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• 1. [Article] Investigation and Evaluation of Current and Emerging Whole-Water Sampling Technologies for U.S. Geological Survey National Water Quality Assessment Program

  An investigation was conducted into current and emerging surface water sampling technologies. These technologies were compared and recommendations given to the United States Geological Survey (USGS) for ...

  Citation × Citation Citation Abstract Copy Title: Investigation and Evaluation of Current and Emerging Whole-Water Sampling Technologies for U.S. Geological Survey National Water Quality Assessment Program Author: Gareau, Keith D. Year: 2011 An investigation was conducted into current and emerging surface water sampling technologies. These technologies were compared and recommendations given to the United States Geological Survey (USGS) for adoption by the National Water Quality Assessment (NAWQA) Program. The goal is to reduce labor costs and increase information content. This paper examines lotic system samplers, portable autonomous whole-water samplers, and autonomous submergible whole-water samplers. When investigating whole-water sampling technology, it was imperative to take into consideration what chemical classifications can be sampled for by each respected technology. Chemical classifications considered are: emerging contaminants, major ions, nutrients, polychlorinated biphenyls, pesticides, volatile and semi-volatile organic compounds, and trace elements. The result of this project shows that USGS is currently using the best technology available for lotic systems. For portable autonomous whole-water samplers it is recommended that USGS incorporate certain brands and models to reduce cost and improve data collection for their sampling events. Autonomous submergible whole-water samplers are primarily advertised for oceanic research; however, if deployed in fresh water systems, USGS can reduce labor cost and increase data collection. In terms of emerging technology, it has been recommended to USGS to consider recent patents. Title: Investigation and Evaluation of Current and Emerging Whole-Water Sampling Technologies for U.S. Geological Survey National Water Quality Assessment Program Author: Gareau, Keith D. Year: 2011 An investigation was conducted into current and emerging surface water sampling technologies. These technologies were compared and recommendations given to the United States Geological Survey (USGS) for adoption by the National Water Quality Assessment (NAWQA) Program. The goal is to reduce labor costs and increase information content. This paper examines lotic system samplers, portable autonomous whole-water samplers, and autonomous submergible whole-water samplers. When investigating whole-water sampling technology, it was imperative to take into consideration what chemical classifications can be sampled for by each respected technology. Chemical classifications considered are: emerging contaminants, major ions, nutrients, polychlorinated biphenyls, pesticides, volatile and semi-volatile organic compounds, and trace elements. The result of this project shows that USGS is currently using the best technology available for lotic systems. For portable autonomous whole-water samplers it is recommended that USGS incorporate certain brands and models to reduce cost and improve data collection for their sampling events. Autonomous submergible whole-water samplers are primarily advertised for oceanic research; however, if deployed in fresh water systems, USGS can reduce labor cost and increase data collection. In terms of emerging technology, it has been recommended to USGS to consider recent patents. Close

• 2. [Article] Greenhouse Gas Fluxes in Southeastern U.S. Coastal Plain Wetlands Under Contrasting Land Uses

  Whether through sea level rise or wetland restoration, agricultural soils in coastal areas will be inundated at increasing rates, renewing connections to sensitive surface waters and raising critical questions ...

