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• 1. [Article] Abundance and Distribution of Major and Understudied Archaeal Lineages at Globally Distributed Deep-Sea Hydrothermal Vents

  Deep-sea hydrothermal vents are some of the most biologically productive ecosystems on Earth, yet receive little to no input of photosynthetically derived organic matter. The trophic system at hydrothermal ...

  Citation × Citation Citation Abstract Copy Title: Abundance and Distribution of Major and Understudied Archaeal Lineages at Globally Distributed Deep-Sea Hydrothermal Vents Author: Rutherford, Alexander Fenner Year: 2014 Deep-sea hydrothermal vents are some of the most biologically productive ecosystems on Earth, yet receive little to no input of photosynthetically derived organic matter. The trophic system at hydrothermal vents is based primarily on the reduction-oxidation (redox) of inorganic chemicals by Bacteria and Archaea. However, the distributional patterns of the microorganisms that colonize deep-sea hydrothermal vent deposits and their link to the geologic setting are still not deeply understood. The goal of the studies presented in this thesis was to quantify the abundance, and distribution of major and understudied vent colonizing archaeal groups from globally distributed and geochemically distinct hydrothermal vent fields. The archaeal community composition was analyzed using quantitative PCR with lineage specific functional gene primers that target methanogens, and 16S rRNA gene primers designed or optimized from this study for the Thermococcales, Archaeoglobus, Ignicoccus and marine Nanoarchaeota. Overall, a general relationship was demonstrated between the geochemical differences of the hydrothermal vent fields and the archaeal community structure. The archaeal community assemblage varied dramatically from hydrothermal vents with different vent host rocks along the Mid-Atlantic Ridge and Eastern Lau Spreading Center. In contrast, two vent fields in the East Pacific, 9°N on the EPR and Guaymas Basin that are basalt and basalt-sediment hosted were found to have similar community composition. These observed differences may be driven in part by the metabolically available chemical energy as hydrogen oxidizing lineages of the methanogens and Archaeoglobus were found in higher abundance in the samples from vent field that had a high concentration of end-member hydrogen and the heterotrophic Thermococcales constituted a higher proportion of the archaeal community at the less enriched vent fields. Interestingly, the Nanoarchaeota and the genus of its only confirmed symbiont, Ignicoccus, were found to have an inconsistent proportional relationship, with the Nanoarchaeota comprising a larger proportion of the archaeal community at the ultramafic and fast spreading basalt vent fields and Ignicoccus at the ultra-slow spreading basalt and andesite hosted vent fields. There was also a more localized pattern identified within the hydrothermal vent deposit. The chemosynthetic lineages of the methanogens and Archaeoglobus constituted a higher proportion of the archaeal community in chimney samples compared to Thermococcales that was found in a higher proportion at horizontal flange samples. This archaeal proportional shift could be driven by energetic micro-niches within the vent deposit, as the chemolithotrophic lineages colonize the area closest to the venting source, and the heterotrophic Thermococcales dominate in more mature structures further from the venting source. Quantitative assessments of the archaeal community composition from this study provided added insight into the dynamic geologic influence on the archaeal lineages that colonize deep-sea hydrothermal vents, on a global and local scale. Title: Abundance and Distribution of Major and Understudied Archaeal Lineages at Globally Distributed Deep-Sea Hydrothermal Vents Author: Rutherford, Alexander Fenner Year: 2014 Deep-sea hydrothermal vents are some of the most biologically productive ecosystems on Earth, yet receive little to no input of photosynthetically derived organic matter. The trophic system at hydrothermal vents is based primarily on the reduction-oxidation (redox) of inorganic chemicals by Bacteria and Archaea. However, the distributional patterns of the microorganisms that colonize deep-sea hydrothermal vent deposits and their link to the geologic setting are still not deeply understood. The goal of the studies presented in this thesis was to quantify the abundance, and distribution of major and understudied vent colonizing archaeal groups from globally distributed and geochemically distinct hydrothermal vent fields. The archaeal community composition was analyzed using quantitative PCR with lineage specific functional gene primers that target methanogens, and 16S rRNA gene primers designed or optimized from this study for the Thermococcales, Archaeoglobus, Ignicoccus and marine Nanoarchaeota. Overall, a general relationship was demonstrated between the geochemical differences of the hydrothermal vent fields and the archaeal community structure. The archaeal community assemblage varied dramatically from hydrothermal vents with different vent host rocks along the Mid-Atlantic Ridge and Eastern Lau Spreading Center. In contrast, two vent fields in the East Pacific, 9°N on the EPR and Guaymas Basin that are basalt and basalt-sediment hosted were found to have similar community composition. These observed differences may be driven in part by the metabolically available chemical energy as hydrogen oxidizing lineages of the methanogens and Archaeoglobus were found in higher abundance in the samples from vent field that had a high concentration of end-member hydrogen and the heterotrophic Thermococcales constituted a higher proportion of the archaeal community at the less enriched vent fields. Interestingly, the Nanoarchaeota and the genus of its only confirmed symbiont, Ignicoccus, were found to have an inconsistent proportional relationship, with the Nanoarchaeota comprising a larger proportion of the archaeal community at the ultramafic and fast spreading basalt vent fields and Ignicoccus at the ultra-slow spreading basalt and andesite hosted vent fields. There was also a more localized pattern identified within the hydrothermal vent deposit. The chemosynthetic lineages of the methanogens and Archaeoglobus constituted a higher proportion of the archaeal community in chimney samples compared to Thermococcales that was found in a higher proportion at horizontal flange samples. This archaeal proportional shift could be driven by energetic micro-niches within the vent deposit, as the chemolithotrophic lineages colonize the area closest to the venting source, and the heterotrophic Thermococcales dominate in more mature structures further from the venting source. Quantitative assessments of the archaeal community composition from this study provided added insight into the dynamic geologic influence on the archaeal lineages that colonize deep-sea hydrothermal vents, on a global and local scale. Close

