A Simple Model that Identifies Potential Effects of Sea-Level Rise on Estuarine and Estuary-Ecotone Habitat Locations for Salmonids in Oregon, USA

Diadromous aquatic species that cross a diverse range of habitats (including marine, estuarine, and freshwater) face different effects of climate change in each environment. One such group of species is the anadromous Pacific salmon (Oncorhynchus spp.). Studies of the potential effects of climate change on salmonids have focused on both marine and freshwater environments. Access to a variety of estuarine habitat has been shown to enhance juvenile life-history diversity, thereby contributing to the resilience of many salmonid species. Our study is focused on the effect of sea-level rise on the availability, complexity, and distribution of estuarine, and low-freshwater habitat for Chinook salmon (Oncorhynchus tshawytscha), steelhead (anadromous O. mykiss), and coho salmon (O. kisutch) along the Oregon Coast under future climate change scenarios. Using LiDAR, we modeled the geomorphologies of five Oregon estuaries and estimated a contour associated with the current mean high tide. Contour intervals at 1- and 2-m increments above the current mean high tide were generated, and changes in the estuary morphology were assessed. Because our analysis relied on digital data, we compared three types of digital data in one estuary to assess the utility of different data sets in predicting the changes in estuary shape. For each salmonid species, changes in the amount and complexity of estuarine edge habitats varied by estuary. The simple modeling approach we applied can also be used to identify areas that may be most amenable to pre-emptive restoration actions to mitigate or enhance salmonid habitat under future climatic conditions.     

GROUND-WATER TEMPERATURE FLUCTUATIONS AT LYONS FERRY FISH HATCHERY,WASHINGTON1

ABSTRACT: The well field serving the Lyons Ferry Fish Hatchery has experienced reduced water temperatures following continued, periodic withdrawal of large volumes of water. In January 1985, the well field temperature was 49°F, which is less than the optimal 52°F for raising salmon and steelhead trout. The aquifer supplying the hatchery is in hydraulic and thermal connection with the Snake River and a flooded embayment of the Palouse River. Ground-water temperatures in the well field cycle on an annual basis in response to changes in surface water temperature and pumping rate. Numerical simulation of the well field, using a simplified mixing cell model, demonstrates the coupling of well field hydraulics and aquifer thermal response. Alternative pumping schedules indicate that it is feasible to adjust ground-water pumping to effectively store heat in the aquifer during the summer months when surface water temperatures are elevated. Sensitivity analysis of this model indicated that the primary controls of the system's thermal response are the volume of the aquifer assumed to contribute to the well field and temperature of the overlying surface water body.     

A Review of Habitat Connectivity Research for Pacific Salmon in Marine,Estuary, and Freshwater Environments

Long‐term conservation planning for diadromous fishes would benefit from a better understanding of both the role of connectivity among environments and habitat variability in the expression of life‐history diversity. Most of the scientific knowledge on habitat fragmentation and connectivity has been developed in terrestrial systems in the discipline of landscape ecology. Research on habitat connectivity in aquatic systems (e.g., salmonid research that spans the spectrum of habitats from freshwater to the sea) is uncommon and largely focused on barriers to fish passage. Here, we present a review of the literature characterizing current research patterns on habitat connectivity within and among environments for Pacific salmon. We found this topic is still incipient: the literature is dominated by studies of freshwaters, with few articles focusing on habitat needs in estuary and marine systems. Pan‐environment studies are rare, pointing to a gap in our understanding of complex habitat relationships that might be significant in the development of long‐term conservation and restoration plans for Pacific salmon, particularly in light of the potential impact of climate change.     

COOPERATIVE MANAGEMENT OF THE DUNGENESS WATERSHED TO PROTECT SALMON IN WASHINGTON STATE1

ABSTRACT: Over the last decade, the Jamestown S'Klallam Tribe has formed partnerships with their neighboring county government, irrigation districts, property owners, and state and federal agencies in an effort to save the dwindling runs of Dungeness River salmon. Although considerable progress has been made to begin the recovery process, the watershed is included in recent listings of Pacific Northwest salmon under the Endangered Species Act. Under the coordination of an active watershed council, significant improvements have been made in water conservation and the protection of instream flows. Cooperation between the Tribe, irrigation districts and the Washington Department of Ecology resulted in a trust water rights agreement and the reduction of late summer water withdrawals by one‐third.     

