The use of mussels as indicators of pollution in fresh- and seawater was reviewed and the ability of the freshwater mussel 'Anodonta anatina' to absorb Cadmium-115m and zinc-65 from its environment was studied. The uptake was studied when the metals were available in solution only and in the algal food supply. A higher accumulation occurred in the tissues when the metals were available in the food and they were concentrated up to 2x10[sup]3 times for zinc-65 and 1x10[sup]3 times for cadmium-115m above the levels found in the water. Those tissues with large surface areas in contact with the water (i.e. the gills and the mantle) and those involved with processing food (i.e. the digestive gland and kidney) were found to take up the tracers most rapidly. The muscular tissues took up the least amount of tracers. The uptake into the tissues from each source was compared and the metabolic consequences discussed. Depuration of the metals from the tissues was studied when the mussels were placed in uncontaminated water. Although the total body burdens of the tracers declined, a loss was not recorded for all the tissues. For some tissues, notably the digestive gland and the adductor muscles with cadmium-155m and the gonad and kidney with zinc-65, a continued uptake was recorded. It was concluded that permanent binding sites for the metals might exist in some tissues. The fate of cadmium in the tissues was studied. Cadmium was found to be located in the cytosol and associated with low molecular weight proteins. These proteins were found to have low aromatic amino acid and high cysteine content as indicated by their absorption characteristics at 280 and 250 nm respectively. These properties together with the demonstrated heat stability indicated that the cadmium-binding proteins in 'Andonta' are similar to metallothioneins indentified in other species.

Lake Rotokakahi is a mesotrophic lake located within the Rotorua Lakes District, North Island, New Zealand. Under the legal guardianship of the Tuhourangi and Ngati Tumatawera tribes of Te Arawa it has remained closed to the public since 1948. Lake Rotokakahi was last monitored regularly in 1996 under the Environment Bay of Plenty (EBOP) water quality monitoring programme with only the lake outlet (Te Wairoa Stream) being monitored since that time. Water quality data collected up to 1996 suggests that there may be degradation of water quality in the lake, as indicated by declining levels of dissolved oxygen in the bottom waters. Lake Rotokakahi steeped in historical significance, as well as having major cultural and recreational values was well known for its abundant resources and as the name suggests, particularly for its massive supply of the freshwater mussel or kakahi (Hyridella menziesi). Freshwater mussel species worldwide are in decline however little is known on factors controlling kakahi abundance and distribution. The overarching objective of this thesis is update water quality data last monitored in Lake Rotokakahi in 1996 while also identifying key environmental variables thought to influence kakahi populations. This objective is underpinned by a number of aims that include: Establishment of a 12-13 month water quality programme within Lake Rotokakahi so that data is obtained for comparisons with previous water quality data (pre-1997) to allow assessment of whether there have been water quality changes in the lake. Conduct a population survey of the resident kakahi population examining possible environmental factors influencing their populations. Present an oral history of Lake Rotokakahi focusing on its historical significance, water quality, and collection of kairoto (food collected form lakes). from the 18 September 2006 to 14 September 2007 monthly water sampling was carried out at a mid lake station, the lake outflow and inflow for measures of nutrients, phytoplankton, zooplankton and chlorophyll a. Vertical profiles of temperature dissolved oxygen and chlorophyll fluorescence were also taken on various part of Lake Rotokakahi. A lengthened period of anoxia in the bottom waters during thermal stratification was recorded with increased levels of chlorophyll a in winter and reduced secchi disk depth indicating an increase in phytoplankton biomass. Nutrient concentrations remain moderate relative to historical data. On going water quality monitoring on Lake Rotokakahi is recommended to further evaluate the extent of which water quality change is occurring. This will provide a better understanding of how Lake Rotokakahi can be best managed to further preserve the lake. On 1 March and 20 April kakahi were sampled at five sites. Large kakahi densities were distributed predominantly in depths above the hypolimnion. Chlorophyll a fluorescence and dissolved oxygen were found to be the best correlates for kakahi density and biomass respectively. Low dissolved oxygen concentrations in the hypolimnion are thought to restrict kakahi distributions to above the thermocline in periods of hypolimnetic anoxia.