• 2. [Article] Currents in Fishery Management

  This thesis provides an overview of fishery management policy types and attempts to determine best practices for biological sustainability in terms of species preservation and biomass recovery. Key concepts ...

  Citation × Citation Citation Abstract Copy Title: Currents in Fishery Management Author: DePuy, Genevieve Year: 2016 This thesis provides an overview of fishery management policy types and attempts to determine best practices for biological sustainability in terms of species preservation and biomass recovery. Key concepts include biological sustainability, regulatory forces, and fishery management and output trends. The research question investigated is: what are the best policy practices for regulating marine fishery health and biological stability? The research process of this paper included a review of prior literature in the field of marine policy and fishery management, as well as the use of United States data from the Pacific and Atlantic coasts to evaluate management strategies. Based on both the literature review and the results of the data from Pacific and Atlantic Fisheries, the best management structure appears to be the co-management approach while the best management methodologies involve ecosystem protections and quotas. Title: Currents in Fishery Management Author: DePuy, Genevieve Year: 2016 This thesis provides an overview of fishery management policy types and attempts to determine best practices for biological sustainability in terms of species preservation and biomass recovery. Key concepts include biological sustainability, regulatory forces, and fishery management and output trends. The research question investigated is: what are the best policy practices for regulating marine fishery health and biological stability? The research process of this paper included a review of prior literature in the field of marine policy and fishery management, as well as the use of United States data from the Pacific and Atlantic coasts to evaluate management strategies. Based on both the literature review and the results of the data from Pacific and Atlantic Fisheries, the best management structure appears to be the co-management approach while the best management methodologies involve ecosystem protections and quotas. Close

• 3. [Article] The Interplay Between Landscape Structure and Biotic Interactions

  Landscape structure and biotic interactions are closely linked. We identify five aspects of landscape structure that contribute to the co-occurrence of species and restrict or enable different types of ...