  Citation × Citation Citation Abstract Copy Title: Greenhouse Gas Fluxes in Southeastern U.S. Coastal Plain Wetlands Under Contrasting Land Uses Author: Morse, Jennifer L., Ardón, Marcelo, Bernhardt, Emily S. Year: 2012 Whether through sea level rise or wetland restoration, agricultural soils in coastal areas will be inundated at increasing rates, renewing connections to sensitive surface waters and raising critical questions about environmental trade-offs. Wetland restoration is often implemented in agricultural catchments to improve water quality through nutrient removal. Yet flooding of soils can also increase production of the greenhouse gases nitrous oxide and methane, representing a potential environmental trade-off. Our study aimed to quantify and compare greenhouse gas emissions from unmanaged and restored forested wetlands, as well as actively managed agricultural fields within the North Carolina coastal plain, USA. In sampling conducted once every two months over a two-year comparative study, we found that soil carbon dioxide flux (range: 8000–64 800 kg CO2·ha-1· yr-1) comprised 66–100% of total greenhouse gas emissions from all sites and that methane emissions (range: -6.87 to 197 kg CH4·ha-1·yr-1) were highest from permanently inundated sites, while nitrous oxide fluxes (range: -1.07 to 139 kg N2O·ha-1·yr-1) were highest in sites with lower water tables. Contrary to predictions, greenhouse gas fluxes (as CO2 equivalents) from the restored wetland were lower than from either agricultural fields or unmanaged forested wetlands. In these acidic coastal freshwater ecosystems, the conversion of agricultural fields to flooded young forested wetlands did not result in increases in greenhouse gas emissions. Title: Greenhouse Gas Fluxes in Southeastern U.S. Coastal Plain Wetlands Under Contrasting Land Uses Author: Morse, Jennifer L., Ardón, Marcelo, Bernhardt, Emily S. Year: 2012 Whether through sea level rise or wetland restoration, agricultural soils in coastal areas will be inundated at increasing rates, renewing connections to sensitive surface waters and raising critical questions about environmental trade-offs. Wetland restoration is often implemented in agricultural catchments to improve water quality through nutrient removal. Yet flooding of soils can also increase production of the greenhouse gases nitrous oxide and methane, representing a potential environmental trade-off. Our study aimed to quantify and compare greenhouse gas emissions from unmanaged and restored forested wetlands, as well as actively managed agricultural fields within the North Carolina coastal plain, USA. In sampling conducted once every two months over a two-year comparative study, we found that soil carbon dioxide flux (range: 8000–64 800 kg CO2·ha-1· yr-1) comprised 66–100% of total greenhouse gas emissions from all sites and that methane emissions (range: -6.87 to 197 kg CH4·ha-1·yr-1) were highest from permanently inundated sites, while nitrous oxide fluxes (range: -1.07 to 139 kg N2O·ha-1·yr-1) were highest in sites with lower water tables. Contrary to predictions, greenhouse gas fluxes (as CO2 equivalents) from the restored wetland were lower than from either agricultural fields or unmanaged forested wetlands. In these acidic coastal freshwater ecosystems, the conversion of agricultural fields to flooded young forested wetlands did not result in increases in greenhouse gas emissions. Close

• 3. [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

• 4. [Article] Distributed Modeling of Ablation (1996–2011) and Climate Sensitivity on the Glaciers of Taylor Valley, Antarctica

  The McMurdo Dry Valleys of Antarctica host the coldest and driest ecosystem on Earth, which is acutely sensitive to the availability of water coming from glacial runoff. We modeled the spatial variability ...

  Citation × Citation Citation Abstract Copy Title: Distributed Modeling of Ablation (1996–2011) and Climate Sensitivity on the Glaciers of Taylor Valley, Antarctica Author: Hoffman, Matthew J., Fountain, Andrew G., Liston, Glen E. Year: 2016 The McMurdo Dry Valleys of Antarctica host the coldest and driest ecosystem on Earth, which is acutely sensitive to the availability of water coming from glacial runoff. We modeled the spatial variability in ablation and assessed climate sensitivity of the glacier ablation zones using 16 years of meteorological and surface mass-balance observations collected in Taylor Valley. Sublimation was the primary form of mass loss over much of the ablation zones, except for near the termini where melt, primarily below the surface, dominated. Microclimates in ~10 m scale topographic basins generated melt rates up to ten times higher than over smooth glacier surfaces. In contrast, the vertical terminal cliffs on the glaciers can have higher or lower melt rates than the horizontal surfaces due to differences in incoming solar radiation. The model systematically underpredicted ablation for the final 5 years studied, possibly due to an increase of windblown sediment. Surface mass-balance sensitivity to temperature was ~−0.02 m w.e. K−1, which is among the smallest magnitudes observed globally. We also identified a high sensitivity to ice albedo, with a decrease of 0.02 having similar effects as a 1 K increase in temperature, and a complex sensitivity to wind speed. Title: Distributed Modeling of Ablation (1996–2011) and Climate Sensitivity on the Glaciers of Taylor Valley, Antarctica Author: Hoffman, Matthew J., Fountain, Andrew G., Liston, Glen E. Year: 2016 The McMurdo Dry Valleys of Antarctica host the coldest and driest ecosystem on Earth, which is acutely sensitive to the availability of water coming from glacial runoff. We modeled the spatial variability in ablation and assessed climate sensitivity of the glacier ablation zones using 16 years of meteorological and surface mass-balance observations collected in Taylor Valley. Sublimation was the primary form of mass loss over much of the ablation zones, except for near the termini where melt, primarily below the surface, dominated. Microclimates in ~10 m scale topographic basins generated melt rates up to ten times higher than over smooth glacier surfaces. In contrast, the vertical terminal cliffs on the glaciers can have higher or lower melt rates than the horizontal surfaces due to differences in incoming solar radiation. The model systematically underpredicted ablation for the final 5 years studied, possibly due to an increase of windblown sediment. Surface mass-balance sensitivity to temperature was ~−0.02 m w.e. K−1, which is among the smallest magnitudes observed globally. We also identified a high sensitivity to ice albedo, with a decrease of 0.02 having similar effects as a 1 K increase in temperature, and a complex sensitivity to wind speed. Close

