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Stream channel morphology : comparison of logged and unlogged watersheds in the Queen Charlotte IslandsHogan, Daniel Lewis January 1985 (has links)
This study compares the morphology of coastal, gravel-bed streams in two unlogged and two logged Queen Charlotte Islands watersheds. This comparison quantifies the influence of logging and related activities on channel morphology and, consequently, the fresh water physical habitat of salmonids. Further, it provides a basis upon which to determine habitat rehabilitation criteria for disturbed channels. Pools and riffles are detailed because: a) they reflect changes in sediment supply; b) they are important fish habitats, and; c) their general character has been documented in previously published literature allowing application of geomorphological results to habitat evaluation.
Longitudinal profiles conducted over relatively long channel segments located within each watershed indicate that channels in watersheds logged to the channel banks by old techniques have reduced pool-to-pool spacings and increased riffle amplitudes and magnitudes. There is an increase in channel stored sediment resulting in proportionally larger riffles and smaller pools. This represents a reduction in available rearing habitat. No significant differences exist in pool and riffle characteristics between unlogged watersheds and those logged by contemporary techniques. In all cases the pool and riffle character differed from most previously published results. Results obtained from detailed study reaches located within each channel segment show that large organic debris is a controlling factor influencing the morphology of these streams. Based upon a comparison of reaches, it is concluded that LOD characteristics are altered in the older logged channels. This includes a shift in the size distribution, with smaller material being more prevalent. Orientation of this material is also altered; more LOD is lying parallel to the flow direction, as opposed to the more common diagonal orientation found in unlogged channels. This shift in orientation is responsible for a reduction in channel width and depth variability, reduced sediment texture, fewer cut banks, smaller pool areas and decreased channel stability. This results in reduced habitat diversity and quality. No morphological differences were detected between unlogged and recently logged reaches.
The architecture of unlogged channels can be duplicated to rehabilitate disturbed streams. Pool and riffle sequences should be spaced approximately 2½ channel widths apart and riffle magnitudes should average 0.013 m/m. LOD should play a major role in rehabilitation. Long pieces of debris should be placed either diagonally across the channel to increase depth and width variability and to store sediment or parallel to the flow if width is to be reduced. Diversity can be increased by placing large root wads to produce small scour holes. Only small debris steps, accounting for approximately 10% of the overall change in elevation should be used. This comparative study of channel morphology emphasizes the importance of critically evaluating basin morphometric properties and the role of LOD orientation. Further, it indicates that previous studies reporting average values and neglecting LOD provide insufficient detail to quantify fish habitat. / Arts, Faculty of / Geography, Department of / Graduate
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Distribution, social structure and habitat use of short-finned pilot whale, Globicephala macrorhynchus, in the Canary IslandsServidio, Antonella January 2014 (has links)
The Canary Archipelago is considered one of the planet's biodiversity hotspots and the short-finned pilot whale is a key species in need of conservation measures. To address a lack of knowledge, almost 2,000 day-surveys were conducted (1999-2012) resulting in 1,094 short-finned pilot whale sightings. The species was recorded year-round and distributed non-uniformly around the archipelago, with greater densities concentrated in patchy areas mainly on the leeward side of the main islands. A total of 1,320 well-marked individuals were identified, which exhibited a large degree of variability in site fidelity (from core residents to transients). Evidence of an island-associated sub-population and a transient one was found. Longitudinal data were used to infer population structure and estimate abundance, while a spatial modelling approach was used to study spatio-temporal patterns in habitat use, distribution and abundance. Spatial modelling revealed habitat preferences in areas between depths of 1000m and 1500m, and higher densities in the south-west of Tenerife and La Gomera (117 short-finned pilot whales recaptured within the two islands). Abundance of 1,980 individuals (CV = 0.33, 95% CI=1,442 – 2,324) was estimated for the entire archipelago, with higher density predicted during the summer months. Mark-recapture analysis estimated 636 resident individuals (CV = 0.028, 95% CI=602 - 671) in the southwest waters of Tenerife between 2007 and 2009. The social and temporal analyses of the behavioural relationships between pairs of individuals revealed a well-differentiated society with long-lasting and non-random social structure built of constant companions. A hierarchical social system is proposed composed of a population encompassing several clans of pilot whales, each one containing several pods. Nine long-term units were identified with a high degree of association (0.62 - 0.83). This study, the first to provide combined results on distribution, habitat use, and social structure of the species, provides essential information towards the development of recommendations for much needed conservation measures.
