Streams are important habitats, providing shelter and feeding opportunities for a wide range of organisms. The species depending on running waters includes a wide array of fish species, using these waters for their whole or parts of their lifecycle. Streams are also the subject of different anthropogenic impact, e.g. hydropower development. Hydropower development usually means lost connectivity, altered flow regimes and channelization. Channelization is one of the major factors causing stream habitat loss and degradation and thereby a threat to biodiversity of running waters. In the present study, the ecological impact of channelization on the fish fauna along a gradient of channelization severeness was examined. Besides channelization, stream velocity and depth were taken in to account. The study was carried out in two adjacent nemoboreal streams, Gavleån and Testeboån. The study was conducted between the 6th of June and the 10th of October 2012 at 15 sites. Sites were selected using historical maps and field observations and graded 0-3 depending on the degree of channelization. Fish community were sampled with, Nordic multi-mesh Stream Survey Net (NSSN). In all, 1.465 fish were captured, representing 15 species and seven families. The sites differed in species richness, abundance and proportion of individuals. Based on the results from rarefaction curves and ANOVA, channelization was found to be the main factor affecting the fish biota, both in abundance as well as species richness and composition. In general the rheophilic species declined along the gradient of increasing channelization severeness, while limnophilic species increased

The methodological and theoretical considerations that must be addressed when excavating the traditional longhouses of the First Nation peoples who lived in the Pacific Northwest region are the foci of this thesis. The large amount of faunal data contained within the remains of houses require the use of explicit, justifiable sampling strategies; however, the methods used to sample these dwellings are not generally a central research focus. A sampling simulation of faunal data recovered from the excavation of numerous houses from the village site of Ozette is the empirical basis of this research. Specifically, the effects of sample size and sample method on richness, relative abundance and the interpretation of status using faunal data are investigated. The results are of heuristic value for future household archaeology on the Northwest Coast and suggest alternative sampling methods which attempt to cope with the labour-intensive research generally required for shell-midden archaeology.

The methodological and theoretical considerations that must be addressed when excavating the traditional longhouses of the First Nation peoples who lived in the Pacific Northwest region are the foci of this thesis. The large amount of faunal data contained within the remains of houses require the use of explicit, justifiable sampling strategies; however, the methods used to sample these dwellings are not generally a central research focus. A sampling simulation of faunal data recovered from the excavation of numerous houses from the village site of Ozette is the empirical basis of this research. Specifically, the effects of sample size and sample method on richness, relative abundance and the interpretation of status using faunal data are investigated. The results are of heuristic value for future household archaeology on the Northwest Coast and suggest alternative sampling methods which attempt to cope with the labour-intensive research generally required for shell-midden archaeology.

No description available.

Thesis by publication. / Thesis (PhD)--Macquarie University (Division of Environmental & Life Sciences, Graduate School of the Environment), 2007. / Bibliography: p. 267-303. / General introduction -- Redescription of two species of wobbegongs (Chondrichthyes: Orectolobidae) with elevation of Orectolobus halei Whitley 1940 to species level -- Using recreational scuba-divers to survey the relative abundance and distribution of wobbegong sharks (Family: Orectolobidae) in New South Wales, Australia -- Observations of localised movements and residence time of wobbegong sharks (Orectolobus halei) at Fish Rock, New South Wales, Australia -- Length-frequency distribution, length-length, mass-mass and mass-length relationships of wobbegong sharks (Genus Orectolobus) commercially fished in New South Wales, Australia -- Quantitative diet assessment of wobbegong sharks (Genus Orectolobus) in New South Wales, Australia -- Reproductive synchrony of three sympatric species of wobbegong shark (Genus Orectolobus) in New South Wales, Australia -- Age and growth of wobbegong sharks (Genus Orectolobus) in New South Wales, Australia. / In New South Wales, Australia, wobbegong sharks (Orectolobidae) have been commercially targetted by the Ocean Trap and Line Fishery since 1991. A catch decrease of ca. 50% in a decade lead to concern over the sustainability of the fishery and to wobbegongs being listed as vulnerable in NSW under the World Conservation Union Red List assessment. The aim of this research was to investigate wobbegong biology and ecology in relation to its fishery to provide essential data and information for sustainable management of the woggegong fishery. Biological data was obtained from 904 wobbegongs collected from commercial fishing boats, using setlines and lobset pots and by scuba diving. previously two species of wobbegongs were known to occur in NSW: the spotted wobbegong (Orectolobus maculatus) and the ornate wobbegong (O. ornatus). This study discovered a new species (O. halei) described as a subspecies by Whitley (1940), but which had been syonymised with O> ornatus due to a lack of taxonomic investigation. / Mode of access: World Wide Web. / 307 p. ill., some col., maps