• 5. [Article] Processes Controlling Carbon Cycling in Antarctic Glacier Surface Ecosystems

  Glacier surface ecosystems, including cryoconite holes and cryolakes, are significant contributors to regional carbon cycles. Incubation experiments to determine the net production (NEP) of organic matter ...

  Citation × Citation Citation Abstract Copy Title: Processes Controlling Carbon Cycling in Antarctic Glacier Surface Ecosystems Author: Bagshaw, Elizabeth A., Tranter, Martyn, Wadham, Jemma L., Fountain, Andrew G., Dubnick, A., Fitzsimons, S. Year: 2016 Glacier surface ecosystems, including cryoconite holes and cryolakes, are significant contributors to regional carbon cycles. Incubation experiments to determine the net production (NEP) of organic matter in cryoconite typically have durations of 6-24 hours, and produce a wide range of results, many of which indicate that the system is net heterotrophic. We employ longer term incubations to examine the temporal variation of NEP in cryoconite from the McMurdo Dry Valleys, Antarctica to examine the effect of sediment disturbance on system production, and to understand processes controlling production over the lifetimes of glacier surface ecosystems. The shorter-term incubations have durations of one week and show net heterotrophy. The longer term incubations of approximately one year show net autotrophy, but only after a period of about 40 days (~1000 hours). The control on net organic carbon production is a combination of the rate of diffusion of dissolved inorganic carbon from heterotrophic activity within cryoconite into the water, the rate of carbonate dissolution, and the saturation of carbonate in the water (which is a result of photosynthesis in a closed system). We demonstrate that sediment on glacier surfaces has the potential to accumulate carbon over timescales of months to years. Title: Processes Controlling Carbon Cycling in Antarctic Glacier Surface Ecosystems Author: Bagshaw, Elizabeth A., Tranter, Martyn, Wadham, Jemma L., Fountain, Andrew G., Dubnick, A., Fitzsimons, S. Year: 2016 Glacier surface ecosystems, including cryoconite holes and cryolakes, are significant contributors to regional carbon cycles. Incubation experiments to determine the net production (NEP) of organic matter in cryoconite typically have durations of 6-24 hours, and produce a wide range of results, many of which indicate that the system is net heterotrophic. We employ longer term incubations to examine the temporal variation of NEP in cryoconite from the McMurdo Dry Valleys, Antarctica to examine the effect of sediment disturbance on system production, and to understand processes controlling production over the lifetimes of glacier surface ecosystems. The shorter-term incubations have durations of one week and show net heterotrophy. The longer term incubations of approximately one year show net autotrophy, but only after a period of about 40 days (~1000 hours). The control on net organic carbon production is a combination of the rate of diffusion of dissolved inorganic carbon from heterotrophic activity within cryoconite into the water, the rate of carbonate dissolution, and the saturation of carbonate in the water (which is a result of photosynthesis in a closed system). We demonstrate that sediment on glacier surfaces has the potential to accumulate carbon over timescales of months to years. Close

• 6. [Article] Sediment Nutrient Accumulation and Nutrient Availability in Two Tidal Freshwater Marshes Along the Mattaponi River, Virginia, USA

  Sediment deposition is the main mechanism of nutrient delivery to tidal freshwater marshes (TFMs). We quantified sediment nutrient accumulation in TFMs upstream and downstream of a proposed water withdrawal ...