Laboratory bioassays results suggest that early life stages of freshwater mussels are sensitivity to toxicants. However, toxicological databases for unionids are rather limited because standard test methods are yet developed, and no published studies report endpoints for chronic test that are > 9 days. The primary goals of my thesis research were to assess acute and chronic toxicities of chlorine and mercury to early life stages. Inter- and intra-specific species variability in the tolerances of glochidia was observed during acute laboratory bioassays as endpoints were between 8 - 43 ppb for Hg tests, 1.0 - 2.5 ppm for NaCl tests, and 70 - 260 ppb for chlorine (TRC) tests. Glochidia of several species had equal or greater sensitivities to Hg and NaCl than test organisms commonly used to assess environmental risk (i.e.Ceridaphnia dubia, Daphnia magna, Pimephales promelas), whereas they were far more tolerant to TRC than many species. Twenty-one day chronic test endpoints for juveniles were substantially lower than those calculated during acute bioassays with glochidia. Villosa iris 3-mo old juveniles were found to be quite sensitive to Hg as growth was significantly impaired at 8 ppb Hg. Chronic bioassays with TRC revealed a distinct decrease in susceptibility with increased aged for V. iris (relative sensitivities 3-mo > 6-mo > 12-mo), and that 2-mo old Epioblasma capsaeformis were more sensitive than comparable age classes of V. iris. However, both species were tolerant compared to other aquatic organisms, as the lowest endpoint was 20 ppb TRC. / Master of Science

A flow-through pond at White Sulphur Springs National Fish Hatchery was evaluated as culture environment for juvenile freshwater mussels of Villosa iris and Lampsilis fasciola. Survival did not differ significantly (p = 0.1910) over 93 d for V. iris cultured with silt (mean 49.8% ± SD 14.5) and without (mean 32.9% ± SD 11.7). Survival differed significantly (p <0.0001) between juveniles of V. iris (mean 49.8% ± SD 14.5 at age 93 d) and L. fasciola (mean 6.3% ± SD 4.5 at age 86 d). This may indicate that the pond failed to meet requirements of L. fasciola, or may have resulted from microhabitat variables. Growth did not differ significantly between species (p = 0.1315). Villosa iris reached a mean length of 1.81 mm ± SD 0.67, and L. fasciola 1.78 mm ± SD 0.78. Water quality parameters remained within suitable ranges, and planktonic algal densities were between 2850 - 6892 cells/mL. Survival of V. iris and growth of both species compares favorably to previous culture attempts. Juveniles of V. iris and L. fasciola were exposed to ammonium chloride solutions for 96 h in static renewal conditions at 12°C and 20°C. Calculating LC50 values with the Trimmed Spearman-Karber method, juveniles of L. fasciola (mean 96 h LC50 of 0.26 mg/L NH3-N) were significantly more tolerant of unionized ammonia than juveniles of V. iris (mean 96 h LC50 of 0.11 mg/L NH3-N). The only organisms with reported LC50 values lower than those seen for V. iris juveniles were Ceriodaphnia dubia and Hyella azteca. / Master of Science

No description available.

River-floodplain connectivity is the degree of water-driven transport of matter, energy, and organisms between rivers and their floodplains. Recent advancement of high-resolution lidar data and numerical modeling is helpful to explore river-floodplain connectivity precisely to improve our predictions of sediment transport and deposition on floodplains. In the present work, we studied floodplain sediment transport and deposition, and juvenile mussel settling in three river systems in the US. A two-dimensional hydrodynamic model was developed and simulated model results were coupled with field measurements to study river-floodplain systems of the East Fork White River in Indiana, South River in Virginia, and Dan River in North Carolina. Results show that the East Fork White River in Indiana is capable of supplying sand to the channels on the floodplain and these floodplain channels can transport sand in suspension and gravel as bedload. These floodplain channels are supply limited under the current hydrologic regime and identified as net erosional. On the South River floodplain in Virginia, incorporating hydrologic flowpaths as an explicit measure of river-floodplain connectivity can improve predictions of floodplain sediment deposition. Three regression models were developed incorporating flow pathways and the best model was applied to hydrodynamic model results to create a spatial map of floodplain sedimentation rate. The deposition map highlights how floodplain topography and river-floodplain connectivity affect sedimentation rates and can help inform the development of floodplain sediment budgets. Lastly, streamflow conditions were investigated in the Dan River, North Carolina as they affect juvenile freshwater mussel settling. Two uplooking velocity sensors on the river bed were deployed and hydraulic parameters were measured for a 7-mo period in May-November 2019 to estimate the juvenile mussel settling. Results show that juvenile freshwater mussels as large as 280-508 µm could always be suspended during our study period and not be able to settle onto the river bed at the location of our velocity sensors. Therefore, the flow and shear velocity during our study period was high enough to prohibit the recruitment of juvenile freshwater mussels from settling out of suspension at the sensor locations. Modest flow obstructions such as large boulders, downed trees, or large wood that create downstream wakes may be important features that provide suitable conditions for the settling of juvenile freshwater mussels onto the river bed. Furthermore, low flows have been increasing since the year 2000 which may be exacerbating the decline in freshwater mussel populations. / Doctor of Philosophy / Human civilization has developed near rivers due to the wide range of benefits provided by rivers. Rivers provide food, water, and energy to more than 2.7 billion people around the world. However, the health of the rivers is degrading rapidly to meet the increasing demand of the growing population. We studied water, sediment, and mussel transport in the three rivers in the US: East Fork White River in Indiana, South River in Virginia, and Dan River in North Carolina. These rivers play an important role in agriculture, water supply, sediment, and nutrient transport of the surrounding environment. Our research work on East Fork White River in Indiana, USA shows that the area directly adjacent to the river is eroding, which is important information for river managers and policymakers. As part of that work, we identified the potential of various sizes of sediment to move over this area at different flows and developed a method to predict the largest sediment size that could be moved in water and hopping along the ground. This method is also applicable to other areas along rivers and the coast. We estimated the sediment deposition rate, deposition volume, and prepared a spatial map of the sediment deposition pattern for the South River floodplain in Virginia. From this map, deposition hot spots could be identified. We estimated that 66% of the sediment deposited adjacent to the South River was located in 32% of the area. This information will be helpful for understanding how sediment and sediment-associated pollutants deposit around rivers. Our work on the Dan River in North Carolina was focused on freshwater mussels. Our results showed that juvenile freshwater mussels could not have settled onto the river bed at the location of our measurements. Historical data reveal that freshwater mussels are declining at an alarming rate in that river, posing a threat to the river environment. We identified that streamflow has been increasing over the last two decades, which could be a potential cause of declining freshwater mussels.