Prymnesium parvum Control Treatments For Fish Hatcheries1

Barkoh, Aaron, Dennis G. Smith, and Gregory M. Southard, 2010. Prymnesium parvum Control Treatments for Fish Hatcheries. Journal of the American Water Resources Association (JAWRA) 46(1):161-169. DOI: 10.1111/j.1752-1688.2009.00400.x Abstract: In 2001, the ichthyotoxic microalga Prymnesium parvum caused massive fish kills and adversely affected fish production at the Texas Parks and Wildlife Department (TPWD) Dundee State Fish Hatchery. Since then, we have investigated several P. parvum bloom and ichthyotoxicity control treatments to develop management strategies that allow fish production and prevent the spread of the alga into unaffected hatcheries and impoundments. Current control successes include treatments for ponds, water supply, and a hazard analysis and critical control point program. For pond treatment, ammonium sulfate (as 0.14-0.25 mg/l un-ionized ammonia nitrogen for temperatures above 15°C), copper sulfate (2 mg/l), Cutrine^®-Plus (0.2-0.4 mg/l as copper), or potassium permanganate (3 mg/l above the potassium permanganate demand) controls P. parvum blooms. Copper sulfate at 1 mg/l controls P. parvum but is unable to eliminate ichthyotoxicity whereas potassium permanganate at 2 mg/l above the potassium permanganate demand controls ichthyotoxicity. For water treatment, ultraviolet (UV) light at 193-220 mJ/cm² doses or ozone at 0.4-1.2 mg/l for 6 min destroy P. parvum cells and reduce or eliminate ichthyotoxicity. A combination UV and ozone treatment appears to provide the best results; however, successful treatments depend on dosage relative to cell density and toxin concentration. To prevent the spread of the alga, hatchery fish delivery units and equipment are cleaned with household bleach (10% solution for 15 minutes) or hydrogen peroxide (62.5-12,500 mg/l for 0.25-24 hours). These treatments are tailored to water quality conditions and the fish species cultured at affected TPWD hatcheries. We recommend that other users test these treatments before applying them to ponds or other impoundments containing fish or other aquatic life.     

Hydrologic Resilience from Summertime Fog and Recharge: A Case Study for Coho Salmon Recovery Planning

Fog and low cloud cover (FLCC) and late summer recharge increase stream baseflow and decrease stream temperature during arid Mediterranean climate summers, which benefits salmon especially under climate warming conditions. The potential to discharge cool water to streams during the late summer (hydrologic capacity; HC) furnished by FLCC and recharge were mapped for the 299 subwatersheds ranked Core, Phase 1, or Phase 2 under the National Marine Fisheries Service Recovery Plan that prioritized restoration and threat abatement action for endangered Central California Coast Coho Salmon evolutionarily significant unit. Two spatially continuous gridded datasets were merged to compare HC: average hrs/day FLCC, a new dataset derived from a decade of hourly National Weather Satellite data, and annual average mm recharge from the USGS Basin Characterization Model. Two use‐case scenarios provide examples of incorporating FLCC‐driven HC indices into long‐term recovery planning. The first, a thermal analysis under future climate, projected 65% of the watershed area for 8–19 coho population units as thermally inhospitable under two global climate models and identified several units with high resilience (high HC under the range of projected warming conditions). The second use case investigated HC by subwatershed rank and coho population, and identified three population units with high HC in areas ranked Phase 1 and 2 and low HC in Core. Recovery planning for cold‐water fish species would benefit by including FLCC in vulnerability analyses.     

