percent intensity of A. simplex was influenced by maturity of harbour porpoises. Gravid female A. simplex contained up to 818,000 eggs. Egg number was highly correlated with worm uttering volume. Density effects were not demonstrated, possibly due to high variability of egg number, total length, uterine and total worm volume between parasites from each stomach and between stomachs of harbour porpoise.

The harbor porpoise is considered a threatened species in Swedish waters. A full understanding of its ecology and relationship to other species is important when designing effective conservation plans. This thesis aims to investigate the relationships between harbor porpoises and their prey by comparing the acoustic activity patterns of harbor porpoises and the movement patterns of some of their prey species available at Kullaberg, Sweden. For this purpose, the scientific literature of porpoise and fish activity patterns has been reviewed. Results show that harbor porpoises may follow vertically migrating herring, but further studies are needed to confirm this. It is also possible that the activity pattern of porpoises does not follow exactly the movements of a certain species of prey, but that they rather feed upon several species, and therefore change their behavior accordingly throughout the diurnal cycle.

No description available.