  Citation × Citation Citation Abstract Copy Title: Sediment Nutrient Accumulation and Nutrient Availability in Two Tidal Freshwater Marshes Along the Mattaponi River, Virginia, USA Author: Morse, Jennifer L., Megonigal, J. Patrick, Walbridge, Mark R. Year: 2004 Sediment deposition is the main mechanism of nutrient delivery to tidal freshwater marshes (TFMs). We quantified sediment nutrient accumulation in TFMs upstream and downstream of a proposed water withdrawal project on the Mattaponi River, Virginia. Our goal was to assess nutrient availability by comparing relative rates of carbon (C), nitrogen (N), and phosphorus (P) accumulated in sediments with the C, N, and P stoichiometries of surface soils and above ground plant tissues. Surface soil nutrient contents (0.60–0.92% N and 0.09–0.13% P) were low but within reported ranges for TFMs in the eastern US. In both marshes, soil nutrient pools and C, N, and P stoichiometries were closely associated with sedimentation patterns. Differences between marshes were more striking than spatial variations within marshes: both C, N, and P accumulation during summer, and annual P accumulation rates (0.16 and 0.04 g P m−2 year−1, respectively) in sediments were significantly higher at the downstream than at the upstream marsh. Nitrogen:P ratiosbiomass, surface soils, and sediments suggest that N limits primary production in these marshes, but experimental additions of N and/or P did not significantly increase above ground productivity in either marsh. Lower soil N:P ratios are consistent with higher rates of sediment P accumulation at the downstream site, perhaps due to its greater proximity to the estuarine turbidity maximum. Title: Sediment Nutrient Accumulation and Nutrient Availability in Two Tidal Freshwater Marshes Along the Mattaponi River, Virginia, USA Author: Morse, Jennifer L., Megonigal, J. Patrick, Walbridge, Mark R. Year: 2004 Sediment deposition is the main mechanism of nutrient delivery to tidal freshwater marshes (TFMs). We quantified sediment nutrient accumulation in TFMs upstream and downstream of a proposed water withdrawal project on the Mattaponi River, Virginia. Our goal was to assess nutrient availability by comparing relative rates of carbon (C), nitrogen (N), and phosphorus (P) accumulated in sediments with the C, N, and P stoichiometries of surface soils and above ground plant tissues. Surface soil nutrient contents (0.60–0.92% N and 0.09–0.13% P) were low but within reported ranges for TFMs in the eastern US. In both marshes, soil nutrient pools and C, N, and P stoichiometries were closely associated with sedimentation patterns. Differences between marshes were more striking than spatial variations within marshes: both C, N, and P accumulation during summer, and annual P accumulation rates (0.16 and 0.04 g P m−2 year−1, respectively) in sediments were significantly higher at the downstream than at the upstream marsh. Nitrogen:P ratiosbiomass, surface soils, and sediments suggest that N limits primary production in these marshes, but experimental additions of N and/or P did not significantly increase above ground productivity in either marsh. Lower soil N:P ratios are consistent with higher rates of sediment P accumulation at the downstream site, perhaps due to its greater proximity to the estuarine turbidity maximum. Close

• 7. [Article] 2005 Diamond Lake Submersed Aquatic Vegetation Survey

  Diamond Lake is a large natural lake having a surface area of some 3214 acres (1300.7 hectares) and a maximum depth of 52 feet (15.8 meters). It is located within the Umpqua National Forest in the Southern ...