Conservation efforts that involve habitat protection, population augmentation, and species reintroductions require knowledge of the habitat requirements, distribution, and abundance of a species—information that can be challenging to acquire, especially for rare organisms with patchy distributions. In this thesis, I develop a protocol for the use of environmental DNA (eDNA) and create a Species Distribution Model for the endangered James spinymussel, Parvaspina collina (Unionidae). The results of this work show that eDNA is a robust tool for identifying species presence but not for estimating the relative abundance of populations. This study found that P. collina’s distribution is influenced by abiotic habitat characteristics related to sedimentation and runoff rather than by the distribution of its host fishes. The predicted habitat suitability was used to identify locations of priority conservation concern and these results can be used to direct future sampling efforts, identify potential dispersal routes, and inform conservation decisions.

Submitted by Jordan (jordanbiblio@gmail.com) on 2017-03-13T15:32:07Z No. of bitstreams: 1 DISS_2015_Anderson Wakinaguni Michiura.pdf: 703669 bytes, checksum: 60597a6b6125e23795b4c0739d397627 (MD5) / Approved for entry into archive by Jordan (jordanbiblio@gmail.com) on 2017-03-14T15:58:39Z (GMT) No. of bitstreams: 1 DISS_2015_Anderson Wakinaguni Michiura.pdf: 703669 bytes, checksum: 60597a6b6125e23795b4c0739d397627 (MD5) / Made available in DSpace on 2017-03-14T15:58:39Z (GMT). No. of bitstreams: 1 DISS_2015_Anderson Wakinaguni Michiura.pdf: 703669 bytes, checksum: 60597a6b6125e23795b4c0739d397627 (MD5) Previous issue date: 2015-02-27 / CAPES / Os bivalves de água doce são um grupo com alto risco de extinção devido às mudanças climáticas, expansão urbana, construção de reservatórios hidrelétricos, crescimento populacional, eutrofização, degradação dos habitats, poluição pontual e difusa dos ecossistemas aquáticos. O objetivo deste trabalho foi identificar quais fatores físicos e químicos da água e sedimento que determinam a estrutura da comunidade de bivalves em 18 lagoas adjacentes ao rio Cuiabá, nos ambientes urbanos e não urbanos. A amostragem dos bivalves foi realizada pelo tateio no fundo das lagoas e por coleta de sedimentos ao longo do transecto com auxílio de uma peneira. Variáveis físicas e químicas da água e % de matéria orgânica do sedimento foram mensuradas e usadas como preditoras da abundância e estrutura da comunidade de bivalves pela ordenação da análise de componentes principais, regressão multivariada e análise de redundância (RDA). A RDA demonstrou uma relação das concentrações de nitrato e % de matéria orgânica com a estrutura da comunidade de bivalves. As espécies encontradas foram A. trapesialis (50,66%), Pisidium sp. (26,98%), C. fluminea (7,48%), C. inflata (6,82%) e A. elongatus (6,16%). As populações de A. trapesialis e A. elongatus estiveram relacionadas positiva e significativa com o nitrato. O aumento da % de matéria orgânica no sedimento esteve relacionado com menor abundância de A. elongatus, entretanto pouca relação com a classe de comprimento das valves. A espécie A. trapesialis teve efeito positivo e significativo com a variável oxigênio dissolvido em relação à classe de comprimento das valves. Os fatores ambientais que refletem os nutrientes podem influenciar na distribuição da comunidade de bivalves de água doce, no entanto, não determinam a estrutura da comunidade em lagoas urbanas e não urbanas. / Freshwater mussels are a group at high risk of extinction due to climate change, urban expansion, construction of hydroelectric reservoirs, population growth, eutrophication, habitat degradation, pollution and diffuse spot of aquatic ecosystems. This works was to identify which physical and chemical factors of the water and sediment that determine the structure of mussels community in 18 of ponds the Cuiaba river, in urban and non-urban environments. Sampling of mussels was conducted by groping the bottom of ponds and collecting sediment along transect with the aid of a sieve. The physical and chemical water variables and % organic matter in the sediment were measured and used as predictors of abundance and structure of the mussel community by ordering the principal component analysis, multivariate regression and redundancy analysis (RDA). The RDA showed a ratio of nitrate concentrations and % organic matter having the structure of mussels community. The species were A. trapesialis (50,66%), Pisidium sp. (26.98%) C. fluminea (7,48%), C. inflata (6,82%) and A. elongatus (6,16%). Populations of A. trapesialis and A. elongatus were positively and significantly related to nitrate. Increased % of organic matter in the sediment was associated with a lower abundance of A. elongatus, however little to do with the length class of valves. The species A. trapesialis had a positive and significant effect on the variable dissolved oxygen relative to the valves length class. Environmental factors that reflect the nutrients may influence the distribution of freshwater mussels community, however, not determine the community structure in urban and non-urban environments.

