published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

In 1961 the Green River was poisoned and its native fishes killed so that the new Flaming Gorge Reservoir could be stocked with non-native game fishes for sportsmen. This incident was representative of water management in the West, where dams and other projects have been built to serve human needs without consideration for the effects of water diversion or depletion on the ecosystem. Indeed, it took a Supreme Court decision in 1976 to save Devils Hole pupfish from habitat destruction at the hands of developers. Nearly a third of the native fish fauna of North America lives in the arid West; this book traces their decline toward extinction as a result of human interference and the threat to their genetic diversity posed by decreases in their populations. What can be done to slow or end this tragedy? As the most comprehensive treatment ever attempted on the subject, Battle Against Extinction shows how conservation efforts have been or can be used to reverse these trends. In covering fishes in arid lands west of the Mississippi Valley, the contributors provide a species by species appraisal of their status and potential for recovery, bringing together in one volume nearly all the scattered literature on western fishes to produce a monumental work in conservation biology. They also ponder ethical considerations related to the issue, ask why conservation efforts have not proceeded at a proper pace, and suggest how native fish protection relates to other aspects of biodiversity planetwide. Their insights will allow scientific and public agencies to evaluate future management of these animal population and will offer additional guidance for those active in water rights and conservation biology.

This study focuses on the taxonomy, biogeography and biological aspects of the fishes of Tristan da Cunha and Gough Island in the cental South Atlantic Ocean. Oceanographic measurements were undertaken to determine the position and nature of the Subtropical Convergence (STC) in the vicinity of the islands. The Tristan da Cunha group is thought to be situated on the northern edge of the STC while Gough Island is situated on the southern edge of the front. The seasonal environmental cycle at the islands is characterised by an annual sea surface temperature fluctuation of approximately 5 °C and an annual change in stratification of the water column. It is suggested that this increase in stratification at the STC, brought about in the summer by insolation warming the surface layers of the ocean, enhances primary production. The STC is identified as a unique habitat for fishes and as an important barrier to dispersal of species in the Southern Ocean. The present study has produced 18 new distributional records from the shelf waters of Tristan da Cunha and Gough Island. The fish fauna known from the shelf waters of these islands is reviewed, and a diagnosis, synonymy, and in some cases an illustration are provided. For certain species, brief notes on their biology, relative abundance and seasonal distribution are included. An analysis of the ichthyofaunal relationships between shallow water areas in the vicinity of the STC has resulted in the identification of a characteristic neritic STC ichthyofauna. The circumglobal distribution of many of these species is thought to be a consequence of a dispersive pelagic phase in their life-cycles. Biological processes in fishes at these islands are temporally and spatially affected by seasonal changes in oceanographic conditions. Seasonal sea temperature variation was identified as being an indicator of other oceanographic phenomena that may affect processes such as growth, reproduction and feeding in fishes at the islands. Most species have a summer spawning season and growth rate increased during the summer months. It was hypothesised that enhanced primary production and a related increase in food quality and availability during the summer were the major factors temporally regulating the growth and reproduction of fishes at the islands. Twenty families of neritic fishes have been recorded in the shelf waters of Tristan da Cunha and Gough Island. Most families are represented by only one species. Because of this a wide range of life-history strategies are apparent in the fauna. Nevertheless, there are a number of common life-history characteristics shared by most of the neritic species. Firstly, the early lifehistory of many species included an extended pelagic phase which might have facilitated colonisation throughout the STC zone in the past, thereby regulating extant species diversity in this region. Secondly, the common occurrence of an extended summer breeding season and iteroparity suggested that these characters also contributed to survival in what is considered to be an unpredictable environment. It would appear that these common characteristics hold the key to the success of many fishes in the STC zone. This study has contributed to our understanding of oceanic island ecosystems and has revealed distributional patterns of fishes that were unknown previously. By focusing on the biological processes of selected species the regulatory role played by local environmental conditions became apparent. The results of this study are also relevant to proposed conservation measures for Tristan da Cunha and Gough Island.

