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USGS2007

Longitudinal patterns of fish assemblages, aquatic habitat, and water temperature in the Lower Crooked River, Oregon

The Lower Crooked River is a remarkable groundwater-fed stream flowing through vertical basalt canyons in the Deschutes River Valley ecoregion in central Oregon (Pater and others, 1998). The 9-mile section of the river between the Crooked River National Grasslands boundary near Ogden Wayside and river mile (RM) 8 is protected under the National Wild and Scenic Rivers Act (16 U.S.C. 1271-1287) for its outstandingly remarkable scenic, recreational, geologic, hydrologic, wildlife, and botanical values (ORVs), and significant fishery and cultural values. Groundwater springs flow directly out of the canyon walls into the Lower Crooked River and create a unique hydrologic setting for native coldwater fish, such as inland Columbia Basin redband trout (Oncorhynchus mykiss gairdneri). To protect and enhance the ORVs that are the basis for the wild and scenic designation, the Bureau of Land Management (BLM) has identified the need to evaluate, among other conditions, fish presence and habitat use of the Lower Crooked River. The results of this and other studies will provide a scientific basis for communication and cooperation between the BLM, Oregon Water Resources Department, Oregon Department of Fish and Wildlife (ODFW) and all water users within the basin. These biological studies initiated by the BLM in the region reflect a growing national awareness of the impacts of agricultural and municipal water use on the integrity of freshwater ecosystems. Biological surveys are needed to better understand the aquatic ecosystem of the Lower Crooked River. This baseline information will be valuable to public land managers whose task is to balance resource use while protecting the unique attributes (that is, ORVs) of the Lower Crooked River. The habitat requirements of coldwater fishes in this section of stream are of particular interest due to state and federal regulation of water temperature in order to protect and restore fish populations. Historical data on the distribution and abundance of stream fishes in the Lower Crooked River are limited to point observations by fishermen and local biologists because steep canyon walls have limited access to most of the river. Surveys of aquatic habitat (channel morphology and substrate composition) have been conducted for the BLM by the ODFW (Oregon Department of Fish and Wildlife, 1997), U.S. Forest Service (United States Forest Service, 2003), and the U.S. Fish and Wildlife Service (USFWS), but fish surveys using electrofishing gear have never been conducted in the isolated 11-mile section of the Crooked River Gorge, and visual observations with mask and snorkel have only been made at isolated point locations where hiking trails provide access to the river (K. Jones, Steve Marx, and Brett Hodgson, ODFW; P. Lickwar, USFWS; pers. comm.). Thus, there is a poor understanding of stream fish presence and distribution throughout Lower Crooked River. Information on fish assemblages is available for the Deschutes River basin and applies generally to the Lower Crooked River because the two rivers were connected historically (Zimmerman and Ratliff 2003). The construction of dams throughout the Deschutes River basin has eliminated historic runs of salmon and steelhead and prevented migration of bull trout and Pacific lamprey into the Crooked River system. Native fish species expected to occur in the Lower Crooked River include Columbia Basin redband trout ( Oncorhynchus mykiss gairdneri ), mountain whitefish ( Prosopium williamsoni ), sculpin ( Cottus spp.), two species of dace ( Rhinichthys spp.), two species of sucker ( Catostomus spp.), northern pikeminnow ( Ptychocheilus oregonensis ), chiselmouth ( Acrocheilus alutaceus ), and redside shiner ( Richardsonius balteatus ). Threespine stickleback ( Gasterosteus aculeatus ), a species native to western Oregon, also occurs in the basin but is believed to be introduced (D. Markle, Department of Fisheries and Wildlife, Oregon State University, personnel commun.). Extensive stocking of rainbow trout has contributed to a large population of naturalized fish of hatchery origin in the Lower Crooked River. Due to the difficulty of differentiating between wild redband trout and naturalized rainbow trout of hatchery origin, the general classification of rainbow trout ( Oncorhynchus mykiss ) is used throughout this report to describe the fish that were observed in the Lower Crooked River. Exotic fish species expected to occur in the Lower Crooked River include large- and smallmouth bass ( Micropterus spp.), yellow perch ( Perca flavescens ), and brown bullhead (Ameiurus nebulosis) (Zimmerman and Ratliff 2003). The goal of this project was to examine longitudinal patterns in fish assemblages, aquatic habitat, and water temperature in the Lower Crooked River during summer conditions. Specific objectives were to (1) characterize the spatial distribution of native and non-native fishes, (2) describe variation in channel morphology, substrate composition, and water temperature, and (3) evaluate the associations between fishes, aquatic habitat, and water temperature.