No description available.

Freshwater mussels is one the most endangered groups of organisms worldwide and stand in front of several threats. Global warming along with anthropogenic influence affect the mussel’s natural habitat and stress leads to changes in their behaviour. The aim was to investigate if the behaviour of Unio tumidus exposed to thermal stress differs depending on fine particulate matter exposure. This study hypothesises that (1) the critical thermal maximum of mussels is lower in high turbidity than in clear water (2) mussels in highly turbid water extend their foot at a lower temperature than in clear water (3) mussels have a more frequent gaping behaviour in high turbidity than in clear water. Mussels were placed in each water filled beaker with sensors glued to their shells for monitoring gaping behaviour. Aquarium heaters increased the water temperature gradually until the mussels reached their CTM. One group were placed in clear river water and one group in water with high turbidity. There was no significant difference in the CTM between the highly turbid and clear water. The mussels in the river water extended their foot at a lower temperature compared to the mussels in high turbidity. One possible explanation is that the mussels remain shut to protect themselves due to higher stress levels. Valve gaping behaviour was visually investigated and displayed different patterns between mussels in clear and highly turbid water. This study contributes with information regarding mussel behaviour and response to thermal stress which can be of value for future studies. / Sötvattenmusslor är en av de mest hotade organismerna i världen och står inför flera hot. Global uppvärmning tillsammans med antropogen inverkan påverkar musslornas naturliga livsmiljö och stress leder till förändringar i deras beteende. Syftet var att undersöka om beteendet hos Unio tumidus som utsätts för termisk stress skiljer sig beroende på exponering av fina partiklar. Denna studie antar att (1) critical thermal maximum för musslor är lägre vid hög turbiditet än i åvatten (2) musslor i hög turbiditet sträcker ut sin fot vid en lägre temperatur än i åvatten (3) musslor har ett mer frekvent öppningsbeteende vid hög turbiditet än i åvatten. Musslor placerades i vattenfyllda bägare med sensorer limmade på sina skal för att övervaka öppningsbeteende. Akvarievärmare ökade vattentemperaturen gradvis tills musslorna nådde sitt critical thermal maximum. En grupp placerades i åvatten och en grupp i vatten med hög turbiditet. Det fanns ingen signifikant skillnad i CTM mellan hög turbiditet och åvattnet. Musslorna i åvattnet sträckte ut sin fot vid en lägre temperatur jämfört med musslorna i hög turbiditet. En möjlig förklaring är att musslorna förblir stängda för att skydda sig på grund av högre stress. Öppningsbeteende undersöktes visuellt och visade olika mönster mellan musslor i åvatten och vatten med hög turbiditet. Denna studie bidrar med information om musslornas beteende och respons på termisk stress som kan vara av värde för framtida studier.