Graduation date: 1995

Zebra mussels (Dreissena polymorpha) have invaded a great proportion of the waters of the eastern part of North America. This mollusk may be a useful sentinel species for bioaccumulation of heavy metals and organic contaminants in aquatic ecosystems. The zebra mussel's capacity to bioaccumulate cadmium at environmentally relevant exposure and to sequester metals in metal-binding proteins, metallothioneins, was investigated. Elevated (relative to control) concentrations of Cd$ sp{2+}$ were detected in Dreissena exposed to $ ge$2 $ mu$g Cd/liter suggesting that zebra mussels cannot regulate Cd$ sp{2+}$ of trace exposure concentration. More than 85% of the measured Cd$ sp{2+}$ was bound to metallothioneins. / Lesser scaup (Aythya affinis) was assessed as a model species for potential impacts of zebra mussels on higher trophic levels. The feasibility of incubating and rearing scaup in semi-natural conditions was evaluated. A series of biomarkers was assessed in 3 groups of scaup fed a contaminant-free diet or diets containing zebra mussels from the St-Lawrence River or Lake Erie. / Lesser scaup proved to be a suitable species to raise in captivity providing daily water misting through out incubation and strict hygiene conditions during brooding. A hatching success of 89% was achieved. Appropriate housing, feeding and bathing conditions yielded low (3%) post-hatching mortality. / Phagocytosis and respiratory burst activities of heterophils of scaup were suppressed after 6 weeks of feeding on zebra mussels, compared to the control group. These two heterophilic functions were negatively correlated with the incidence of pododermatitis (bacterial feet infection), suggesting a suppression of the non specific immunity. Increased liver/body mass ratio and decreased hepatic vitamin A (retinol and retinyl palmitate) concentrations were observed in scaups fed zebra mussels. Lipid accumulation and glycogen overload were found in the livers of scaups fed mussels from the St-Lawrence River and the Lake Erie groups, respectively. These immunological, biochemical and histopathological biomarkers show promise for monitoring "early" injury and may help in the understanding of health impairment of different species of waterfowl exposed to xenobiotics via contaminated food sources.

No description available.

This study consisted of a site characterization followed by a biomonitoring study utilizing the zebra mussel, <i>Dreissena polymorpha</i>, at the Times Beach Confined Disposal Facility (CDF), located in Buffalo, New York. Concentrations of the selected contaminants (polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and the following metals: arsenic (As), chromium (Cr), barium (Ba), mercury (Hg), cadmium (Cd), lead (Pb), selenium (Se) and silver (Ag), were at or below detection limits in the water column. In the sediment toxicant concentrations were as high as 549 mg/kg for total PAHs, 9 mg/kg for PCB Aroclor 1248, and 54, 99, 6, 355, 637, and 16 mg/kg for the metals: As, Ba, Cd, Cr, Pb, and Hg respectively. To predict contaminant bioavailability, elutriate and whole sediment toxicity tests were performed utilizing the cladoceran, <i>Daphnia magna</i>. The whole sediment tests showed a significant impact. Control survival was 84%, while the sediment treatment survival range was 1-7%. Mean control reproduction was 86.8 neonates, whereas treatment group reproduction ranged from 1.4 to 9.0. Zebra mussels, placed both in the water column (Upper) and at the sediment level (Lower), survived the 34-day exposure. Contaminants which significantly accumulated in zebra mussel tissue during the exposure period (mg/kg) were total PAHs (6.58), fluoranthene (1.23), pyrene (1.08), chrysene (0.98), benzo(a)anthracene (0.60), PCB Aroclor 1248 (1.64), As (0.97), Cr (2.87), and Ba (7.00). The accumulation of benzo(a)anthracene was statistically higher in the Upper mussels; however, this did not occur for any other toxicant. Accumulation of these contaminants in zebra mussel tissue represent a potential hazard to organisms (ie. fish and birds) which feed on them. / Master of Science

Risk assessment of environmental exposure to chronic, trace concentrations of contaminants presents an analytical challenge to interpret data in a biologically meaningful way. Biomarkers are compounds that can provide integrated information concerning the effects of contaminants on biochemical processes. The metal-binding protein, metallothionein (MT), is a biomarker of toxic heavy metals, such as cadmium (Cd), since these metals bind to MT in vivo and induce transcription of MT genes with subsequent MT protein synthesis. A high performance liquid chromatography (HPLC)-thermospray microatomization-atomic absorption spectroscopy (AAS) method was developed for detecting Cd proteins from two invertebrate models; freshwater mussels (Pyganodon grandis) from a whole lake ecosystem exposure to Cd (Experimental Lakes Area, Canada), and zebra mussels (Dreissena polymorpha) recently introduced to North America. Methods for coupling gel filtration HPLC to AAS or inductively coupled-mass spectrometry (ICP-MS) were developed to provide sensitive and selective information on metal-binding proteins in freshwater mussel extracts. Sensitive metal detection by these methods necessitated precautions to minimize HPLC column-protein exchange of metals. These interactions were relevant to the determination of low concentrations of mussel MT-like proteins (MLPs) by these metal-specific detection systems. Saturation methods employing Cd as a metallic marker for the quantification of characterized MTs were adapted for freshwater mussels exposed to low environmental Cd concentrations. Characterization of Cd-saturated mussel extracts by HPLC-ICP-MS demonstrated the presence of copper and zinc, metals physiologically bound to MT, in the principal metal-binding fraction of mussel extracts. Experimental results also indicated that mussel MLPs are not as heat-stable as mammalian MT. Zebra mussels were chosen as a bioindicator species for obtaining a standard of freshwater MT biomarker for toxi