A multidecadal oscillation in precipitation and temperature series is pronounced in low flow series from Puget Sound streams

In Pacific Northwest streams, summer low flows limit water available to competing instream (salmon) and out-of-stream (human) uses, creating broad interest in how and why low flows are trending. Analyses that assumed linear (monotonic) change over the last ~60 years revealed declining low flow trends in minimally disturbed streams. Here, polynomials were used to model flow trends between 1929 and 2015. A multidecadal oscillation was observed in flows, which increased initially from the 1930s until the 1950s, declined until the 1990s, and then increased again. A similar oscillation was detected in precipitation series, and opposing oscillations in surface temperature, Pacific Decadal Oscillation, and Interdecadal Pacific Oscillation series. Multidecadal oscillations with similar periods to those described here are well known in climate indices. Fitted model terms were consistent with flow trends being influenced by at least two drivers, one oscillating and the other monotonic. Anthropogenic warming is a candidate driver for the monotonic decline, and variation in (internal) climatic circulation for the oscillating trend, but others were not ruled out. The recent upturn in streamflows suggests that anthropogenic warming has not been the dominant factor driving streamflow trends, at least until 2015. Climate projections based on simulations that omit drivers of multidecadal variation are likely to underestimate the range, and rate of change, of future climatic variation.     

Climate Trends but Little Net Water Supply Shift in One of Canada's Most Water‐Stressed Regions over the Last Century

The southern interior ecoprovince (SIE) of British Columbia, Canada represents the northernmost extent of the great western North American deserts, it is experiencing some of the nation's fastest economic and population growth making it one of Canada's most water‐stressed regions, and it includes two headwater basins of the transboundary (Canada‐US) Columbia River. Statistical trend analyses were performed on 90‐year regional indicator time series for annual conditions in observed temperature, precipitation, and streamflow reflecting the three major SIE river basins: the Thompson, and transboundary Okanagan and Similkameen. Results suggest that regional climate has grown warmer and wetter, but with little net impact on total water supply availability. The outcome might reflect mutual cancellation of increases in precipitation inputs vs. evapotranspiration losses. Conclusions appeared largely insensitive to low‐pass data filtering, Pacific Decadal Oscillation effects, or solar output variability. Ensemble historical global climate model runs over the same time interval support this absence of appreciable trend in regionally integrated annual runoff volume, but a possible mismatch in precipitation results suggests a direction for further study. Overall, while important changes in hydrologic timing and extremes are likely occurring here, there is limited evidence for a net change in overall water supply availability over the last century.     

Vulnerability of Fraser River sockeye salmon to climate change: A life cycle perspective using expert judgments

Fraser River sockeye salmon have been the basis for a major commercial fishery shared by Canada and the United States, and an important cultural foundation for many aboriginal groups; they are also of huge ecological significance throughout the Fraser Basin. The potential for altered aquatic habitat and temperature regimes due to climate change is an important concern for Fraser River sockeye salmon. This paper characterizes the vulnerability of Fraser River sockeye salmon to future climate change using an approach that is novel on three counts. First, previous efforts to assess the vulnerability of salmon to climate change have largely focused on only part of the life cycle, whereas we consider climate vulnerability at all stages in the life cycle. Second, we use the available scientific literature to provide a basis for structuring and eliciting judgments from fisheries science and management experts who research and manage these systems. Third, we consider prospects for mitigating the effects of climate change on sockeye salmon. Tests showed that participants’ judgments differentiated in statistically significant ways among questions that varied in terms of life stages, spawning regions and climate scenarios. The consensus among participants was that Fraser River sockeye are most vulnerable to climate change during the egg and returning adult stages of the life cycle. A high temperature scenario was seen as imposing the greatest risk on sockeye stocks, particularly those that migrate to the upper reaches of the Fraser River system and spawn earlier in the summer. The inability to alter water temperature and the highly constrained nature of sockeye management, with competing gear types and sequential fisheries over a long distance, suggest the potential to mitigate adverse effects is limited. Fraser River sockeye already demonstrate a great deal of adaptive capacity in utilizing heterogeneous habitats in different river sub-basins. This adaptability points to the potential value of policies to make stocks more resilient to uncertain futures.     

Do Open-Cycle Hatcheries Relying on Tourism Conserve Sea Turtles? Sri Lankan Developments and Economic–Ecological Considerations

By combining economic analysis of markets with ecological parameters, this article considers the role that tourism-based sea turtle hatcheries (of an open-cycle type) can play in conserving populations of sea turtles. Background is provided on the nature and development of such hatcheries in Sri Lanka. The modeling facilitates the assessment of the impacts of turtle hatcheries on the conservation of sea turtles and enables the economic and ecological consequences of tourism, based on such hatcheries, to be better appreciated. The results demonstrate that sea turtle hatcheries serving tourists can make a positive contribution to sea turtle conservation, but that their conservation effectiveness depends on the way they are managed. Possible negative effects are also identified. Economic market models are combined with turtle population survival relationships to predict the conservation impact of turtle hatcheries and their consequence for the total economic value obtained from sea turtle populations.     