  Citation × Citation Citation Abstract Copy Title: 2005 Diamond Lake Submersed Aquatic Vegetation Survey Author: Sytsma, Mark D., Pfauth, Mary Year: 2006 Diamond Lake is a large natural lake having a surface area of some 3214 acres (1300.7 hectares) and a maximum depth of 52 feet (15.8 meters). It is located within the Umpqua National Forest in the Southern Cascade Mountains of Oregon, at an elevation of over 5000 feet (>1524 meters). Diamond Lake is a high-use waterbody that supports angling, public campgrounds, recreational boating, swimming, and water skiing. The human activity associated with the lake has been a significant contributor to the economy of southern Oregon since the early part of the twentieth century. Historically Diamond Lake was fishless but since 1910 the lake has been managed as a popular trophy trout fishery. The unauthorized introduction of the tui chub (Gila bicolor) into the lake in the 1930s caused disruption of the food web and a decline in the fishery. In 1954, the Oregon Game Commission constructed a canal near the Lake Creek outlet, lowered the lake level, and treated Diamond Lake with rotenone, to eradicate tui chub. The lake was restocked with trout following the successful rotenone treatment and a fishery was maintained for several decades. In 1992, tui chub were reintroduced, through accidental introduction or intentional illegal stocking, and again caused a decline in the trout fishery. Originally mesotrophic, Diamond Lake Diamond Lake productivity increased over the last century to a eutrophic state, and is currently included on the Oregon Department of Environmental Quality (ODEQ) 303(d) list of water quality limited water bodies for pH and algae. The lake had severe blooms of the cyanobacteria (blue-green algae) Anabaena flos-aquae, which produce neurotoxins, in the summers of 2001, 2002, and 2003. Microcystis aeruginosa, another toxin producing cyanobacterium species, was also present in the 2003 bloom. Diamond Lake was closed to some public uses (wading, swimming, water skiing, and boating) during portions of all three summers due to public health and safety concerns. Algae blooms and declining trout fishery have been attributed to alteration of the food web by the tui chubs. The chubs spawn early and consume the zooplankton in the lake, which reduces grazing pressure on phytoplankton. Since the lake is nitrogen limited, nitrogen-fixing cyanobacteria dominate the phytoplankton community. Therefore, the chubs reduce the quality of the trout fishery by reducing food available for trout and impact water quality by facilitating cyanobacteria blooms, which can be toxic. In response to the impact of the tui chub on Diamond Lake the US Forest Service and Oregon Department of Fish and Wildlife are collaborating in a tui chub eradication effort. The eradication plan includes a 2.4-m (8 ft) drawdown of the lake in the winter and spring of 2006 and a rotenone treatment of remaining lake volume in 2006 to kill any remaining fish. The US Forest Service prepared an EIS for the drawdown and rotenone treatment. Potential impacts of the drawdown on littoral aquatic plant communities were identified in the EIS. The US Forest Service conducted a qualitative survey to develop a species list for the lake. The survey described here provides a quantitative, pretreatment measure of cover and biomass of aquatic plants in Diamond Lake. Follow-up sampling, using similar methods, will permit assessment of changes in the plant community following drawdown and refilling of the lake. Title: 2005 Diamond Lake Submersed Aquatic Vegetation Survey Author: Sytsma, Mark D., Pfauth, Mary Year: 2006 Diamond Lake is a large natural lake having a surface area of some 3214 acres (1300.7 hectares) and a maximum depth of 52 feet (15.8 meters). It is located within the Umpqua National Forest in the Southern Cascade Mountains of Oregon, at an elevation of over 5000 feet (>1524 meters). Diamond Lake is a high-use waterbody that supports angling, public campgrounds, recreational boating, swimming, and water skiing. The human activity associated with the lake has been a significant contributor to the economy of southern Oregon since the early part of the twentieth century. Historically Diamond Lake was fishless but since 1910 the lake has been managed as a popular trophy trout fishery. The unauthorized introduction of the tui chub (Gila bicolor) into the lake in the 1930s caused disruption of the food web and a decline in the fishery. In 1954, the Oregon Game Commission constructed a canal near the Lake Creek outlet, lowered the lake level, and treated Diamond Lake with rotenone, to eradicate tui chub. The lake was restocked with trout following the successful rotenone treatment and a fishery was maintained for several decades. In 1992, tui chub were reintroduced, through accidental introduction or intentional illegal stocking, and again caused a decline in the trout fishery. Originally mesotrophic, Diamond Lake Diamond Lake productivity increased over the last century to a eutrophic state, and is currently included on the Oregon Department of Environmental Quality (ODEQ) 303(d) list of water quality limited water bodies for pH and algae. The lake had severe blooms of the cyanobacteria (blue-green algae) Anabaena flos-aquae, which produce neurotoxins, in the summers of 2001, 2002, and 2003. Microcystis aeruginosa, another toxin producing cyanobacterium species, was also present in the 2003 bloom. Diamond Lake was closed to some public uses (wading, swimming, water skiing, and boating) during portions of all three summers due to public health and safety concerns. Algae blooms and declining trout fishery have been attributed to alteration of the food web by the tui chubs. The chubs spawn early and consume the zooplankton in the lake, which reduces grazing pressure on phytoplankton. Since the lake is nitrogen limited, nitrogen-fixing cyanobacteria dominate the phytoplankton community. Therefore, the chubs reduce the quality of the trout fishery by reducing food available for trout and impact water quality by facilitating cyanobacteria blooms, which can be toxic. In response to the impact of the tui chub on Diamond Lake the US Forest Service and Oregon Department of Fish and Wildlife are collaborating in a tui chub eradication effort. The eradication plan includes a 2.4-m (8 ft) drawdown of the lake in the winter and spring of 2006 and a rotenone treatment of remaining lake volume in 2006 to kill any remaining fish. The US Forest Service prepared an EIS for the drawdown and rotenone treatment. Potential impacts of the drawdown on littoral aquatic plant communities were identified in the EIS. The US Forest Service conducted a qualitative survey to develop a species list for the lake. The survey described here provides a quantitative, pretreatment measure of cover and biomass of aquatic plants in Diamond Lake. Follow-up sampling, using similar methods, will permit assessment of changes in the plant community following drawdown and refilling of the lake. Close

