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Currently there are three companies producing bitumen from the Athabasca Oil Sands Region located near Fort McMurray, Alberta, Canada. Extraction of bitumen produces solid (sand) and liquid (water with suspended fine particles) tailings material, called oil sands process affected-materials (OSPM). These waste materials are stored on site due to a zero discharge policy and must be reclaimed when operations end. The OSPM is known to contain naphthenic acids (NAs) and polycyclic aromatic hydrocarbons (PAHs) and has high pH and salinity. A possible method of reclamation is the wet landscape approach, which involves using OSPM to form wetlands that would mimic natural wetland ecological functioning. This study investigated the effects of wetlands formed with OSPM on wood frog larvae (<i>Rana sylvatica</i>), using endpoints including survival, growth, time to metamorphosis, hormonal status, and detoxification enzyme induction [ethoxyresorufin-o-dealkylase (EROD) activity].<p> <i>In-situ</i> caging studies were completed in 2006 and 2007. Four wetlands were studied in 2006 and 14 wetlands were studied in 2007. The 2006 season saw a host of problems that were resolved for the 2007 season. In 2006, tadpole survival did not differ among reference wetlands and old OSPM-affected wetlands but there was 100% mortality of tadpoles in the young OSPM-affected sites that contain the highest concentration of toxic components. Results were similar in 2007, with tadpoles raised in young OSPM-affected wetlands having 41.5%, 62.6%, and 54.7% higher tadpole mortality than old OSPM-affected, young reference, and old reference wetlands, respectively. In 2007, tadpoles from young OSPM-affected sites had delayed metamorphosis (12 days longer than tadpoles from old reference wetlands and 18 days longer than tadpoles in old OSPM-affected wetlands). The thyroid hormone ratios of tadpoles in young OSPM-affected wetlands were between 25% and 42% lower than tadpoles in all other wetlands groups. The EROD activity of tadpoles in young OSPM-affected wetlands was an average 223% higher than those in old OSPM-affected wetlands, showing us that tadpoles were responding to higher levels of contaminants in young OSPM-affected wetlands. Size differences were only noted in 2007, most likely not as a result of exposure to OSPM, but due to differences in population density. The results of this study lead us to believe that toxicity due to OSPM decreases as wetlands get older and OSPM-affected wetlands could support native amphibian populations if they are allowed to mature. Since we considered wetlands to be old if they were seven years or older and the fact that old-OSPM wetlands showed effects on tadpoles similar to those of reference wetlands and showed much less toxicity than young OSPM-affected wetlands, we believe wetlands that are at least seven years old would sustain amphibian life.

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The importance of fossils to phylogenetic reconstruction is well established. However, analyses of fossil data sets are confounded by problems related to the incomplete nature of the specimens. Taxa that are incompletely known are problematic because of the uncertainty of their placement within a tree, leading to a proliferation of most parsimonious solutions because of wild card behavior. Problematic taxa are commonly deleted based on a priori criteria of completeness. Paradoxically, a taxon's problematic behavior is tree dependent, and levels of completeness are not necessarily associated with problematic behavior. Exclusion of taxa based on completeness eliminates real character conflict and, by not allowing incomplete taxa to determine tree topology, the phylogenetic hypothesis is diminished. / A method is proposed to allow optimization of taxonomic inclusion and tree stability. It identifies and removes taxa causing multiple most parsimonious solutions, producing a more stable topology, called the phylogenetic trunk. This method is used in an analysis of the Paleozoic Lepospondyli. A single most parsimonious tree, or trunk, was found after removal of one taxon identified as being problematic. The 38 trees found one additional step from this primary trunk are reduced to two by removal of one additional taxon. These trunks are compared to the trees found by excluding taxa with various degrees of completeness. Effects of incomplete taxa are explored by comparison with the stable tree. Correlated characters associated with limblessness are discussed regarding the assumption of character independence. Inclusion of intermediate taxa is found to be the single best method for breaking down long branches.

Amphibians are of great ecological importance and a loss of species will have widespread and dire consequences. Recent population declines and extinctions have resulted in amphibians being labelled the most threatened vertebrate class on a global scale. The unique Okavango ecosystem is well known and documented, yet the amphibians of this region are poorly known. This project aimed at assessing diversity in the Okavango Delta by testing isolation as a possible driver for community composition; determining the effect of hydrology on breeding behaviour; and assessing the status and prevalence of the pathogen Batrachochytrium dendrobatidis (Bd) responsible for the widespread epidemic chytridiomycosis implicated in amphibian decline. Using various monitoring techniques, observations of species occurrence were made at three locations representing different degrees of isolation over a 20 month period. Breeding indicators were observed and frogs were screened for amphibian chytrid fungus. A total of 29 species were recorded, and results indicated that there were no significant differences in community composition between the sampled localities. Species presence, however, was significantly correlated with habitat type. Thus, the availability of suitable habitat appears to be driving amphibian diversity patterns, rather than geographic isolation; and increased habitat diversity near the Delta periphery explains increased amphibian diversity in these areas. Results from breeding indicators suggested that reproduction in continuous breeders was correlated with the annual flood as well as rainfall, whilst that of explosive breeders was correlated with rainfall alone. It is thus proposed that opportunistic breeding behaviour for some amphibian species is driven by the hydrology of the ecosystem; and this may be explained by increased biological production associated with the flood pulse. Outcomes highlight the unique nature of the Okavango Delta system, and emphasises the need for its preservation. A total of 249 swab samples were collected and screened for amphibian chytrid fungus. The geographical distribution of collection samples were evenly spread throughout the localities, and were obtained from at least 25 amphibian species. Analyses proved negative for Bd for the 79.92% swabs analysed thus far and it is concluded that Bd seems absent in the study region, a result which has massive conservation implications for the region. Despite the fact that the Okavango Delta has benefitted from conservation and tourism efforts in the past, the system and its biodiversity remains threatened and effective conservation management strategies must be devised and implemented to ensure its preservation. / Thesis (M.Sc. (Environmental Science))--North-West University, Potchefstroom Campus, 2011.

