Search

Search Results

• 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] 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

• 5. [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

• 6. [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

• 7. [Article] Investigations of Larval Pacific Lamprey Entosphenus tridentatus Osmotic Stress Tolerance and Occurrence in a Tidally-Influenced Estuarine Stream

  Pacific lamprey is a culturally valuable species to indigenous people, and has significant ecological importance in freshwater and marine ecosystems. Over the past several decades, constrictions in range ...

  Citation × Citation Citation Abstract Copy Title: Investigations of Larval Pacific Lamprey Entosphenus tridentatus Osmotic Stress Tolerance and Occurrence in a Tidally-Influenced Estuarine Stream Author: Silver, Gregory Shell Year: 2015 Pacific lamprey is a culturally valuable species to indigenous people, and has significant ecological importance in freshwater and marine ecosystems. Over the past several decades, constrictions in range and reductions in Pacific lamprey abundance have been observed in Western North America, and may be indicators of range-wide declines. In the face of declining populations, the U.S. Fish and Wildlife Service has partnered with tribal, state, federal, and local entities to implement a regional Pacific lamprey conservation agreement aimed at reducing threats to Pacific lamprey and improving their habitats and population status. Research needs identified in the conservation agreement include assessing larval Pacific lamprey occupancy and distribution, habitat requirements, and the limiting factors of larval distribution in the freshwater ecosystem. As part of the effort to address these knowledge gaps, we investigated the potential for larval lampreys to occur in tidally-influenced estuarine environments. Research of this type may be valuable for future conservation, management or recovery efforts of Pacific lamprey throughout its range. We employed a two-phased approach, consisting of laboratory and field components to address our aims. We first conducted a series of controlled laboratory experiments to evaluate osmotic stress tolerance and osmoregulatory status of larval Pacific lamprey exposed to a range of (1) fixed salinity in various dilutions of saltwater and (2) oscillating salinity treatments designed to simulate tidal activity. Tolerance was assessed by monitoring and comparing survival of larvae in various treatments through 96 h. Osmoregulatory status was assessed by quantifying and comparing total body water content, plasma osmolality, and plasma cation (i.e., sodium) concentrations among larvae surviving various treatments. In fixed salinity experiments, 100% survival was observed in 0‰, 6‰, 8‰ and 10‰ through 96 h, while 0% survival was observed through 48 h in 12‰, 30 h in 15‰, and 12 h in 25‰ and 35‰. In oscillating salinity experiments, on the other hand, a significant increase in survival (100%) was observed through 96 h in treatments that oscillated between 12‰ and 0‰ (freshwater) at about 6 h intervals versus fixed 12‰ salinity experiments. A significant increase in survival also occurred in oscillating 15‰ treatments (60%) versus fixed 15‰ through 96 h. Linear regression analysis indicated higher environmental salinity in laboratory experiments was significantly related to increases in plasma osmolality and plasma sodium (the most abundant osmotically active plasma cation) concentrations, and concurrent decreases in total body water content among larvae that survived various treatments. Tidal oscillations in salinity appeared to temper the desiccating effects of salinity, as changes in body water content and sodium ion concentration were less abrupt than fixed salinity treatments. These results suggest larvae cannot osmoregulate in hyperosmotic environments, but are able to tolerate some fixed and oscillating hyperosmotic salinity exposure. Consequently, larvae may be able to occur in certain areas of estuaries, such as oligohaline habitats that are characterized by low levels of salinity. Experimental results were used, in part, to guide larval sampling in a tidally-influenced habitat. Occurrence of larval Pacific lamprey and Lampetra spp. (western brook and river lampreys) was subsequently investigated across a gradient of salinity in Ellsworth Creek (Pacific County, Washington) by electrofishing. Larval Pacific and Lampetra spp. were detected within an approximately 300 m long tidally-influenced segment of the study area. Salinity monitoring was conducted in six tidally-influenced reaches where larvae were detected for up to 14 d following electrofishing. Maximum tidal cycle salinity exceeded 15 ppt during 52% to 80% of tidal cycles within tidally-influenced reaches where larvae were detected. These results suggest potential for larval lamprey to occur in certain portions of tidal estuaries. However, long-term residence of larvae in tidally-influenced habitats and whether larvae are able to subsequently survive, grow, transform, and out-migrate is not known and requires further study. Given the potential for