• 8. [Article] Initial evaluations of a U.S. Navy Rapidly Relocatable Gulf of Mexico/Caribbean Ocean Forecast System in the Context of the Deepwater Horizon Oil Spill Disaster

  In response to the Deepwater Horizon (DwH) oil spill event in 2010, the Naval Oceanographic Office deployed a nowcast-forecast system covering the Gulf of Mexico and adjacent Caribbean Sea that was designated ...

  Citation × Citation Citation Abstract Copy Title: Initial evaluations of a U.S. Navy Rapidly Relocatable Gulf of Mexico/Caribbean Ocean Forecast System in the Context of the Deepwater Horizon Oil Spill Disaster Author: Zaron, Edward D., Fitzpatrick, Patrick J., Cross, Scott L., Harding, John M., Bub, Frank L., Wiggert, Jerry D., Ko, Dong S., Lau, Yee, Woodward, Katharine, Mooers, Christopher N.K. Year: 2015 In response to the Deepwater Horizon (DwH) oil spill event in 2010, the Naval Oceanographic Office deployed a nowcast-forecast system covering the Gulf of Mexico and adjacent Caribbean Sea that was designated Americas Seas, or AMSEAS, which is documented in this manuscript. The DwH disaster provided a challenge to the application of available ocean-forecast capabilities, and also generated a historically large observational dataset. AMSEAS was evaluated by four complementary efforts, each with somewhat different aims and approaches: a university research consortium within an Integrated Ocean Observing System (IOOS) testbed; a petroleum industry consortium, the Gulf of Mexico 3-D Operational Ocean Forecast System Pilot Prediction Project (GOMEX-PPP); a British Petroleum (BP) funded project at the Northern Gulf Institute in response to the oil spill; and the Navy itself. Validation metrics are presented in these different projects for water temperature and salinity profiles, sea surface wind, sea surface temperature, sea surface height, and volume transport, for different forecast time scales. The validation found certain geographic and time biases/errors, and small but systematic improvements relative to earlier regional and global modeling efforts. On the basis of these positive AMSEAS validation studies, an oil spill transport simulation was conducted using archived AMSEAS nowcasts to examine transport into the estuaries east of the Mississippi River. This effort captured the influences of Hurricane Alex and a non-tropical cyclone off the Louisiana coast, both of which pushed oil into the western Mississippi Sound, illustrating the importance of the atmospheric influence on oil spills such as DwH. Title: Initial evaluations of a U.S. Navy Rapidly Relocatable Gulf of Mexico/Caribbean Ocean Forecast System in the Context of the Deepwater Horizon Oil Spill Disaster Author: Zaron, Edward D., Fitzpatrick, Patrick J., Cross, Scott L., Harding, John M., Bub, Frank L., Wiggert, Jerry D., Ko, Dong S., Lau, Yee, Woodward, Katharine, Mooers, Christopher N.K. Year: 2015 In response to the Deepwater Horizon (DwH) oil spill event in 2010, the Naval Oceanographic Office deployed a nowcast-forecast system covering the Gulf of Mexico and adjacent Caribbean Sea that was designated Americas Seas, or AMSEAS, which is documented in this manuscript. The DwH disaster provided a challenge to the application of available ocean-forecast capabilities, and also generated a historically large observational dataset. AMSEAS was evaluated by four complementary efforts, each with somewhat different aims and approaches: a university research consortium within an Integrated Ocean Observing System (IOOS) testbed; a petroleum industry consortium, the Gulf of Mexico 3-D Operational Ocean Forecast System Pilot Prediction Project (GOMEX-PPP); a British Petroleum (BP) funded project at the Northern Gulf Institute in response to the oil spill; and the Navy itself. Validation metrics are presented in these different projects for water temperature and salinity profiles, sea surface wind, sea surface temperature, sea