The cichlid fish Pseudocrenilabrus philander is widely distributed in southern Africa. Many of the populations occur in small, insular, geographically isolated water bodies, some of which are in arid areas. These small allopatric populations have been isolated for thousands of years and gene flow between them is non-existent or severely restricted. Populations were found to be different in terms of coloration, size of individuals, sexual dimorphism and behaviour. This thesis involved the determination of the taxonomic status of these isolated populations, from a morphological point of view. This has been part of a larger project, involving genetic and behavioural studies, to determine whether the different populations are geographic races of a single species, or whether they are species. Heritability of the observed differences was tested by breeding through three generations under uniform laboratory conditions. The populations from which wild-caught individuals were drawn could be identified on the basis of colour. There were some differences in anatomy between populations, but none of these were entirely distinctive for a particular population. When bred under laboratory conditions, populations did not show a tendency towards uniformity, as would be expected if morphological differences were environmentally induced. However, there were slight changes in the oral and pharyngeal bone form which may be diet related. Although there are morphological differences between populations and between wild-caught and laboratory-bred populations, it is suggested that the populations of P. philander are not fully differentiated and thus in the stages of incipient speciation. other studies on P. philander have introduced an element of uncertainty in that they show different results. Behavioural work suggests that different populations would behave as different species if they were to become sympatric. Karyological and mitochondrial studies showed that there were no differences between populations. Protein electrophoresis showed that populations were genetically unique. Since the various species and subspecies of Pseudocrenilabrus have been based on morphological criteria, the approach and conclusions in this study are based entirely on morphological criteria. These studies have practical implications for conservation, as some of the small populations are threatened with extinction. If the differences between the populations were ecophenotypic (i.e. related to their environment), then threats to some populations would not affect the conservation status of the species as a whole. If, however, such differences were genetic (i.e. the populations have evolved separately), then the extinction of small, isolated populations could mean the loss of actual species. This study strongly suggests that populations are incipient species and thus should be conserved.

This paper traces the history of Oregon Trout, an environmental organization in Portland, Oregon, from its beginning in the fall of 1983 through the spring of 1990, when it filed petitions on behalf of four stocks of Columbia and Snake River salmon under the Endangered Species Act. It focuses on Oregon Trout's efforts to preserve the wild salmon of the Columbia River as a contemporary example of anglers acting as environmentalists to conserve threatened or endangered species. According to historian John Reiger in American Sportsmen and the Origins of Conservation, hunters and anglers have been acting in this role in the United States since the Civil War, well before the Progressive Era in which the conservation movement is generally thought to have originated. However, the paper contends that Oregon Trout's advocacy for the interests of fish rather than fishermen is unique in the tradition to which Reiger points.