PRELIMINARY ESTIMATION OF COLD WATER AVAILABILITY IN LAKES FOR FISH HATCHERIES1

ABSTRACT: Fish hatcheiies for cold water species (e.g., salmonids) require water below a certain specified optimum temperature. Deep lakes and reservoirs, which are thermally stratified, will have cold water below the thermocline suitable for fish hatchery supplies. Proper management will require withdrawal of water at different depths and a mixture of correct proportions can yield water at desired temperatures and quality. For preliminary studies, a mathematical model can be used to show by a comparatively simple computation the effect of different withdrawal rates of cold water and to check if the situation is critical. A critical situation may warrant the application of sophisticated computer models and/or the use of chilling at the hatchery. The method is illustrated by a case study for a small lake in the Province of Nova Scotia.     

Meadow Restoration Increases Baseflow and Groundwater Storage in the Sierra Nevada Mountains of California

In mountains of the western United States, channel incision has drawn down the water table across thousands of square kilometers of meadow floodplain. Here climate change is resulting in earlier melt and reduced snowpack and water resource managers are responding by investing in meadow restoration to increase springtime storage and summer flows. The record‐setting California drought (2012–2015) provided an opportunity to evaluate this strategy under the warmer and drier conditions expected to impact mountain water supplies. In 2012, 0.1 km² of meadow floodplain was reconnected by filling an incised channel through Indian Valley in the central Sierra Nevada Mountains of California. Despite sustained drought conditions after restoration, summer baseflow from the meadow increased 5–12 times. Before restoration, the total summer outflow from the meadow was 5% more than the total summer inflow. After restoration, total summer outflow from the meadow was between 35% and 95% more than total summer inflow. In the worst year of the drought (2015), when inflow to the meadow ceased for at least one month, summer baseflow was at least five times greater than before restoration. Groundwater levels also rose at four out of five sites near the stream channel. Filling the incised channel and reconnecting the meadow floodplain increased water availability and streamflow, despite unprecedented drought conditions.     

Predicting the Thermal Effects of Dam Removal on the Klamath River

The Klamath River once supported large runs of anadromous salmonids. Water temperature associated with multiple mainstem hydropower facilities might be one of many factors responsible for depressing Klamath salmon stocks. We combined a water quantity model and a water quality model to predict how removing the series of dams below Upper Klamath Lake might affect water temperatures, and ultimately fish survival, in the spawning and rearing portions of the mainstem Klamath. We calibrated the water quantity and quality models and applied them for the hydrometeorological conditions during a 40-year postdam period. Then, we hypothetically removed the dams and their impoundments from the models and reestimated the rivers water temperatures. The principal thermal effect of dam and reservoir removal would be to restore the timing (phase) of the rivers seasonal thermal signature by shifting it approximately 18 days earlier in the year, resulting in river temperatures that more rapidly track ambient air temperatures. Such a shift would likely cool thermal habitat conditions for adult fall chinook (Oncorhynchus tshawytscha) during upstream migration and benefit mainstem spawning. By contrast, spring and early summer temperatures could be warmer without dams, potentially harming chinook rearing and outmigration in the mainstem. Dam removal might affect the rivers thermal regime during certain conditions for over 200 km of the mainstem.     

ESTIMATED IMPACTS OF CLIMATE WARMING ON CALIFORNIA WATER AVAILABILITY UNDER TWELVE FUTURE CLIMATE SCENARIOS1

Spatially disaggregated estimates of over 131 stream‐flow, ground water, and reservoir evaporation monthly time series in California have been created for 12 different climate warming scenarios for a 72‐year period. Such disaggregated hydrologic estimates of multiple hydrologic cycle components are important for impact and adaptation studies of California's water system. A statewide trend of increased winter and spring runoff and decreased summer runoff is identified. Without operations modeling, approximate changes in water availability are estimated for each scenario. Even most scenarios with increased precipitation result in less available water because of the current storage systems' inability to catch increased winter streamflow in compensation for reduced summer runoff. The water availability changes are then compared with estimated changes in urban and agricultural water uses in California between now and 2100. The methods used in this study are relatively simple, but the results are qualitatively consistent with other studies focusing on the hydrologies of single basins or surface water alone.     