surface height, and volume transport, for different forecast time scales. The validation found certain geographic and time biases/errors, and small but systematic improvements relative to earlier regional and global modeling efforts. On the basis of these positive AMSEAS validation studies, an oil spill transport simulation was conducted using archived AMSEAS nowcasts to examine transport into the estuaries east of the Mississippi River. This effort captured the influences of Hurricane Alex and a non-tropical cyclone off the Louisiana coast, both of which pushed oil into the western Mississippi Sound, illustrating the importance of the atmospheric influence on oil spills such as DwH. Close

• 9. [Article] Utilizing Humidity and Temperature Data to Advance Monitoring and Prediction of Meteorological Drought

  The fraction of land area over the Continental United States experiencing extreme hot and dry conditions has been increasing over the past several decades, consistent with expectation from anthropogenic ...

  Citation × Citation Citation Abstract Copy Title: Utilizing Humidity and Temperature Data to Advance Monitoring and Prediction of Meteorological Drought Author: Behrangi, Ali, Loikith, Paul C., Fetzer, Eric J., Nguyen, Hai M., Granger, Stephanie L. Year: 2015 The fraction of land area over the Continental United States experiencing extreme hot and dry conditions has been increasing over the past several decades, consistent with expectation from anthropogenic climate change. A clear concurrent change in precipitation, however, has not been confirmed. Vapor pressure deficit (VPD), combining temperature and humidity, is utilized here as an indicator of the background atmospheric conditions associated with meteorological drought. Furthermore, atmospheric conditions associated with warm season drought events are assessed by partitioning associated VPD anomalies into the temperature and humidity components. This approach suggests that the concurrence of anomalously high temperature and low humidity was an important driver of the rapid development and evolution of the exceptionally severe 2011 Texas and the 2012 Great Plains droughts. By classification of a decade of extreme drought events and tracking them back in time, it was found that near surface atmospheric temperature and humidity add essential information to the commonly used precipitation-based drought indicators and can advance efforts to determine the timing of drought onset and its severity. Title: Utilizing Humidity and Temperature Data to Advance Monitoring and Prediction of Meteorological Drought Author: Behrangi, Ali, Loikith, Paul C., Fetzer, Eric J., Nguyen, Hai M., Granger, Stephanie L. Year: 2015 The fraction of land area over the Continental United States experiencing extreme hot and dry conditions has been increasing over the past several decades, consistent with expectation from anthropogenic climate change. A clear concurrent change in precipitation, however, has not been confirmed. Vapor pressure deficit (VPD), combining temperature and humidity, is utilized here as an indicator of the background atmospheric conditions associated with meteorological drought. Furthermore, atmospheric conditions associated with warm season drought events are assessed by partitioning associated VPD anomalies into the temperature and humidity components. This approach suggests that the concurrence of anomalously high temperature and low humidity was an important driver of the rapid development and evolution of the exceptionally severe 2011 Texas and the 2012 Great Plains droughts. By classification of a decade of extreme drought events and tracking them back in time, it was found that near surface atmospheric temperature and humidity add essential information to the commonly used precipitation-based drought indicators and can advance efforts to determine the timing of drought onset and its severity. Close