Oregon↗

USGS2025

Reframing fish passage prioritization for human nutrition outcomes

Water control infrastructure forms barriers that fragment river habitats, reducing aquatic biodiversity and the ecosystem services it provides. Irrigation infrastructure, for example, although implemented to support food production, highlights problematic trade-offs against wild food systems like inland fisheries which are a critical food resource for tens of millions of people, particularly in tropical countries. To reduce fragmentation at a broad range of barriers, fish passage technology is sometimes implemented to support migrating fish, aided by frameworks designed to prioritize barriers for remediation. This study critically evaluated 93 fish passage barrier prioritization frameworks globally to explore how they could strategically guide fish passage investments in tropical contexts and identify criteria relevant to delivering on nutrition security outcomes. Results showed prioritization frameworks were ill-equipped to support the broader human development goals that may drive fish passage investments in tropical countries, such as supporting human nutrition under United Nations Sustainable Development Goal (SDG) 2: Zero Hunger. Tropical contexts were underrepresented despite substantial recent fish passage investment, whereas temperate and conservation focused frameworks, particularly from North America, dominated. These findings prompt reflection on the inherent biases in fish passage barrier prioritization frameworks and criteria. Improving understanding of and collaboration with local partners to integrate SDG 2 into future prioritization frameworks could improve fish passage infrastructure and help support better nutrition and food production for communities.

Environmental Management↗

USGS2011

New insights of tsunami hazard from the 2011 Tohoku-oki event

We report initial results from our recent field survey documenting the inundation and resultant deposits of the 2011 Tohoku-oki tsunami from Sendai Plain, Japan. The tsunami inundated up to 4.5 km inland but the > 0.5 cm-thick sand deposit extended only 2.8 km (62% of the inundation distance). The deposit however continued as a mud layer to the inundation limit. The mud deposit contained high concentrations of water-leachable chloride and we conclude that geochemical markers and microfossil data may prove to be useful in identifying the maximum inundation limit of paleotsunamis that could extend well beyond any preserved sand layer. Our newly acquired data on the 2011 event suggest that previous estimates of paleotsunamis (e.g. 869 AD Jōgan earthquake and tsunami) in this area have probably been underestimated. If the 2011 and 869 AD events are indeed comparable, the risk from these natural hazards in Japan is much greater than previously recognized.

Sendai Plain↗

USGS2015

Changes in total phosphorus concentration in the Red River of the North Basin, 1970-2012

The Red River of the North drains much of eastern North Dakota and northwestern Minnesota and flows north into Manitoba, Canada, ultimately into Lake Winnipeg; therefore, water quality is an International concern. With increased runoff in the past few decades, phosphorus flux (the amount of phosphorus transported by the river) has increased. This is a concern, especially with respect to Lake Winnipeg, an important inland fishery and recreational destination. There is pressure at the State and International levels to reduce phosphorus flux, an expensive proposition. Depending on the method (controlling sources, settling ponds, buffer strips), control of phosphorus flux is not always effective during spring runoff. This work represents a first step in developing a causal model for phosphorus flux by examining available data and changes in concentration over time. Total phosphorus concentration data for the Red River at Emerson, Manitoba, and at Fargo, North Dakota-Moorhead, Minnesota, were summarized and then analyzed using WRTDS (Weighted Regressions on Time, Discharge, and Season) to describe total phosphorus changes over time in two analysis periods: 1970-1993 and 1993-2012. Total phosphorus concentration increased in the first period at Emerson, Manitoba, indicating phosphorus was likely being transported to streams during runoff events. A very different pattern occurred at Fargo-Moorhead with declines in concentration, except at high discharge. While concentration continually changes, during the second period it decreased during spring runoff at Emerson and Fargo-Moorhead and during the growing season at Fargo-Moorhead, perhaps because of improved agricultural practices and declines in some uses of phosphorus.