It is now widely accepted that over one-third of the global food supply depends upon pollinators. Risking severe ecological and economic implications, the status of the 4000 species of bees native to North America has been poorly understood due to a lack of long-term survey data. In this study, I conducted bee surveys on Massachusetts cranberry (Vaccinium macrocarpon Ait.) bogs from 2007-2009 and compared diversity and abundance data to those from historical surveys performed in 1990-1992 on the same bogs. I found that overall bee diversity declined severely in the 19-year survey period, while total bee abundance remained consistent. My data provide supporting evidence for the loss of North American bumble bees (Bombus spp.), but also provide the first evidence for declines in the U.S. in overall wild bee diversity. Maximizing the potential for agricultural landscapes to serve as quality pollinator habitat and identifying appropriate integrated pest management strategies should involve a comprehensive understanding of each species’ life history traits and conservation status. The loss of biodiversity associated with the intensification of agriculture has been well documented for several wildlife species but remains poorly understood for bees, which provide pollination to many agricultural crops. Most pollinator-dependent crops rely heavily on managed honey bees (Apis mellifera L.) for pollination. Four thousand other species of bees native to North America may provide pollination insurance in the event of honey bee losses, but without a clear understanding of how agricultural intensification affects wild bees, habitat conservation measures aimed at protecting them may be futile. In the second part of this study, I evaluated six metrics of agricultural intensification with respect to native bee diversity and abundance in Massachusetts cranberry bogs, including honey bee competition, bog management type (i.e. organic versus conventional), distance from epicenter of cranberry-growing region, toxicity of insecticide program, susceptibility of reproductive bees to insecticide, and surrounding land use. I found a clear association between reduced native bee diversity and abundance and the effects of increased agricultural intensification of the landscape. Recognition that native bee communities in North America are diminishing as a consequence of agricultural intensification may help to unify a movement toward improved conservation management.

The dark kangaroo mouse, Microdipodops megacephalus, is a sensitive species in the Great Basin Desert. This thesis explores the structure of desert rodent communities of the Great Basin to better understand M. megacephalus' place in the community and the conditions that promote large and stable populations. To determine community structure, I used nestedness analysis to evaluate 99 communities of nocturnal granivorous rodents. I found that the community structure was non-random, indicating the existence of assembly rules and ecological constraints. I also found that M. megacephalus was the second most vulnerable species in the community. To explore the correlation between species diversity and relative abundance, I performed regression analyses on M. megacephalus and five commonly co-occurring species of the nocturnal granivore guild: Perognathus longimembris (little pocket mouse), Perognathus parvus (Great Basin pocket mouse), Dipodomys ordii (Ord's kangaroo rat), Dipodomys microps (chisel-toothed kangaroo rat), and Peromyscus maniculatus (deer mouse). Results showed a positive correlation between rodent species diversity and relative abundance for M. megacephalus, P. longimembris, P. parvus, and D. microps, and a negative correlation for D. ordii and P. maniculatus. To further understand community composition, I ran interspecific association analyses based on presence-absence data for the six species using chi-square to determine strength of interspecific associations. I found positive interspecific associations between M. megacephalus and P. parvus, between P. longimembris and P. parvus, between P. longimembris and D. microps, and between D. microps and P. maniculatus, and a negative association between P. longimembris and P. maniculatus. A species cluster dendogram with respect to sites in common further supports the interspecific association results. A site cluster dendogram with respect to species abundances implies that dune habitat promotes diversity but not uniformity. All results indicate that M. megacephalus is more abundant and stable at sites with high species richness. The results also provide evidence for the existence of assembly rules, competition, and niche partitioning in desert rodent communities.

No description available.

No description available.