• 10. [Article] Dispersal Limitation and Climate-Related Environmental Gradients Structure Microcrustacean Composition in Freshwater Lakes, Ellesmere Island, Canada

  Dramatic environmental change is expected in the Arctic, yet little is known about the occurrence and community composition of microcrustaceans in Arctic lakes and how this will be influenced by future ...

  Citation × Citation Citation Abstract Copy Title: Dispersal Limitation and Climate-Related Environmental Gradients Structure Microcrustacean Composition in Freshwater Lakes, Ellesmere Island, Canada Author: Strecker, Angela L., Milne, Rebecca, Arnott, Shelley E. Year: 2008 Dramatic environmental change is expected in the Arctic, yet little is known about the occurrence and community composition of microcrustaceans in Arctic lakes and how this will be influenced by future environmental change. We sampled and calculated relative abundances of microcrustacean species in 54 lakes on Ellesmere Island, Canada. New species records on Ellesmere Island included Daphnia umbra, Tachidius discipes, and Artemeopsis stefanssoni. Daphnia middendorffiana/tenebrosa was the most common taxon and often dominated microcrustacean assemblages, likely a result of its pigmentation, which offers resistance to ultraviolet radiation. Species richness was positively associated with nutrients, dissolved organic carbon (DOC), temperature, calcium, and conductivity and negatively affected by elevation. In contrast to most findings in temperate systems, we detected a negative relationship between species richness and surface area. Community composition was influenced by DOC, nutrients, and elevation but was also related to spatial variables, suggesting that spatial gradients in environmental conditions and dispersal are important drivers of differences among sites. Arctic ecosystems are expected to change rapidly in the coming years because of climate change and ozone thinning, and we expect that associated changes in DOC, temperature, and nutrients will affect microcrustacean species richness and distribution throughout the landscape. Title: Dispersal Limitation and Climate-Related Environmental Gradients Structure Microcrustacean Composition in Freshwater Lakes, Ellesmere Island, Canada Author: Strecker, Angela L., Milne, Rebecca, Arnott, Shelley E. Year: 2008 Dramatic environmental change is expected in the Arctic, yet little is known about the occurrence and community composition of microcrustaceans in Arctic lakes and how this will be influenced by future environmental change. We sampled and calculated relative abundances of microcrustacean species in 54 lakes on Ellesmere Island, Canada. New species records on Ellesmere Island included Daphnia umbra, Tachidius discipes, and Artemeopsis stefanssoni. Daphnia middendorffiana/tenebrosa was the most common taxon and often dominated microcrustacean assemblages, likely a result of its pigmentation, which offers resistance to ultraviolet radiation. Species richness was positively associated with nutrients, dissolved organic carbon (DOC), temperature, calcium, and conductivity and negatively affected by elevation. In contrast to most findings in temperate systems, we detected a negative relationship between species richness and surface area. Community composition was influenced by DOC, nutrients, and elevation but was also related to spatial variables, suggesting that spatial gradients in environmental conditions and dispersal are important drivers of differences among sites. Arctic ecosystems are expected to change rapidly in the coming years because of climate change and ozone thinning, and we expect that associated changes in DOC, temperature, and nutrients will affect microcrustacean species richness and distribution throughout the landscape. Close