Red River of the North Basin↗

USGS1988

Potentiometric surface of the upper Floridan Aquifer in the St. Johns River Water Management District and vicinity, Florida, May 1988

This map shows the potentiometric surface of the Upper Floridan aquifer in the St. Johns River Water Management District and vicinity, for May 1988. The Upper Floridan aquifer is the principal source of potable water in the area. Water level measurements were made on approximately 1,000 wells and on several springs. The potentiometric surface is shown mostly by 5-foot contour intervals. In the Fernandina Beach area of Nassau County, a 30-foot interval is used to show a deep cone of depression. The potentiometric surface ranged from 127 ft above sea level in Polk County to 79 ft below sea level in Nassau County. Water levels in many key wells were about the May average. Most levels in the district were below the levels of May 1987. Declines of about a foot or less from May 1987 levels were common along the coast, but inland, the potentiometric surface declined as much as 2 to 6 ft in places.

Florida↗

USGS1977

Summary of hydrologic data collected during 1975 in Dade County, Florida

During the 1975 calendar year rainfall in Dade County, Fla., was 14.89 inches below the long-term average (57.17 in.). Ground-water levels ranged from 0.1 foot above to 1.1 feet below average. The highest and lowest ground-water levels for the year were both 1 foot below their long-term averages. In the Hialeah-Miami Springs area, ground-water levels in wells near the centers of the heaviest pumping ranged from 9.8 to 11.2 feet below mean sea level and in the Southwest well field area, ground-water levels near the centers of pumping ranged from 3.5 feet above to 3.4 feet below mean sea level. The combined average daily discharge from eight major streams and canals that flow into Biscayne Bay was 1,014 cubic feet per second (cfs), 124 cfs above the combined average daily flow for the 1974 water year. The combined average daily flow through the Tamiami Canal outlets was 568 cfs, 202 cfs below that of the 1974 water year. The position of the salt front in 1975 in the coastal part of the Biscayne aquifer was about the same as in 1974 except at Miami International Airport and Homestead Air Force Base where the salt front had encroached farther inland. (Woodard-USGS)

Open-File Report↗

USGS2024

A conceptual site model of contaminant transport pathways from the Bremerton Naval Complex to Sinclair Inlet, Washington, 2011–21