  Citation × Citation Citation Abstract Copy Title: The Interplay Between Landscape Structure and Biotic Interactions Author: Zarnetske, Phoebe, Baiser, Benjamin, Strecker, Angela L., Record, Sydne, Belmaker, Jonathan, Tuanmu, Mao-Ning Year: 2017 Landscape structure and biotic interactions are closely linked. We identify five aspects of landscape structure that contribute to the co-occurrence of species and restrict or enable different types of biotic interactions: patch size and habitat amount, isolation of patches, barriers to dispersal and movement, persistence of landscape structure, and landscape complexity. In addition, these aspects of landscape structure influence the strength and outcome of biotic interactions. Whereas most research focuses on the effects of the abiotic environment on species and their biotic interactions, research on foundation species and ecosystem engineers demonstrates the important influence of biotic interactions on landscape structure itself, including effects on landscape complexity, extent of habitat, and the structure of landscape features. In this review, we describe ecological theories that lay the foundation for interplay between landscape structure and biotic interactions, and summarize these connections across an array of interacting species in freshwater, marine, and terrestrial systems. We end with suggestions for integrating the fields of landscape ecology and community ecology to better understand the connections between landscape structure and biotic interactions and better predict their dynamics in light of global change. Title: The Interplay Between Landscape Structure and Biotic Interactions Author: Zarnetske, Phoebe, Baiser, Benjamin, Strecker, Angela L., Record, Sydne, Belmaker, Jonathan, Tuanmu, Mao-Ning Year: 2017 Landscape structure and biotic interactions are closely linked. We identify five aspects of landscape structure that contribute to the co-occurrence of species and restrict or enable different types of biotic interactions: patch size and habitat amount, isolation of patches, barriers to dispersal and movement, persistence of landscape structure, and landscape complexity. In addition, these aspects of landscape structure influence the strength and outcome of biotic interactions. Whereas most research focuses on the effects of the abiotic environment on species and their biotic interactions, research on foundation species and ecosystem engineers demonstrates the important influence of biotic interactions on landscape structure itself, including effects on landscape complexity, extent of habitat, and the structure of landscape features. In this review, we describe ecological theories that lay the foundation for interplay between landscape structure and biotic interactions, and summarize these connections across an array of interacting species in freshwater, marine, and terrestrial systems. We end with suggestions for integrating the fields of landscape ecology and community ecology to better understand the connections between landscape structure and biotic interactions and better predict their dynamics in light of global change. Close

• 4. [Article] Rapid Change in Shallow Water Fish Species Composition in an Historically Stable Antarctic Environment

  McMurdo Sound, Antarctica, is home to a unique marine biota with an ecology that has evolved in this frigid environment over millions of years. The region is one of the least disturbed, and possibly the ...

  Citation × Citation Citation Abstract Copy Title: Rapid Change in Shallow Water Fish Species Composition in an Historically Stable Antarctic Environment Author: Buckley, Bradley A. Year: 2013 McMurdo Sound, Antarctica, is home to a unique marine biota with an ecology that has evolved in this frigid environment over millions of years. The region is one of the least disturbed, and possibly the last pristine, marine ecosystem on Earth. Here, the results of three seasons of fishing in the shallow nearshore waters of McMurdo Sound are reported. A shift in the composition of small fish species at one site, Inaccessible Island, has been observed in just five years. The shift in shallow water species composition occurred during a period that followed the maturation of a commercial fishery for the Antarctic toothfish, Dissostichus mawsoni Norman, a predator of smaller fish, and the presence of a large iceberg, termed B-15, at the mouth of McMurdo Sound during the early 2000s that trapped the annual sea ice in the area leading to the unusual accrual of multi-year sea ice. The data presented here provide a current record of species composition and physiological condition of small, shallow water fishes at three sites in McMurdo Sound, providing a current baseline for the assessment of future changes wrought by environmental changes and unprecedented fishery pressures in the Ross Sea. Title: Rapid Change in Shallow Water Fish Species Composition in an Historically Stable Antarctic Environment Author: Buckley, Bradley A. Year: 2013 McMurdo Sound, Antarctica, is home to a unique marine biota with an ecology that has evolved in this frigid environment over millions of years. The region is one of the least disturbed, and possibly the last pristine, marine ecosystem on Earth. Here, the results of three seasons of fishing in the shallow nearshore waters of McMurdo Sound are reported. A shift in the composition of small fish species at one site, Inaccessible Island, has been observed in just five years. The shift in shallow water species composition occurred during a period that followed the maturation of a commercial fishery for the Antarctic toothfish, Dissostichus mawsoni Norman, a predator of smaller fish, and the presence of a large iceberg, termed B-15, at the mouth of McMurdo Sound during the early 2000s that trapped the annual sea ice in the area leading to the unusual accrual of multi-year sea ice. The data presented here provide a current record of species composition and physiological condition of small, shallow water fishes at three sites in McMurdo Sound, providing a current baseline for the assessment of future changes wrought by environmental changes and unprecedented fishery pressures in the Ross Sea. Close

• 5. [Article] New Insights into the Controls and Mechanisms of Plankton Productivity Along the US West Coast

  During the lifetime of the National Science Foundation's Coastal Ocean Processes program, four experiments were conducted on the US West Coast in the northern California Current System. Although each project ...