tidally-influenced habitats to be occupied by larvae, assessments of larval occurrence in other areas, such as the lower Columbia River, may be warranted. Knowledge of larval lamprey distribution in estuarine environments may be valuable for habitat restoration, and mitigating potential impacts from dredging and other human disturbances. Title: Investigations of Larval Pacific Lamprey Entosphenus tridentatus Osmotic Stress Tolerance and Occurrence in a Tidally-Influenced Estuarine Stream Author: Silver, Gregory Shell Year: 2015 Pacific lamprey is a culturally valuable species to indigenous people, and has significant ecological importance in freshwater and marine ecosystems. Over the past several decades, constrictions in range and reductions in Pacific lamprey abundance have been observed in Western North America, and may be indicators of range-wide declines. In the face of declining populations, the U.S. Fish and Wildlife Service has partnered with tribal, state, federal, and local entities to implement a regional Pacific lamprey conservation agreement aimed at reducing threats to Pacific lamprey and improving their habitats and population status. Research needs identified in the conservation agreement include assessing larval Pacific lamprey occupancy and distribution, habitat requirements, and the limiting factors of larval distribution in the freshwater ecosystem. As part of the effort to address these knowledge gaps, we investigated the potential for larval lampreys to occur in tidally-influenced estuarine environments. Research of this type may be valuable for future conservation, management or recovery efforts of Pacific lamprey throughout its range. We employed a two-phased approach, consisting of laboratory and field components to address our aims. We first conducted a series of controlled laboratory experiments to evaluate osmotic stress tolerance and osmoregulatory status of larval Pacific lamprey exposed to a range of (1) fixed salinity in various dilutions of saltwater and (2) oscillating salinity treatments designed to simulate tidal activity. Tolerance was assessed by monitoring and comparing survival of larvae in various treatments through 96 h. Osmoregulatory status was assessed by quantifying and comparing total body water content, plasma osmolality, and plasma cation (i.e., sodium) concentrations among larvae surviving various treatments. In fixed salinity experiments, 100% survival was observed in 0‰, 6‰, 8‰ and 10‰ through 96 h, while 0% survival was observed through 48 h in 12‰, 30 h in 15‰, and 12 h in 25‰ and 35‰. In oscillating salinity experiments, on the other hand, a significant increase in survival (100%) was observed through 96 h in treatments that oscillated between 12‰ and 0‰ (freshwater) at about 6 h intervals versus fixed 12‰ salinity experiments. A significant increase in survival also occurred in oscillating 15‰ treatments (60%) versus fixed 15‰ through 96 h. Linear regression analysis indicated higher environmental salinity in laboratory experiments was significantly related to increases in plasma osmolality and plasma sodium (the most abundant osmotically active plasma cation) concentrations, and concurrent decreases in total body water content among larvae that survived various treatments. Tidal oscillations in salinity appeared to temper the desiccating effects of salinity, as changes in body water content and sodium ion concentration were less abrupt than fixed salinity treatments. These results suggest larvae cannot osmoregulate in hyperosmotic environments, but are able to tolerate some fixed and oscillating hyperosmotic salinity exposure. Consequently, larvae may be able to occur in certain areas of estuaries, such as oligohaline habitats that are characterized by low levels of salinity. Experimental results were used, in part, to guide larval sampling in a tidally-influenced habitat. Occurrence of larval Pacific lamprey and Lampetra spp. (western brook and river lampreys) was subsequently investigated across a gradient of salinity in Ellsworth Creek (Pacific County, Washington) by electrofishing. Larval Pacific and Lampetra spp. were detected within an approximately 300 m long tidally-influenced segment of the study area. Salinity monitoring was conducted in six tidally-influenced reaches where larvae were detected for up to 14 d following electrofishing. Maximum tidal cycle salinity exceeded 15 ppt during 52% to 80% of tidal cycles within tidally-influenced reaches where larvae were detected. These results suggest potential for larval lamprey to occur in certain portions of tidal estuaries. However, long-term residence of larvae in tidally-influenced habitats and whether larvae are able to subsequently survive, grow, transform, and out-migrate is not known and requires further study. Given the potential for tidally-influenced habitats to be occupied by larvae, assessments of larval occurrence in other areas, such as the lower Columbia River, may be warranted. Knowledge of larval lamprey distribution in estuarine environments may be valuable for habitat restoration, and mitigating potential impacts from dredging and other human disturbances. Close

