In January-February 1971 five replicate 0.07 m² Van Veen grabs were obtained from each of 12 stations in Arthur Harbor and nine Van Veen grabs were obtained from two stations in nearby Bismark Strait. The 69 grab samples yielded 78,395 individuals which were separated into 282 taxa, including 108 species of annelids (54.5% of the individuals), 117 species of arthropods (30.3%), 35 species of molluscs (11.3%) and 22 species in other phyla (4.0%). The density of macrofauna (17,522 individuals/m²) found in Arthur Harbor was high compared to other reported areas. This high density was considered to be the result of high organic input from phytoplankton, phytobenthos and attached macroalgae, the efficient utilization of organic matter by macrobenthos and the slow growth rate of macrobenthic species as an indirect result of cold temperatures. Diversity values were moderately high with high species richness values and low evenness values. The high species richness values may be the consequence of seasonal constancy of temperature and salinity in Arthur Harbor, while low evenness values probably result from the physical stress of iceberg grounding coupled with high organic input. Six macrobenthic assemblages (site groups) and 11 species groups were found in the study area by classification analysis (Bray-Curtis dissimilarity, group-average sorting). Station groups were described by dominant species, density and diversity. Species groups were described by the dominance, fidelity, constancy, and percent abundance of constituent species restricted to site groups. The existence of discrete assemblages derived from the classification analysis was supported by direct ordination. Assemblages were interpreted to be areas of relative homogeneity which interrupt a general continuum of distribution of species with depth. The depth gradient probably represents several factors including increased constancy of temperature and salinity, lower organic input from attached macroalgae and phytobenthos, and a reduced incidence of iceberg grounding. Diversity, species richness, and evenness values increased with the depth gradient, while density values decreased with depth. The dominant species obtained in this study are widely distributed throughout the Antarctic, and 4% of the 162 taxa identified to species were also found at Terre Adelie, East Antarctica. Thus assemblages found in Arthur Harbor are probably circumpolar. In spite of the stability of temperature and salinity, Arthur Harbor macrobenthic assemblages were moderately stressed by glacial activity Icebergs, which often ground in Arthur Harbor, destroyed the benthos by crushing and churning the sediment. The disturbed area was first repopulated by motile, opportunistic species. These species fed on macroalgae which collected in the depression left by the iceberg. Scavengers and carnivores appeared later to feed on the grazers and macrofauna destroyed by iceberg grounding. Within a year the depression filled, and typical meiobenthic assemblages were re-established. Several years may be required before macrobenthic assemblages are re-established. Station 8, located near the glacial face had the lowest values of diversity, species richness, evenness, and density of any station in Arthur Harbor. These low values resulted from physical stress of glacial calving. Large pieces of ice calved from the glacial face and crushed the sediment by impact with the bottom. The waves created by impact of the calved ice with the water also disturbed the sediment creating an unstable sediment surface. / Graduation date: 1977

Thesis (Ph. D.)--University of Washington, 1981. / Vita. Bibliography: leaves [109]-116.

Thesis (Ph. D.)--University of Washington, 1982. / Vita. Bibliography: leaves 145-165.

Thesis (M.S.)--University of North Carolina Wilmington, 2008. / Vita. Title from PDF title page (viewed May 27, 2009) Includes bibliographical references (p. 126-127)

Thesis (M.S.)--Naval Postgraduate School, 1978. / Includes bibliographical references.

Thesis (M.S.)--Naval Postgraduate School, 1975. / Includes bibliographical references (leaves 82-83).

No description available.