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Comparative phylogeographic patterns among selected indigenous and introduced Collembola on Marion IslandMyburgh, Marike 04 1900 (has links)
Thesis (MSc)--University of Stellenbosch, 2006. / ENGLISH ABSTRACT: Marion Island is situated approximately 2600 km southeast of Cape Town and is the larger of
the two islands that comprise the Prince Edward Island group. During past glaciation events,
Marion was partially covered by ice with fauna and flora confined to isolated refugia across
the island. As a result of these long-term isolation events, it is postulated that species
predating these glaciation events might show geographic partitioning of genetic variation.
Subsequently, the majority of Southern Oceanic islands have a history of sealing activities
with vessels frequenting various islands in their hunt for seals. These combined visits to
several islands could have facilitated the introduction of alien species, or the reintroduction of
species already present on islands. These incidents, combined with more recent scientific
voyages, have led to the establishment of several exotic species on Marion Island. Two
indigenous Collembola species (Cryptopygus antarcticus (Willem, 1901) and Tullbergia
bisetosa (Börner, 1903)) were chosen as model species to investigate the possible effects of
glaciation on the spatial distribution of genetic variation on indigenous species. Given the
negative impact that alien taxa have on indigenous species and ecosystems, the
phylogeographic population structure of the recently introduced Isotomurus cf. palustris
(Müller, 1876) was determined and compared to those described for the two indigenous
species. To address these questions, two mitochondrial DNA genes were targeted:
cytochrome oxidase subunit I (COI) and cytochrome oxidase subunit II (COII). These genes
were sequenced (GENBANK accession numbers DQ147289-DQ147558) and analysed using,
amongst others, AMOVA (Analysis of Molecular Variance), SAMOVA (Spatial Analysis of
Molecular Variance) and NCA (Nested Clade Analysis). As expected, the two indigenous
species showed distinct signs of population expansion, whilst the recently introduced species
exhibits little genetic variance across its range. The life histories of species have an influence
on their resultant genetic signature; therefore life history parameters were incorporated to
explain differences in the phylogeographic patterns observed for these three species. / AFRIKAANSE OPSOMMING: Marion Eiland is die groter van twee eilande wat die Prins Edward eilandgroep vorm,
ongeveer 2600 km suid-oos vanaf Kaapstad. Gedurende glasiasie episodes in die verlede, was
Marion gedeeltelik met ys bedek en fauna en flora was geisoleer in klein gedeeltes van die
eiland wat beskut was. As gevolg van hierdie langtermyn isolasie word daar voorgestel dat
spesies wat op die eiland was voor hierdie gebeurtenisse plaasgevind het, ‘n geografiese
verdeling van genetiese variasie sal toon. Sedertdien het die meerderheid van die eilande in
die Suidelike Oseaan ook ‘n geskiedenis van skepe wat op een of meer van die eilande
aangedoen het in die jag op robbe. Hierdie besoeke deur die robjagters aan die eilande het
meegebring dat daar eksotiese spesies op die eiland aangekom het of dat spesies wat reeds op
die eiland voorgekom het, opnuut daar geland het. Hierdie, tesame met die onlangse
wetenskaplike reise na Marion Eiland, het daartoe gelei dat baie eksotiese spesies ingevoer is
na die eiland. Twee inheemse spesies, naamlik Cryptopygus antarcticus (Willem, 1901) en
Tullbergia bisetosa (Börner, 1903) is gekies om as model spesies te dien om die moontlike
gevolge van glasiasie op die geografiese verspreiding van genetiese variasie te toets. In ag
geneem die moontlike negatiewe impak wat eksotiese spesies op die inheemse spesies mag
hê, is die filogeografie van ‘n uitheemse spesie, Isotomurus cf. palustris (Müller, 1876) ook
bepaal en vergelyk met díe van die bogenoemde inheemse spesies. Dit is gedoen deur twee
gene, sitokroom oksidase I (COI) en sitokroom oksidase II (COII) te analiseer. Hierdie gene
se basispaarvolgordes is bepaal (GENBANK toetreenommers DQ147289-DQ147558), en
hulle is ge-analiseer deur gebruik te maak van AMOVA (Analise van Molekulêre Variasie),
SAMOVA (Ruimtelike Analises van Molekulêre Variasie) en NCA
(geseteldegroepsanalises). Net soos verwag, het die twee inheemse spesies albei duidelike
tekens getoon van ‘n bevolkingstoename terwyl die uitheemse spesie amper geen variasie oor
sy verspreidingsgebied getoon het nie. Die lewensstyle van spesies het ‘n beduidende invloed
op hulle genetiese bevolkingstruktuur. As sulks is díe in ag geneem om die verskille tussen
hulle genetiese strukture te verduidelik.