• 8. [Article] Spatial and Temporal Variability of Contaminants Within Estuarine Sediments and Native Olympia Oysters: A Contrast Between a Developed and an Undeveloped Estuary

  Chemical contaminants can be introduced into estuarine and marine ecosystems from a variety of sources including wastewater, agriculture and forestry practices, point and non-point discharges, runoff from ...

  Citation × Citation Citation Abstract Copy Title: Spatial and Temporal Variability of Contaminants Within Estuarine Sediments and Native Olympia Oysters: A Contrast Between a Developed and an Undeveloped Estuary Author: Granek, Elise F., Conn, Katherine E., Nilsen, Elena B., Pillsbury, Lori, Strecker, Angela L., Rumrill, Steven S., Fish, William Year: 2016 Chemical contaminants can be introduced into estuarine and marine ecosystems from a variety of sources including wastewater, agriculture and forestry practices, point and non-point discharges, runoff from industrial, municipal, and urban lands, accidental spills, and atmospheric deposition. The diversity of potential sources contributes to the likelihood of contaminated marine waters and sediments and increases the probability of uptake by marine organisms. Despite widespread recognition of direct and indirect pathways for contaminant deposition and organismal exposure in coastal systems, spatial and temporal variability in contaminant composition, deposition, and uptake patterns are still poorly known. We investigated these patterns for a suite of persistent legacy contaminants including polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) and chemicals of emerging concern including pharmaceuticals within two Oregon coastal estuaries (Coos and Netarts Bays). In the more urbanized Coos Bay, native Olympia oyster (Ostrea lurida) tissue had approximately twice the number of PCB congeners at over seven times the total concentration, yet fewer PBDEs at one-tenth the concentration as compared to the more rural Netarts Bay. Different pharmaceutical suites were detected during each sampling season. Variability in contaminant types and concentrations across seasons and between species and media (organisms versus sediment) indicates the limitation of using indicator species and/or sampling annually to determine contaminant loads at a site or for specific species. The results indicate the prevalence of legacy contaminants and CECs in relatively undeveloped coastal environments highlighting the need to improve policy and management actions to reduce contaminant releases into estuarine and marine waters and to deal with legacy compounds that remain long after prohibition of use. Our results point to the need for better understanding of the ecological and human health risks of exposure to the diverse cocktail of pollutants and harmful compounds that will continue to leach from estuarine sediments over time. Title: Spatial and Temporal Variability of Contaminants Within Estuarine Sediments and Native Olympia Oysters: A Contrast Between a Developed and an Undeveloped Estuary Author: Granek, Elise F., Conn, Katherine E., Nilsen, Elena B., Pillsbury, Lori, Strecker, Angela L., Rumrill, Steven S., Fish, William Year: 2016 Chemical contaminants can be introduced into estuarine and marine ecosystems from a variety of sources including wastewater, agriculture and forestry practices, point and non-point discharges, runoff from industrial, municipal, and urban lands, accidental spills, and atmospheric deposition. The diversity of potential sources contributes to the likelihood of contaminated marine waters and sediments and increases the probability of uptake by marine organisms. Despite widespread recognition of direct and indirect pathways for contaminant deposition and organismal exposure in coastal systems, spatial and temporal variability in contaminant composition, deposition, and uptake patterns are still poorly known. We investigated these patterns for a suite of persistent legacy contaminants including polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) and chemicals of emerging concern including pharmaceuticals within two Oregon coastal estuaries (Coos and Netarts Bays). In the more urbanized Coos Bay, native Olympia oyster (Ostrea lurida) tissue had approximately twice the number of PCB congeners at over seven times the total concentration, yet fewer PBDEs at one-tenth the concentration as compared to the more rural Netarts Bay. Different pharmaceutical suites were detected during each sampling season. Variability in contaminant types and concentrations across seasons and between species and media (organisms versus sediment) indicates the limitation of using indicator species and/or sampling annually to determine contaminant loads at a site or for specific species. The results indicate the prevalence of legacy contaminants and CECs in relatively undeveloped coastal environments highlighting the need to improve policy and management actions to reduce contaminant releases into estuarine and marine waters and to deal with legacy compounds that remain long after prohibition of use. Our results point to the need for better understanding of the ecological and human health risks of exposure to the diverse cocktail of pollutants and harmful compounds that will continue to leach from estuarine sediments over time. Close

• 9. [Article] The Impact of a Large-Scale Climate Event on Antarctic Ecosystem Processes

  Extreme climate and weather events, such as a drought, hurricanes, or ice storms, can strongly imprint ecosystem processing and may alter ecosystem structure. Ecosystems in extreme environments are particularly ...