The intertidal ecology of approximately seventy miles of coast, along the southwest shores of Vancouver Island from Port Renfrew to Victoria, was studied during the period from May 1957 until July 1958. This coast is a transition area between the open ocean at Port Renfrew and more sheltered waters east of Victoria, which are much freshened by the influx of the Fraser River. Attention was concentrated on the more conspicuous forms, mostly on those algae of the order Laminariales which do not occur in the more sheltered localities. Observations were made at twenty-six stations spaced along this coast. In collecting specimens, particular attention was given to those algae where identification is difficult or doubtful. These collections were made to complement the direct observations on those entities which could readily be identified in the field. The presence or absence of the entities studied was noted at each station. The distribution of some of the very conspicuous forms was determined along most of the coast between the stations. Any distinct upper or lower limits in the intertidal organisms at a station were recorded. Limited observations were made at fourteen other points, where these were needed to elucidate questions raised by the earlier data. Conditions of the physical environment, particularly of salinity, sea temperature, and tidal rhythms, were monitored at each of the stations wherever possible. Most of the twenty-six stations were occupied at least once each summer. Some of the more centrally located ones were visited at various times throughout the year in order to observe seasonal changes in the organisms and environmental conditions studied. When two or more measurements of the same upper or lower limit of an organism were made at different times, these replicates were used to calculate error in the technique used in finding the levels of these limits. The open coast forms penetrate varying distances along the coast into Juan de Fuca Strait in an easterly direction. Evidence is presented that different factors in the physical environment may be limiting for the geographical distribution of different organisms. Thirty-six vertical limits of the organisms studied are discussed. These are all the limits which were measured at nine or more stations throughout the area studied. The heights of each limit were plotted against the headland to headland distance between stations. Each limit was approximated by a line of least squares. The validity of this approach is discussed. The limits studied were grouped as follows: 1. Limits which are very variable throughout the area studied. 2. Limits which are more variable on the coast west of Sooke, than east of it. 3. Only slightly variable limits which have a definite slope downward from Port Renfrew to Victoria. 4. Only slightly variable limits which have no definite slope between Port Renfrew and Victoria. Various combinations of factors are suggested as explanations for these various types of limits. These factors include surf, light, desiccation, and nutrients, together with adult size and longevity of the organism. The theory of critical tidal factors is criticised. Species of the order Laminariales in this area which are as yet of questionable taxonomic status, are found in the following genera: Hedophyllum, Alaria, Costaria, Cymathere, and Laminaria. Of these, Hedophyllum and Alaria were studied in some detail. Hedophyllum was cultured from zoospores obtained from the sporophyte, through gametophyte stages, to what was presumably a young sporophyte of the same entity. The young sporophytes were not grown to stage where positive identification of secondary morphological characteristics was possible. The alternation of generations observed conformed to the pattern known for the other members of the Laminariales. Hedophyllum subsessile (Areschoug) Setchell, one of the two species of Hedophyllum reported from British Columbia, is reduced to synonomy under the other, H. sessile (C. Agardh) Setchell. A transitory stage in the development of H. sessile in its second season corresponds closely to the herbarium material on which Setchell appears to have based his description of H, subsessile. Variations in the bullation of the lamina of H. sessile are largely the result of environment, probably of exposure to, or shelter from, sunshine. Although the species of Alaria (A. marginata Postels and Ruprecht, A. nana Schrader, A. tenuifolia Setchell, and A. valida Kjellraan and Setchell) reported from British Columbia are very variable, they may usually be distinguished by the morphological characters of those sporophylls which are in a mature and fertile condition. These four species are therefore regarded as taxonomically valid in this study. / Science, Faculty of / Botany, Department of / Graduate

Thesis (Ph. D.)--Oregon State University, 2008. / Printout. Includes bibliographical references. Also available on the World Wide Web.

Understanding the movement and feeding habits of marine animals is crucial when managing their populations. The molecular, and stable carbon isotope composition of fatty acids from an organism provides time-integrated information on its dietary intake. Hence, when spatial differences in the quality of seston exist it should be able to trace these differences up into higher trophic level organisms. The presented study evaluates the applicability of 13C/12C ratios of individual fatty acids, as natural tags and dietary markers in marine pelagic organisms. In addition, the use of 13C/12C ratios of bulk sample, as well as fatty acid composition data in examining the movement, and diet of animals are further explored. Samples of particulate organic matter, zooplankton, larval fish and juvenile salmon collected during three cruises off the west coast of Vancouver Island were analyzed. The fatty acid composition, stable carbon isotope ratio of either bulk sample, or individual fatty acids could typically distinguish samples collected in continental shelf waters from off-shelf samples. The differences in fatty acid composition between the adjoining food webs seem to be mainly caused by the different contribution of diatom-derived material to the base of the food web. The higher 13C/12C ratios found in the diatom-richer seston in shelf waters were not simply caused by the higher contribution of diatoms. Instead, stable carbon isotope data on individual fatty acids indicate that growth conditions favouring diatom growth caused 13C-enrichment in algae other than diatoms as well. The relative abundance of polyunsaturated fatty acids, such as docosahexaenoic acid (22:6n-3), were found to increase with trophic level. Whereas the abundance of saturated, and monounsaturated fatty acids was higher in organisms from lower trophic levels. This suggests that the fatty acid composition may be a useful trophic level indicator. However, literature data indicate that these trends observed in seston. zooplankton, larval fish and juvenile salmon, do not hold for larger organisms and adult life stages. / Graduate