Caffeine, a biologically active drug with many known molecular targets, is recognized as a contaminant of aquatic systems including marine systems. Although the concentrations of caffeine reported from aquatic systems are low (ng/L to μ/L), harmful ecological effects not detected by traditional toxicity tests could occur as a result of caffeine contamination. The goals of this thesis project were to: 1) quantify concentrations of caffeine occurring in the coastal ocean off of the Oregon Coast and to determine if higher levels were correlated with proximity to caffeine pollution sources; and 2) investigate the sub-lethal cellular toxicity of environmentally relevant concentrations of caffeine on Mytilus californianus, an intertidal mussel that is one of the dominant species of the Oregon Coast. Caffeine was analyzed at 14 locations in the coastal ocean off of the Oregon Coast. Sampling locations were stratified between populated areas identified as having sources of caffeine pollution and sites located in sparsely populated areas not in proximity to major caffeine pollution sources. Caffeine concentrations were also measured in the major water body discharging near sampling locations. Caffeine was detected in water from the coastal ocean off of the Oregon Coast at concentrations ranging from below the reporting limit to 44.7 ng/L. The occurrence and concentrations of caffeine in the coastal ocean did not correspond well with pollution threats from population density and point and non-point sources, but did correspond with a storm event occurrence. Caffeine concentrations in rivers and estuaries draining to the coast ranged from below the reporting limit to 152.2 ng/L. Hsp70, a molecular biomarker of cellular stress, was used to investigate the sub-lethal toxicity of environmentally relevant concentrations of caffeine to the mussel M. californianus. Hsp70 concentrations in the gill and mantle tissue of mussels exposed to 0.05, 0.2, and 0.5 μ/L of caffeine for 10, 20, and 30 days were compared to basal levels in control mussels. Hsp70 in the gill tissue of M. californianus had an initial attenuation of the stress protein followed by a significant albeit moderate up-regulation relative to controls in all but the 0.5 μ/L treatment. Hsp70 in the mantle tissue of mussels exposed to caffeine did not differ from control mussels. This Study confirms the presence of caffeine in Oregon's coastal ocean and provides laboratory evidence that environmentally relevant concentrations of caffeine can exert an effect on M. californianus gill tissue at the molecular-level.

No description available.

Contaminants such as pharmaceuticals are of increasing concern due to their ubiquitous use and persistence in surface waters worldwide. Limited attention has been paid to the effects of pharmaceuticals on marine life, despite widespread detection of these contaminants in the marine environment. Of the existing studies, the majority assess the negative effects of pharmaceuticals over an exposure period of 30 days or less and focus on cellular and subcellular biomarkers. Longer studies are required to determine if chronic contaminant exposure poses risks to marine life at environmentally relevant concentrations. Also scarce in the literature is examination of whole organism effects to identify potential community-level consequences. Two long-term studies with the antidepressant pharmaceutical, fluoxetine (the active constituent in Prozac®) were conducted to determine whether nominal concentrations detected in estuarine and coastal environments affect organism health and interactions. First, we measured whole organism metrics in the California mussel, Mytilus californianus over a period of 107 days. Specifically, we measured algal clearance rates, growth, and condition indices for both reproductive and overall health. We found that fluoxetine negatively affects all measured characteristics, however many effects are mediated by length of exposure. Perhaps the most notable result was that mussels spiked with fluoxetine cleared less algae after 30 days of exposure. Reduced growth and condition indices likely are a consequence of improper nutrition among fluoxetine-treated mussels. Any level of fluoxetine significantly affected the gonadosomatic index after 47 days. The results from this study on mussels fill an important data gap, highlighting organism-level effects of chronic exposure periods; such data more explicitly identify the impacts of pharmaceuticals and other contaminants on marine communities and ecosystems. Fluoxetine has also been documented to affect the behavior of fish and invertebrates, including freshwater and marine bivalves, crustaceans, and fish. Given that other crustaceans exhibited increased activity levels under fluoxetine exposure, we hypothesized that this would subject them to greater predation risk. In our second exposure study, we assessed whether a similar range of fluoxetine concentrations used in the mussel study altered the risk behavior of the Oregon mud crab, Hemigrapsus oregonensis, in response to a common predator, the red rock crab, Cancer productus. We conducted this study for 60 days, conducting day and night behavioral trials (with and without predators) four times a week. We found that crabs exposed to any amount of fluoxetine (3 or 30 ng/L) had increased activity levels relative to controls; however behaviors of 3 ng/L-spiked crabs were not always significantly different from controls. Among control crabs, day and night trials yielded similar results, where a clear response to the addition of the predator was observed. Crabs dosed with fluoxetine exhibited more foraging and active behaviors in the presence of the predator. Additionally, crabs spiked with fluoxetine at 30 ng/L had the greatest risk of mortality either by predation by red rock crabs or due to more aggressive behaviors among conspecifics. The results of this study shed light on a particularly unexplored area of contaminants research: how do psychoactive pharmaceuticals affect animal behavior when exposed to the low concentrations persisting in the aquatic environment for a prolonged period of time?