  Citation × Citation Citation Abstract Copy Title: New Insights into the Controls and Mechanisms of Plankton Productivity Along the US West Coast Author: Kudela, Raphael M., Banas, Neil S., Barth, John A., Frame, Elizabeth R., Jay, David A., Largier, John L., Lessard, Evelyn J., Peterson, Tawnya D., Vander Woude, Andrea J. Year: 2008 During the lifetime of the National Science Foundation's Coastal Ocean Processes program, four experiments were conducted on the US West Coast in the northern California Current System. Although each project had a unique scientific focus, all four addressed the mechanisms causing eastern boundary current systems in general, and the California Current System in particular, to be biologically rich, from phytoplankton to apex predators. Taken together, findings from these projects provide new insights into the canonical view that upwelling systems are simple wind-driven "conveyor belts," bringing cold, nutrient-rich waters to the well-lit surface ocean where biological organisms flourish. We highlight new insights and advances gained from these programs, including recognition that (a) elements other than nitrogen, particularly iron, may limit the base of the food chain, and (b) the source of these nutrients is not solely a result of wind-driven Ekman transport. The importance of retentive features has clearly emerged, whether these are associated with topography, bathymetry, or more transient features such as river plumes. These new insights into the drivers and fate of this high biological productivity should greatly improve current and future generations of ecosystem models and provide a better understanding of the unique physical-biological coupling that makes the California Current System so rich. Title: New Insights into the Controls and Mechanisms of Plankton Productivity Along the US West Coast Author: Kudela, Raphael M., Banas, Neil S., Barth, John A., Frame, Elizabeth R., Jay, David A., Largier, John L., Lessard, Evelyn J., Peterson, Tawnya D., Vander Woude, Andrea J. Year: 2008 During the lifetime of the National Science Foundation's Coastal Ocean Processes program, four experiments were conducted on the US West Coast in the northern California Current System. Although each project had a unique scientific focus, all four addressed the mechanisms causing eastern boundary current systems in general, and the California Current System in particular, to be biologically rich, from phytoplankton to apex predators. Taken together, findings from these projects provide new insights into the canonical view that upwelling systems are simple wind-driven "conveyor belts," bringing cold, nutrient-rich waters to the well-lit surface ocean where biological organisms flourish. We highlight new insights and advances gained from these programs, including recognition that (a) elements other than nitrogen, particularly iron, may limit the base of the food chain, and (b) the source of these nutrients is not solely a result of wind-driven Ekman transport. The importance of retentive features has clearly emerged, whether these are associated with topography, bathymetry, or more transient features such as river plumes. These new insights into the drivers and fate of this high biological productivity should greatly improve current and future generations of ecosystem models and provide a better understanding of the unique physical-biological coupling that makes the California Current System so rich. Close

• 6. [Article] Biological Erosion of Marine Habitats and Structures by Burrowing Crustaceans

  Marine bioeroders, borers, and burrowers can have drastic effects to marine habitats and facilities. By physically altering the structure of marine habitats, these organisms may elicit ecosystem-level ...