  Citation × Citation Citation Abstract Copy Title: The Impact of a Large-Scale Climate Event on Antarctic Ecosystem Processes Author: Fountain, Andrew G., Saba, Grace, Adams, Byron, Doran, Peter, Fraser, William, Gooseff, Michael N., Obryk, Maciej K., Priscu, John Charles, Stammerjohn, Sharon, Virginia, Ross A. Year: 2016 Extreme climate and weather events, such as a drought, hurricanes, or ice storms, can strongly imprint ecosystem processing and may alter ecosystem structure. Ecosystems in extreme environments are particularly vulnerable because of their adaptation to severe limitations in energy, water, or nutrients. The vulnerability can be expressed as a relatively long-lasting ecosystem response to a small or brief change in environmental conditions. Such an event occurred in Antarctica and affected two vastly different ecosystems: a marine-dominated coastal system and a terrestrial polar desert. Both sites experienced winds that warmed air temperatures above the 0°C threshold, resulting in extensive snow and ice melt and triggering a series of cascading effects through the ecosystems that are continuing to play out more than a decade later. This highlights the sensitivity of Antarctic ecosystems to warming events, which should occur more frequently in the future with global climate warming. Title: The Impact of a Large-Scale Climate Event on Antarctic Ecosystem Processes Author: Fountain, Andrew G., Saba, Grace, Adams, Byron, Doran, Peter, Fraser, William, Gooseff, Michael N., Obryk, Maciej K., Priscu, John Charles, Stammerjohn, Sharon, Virginia, Ross A. Year: 2016 Extreme climate and weather events, such as a drought, hurricanes, or ice storms, can strongly imprint ecosystem processing and may alter ecosystem structure. Ecosystems in extreme environments are particularly vulnerable because of their adaptation to severe limitations in energy, water, or nutrients. The vulnerability can be expressed as a relatively long-lasting ecosystem response to a small or brief change in environmental conditions. Such an event occurred in Antarctica and affected two vastly different ecosystems: a marine-dominated coastal system and a terrestrial polar desert. Both sites experienced winds that warmed air temperatures above the 0°C threshold, resulting in extensive snow and ice melt and triggering a series of cascading effects through the ecosystems that are continuing to play out more than a decade later. This highlights the sensitivity of Antarctic ecosystems to warming events, which should occur more frequently in the future with global climate warming. Close

• 10. [Article] Information Needs Assessment for Coastal and Marine Management and Policy: Ecosystem Services Under Changing Climatic, Land Use, and Demographic Conditions

  Changing climatic, demographic, and land use conditions are projected to alter the provisioning of ecosystem services in estuarine, coastal, and nearshore marine ecosystems, necessitating mitigation and ...

  Citation × Citation Citation Abstract Copy Title: Information Needs Assessment for Coastal and Marine Management and Policy: Ecosystem Services Under Changing Climatic, Land Use, and Demographic Conditions Author: Goldsmith, Kaitlin, Granek, Elise F., Lubitow, Amy Year: 2015 Changing climatic, demographic, and land use conditions are projected to alter the provisioning of ecosystem services in estuarine, coastal, and nearshore marine ecosystems, necessitating mitigation and adaptation policies and management. The current paradigm of research efforts occurring in parallel to, rather than in collaboration with, decision makers will be insufficient for the rapid responses required to adapt to and mitigate for projected changing conditions. Here, we suggest a different paradigm: one where research begins by engaging decision makers in the identification of priority data needs (biophysical, economic, and social). This paper uses synthesized interview data to provide insight into the varied demands for scientific research as described by decision makers working on coastal issues in Oregon, USA. The findings highlight the need to recognize (1) the differing framing of ecosystem services by decision makers versus scientists; and (2) the differing data priorities relevant to inland versus coastal decision makers. The findings further serve to highlight the need for decision makers, scientists, and funders to engage in increased communication. This research is an important first step in advancing efforts toward evidence-based decision making in Oregon and provides a template for further research across the US. Title: Information Needs Assessment for Coastal and Marine Management and Policy: Ecosystem Services Under Changing Climatic, Land Use, and Demographic Conditions Author: Goldsmith, Kaitlin, Granek, Elise F., Lubitow, Amy Year: 2015 Changing climatic, demographic, and land use conditions are projected to alter the provisioning of ecosystem services in estuarine, coastal, and nearshore marine ecosystems, necessitating mitigation and adaptation policies and management. The current paradigm of research efforts occurring in parallel to, rather than in collaboration with, decision makers will be insufficient for the rapid responses required to adapt to and mitigate for projected changing conditions. Here, we suggest a different paradigm: one where research begins by engaging decision makers in the identification of priority data needs (biophysical, economic, and social). This paper uses synthesized interview data to provide insight into the varied demands for scientific research as described by decision makers working on coastal issues in Oregon, USA. The findings highlight the need to recognize (1) the differing framing of ecosystem services by decision makers versus scientists; and (2) the differing data priorities relevant to inland versus coastal decision makers. The findings further serve to highlight the need for decision makers, scientists, and funders to engage in increased communication. This research is an important first step in advancing efforts toward evidence-based decision making in Oregon and provides a template for further research across the US. Close