LONG-TERM VARIATIONS IN SEASONAL WEATHER CONDITIONS IMPORTANT TO WATER RESOURCES IN ILLINOIS1

ABSTRACT: An analysis of historical relationships between seasonal weather conditions and water resource conditions in Illinois provides insights to the challenges of projecting such relationships under conditions of climate change. In Illinois for 1901–1997 there were major temporal shifts in types of seasonal conditions that have positive and negative effects on surface water and ground water supplies and their quality. Major seasonal effects came in the spring and summer seasons and when either wet-and-warm or dry-and-warm weather conditions prevailed in either season. Sixty percent of the summer seasons creating negative impacts occurred during only 40 years: 1911–1940 and 1951–1960. Seasons creating impacts relate well to the frequency of cyclone passages and to the incidence of El Niño or La Niña conditions. This reveals that future climate fluctuations that shift the frequency of cyclones and/or ENSO events will have profound effects on Midwestern seasonal conditions that affect water resources. Projecting future effects of climate change on water resources will need to consider how shifts in water use and water management technologies act to re-define the seasonal weather conditions that are critical.     

Modeling Hydrological and Environmental Consequences of Climate Change and Urbanization in the Boise River Watershed,Idaho

The potential impacts driven by climate variability and urbanization in the Boise River Watershed (BRW), located in southwestern Idaho, are evaluated. The outcomes from Global Circulation Models (GCMs) and land use and land cover (LULC) analysis have been incorporated into a hydrological and environmental modeling framework to characterize how climate variability and urbanization can affect the local hydrology and environment at the BRW. The combined impacts of future climate and LULC change are also evaluated relative to the historical baseline conditions. For modeling exercises, Hydrological Simulation Program‐Fortran (HSPF) is used in parallel computing and statistical techniques, including spatial downscaling and bias correlation, are employed to evaluate climate consequences derived from GCMs as well. The implications of climate variability and land use change driven by urbanization are then observed to evaluate how these overall global challenges can affect water quantity and quality conditions at the BRW. The results show the combined impacts of both climate change and urbanization can lead to more seasonal variability of streamflow (from ?27.5% to 12.5%) and water quality, including sediment (from ?36.5% to 49.3%), nitrogen (from ?24% to 124.2%), and phosphorus (from ?13.3% to 21.2%) during summer and early fall over the next several decades.     

EFFECTS OF CLIMATE CHANGE ON HYDROLOGY AND WATER RESOURCES IN THE COLUMBIA RIVER BASIN1

ABSTRACT: As part of the National Assessment of Climate Change, the implications of future climate predictions derived from four global climate models (GCMs) were used to evaluate possible future changes to Pacific Northwest climate, the surface water response of the Columbia River basin, and the ability of the Columbia River reservoir system to meet regional water resources objectives. Two representative GCM simulations from the Hadley Centre (HC) and Max Planck Institute (MPI) were selected from a group of GCM simulations made available via the National Assessment for climate change. From these simulations, quasi-stationary, decadal mean temperature and precipitation changes were used to perturb historical records of precipitation and temperature data to create inferred conditions for 2025, 2045, and 2095. These perturbed records, which represent future climate in the experiments, were used to drive a macro-scale hydrology model of the Columbia River at 1/8 degree resolution. The altered streamflows simulated for each scenario were, in turn, used to drive a reservoir model, from which the ability of the system to meet water resources objectives was determined relative to a simulated hydrologic base case (current climate). Although the two GCM simulations showed somewhat different seasonal patterns for temperature change, in general the simulations show reasonably consistent basin average increases in temperature of about 1.8–2.1°C for 2025, and about 2.3–2.9°C for 2045. The HC simulations predict an annual average temperature increase of about 4.5°C for 2095. Changes in basin averaged winter precipitation range from -1 percent to + 20 percent for the HC and MPI scenarios, and summer precipitation is also variously affected. These changes in climate result in significant increases in winter runoff volumes due to increased winter precipitation and warmer winter temperatures, with resulting reductions in snowpack. Average March 1 basin average snow water equivalents are 75 to 85 percent of the base case for 2025, and 55 to 65 percent of the base case by 2045. By 2045 the reduced snowpack and earlier snow melt, coupled with higher evapotranspiration in early summer, would lead to earlier spring peak flows and reduced runoff volumes from April-September ranging from about 75 percent to 90 percent of the base case. Annual runoff volumes range from 85 percent to 110 percent of the base case in the simulations for 2045. These changes in streamflow create increased competition for water during the spring, summer, and early fall between non-firm energy production, irrigation, instream flow, and recreation. Flood control effectiveness is moderately reduced for most of the scenarios examined, and desirable navigation conditions on the Snake are generally enhanced or unchanged. Current levels of winter-dominated firm energy production are only significantly impacted for the MPI 2045 simulations.     