  Citation × Citation Citation Abstract Copy Title: Biological Erosion of Marine Habitats and Structures by Burrowing Crustaceans Author: Davidson, Timothy Mathias Year: 2011 Marine bioeroders, borers, and burrowers can have drastic effects to marine habitats and facilities. By physically altering the structure of marine habitats, these organisms may elicit ecosystem-level effects that cascade through the community. While borer damage is typically restricted to a few substratum types, burrowing isopods in the genus Sphaeroma attack a diversity of substrata in tropical and temperate systems. My dissertation examined how boring sphaeromatid isopods affect coastal habitats (saltmarshes, mangroves) and other estuarine substrata as well as marine structures. I used a combination of lab and mensurative field experiments to quantify the effects of boring by isopods and examine how select factors affect the colonization, hence burrowing damage by isopods. I explored these questions primarily using the temperate boring sphaeromatid, Sphaeroma quoianum, as a model organism. My initial lab experiments quantified the per capita erosion rates of S. quoianum in four commonly attacked estuarine substrata. I found marsh banks and Styrofoam substrata were the most affected per capita. I supplemented this lab experiment with a year-long mensurative field experiment examining how erosion rates differ between marshes infested and uninfested by boring isopods. Marshes infested with isopods eroded 300% faster than uninfested marshes. I further examined the boring effects on Styrofoam floats. I compiled surveys and observations and conducted a short experiment to describe how isopods affect Styrofoam floats used in floating docks. I observed dense colonies of isopods attacking floats and expelling millions of plastic particles in the ocean. The boring effects to simulated Styrofoam floats were also affected by seawater temperature. Burrowing effects in Styrofoam floats exhibited a curvilinear relationship with temperature and peaked around 18°C. These results suggest a 1-2°C increase in water temperature could increase boring effects 5-17% of populations of isopods in Oregon and California bays. To examine the small-scale factors that mediate colonization and boring, I conducted a series of binary choice experiments. I found the presence of conspecifics, biofilm, and shade were important factors influencing colonization. These small scale factors likely explain why isopod attack is focused in some substrata. Finally, to examine the boring effects of tropical isopods in mangroves, I examined the associations between burrowing by S. terebrans and mangrove performance and fecundity. I found negative relationships between boring effects and performance and fecundity in two mangrove species in a restored mangrove stand in Taiwan. Together, these studies elucidate the effects of bioerosive isopods on saltmarshes, mangroves, and marine structures. However, the similar mechanisms involved in bioerosion in other boring species suggest that these results can be used to infer similar effects of other borers. In addition, since many species of sphaeromatid isopods have been introduced, this research shows how the effects of a non-native bioeroder can damage marine facilities and degrade and alter marine habitats. Through biological erosion and thus changing the physical structure of a marine habitat these non-native species can have ecosystem-level effects that cascade throughout the local community. Title: Biological Erosion of Marine Habitats and Structures by Burrowing Crustaceans Author: Davidson, Timothy Mathias Year: 2011 Marine bioeroders, borers, and burrowers can have drastic effects to marine habitats and facilities. By physically altering the structure of marine habitats, these organisms may elicit ecosystem-level effects that cascade through the community. While borer damage is typically restricted to a few substratum types, burrowing isopods in the genus Sphaeroma attack a diversity of substrata in tropical and temperate systems. My dissertation examined how boring sphaeromatid isopods affect coastal habitats (saltmarshes, mangroves) and other estuarine substrata as well as marine structures. I used a combination of lab and mensurative field experiments to quantify the effects of boring by isopods and examine how select factors affect the colonization, hence burrowing damage by isopods. I explored these questions primarily using the temperate boring sphaeromatid, Sphaeroma quoianum, as a model organism. My initial lab experiments quantified the per capita erosion rates of S. quoianum in four commonly attacked estuarine substrata. I found marsh banks and Styrofoam substrata were the most affected per capita. I supplemented this lab experiment with a year-long mensurative field experiment examining how erosion rates differ between marshes infested and uninfested by boring isopods. Marshes infested with isopods eroded 300% faster than uninfested marshes. I further examined the boring effects on Styrofoam floats. I compiled surveys and observations and conducted a short experiment to describe how isopods affect Styrofoam floats used in floating docks. I observed dense colonies of isopods attacking floats and expelling millions of plastic particles in the ocean. The boring effects to simulated Styrofoam floats were also affected by seawater temperature. Burrowing effects in Styrofoam floats exhibited a curvilinear relationship with temperature and peaked around 18°C. These results suggest a 1-2°C increase in water temperature could increase boring effects 5-17% of populations of isopods in Oregon and California bays. To examine the small-scale factors that mediate colonization and boring, I conducted a series of binary choice experiments. I found the presence of conspecifics, biofilm, and shade were important factors influencing colonization. These small scale factors likely explain why isopod attack is focused in some substrata. Finally, to examine the boring effects of tropical isopods in mangroves, I examined the associations between burrowing by S. terebrans and mangrove performance and fecundity. I found negative relationships between boring effects and performance and fecundity in two mangrove species in a restored mangrove stand in Taiwan. Together, these studies elucidate the effects of bioerosive isopods on saltmarshes, mangroves, and marine structures. However, the similar mechanisms involved in bioerosion in other boring species suggest that these results can be used to infer similar effects of other borers. In addition, since many species of sphaeromatid isopods have been introduced, this research shows how the effects of a non-native bioeroder can damage marine facilities and degrade and alter marine habitats. Through biological erosion and thus changing the physical structure of a marine habitat these non-native species can have ecosystem-level effects that cascade throughout the local community. Close

• 7. [Article] Pharmaceutical Contaminants as Stressors on Rocky Intertidal and Estuarine Organisms: a Case Study of Fluoxetine

  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 ...