The movements of Western Chorus Frogs (Pseudacris, triseriata triseriata) were studied from March, 1970, to March, 1971, at the Robert H. and Esther L. Cooper Woodland Area near Muncie, Delaware County, Indiana. The objectives of the study were to determine: (1) the time and rate of dispersal from the breeding pool; (2) the day-to-day movements, including the time and minimal distance traveled; (3) the preferred cover or microhabitat; and (4) the site of hibernation.Seventy-three Chorus Frogs were tagged with approximately 50 μc Co60 and toe-clipped, and each was released at its capture site. The frogs were then sought at intervals by surveying the area with a portable survey meter equipped with a scintillation probe. The location of each recovered specimen and a description of the recapture site was recorded.Sixty-two individual specimens were recaptured at least one time. The number of recaptures for each specimen was variable, and the maximum number of recaptures for a single specimen was 26 times. In all, 324 recoveries of tagged specimens were made. The tagged specimens graduallybecame lost to the investigator, and the last specimen was found on August 4. The longest period of contact for an individual frog was 134 days.Some Chorus Frogs began leaving the breeding pools soon after the first eggs were observed on April 1. The exodus appeared to be gradual as a few (one to eight) additional tagged specimens were found out of the pools throughout April and early May. Four of these specimens returned at least once to their original pool and seventeen frogs entered a second pool.From a single attempt to monitor the overnight activities of these frogs, it appears that they remain quiescent during the daylight hours and become active between dusk and dawn.The minimal distances traveled by the tagged, specimens during the study are more a function of the length of the contact period and the number of recaptures than of the activity of the frogs. The average rate of movement for all of the specimens over the entire study period was 11.3 feet/day. However, the fastest observed rate of movement for a single specimen between two recapture sites was 138 feet/day. The greatest straight distance any specimen was found from its original pool was 700 feet. Most recaptures were within 500 feet of the pools where the specimens were tagged.In 213 (91.3%) of the 234 recaptures made daylight hours after the frogs left the breeding pools,the frogs were hidden in the leaf litter of the woods or dead grasses of the grassland. In the remaining recaptures the frogs were hidden under small objects. The frogs seemed to prefer moist rather than dry or wet cover, but this is possibly more a reflection of conditions at the time of the study than a preference on the part of the frogs.The gradual disappearance of the tagged frogs from the study area, the woodland situation of the breeding pools, and the concentration of searching efforts in the vicinity of the pools prevented the determination of the preferred habitat type (woodland or grassland). Also, because of the loss of all tagged specimens by the end of summer, hibernating sites were not located.There is evidence that the gradual disappearance of tagged specimens may be explained by predation or movement of the frogs underground or out of the study area. Other frogs lost their cobalt wires and could no longer be located.

Amphibians are of great ecological importance and a loss of species will have widespread and dire consequences. Recent population declines and extinctions have resulted in amphibians being labelled the most threatened vertebrate class on a global scale. The unique Okavango ecosystem is well known and documented, yet the amphibians of this region are poorly known. This project aimed at assessing diversity in the Okavango Delta by testing isolation as a possible driver for community composition; determining the effect of hydrology on breeding behaviour; and assessing the status and prevalence of the pathogen Batrachochytrium dendrobatidis (Bd) responsible for the widespread epidemic chytridiomycosis implicated in amphibian decline. Using various monitoring techniques, observations of species occurrence were made at three locations representing different degrees of isolation over a 20 month period. Breeding indicators were observed and frogs were screened for amphibian chytrid fungus. A total of 29 species were recorded, and results indicated that there were no significant differences in community composition between the sampled localities. Species presence, however, was significantly correlated with habitat type. Thus, the availability of suitable habitat appears to be driving amphibian diversity patterns, rather than geographic isolation; and increased habitat diversity near the Delta periphery explains increased amphibian diversity in these areas. Results from breeding indicators suggested that reproduction in continuous breeders was correlated with the annual flood as well as rainfall, whilst that of explosive breeders was correlated with rainfall alone. It is thus proposed that opportunistic breeding behaviour for some amphibian species is driven by the hydrology of the ecosystem; and this may be explained by increased biological production associated with the flood pulse. Outcomes highlight the unique nature of the Okavango Delta system, and emphasises the need for its preservation. A total of 249 swab samples were collected and screened for amphibian chytrid fungus. The geographical distribution of collection samples were evenly spread throughout the localities, and were obtained from at least 25 amphibian species. Analyses proved negative for Bd for the 79.92% swabs analysed thus far and it is concluded that Bd seems absent in the study region, a result which has massive conservation implications for the region. Despite the fact that the Okavango Delta has benefitted from conservation and tourism efforts in the past, the system and its biodiversity remains threatened and effective conservation management strategies must be devised and implemented to ensure its preservation. / Thesis (M.Sc. (Environmental Science))--North-West University, Potchefstroom Campus, 2011.

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