The Groot Marico catchment in the North West Province is a National Freshwater Ecosystem Priority Area (NFEPA) because it represents unique landscape features with unique biodiversity that are considered to be of special ecological significance. Three native freshwater species Amphilius uranoscopus, Chiloglanis pretoriae and Barbus motebensis, have high local conservation importance and B. motebensis is endemic to the catchment and is IUCN-listed as vulnerable. The main objective of this study is to contribute towards the effective conservation of these three species in the Groot Marico River system by assessing their genetic structure to determine whether tributary populations of the three species comprise of one genetic population or whether they are divided into genetically distinct subpopulations, in order to prioritise areas for conservation. The central null hypothesis was that there is no genetic differentiation between tributary populations (i.e., panmixia) of B. motebensis, A. uranoscopus and C. pretoriae in the Groot Marico catchment, North West Province. In total, 80 individuals per species were collected, targeting at least 10 individuals per population from a total of eight populations (seven tributaries and the Groot Marico main stem) and across the study area. Samples were collected by electrofishing and specimens were euthanized using an overdose of clove oil. A sample of muscle tissue was removed for genetic evaluation and the remainder of the specimens served as voucher specimens. For the genetic evaluation, mitochondrial (ND2, cyt b) and nuclear (S7) genes were used. Genetic techniques used were DNA extraction, polymerase chain reaction (PCR), purification and sequencing. From the 240 individuals collected, 123 sequences for B. motebensis, 111 sequences for A. uranoscopus and 103 sequences for C. pretoriae were analysed across all three genes. Statistical analysis included looking at cleaned sequences in order to obtain models using MODELTEST (version 3.06). Population structuring and phylogeographic analysis was performed in Arlequin (version 2000), TCS (version 1.2.1) and PAUP*. Results indicated that for B. motebensis the null hypothesis could be rejected as there were two distinct lineages (the Draai and Eastern lineages) that demonstrated significant divergence in both the ND2 and S7 genes, suggesting historical isolation. The low divergence in the mitochondrial cytochrome b gene (0% < D < 0.8%) suggests that this isolation is not very old and is probably not comparable to species level differentiation. The null hypothesis was also rejected for A. uranoscopus as there were also significant levels of differentiation between tributary populations resulting in the identification of two lineages (the Ribbok and Western lineages). However, for C. pretoriae, the null hypothesis could not be rejected as there was no genetic differentiation between tributary populations i.e., one panmictic population. Therefore, due to each species showing different genetic structuring within the tributary populations, more than one priority area for conservation needs to be implemented. These priority areas of conservation where therefore evaluated based on the current conservation status of the species (B. motebensis being vulnerable on the IUCN Red List), the number of Evolutionary Significant Units for each species and the overall genetic diversity of all three species in the Groot Marico catchment. In total, four tributary populations were conservation priorities areas, these were the Draai, Vanstraatens, Ribbok and Kaaloog tributaries. The Draai, Vanstraatens and Kaaloog tributaries were selected as priority areas for B. motebensis (B. motebensis is considered to be the most vulnerable of all three species). The Draai tributary was selected due to the B. motebensis population within the tributary showing isolation from the rest of the tributary populations. In order to conserve B. motebensis from the Southern lineage, the Vanstraatens and Kaaloog tributaries were selected. Reasons for selecting these two specific tributaries within the Southern lineage were that the Vanstraatens tributary had unique alleles (three Evolutionary Significant Units) for B. motebensis and the Kaaloog tributary had high genetic diversity (HD = 0.889, ND2 gene) when compared to the other tributary populations. The Ribbok and Vanstraatens tributaries were selected as priority areas for the conservation of A. uranoscopus. The Ribbok tributary was selected as it showed isolation from the rest of the tributary populations, as seen with the Draai tributary (B. motebensis) and the Vanstraatens tributary was selected to represent the Western lineage as it had the highest diversity for both genes (ND2 and S7). The Ribbok tributary has the highest prioritisation when compared to the Vanstraatens tributary. Chiloglanis pretoriae occurs within the Draai, Vanstraatens, Ribbok and Kaaloog tributaries, therefore by prioritising these tributaries for conservation, C. pretoriae will in turn be conserved.

The Sustainable Seafood Movement's "theory of change" is predicated on using markets to improve the supply of, demand for and governance of sustainable fisheries. Over four articles, this thesis will examine the implications of this approach. Article I evaluates the cultural model of seafood eco-labelling and demonstrates that while the theory of using market demand to motivate fishery improvements has been a powerful incentive, consumers have had a minimal role in incentivising that change. This is validated through semi-structured consumer interviews and structured surveys (n=196), which indicate consumers' general understanding of sustainability issues. Article II examines the roles of actors in the Sustainable Seafood Movement in facilitating the growth of sustainable seafood products in the supply chain, thus explaining how in the absence of large consumer demand, certified sustainable seafood product offerings have continued to grow. Article III examines the private governance mechanisms that the Sustainable Seafood Movement has established in the supply chain and how these are rivalling, complementing and substituting those of state-led fisheries governance mechanisms. At the same time both private and public governance mechanisms continue to monopolise certain spaces, such as flag state authority. Greater coordination between these two governance systems is needed to facilitate additional sustainability gains and strengthen the resilience of these governance systems. When public and private governance efforts to improve the supply, demand and governance of sustainable seafood are looked as whole, as in Article IV, it is evident that consumers/citizens are minimally engaged. Lack of consumer/citizen engagement could lead to an undervaluing of these governance systems by society. Civic engagement organizations are needed to bridge these systems and facilitate citizen/consumer/steward engagement. Public accountability mechanisms are one means to better engage the public in both governance systems, so that sustainable fisheries are realised by collective engagement of all actors.