  Citation × Citation Citation Abstract Copy Title: Pharmaceutical Contaminants as Stressors on Rocky Intertidal and Estuarine Organisms: a Case Study of Fluoxetine Author: Peters, Joseph Richard Year: 2016 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? Title: Pharmaceutical Contaminants as Stressors on Rocky Intertidal and Estuarine Organisms: a Case Study of Fluoxetine Author: Peters, Joseph Richard Year: 2016 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? Close

• 8. [Article] Effects of Antibiotic Mixtures across Marine Intertidal Trophic Levels: Examining Environmentally-Relevant Contaminant Concentrations

  Approximately 48% of Americans use prescription drugs within each 30-day period, and there are signs this trend is increasing. Although many studies track pharmaceuticals’ fates in contaminating waterways, ...

  Citation × Citation Citation Abstract Copy Title: Effects of Antibiotic Mixtures across Marine Intertidal Trophic Levels: Examining Environmentally-Relevant Contaminant Concentrations Author: Teixeira, Jaclyn Rebecca Year: 2016 Approximately 48% of Americans use prescription drugs within each 30-day period, and there are signs this trend is increasing. Although many studies track pharmaceuticals’ fates in contaminating waterways, only fairly recent efforts have examined the potential impacts of these drugs on non-target organisms. The antibiotics sulfamethoxazole and trimethoprim, often prescribed together to treat bacterial infections, have been detected worldwide in marine and estuarine environments at concentrations up to 700-800 ng/L each. Toxic effects of these drugs have been identified in freshwater organisms, with synergistic effects observed in short-term studies of mixtures of the two; however, little research has examined possible sub-lethal and longer-term effects of antibiotics in environmentally-relevant mixture concentrations on marine organisms. I examined the long-term effects of mixtures of these two antibiotics in species of a marine system: marine microalgal species, and marine mussels, to determine whether the levels currently present in waterways affect organism health and reproduction. Microalgal species may be among the most sensitive organisms to pharmaceutical contaminants based on ecotoxicity research. I exposed three species of marine microalgae (Isochrysis galbana, Chaetoceros neogracile, and Nannochloropsis oculata) to environmentally-relevant mixtures of sulfamethoxazole and trimethoprim and examined their three-week growth rates. I found that for each species, the antibiotic treatments significantly suppressed algal growth. Specifically, I found that sulfamethoxazole was a driving factor in suppression of C. neogracile and I. galbana growth, while N. oculata responded more sensitively to a broader range of treatment mixture levels, which also included trimethoprim-only treatment groups and mixtures. These results on marine microalgae address critical data gaps, and identify the impacts of pharmaceuticals on marine primary producers, which could have direct ecosystem implications to higher trophic levels. Antibiotic pharmaceuticals can also affect marine mussel health, based on previous study of sub-cellular endpoints. I hypothesized that the important benthic foundational species, the Mytilus californianus mussel, would be significantly impacted by long-term 12-week exposure to environmentally-relevant concentrations and mixtures of sulfamethoxazole and trimethoprim. Specifically, I measured growth rate, feeding rate, condition index, and gonando-somatic index as indicators of whole-organism and reproductive health. Sulfamethoxazole concentrations, in particular, and trimethoprim to a lesser extent, suppressed mussel growth and significantly affected condition index and gonandosomatic index over time. The results of this study offer an understanding of how an intertidal system responds to chronic presence of antibiotic mixtures in the water, and a more complete picture of the environmental consequences of pharmaceutical contaminants released into marine ecosystems at ever-growing rates. Title: Effects of Antibiotic Mixtures across Marine Intertidal Trophic Levels: Examining Environmentally-Relevant Contaminant Concentrations Author: Teixeira, Jaclyn Rebecca Year: 2016 Approximately 48% of Americans use prescription drugs within each 30-day period, and there are signs this trend is increasing. Although many studies track pharmaceuticals’ fates in contaminating waterways, only fairly recent efforts have examined the potential impacts of these drugs on non-target organisms. The antibiotics sulfamethoxazole and trimethoprim, often prescribed together to treat bacterial infections, have been detected worldwide in marine and estuarine environments at concentrations up to 700-800 ng/L each. Toxic effects of these drugs have been identified in freshwater organisms, with synergistic effects observed in short-term studies of mixtures of the two; however, little research has examined possible sub-lethal and longer-term effects of antibiotics in environmentally-relevant mixture concentrations on marine organisms. I examined the long-term effects of mixtures of these two antibiotics in species of a marine system: marine microalgal species, and marine mussels, to determine whether the levels currently present in waterways affect organism health and reproduction. Microalgal species may be among the most sensitive organisms to pharmaceutical contaminants based on ecotoxicity research. I exposed three species of marine microalgae (Isochrysis galbana, Chaetoceros neogracile, and Nannochloropsis oculata) to environmentally-relevant mixtures of sulfamethoxazole and trimethoprim and examined their three-week growth rates. I found that for each species, the antibiotic treatments significantly suppressed algal growth. Specifically, I found that sulfamethoxazole was a driving factor in suppression of C. neogracile and I. galbana growth, while N. oculata responded more sensitively to a broader range of treatment mixture levels, which also included trimethoprim-only treatment groups and mixtures. These results on marine microalgae address critical data gaps, and identify the impacts of pharmaceuticals on marine primary producers, which could have direct ecosystem implications to higher trophic levels. Antibiotic pharmaceuticals can also affect marine mussel health, based on previous study of sub-cellular endpoints. I hypothesized that the important benthic foundational species, the Mytilus californianus mussel, would be significantly impacted by long-term 12-week exposure to environmentally-relevant concentrations and mixtures of sulfamethoxazole and trimethoprim. Specifically, I measured growth rate, feeding rate, condition index, and gonando-somatic index as indicators of whole-organism and reproductive health. Sulfamethoxazole concentrations, in particular, and trimethoprim to a lesser extent, suppressed mussel growth and significantly affected condition index and gonandosomatic index over time. The results of this study offer an understanding of how an intertidal system responds to chronic presence of antibiotic mixtures in the water, and a more complete picture of the environmental consequences of pharmaceutical contaminants released into marine ecosystems at ever-growing rates. Close