POTENTIAL CLIMATE CHANGE IMPACTS ON MOUNTAIN WATERSHEDS IN THE PACIFIC NORTHWEST1

ABSTRACT: Global climate change due to the buildup of greenhouse gases in the atmosphere has serious potential impacts on water resources in the Pacific Northwest. Climate scenarios produced by general circulation models (GCMs) do not provide enough spatial specificity for studying water resources in mountain watersheds. This study uses dynamical downscaling with a regional climate model (RCM) driven by a GCM to simulate climate change scenarios. The RCM uses a subgrid parameterization of orographic precipitation and land surface cover to simulate surface climate at the spatial scale suitable for the representation of topographic effects over mountainous regions. Numerical experiments have been performed to simulate the present-day climatology and the climate conditions corresponding to a doubling of atmospheric CO₂ concentration. The RCM results indicate an average warming of about 2.5°C, and precipitation generally increases over the Pacific Northwest and decreases over California. These simulations were used to drive a distributed hydrology model of two snow dominated watersheds, the American River and Middle Fork Flathead, in the Pacific Northwest to obtain more detailed estimates of the sensitivity of water resources to climate change. Results show that as more precipitation falls as rain rather than snow in the warmer climate, there is a 60 percent reduction in snowpack and a significant shift in the seasonal pattern of streamflow in the American River. Much less drastic changes are found in the Middle Fork Flathead where snowpack is only reduced by 18 percent and the seasonal pattern of streamflow remains intact. This study shows that the impacts of climate change on water resources are highly region specific. Furthermore, under the specific climate change scenario, the impacts are largely driven by the warming trend rather than the precipitation trend, which is small.     

Water Supply Planning Considering Uncertainties in Future Water Demand and Climate: A Case Study in an Illinois Watershed

Ensuring an adequate, reliable, clean, and affordable water supply for citizens and industries requires informed, long-range water supply planning, which is critically important for water security. A balance between water supply and demand must be considered for a long-term plan. However, water demand projections are often highly uncertain. Climate change could impact the hydrologic processes, and consequently, threaten water supply. Thus, understanding the uncertainties in future water demand and climate is critical for developing a sound water supply plan. In Illinois, regional water supply planning attempts to explore the impacts of future water demand and climate on water supply using scenario analyses and hydrologic modeling. This study is aimed at developing a water supply planning framework that considers both future water demand and climate change impacts. This framework is based on the Soil and Water Assessment Tool to simulate the watershed hydrology and conduct scenario analyses that consider the uncertainties in both future water demand and climate as well as their impacts on water supply. The framework was applied to water supply planning efforts in the Kankakee River watershed. The Kankakee River watershed model was calibrated and validated to observed streamflow records at four long-term United States Geological Survey streamflow gages. Because of the many model parameters involved, the calibration process was automated and was followed by a manual refinement, resulting in good model performance. Long-range water demand projections were prepared by the Illinois State Water Survey. Six future water demand scenarios were established based on a suite of assumptions. Climate scenarios were obtained from the Coupled Model Intercomparison Projection Phase 5 datasets. Three representative concentration pathways (RCPs), RCP2.6, RCP4.5, and RCP8.5, are used in the study. The scenario simulation results demonstrated that climate change appears to have a greater impact on water availability in the study area than water demand. The framework developed in this study can also be used to explore the impacts of uncertainties of water demand and climate on water supply and can be extended to other regions and watersheds.