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Anthropology in the vernacular : an ethnography of doing knowledge on Choiseul Island, Solomon IslandsTracey, Jonathan M. January 2015 (has links)
This thesis absorbs and reflects on Choiseul Island responses and caution towards the making of anthropological knowledge. Initial interests that can easily become familiar to anthropology as research topics such as village life, local cosmology and local alternatives to cosmologies of climate and ecology, make way here for another activity of working through Choiseul responses to anthropology. In taking seriously the precautions and the considerations of people in this Solomon Islands locality, anthropology is invited to put a stoppage to practices that it would consider ordinary and part of anthropological knowledge making. This impasse for the discipline is outlined and explored in various chapters, in which usual styles of ethnography and topic-making take formation in respect of a Choiseul world that does not fit easily into encapsulation by anthropology. Effects for the discipline of anthropology are given consideration, within a wider view of imagining how an alternative anthropology in the vernacular can also entail an obviation of anthropology itself in favour of new forms of cultural sensitivity.
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The identification of marine areas of importance for albatrosses and petrels breeding at South Georgia, Antarctica, and implications for managementTancell, Claire January 2015 (has links)
No description available.
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Being and becoming : ritual and reproduction in an island Melanesian societyFergie, Deane Joanne. January 1985 (has links) (PDF)
Bibliography: leaves 359-381.
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INTERGENERATIONAL LAND TRANSACTIONS ON ROTA, MARIANA ISLANDS: A STUDY OF ETHNOGRAPHIC THEORYSmith, James Jerome, 1943- January 1972 (has links)
No description available.
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Debris recharge rates in torrented gullies on the Queen Charlotte IslandsOden, Marian Elizabeth 11 1900 (has links)
This study is an examination of the rate at which organic debris and clastic sediment
accumulate in a gully after it is scoured by a debris torrent. Of particular interest is the
effect that a change in land use from old-growth to clear-cut conditions may have on these
rates. This change should result in a reduction in the delivery of large organic debris
(LOD), which is a major factor in sediment storage in gullies. It is hypothesized that this
change in land use, and the subsequent reduction in the LOD supply, should result in a
significant difference in debris recharge rates between old-growth and clear-cut gullies.
Twenty-nine gullies in both land-treatment groups were sampled on the west coast of
the Queen Charlotte Islands. Sampling procedures involved the estimation of the volume of
LOD and sediment in storage (normalized by the gully surface area) and the determination
of the time elapsed since the last debris torrent. These data were then used to estimate
recharge rates(3h1)am’year of LOD, sediment, and total debris.
Recharge rates of each material were compared between land-treatment groups using
the nonparametric Mann-Whitney test. This test revealed that LOD has been delivered to
old-growth gullies at a significantly higher rate relative to clear-cut gullies. There was no
significant difference in sediment and total debris recharge rates between gullies in the two
groups, but this outcome was partially a result of the small samples and the different debris
recharge times in each data set. Graphical representations of the data permitted the
identification of possible temporal trends in sediment and debris accumulation, which may
be strengthened with larger data sets.
Debris recharge rates have several applications. The estimate of sediment volume
stored in a gully can be used in the construction of local sediment budgets, as one
component of a watershed sediment cascade is quantified. The calculation of debris
recharge rates will provide insight into the transfer rate of sediment from hillslopes to low
order channels and to the storage capacity of the channels. Finally, debris recharge rates
can be used to improve knowledge of the frequency-magnitude characteristics of debris
torrents in an area.
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Marine parks and reserves : management for Philippine, Indonesian and Malaysian coastal reef environmentsWhite, Alan Tyler January 1984 (has links)
Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1984. / Bibliography: leaves [259]-275. / Photocopy. / Microfilm. / xvii, 275 leaves, bound ill., maps 29 cm
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The sea people: Maritime hunter-gatherers on the tropical coast: A late Holocene maritime specialisation in the Whitsunday Islands, central QueenslandBarker, Bryce. Unknown Date (has links)
No description available.
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