• 9. [Article] Microbial Ecology of Active Marine Hydrothermal Vent Deposits: The Influence of Geologic Setting on Microbial Communities

  The discovery of deep-sea hydrothermal vents in 1977 revealed an ecosystem supported by chemosynthesis with a rich diversity of invertebrates, Archaea and Bacteria. While the invertebrate vent communities ...

  Citation × Citation Citation Abstract Copy Title: Microbial Ecology of Active Marine Hydrothermal Vent Deposits: The Influence of Geologic Setting on Microbial Communities Author: Flores, Gilberto Eugene Year: 2011 The discovery of deep-sea hydrothermal vents in 1977 revealed an ecosystem supported by chemosynthesis with a rich diversity of invertebrates, Archaea and Bacteria. While the invertebrate vent communities are largely composed of endemic species and exist in different biogeographical provinces, the possible factors influencing the distribution patterns of free-living Archaea and Bacteria are still being explored. In particular, how differences in the geologic setting of vent fields influence microbial communities and populations associated with active vent deposits remains largely unknown. The overall goal of the studies presented in this dissertation was to examine the links between the geologic setting of hydrothermal vent fields and microorganisms associated with actively venting mineral deposits at two levels of biological organization. At the community level, bar-coded pyrosequencing of a segment of the archaeal and bacterial 16S rRNA gene was employed to characterize and compare the microbial communities associated with numerous deposits from several geochemically different vent fields. Results from these studies suggest that factors influencing end-member fluid chemistry, such as host-rock composition and degassing of magmatic volatiles, help to structure the microbial communities at the vent field scale. At the population level, targeted cultivation-dependent and -independent studies were conducted in order to expand our understanding of thermoacidophily in diverse hydrothermal environments. Results of these studies expanded the phylogenetic and physiological diversity of thermoacidophiles in deep-sea vent environments and provided clues to factors that are influencing the biogeography of an important thermoacidophilic archaeal lineage. Overall, these studies have increased our understanding of the interplay between geologic processes and microorganisms in deep-sea hydrothermal environments. Title: Microbial Ecology of Active Marine Hydrothermal Vent Deposits: The Influence of Geologic Setting on Microbial Communities Author: Flores, Gilberto Eugene Year: 2011 The discovery of deep-sea hydrothermal vents in 1977 revealed an ecosystem supported by chemosynthesis with a rich diversity of invertebrates, Archaea and Bacteria. While the invertebrate vent communities are largely composed of endemic species and exist in different biogeographical provinces, the possible factors influencing the distribution patterns of free-living Archaea and Bacteria are still being explored. In particular, how differences in the geologic setting of vent fields influence microbial communities and populations associated with active vent deposits remains largely unknown. The overall goal of the studies presented in this dissertation was to examine the links between the geologic setting of hydrothermal vent fields and microorganisms associated with actively venting mineral deposits at two levels of biological organization. At the community level, bar-coded pyrosequencing of a segment of the archaeal and bacterial 16S rRNA gene was employed to characterize and compare the microbial communities associated with numerous deposits from several geochemically different vent fields. Results from these studies suggest that factors influencing