Thesis (M.S.)--Washington State University, 2003. / Title from PDF title page (viewed on May 27, 2005). Includes bibliographical references (p. 33-38).

Thesis (Ph. D.)--Ohio State University, 1968. / Includes bibliographical references (leaves 76-77). Available online via OhioLINK's ETD Center

Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (p. 146-149).

Thesis--University of Washington. / Vita. Another copy has number: Thesis 26948. Bibliography: leaves [338]-357.

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.

Nitrogen (N) derived from symbiotic fixation of atmospheric N2 in wild and cultivated populations of Cyclopia, a woody endemic genus used to make honeybush tea in the Western Cape of South Africa, was quantified by the 15N natural abundance method. Because Cyclopia species are naturally mycorrhizal, non-N2-fixing arbuscular mycorrhizal shrubs of similar phenology to Cyclopia were chosen as reference plants to provide the d15Nvalue of soil-derived N. Isotopic analysis showed that wild populations of Cyclopia were highly dependent on N2 fixation for theirNnutrition, ranging from 70 ± 4%to 100 ± 7% (mean ± SE) at all sites, except for one. Further evidence of the high dependency of wild Cyclopia populations on symbiotic N was provided by their significantly higher foliar N concentrations compared with the non-legume reference plants. However, cultivated Cyclopia exhibited variable amounts of N2 fixation, with Cyclopia genistoides (L.) R. Br., for example, showing low amounts of N2 fixation at Sites P2 and P3 (0 ± 51% and 8 ± 46%, respectively) as a result of low D values (D is defined as the difference between the mean d15N value of the reference plants and the B value of the test Cyclopia species, where B is the d15N of an inoculated test legume grown in an N-free growth medium), whereas at Sites P1, P2, P5 and P6, up to 89 ± 2%, 94 ± 13%, 85 ± 13% and 100 ± 18%, respectively, plant N was derived from atmospheric fixation. The high symbiotic N nutrition observed for wild populations of Cyclopia suggests that these populations are major contributors to the N economy of the nutrientpoor soils of the South African fynbos. These data indicate that by breeding for high N2 fixation rates in Cyclopia cultivars and selecting more efficient rhizobial strains, this legume has the potential to achieve higher N2 fixation rates under cultivation. The low variability in Cyclopia d15N values within sites, however, suggests that genetic variability is not a major factor influencing N2 fixation rates in cultivated Cyclopia, and thatmore benefit may be gained from soil amelioration and the selection of improved rhizobial strains

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