published_or_final_version / abstract / Biological Sciences / Master / Master of Philosophy

Orientador: José Augusto Senhorini / Resumo: O Rio Santa Bárbara, pequeno afluente do Rio Sapucaí-Mirim, drena uma área de 1.013 km². Está inserido na bacia do alto rio Paraná, região considerada uma província ictiofaunística natural. Este trabalho estabeleceu como objetivo principal registrar a ictiofauna desse rio, de algumas de suas lagoas marginais e de seu afluente Rio Potreiro, bem como caracterizar o grau de antropização de sua bacia. Quatro campanhas foram realizadas, duas na estação seca e duas na estação chuvosa. Um total de 922 exemplares foram coletados, considerando os doze pontos de amostragens selecionados (seis pontos em lagoas e seis pontos em rios), distribuídos em 33 espécies representativas de 16 famílias e 6 ordens. A ordem Characiformes revelou-se a mais representativa (63%), seguida das ordens Perciformes (13%) e Siluriformes (12%). Com relação às famílias, Characidae (41%) foi a mais abundante, seguida pelas famílias Cichlidae (13%) e Poeciliidae (11%). Um espécime de Brycon nattereri foi coletado no Rio Santa Bárbara, espécie criticamente ameaçada no estado de São Paulo; duas espécies não nativas foram encontradas (Metynnis maculatus e Oreochromis niloticus), representado 0,7% do total de espécimes coletados e três espécies tiveram o seu primeiro registro para a bacia do Rio Sapucaí Mirim: Hyphessobrycon bifasciatus, Moenkhausia intermedia e Brycon nattereri. Foram identificadas 65 lagoas marginais ao longo da bacia do Rio Santa Bárbara (45 permanentes, 19 temporárias e 3 meandros abandonados), ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Santa Bárbara River, a small tributary of the Sapucaí-Mirim River, drains an area of 1,013 km². It is inserted in the upper Paraná river basin, a region considered a natural ichthyofaunistic province. This work aims to record the ichthyofauna of this river, some of its marginal lakes and its affluent Rio Potreiro, as well as to characterize the degree of anthropization of its basin. Four campaigns were carried out, two in the dry season and two in the rainy season. A total of 922 specimens were collected, considering the twelve sampling spots selected (six spots in lakes and six spots in rivers), distributed in 33 representative species of 16 families and 6 orders. The Characiformes order came out to be the most representative (63%), followed by Perciformes (13%) and Siluriformes (12%). Regarding the families, Characidae (41%) was the most abundant, followed by families Cichlidae (13%) and Poeciliidae (11%). A species of Brycon nattereri was collected in Santa Bárbara River, a species critically endangered in the state of São Paulo, two non-native species that were found (Metynnis maculatus and Oreochromis niloticus), represented 0.7% of the total specimens collected and three species had the first record for the Rio Sapucaí Mirim basin: Hyphessobrycon bifasciatus, Moenkhausia intermedia and Brycon nattereri. A total of 65 marginal lakes were identified along Santa Bárbara river’s basin (45 permanent, 19 temporary and 3 abandoned meanders), mapping the spatial patterns of the... (Complete abstract click electronic access below) / Mestre