end-member fluid chemistry, such as host-rock composition and degassing of magmatic volatiles, help to structure the microbial communities at the vent field scale. At the population level, targeted cultivation-dependent and -independent studies were conducted in order to expand our understanding of thermoacidophily in diverse hydrothermal environments. Results of these studies expanded the phylogenetic and physiological diversity of thermoacidophiles in deep-sea vent environments and provided clues to factors that are influencing the biogeography of an important thermoacidophilic archaeal lineage. Overall, these studies have increased our understanding of the interplay between geologic processes and microorganisms in deep-sea hydrothermal environments. Close

• 10. [Article] Long-Term Exposure to Fluoxetine Reduces Growth and Reproductive Potential in the Dominant Rocky Intertidal Mussel, Mytilus californianus

  Environmental stressors shape community composition and ecosystem functioning. Contaminants such as pharmaceuticals are of increasing concern as an environmental stressor due to their persistence in surface ...

  Citation × Citation Citation Abstract Copy Title: Long-Term Exposure to Fluoxetine Reduces Growth and Reproductive Potential in the Dominant Rocky Intertidal Mussel, Mytilus californianus Author: Peters, Joseph R., Granek, Elise F. Year: 2016 Environmental stressors shape community composition and ecosystem functioning. Contaminants such as pharmaceuticals are of increasing concern as an environmental stressor due to their 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; and examination of whole organism effects are necessary to identify potential community-level consequences in estuarine and marine ecosystems. We conducted a long-term exposure study (107 days) with the anti-depressant pharmaceutical, fluoxetine (the active constituent in Prozac®) to determine whether minimal concentrations affected whole organism metrics in the California mussel, Mytilus californianus. We measured algal clearance rates, mussel growth, and the gonadosomatic index, a measure of reproductive health. We found that fluoxetine negatively affects all measured characteristics, however many effects were mediated by length of exposure. Our results fill an important data gap, highlighting organism-level effects of chronic exposure periods; such data more explicitly identify the overall impacts of pharmaceuticals and other contaminants on marine communities and ecosystems. Title: Long-Term Exposure to Fluoxetine Reduces Growth and Reproductive Potential in the Dominant Rocky Intertidal Mussel, Mytilus californianus Author: Peters, Joseph R., Granek, Elise F. Year: 2016 Environmental stressors shape community composition and ecosystem functioning. Contaminants such as pharmaceuticals are of increasing concern as an environmental stressor due to their 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; and examination of whole organism effects are necessary to identify potential community-level consequences in estuarine and marine ecosystems. We conducted a long-term exposure study (107 days) with the anti-depressant pharmaceutical, fluoxetine (the active constituent in Prozac®) to determine whether minimal concentrations affected whole organism metrics in the California mussel, Mytilus californianus. We measured algal clearance rates, mussel growth, and the gonadosomatic index, a measure of reproductive health. We found that fluoxetine negatively affects all measured characteristics, however many effects were mediated by length of exposure. Our results fill an important data gap, highlighting organism-level effects of chronic exposure periods; such data more explicitly identify the overall impacts of pharmaceuticals and other contaminants on marine communities and ecosystems. Close