Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (leaves 157-172).

This study investigated the relationships between cetacean occurrence/relative density and environmental variables, and examined how these links vary both spatially and temporally. Data were collected during surveys carried out from passenger ferries throughout 2001 to 2006. The survey area covered three hydrographically distinct regions: the northern Minch, the Little Minch and the Sea of Hebrides. 17,649 km of survey effort was conducted in Beaufort sea-states 2 or less during which 990 sightings and 2,233 individuals were recorded. Six species of cetacean were recorded: the harbour porpoise, northern minke whale, short-beaked common dolphin, common bottlenose dolphin, white-beaked dolphin and Risso’s dolphin. Basking shark sightings were also recorded. The Minch had the highest diversity of cetacean species, with all six species sighted there. In the Sea of Hebrides, four species were recorded, and the Little Minch had the lowest diversity, with just three species. Relationships between harbour porpoise occurrence and environmental variables differed between months and regions. Minke whale presence was also linked to local environmental variables. However, while some relationships remained constant across all of the regions during specific times of the year, others were only evident in either the northern or southern areas. The habitat preferences of common dolphins and basking sharks in the Sea of Hebrides were found to be similar in some respects, despite their dietary differences. This may reflect the fact that both are pelagic predators. No significant relationships were identified between bottlenose dolphin occurrence and the environmental variables, which may be related to the large spatial scale of this study. These spatio-temporal variations in occurrence and habitat preferences may have important implications for any conservation measures or management strategies which may be applied to these regions, as it cannot be assumed that the Hebrides can be treated as a single homogenous area of habitat.

Thesis (Ph. D.)--University of California, San Diego, 1997. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of California, San Diego, 2005. / Vita. Includes bibliographical references. Also available online in PDF format via the National Marine Fisheries Service Coastal Marine Mammal Program (CMMP) home page.

Thesis (Ph. D.)--University of California, San Diego, 1997. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of St Andrews, January 2007. / Includes bibliographical references. Available in PDF format via the World Wide Web.

As human impact on marine ecosystems continues to grow, so too does the need for sound conservation and management strategies that are informed by science. Cetaceans, the whales, dolphins and porpoises, epitomise this challenge, because they are hard to study, they have been heavily exploited in the past, and because some of their habitats, behaviours and life-history strategies make them acutely vulnerable to human activities. Unfortunately, research on free-ranging cetaceans in remote areas is costly, and financial resources are limited. The approach used in this thesis to acquire inexpensive quantitative information on cetacean populations and behaviour was to seek out platforms of opportunity. Tourism and environmental education projects provided access to remote areas of importance to cetaceans. The topic was explored in two main areas. First, studies were conducted to investigate the use of ships of opportunity in estimating distribution and abundance, namely of Antarctic baleen whales. The second area of interest was the effect of boats on killer whales in the northeast Pacific. Platforms of opportunity proved valuable for collecting data to model the role of measurement error on abundance estimation. Measurement error was found to be a potential source of bias in four distance estimation experiments. Platforms of opportunity could be used to train observers on protocols, and to learn to use range- finding photogrammetric equipment well before conducting dedicated surveys, which would eliminate this source of bias, as well as estimating abundance in some cases. Abundance and distribution of three whale species were modelled using data collected aboard Antarctic tourist ships. Spatial modelling techniques were used to model distribution of minke, fin and humpback whales using line-transect data collected from a survey that could not be randomised. Strong gradients in animal density were predicted, which could be used to inform future surveys. In the meantime, rough estimates of abundance were obtained, and this approach shows promise for other areas where lack of resources makes systematic surveys prohibitively expensive. A government-funded environmental education project provided logistical support for two studies that dealt with effects of boats on killer whale behaviour. One quantified the extent to which a particular style of whalewatching was disruptive to whale behaviour, and commercial whalewatchers agreed to halt this activity. The other found that a protected area conferred benefit to killer whales, even though it protects only a fraction of the whales' habitat for a fraction of the year. The thesis contains four case studies that illustrate how inexpensive methods may be used to obtain practical quantitative information to aid decision-making about conservation and management of wild cetaceans that interact with (i.e., whalewatching), compete with (i.e., fishing) or are exploited by (i.e., whaling) humans.

Thesis (M.S.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 90-108). Also available on the World Wide Web.

Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (p. 144-156).

The efficacy of a Marine Protected Area (MPA) is contingent on it having a design appropriate for the species it is intended to protect. Hector�s dolphin (Cephalorhynchus hectori), a coastal delphinid endemic to New Zealand, is endangered due to bycatch in gillnets. Analyses of survival rate and population viability suggest that the Banks Peninsula population is most likely still declining despite the presence of the Banks Peninsula Marine Mammal Sanctuary (BPMMS), where gillnetting is regulated. More data on distribution and movements of dolphins are therefore required to improve the design of the BPMMS. On aerial surveys of Hector�s dolphin distribution at Banks Peninsula over three years, sightings were made up to 19 n.mi. offshore. On average, 19% of dolphins were sighted outside the BPMMS�s 4 n.mi. offshore boundary in summer, compared to 56% in winter. On similar surveys of the South Island�s west coast, all dolphins were sighted within 6 n.mi. of the coast and there was no seasonal change in distribution. At each location, Mantel tests indicated that distance offshore had the strongest and most consistent effect on distribution. However, a logistic regression model using the combined datasets suggested that distribution was most strongly defined by water depth, with all sightings made inside the 90 m isobath. Boat surveys were carried out at Banks Peninsula (2002 to 2006) to continue the long-term photo-ID project. Using the 22 year dataset, alongshore home-range of the 20 most frequently sighted dolphins was estimated by univariate kernel methods. Mean alongshore range was 49.69 km (SE = 5.29), 60% larger than the previous estimate. Fifteen percent of these individuals had ranges extending beyond the northern boundary of the BPMMS. An acoustic data logger, the T-POD, was trialled for passive acoustic monitoring of Hector�s dolphins. Simultaneous T-POD/theodolite surveys revealed that T-PODs reliably detected dolphins within 200m. No detections were made beyond 500m. To monitor inshore habitat use, T-PODs were deployed in three locations at Banks Peninsula (n = 431 days). A GLM analysis of Detection Positive Minutes (DPM) per day indicated that season had the largest effect on detection rate, with over twice as many DPMs per day in summer (x̄ = 99.8) as winter (x̄ = 47.6). The new findings on Hector�s dolphin distribution and ranging can be used to improve the design of the BPMMS. It is recommended that the offshore boundary of the BPMMS is extended to 20 n.mi. (37 km), the northern boundary is moved 12 km north and recreational gillnetting is prohibited year round. In areas where distribution of Hector�s dolphin has not been studied, the offshore boundary of MPAs should enclose the 100 m isobath.