Historical activities on the Bremerton Naval Complex (BNC) in Puget Sound, Washington, have resulted in Sinclair Inlet sediments with elevated concentrations of contaminants, including organic contaminants such as polychlorinated biphenyls and trace elements including mercury. Six U.S. Geological Survey–U.S. Navy datasets have been collected since the last major assessment, in 2013, of soil and groundwater contaminant transport pathways and mercury loading estimates from the BNC to Sinclair Inlet. These include: mercury isotope analysis to support sourcing of mercury in Sinclair Inlet; mercury sampling within the dry dock systems; nearshore thermal surveys to identify potential groundwater discharge locations to Sinclair Inlet; time-series monitoring in nearshore wells to understand the inland extent and dynamics of the tidal mixing zone; tidal studies of mercury in nearshore monitoring wells in an area of contaminated fill material called Site 1; and a spatial survey of trace elements and other parameters in nearshore monitoring wells, pore water, seeps, surface water, and sediment along unwalled shorelines in the western part of the BNC. The results were incorporated into an updated Conceptual Site Model and used to update contaminant load estimates from the terrestrial BNC to Sinclair Inlet. The results from these studies provide data to the U.S. Navy to support prioritization of on-going remediation actions to manage contamination on the BNC that reduce potential impacts to Sinclair Inlet sediment, surface water, and fish and shellfish tissue. Mercury isotope analysis of surface sediments and particulate material indicated that a similar industrial mercury profile is present throughout Puget Sound, including terrestrial and marine BNC samples and in other Sinclair Inlet sediments and persists across regions with low and elevated mercury concentrations. Two sources of mercury at the BNC are Sites 1 and 2 subsurface soils/fill material, with total mercury concentrations in particulates collected from the bottom of monitoring wells drilled in these materials ranging from 18,000 to 44,000 nanograms per gram (as compared to the Washington State Marine Sediment Cleanup Screening Level of 590 nanograms per gram). Contaminants are transported from the terrestrial BNC to Sinclair Inlet via three primary pathways, (1) stormwater outfalls, (2) dry dock discharges, and (3) direct discharge along unwalled shorelines. Previous loading estimates (based on filtered total mercury) ranked stormwater outfalls, particularly outfall PSNS015 in Site 2 soils, as the largest soil and groundwater contaminant transport pathway from the terrestrial BNC to Sinclair Inlet. Updated loading estimates in this report suggest that the dry dock systems may be a larger pathway of mercury from the terrestrial BNC to Sinclair Inlet than previously thought, within the same order of magnitude as the PSNS015 storm-drain system. Trace-element loads via direct shoreline discharge are difficult to estimate due to the large and dynamic tidal mixing zone of groundwater and seawater in the nearshore along unwalled shorelines. However, current best estimated ranges suggest that direct shoreline discharge is one of the three main pathways and may contribute smaller mercury loads than the stormwater and the dry dock systems. Along unwalled shorelines, direct groundwater discharge of terrestrial contaminants may be less important than recirculating seawater in the nearshore mixing zone that can extract contaminants from nearshore subsurface material. Total estimated mercury loads from the terrestrial BNC to Sinclair Inlet range from approximately 40 to 200 grams of filtered total mercury per year and a minimum of 70–350 grams of particulate total mercury per year, for a minimum total of 110–525 grams of whole (filtered plus particulate) total mercury per year. Data gaps are identified that, if filled, would further refine the Conceptual Site Model and contaminant loading estimates from the terrestrial BNC to Sinclair Inlet.

Washington↗

USGS1995

Estimated discharge and chemical-constituent loading from the upper Floridan aquifer to the lower St. Johns River, northeastern Florida, 1990-91

The lower St. Johns River, a 101-mile long segment of the St. Johns River, begins at the confluence of the Ocklawaha River and ends where the river discharges into the Atlantic Ocean at Mayport. The St. Johns River is affected by tides as far upstream as Lake George, 106 miles from the mouth. Saltwater from the ocean advances inland during each incoming tide and recedes during each outgoing tide. The chemical quality of the lower St. Johns River is highly variable primarily because of the inflow of saltwater from the ocean, and in some areas, from the discharge of mineralized ground water. Three hydrogeologic units are present in the study area: the surficial aquifer system, the intermediate confining unit, and the Floridan aquifer system. The surficial aquifer system overlies the intermediate confining unit and consists of deposits containing sand, clay, shell, and some limestone and dolomite. The intermediate confining unit underlies all of the study area and retards the vertical movement of water between the surficial aquifer system and the Floridan aquifer system. The intermediate confining unit consists of beds of relatively low permeability sediments that vary in thickness and areal extent and can be breached by sinkholes, fractures, and other openings. The Floridan aquifer system primarily consists of limestone and dolomite. The quality of water in the Upper Floridan aquifer varies throughout the study area. Dissolved solids in water range from about 100 to more than 5,000 milligrams per liter. Chloride and sulfate concentrations in water from the Upper Floridan aquifer range from about 4 to 3,700 milligrams per liter and from 1 to 1,300 milligrams per liter, respectively. The rate of leakage through the intermediate confining unit is controlled by the leakance coefficient of the intermediate confining unit and by the head difference between the Upper Floridan aquifer and the surficial aquifer system. The total ground-water discharge from the Upper Floridan aquifer to the St. Johns River within the lower St. Johns River drainage basin, based on the potentiometric surface of the Upper Floridan aquifer in September 1990, was estimated to be 86 cubic feet per second. Total estimated ground-water discharge to the lower St. Johns River in September 1991, when heads in the Upper Floridan aquifer averaged about 4 feet higher than in 1990, was 133 cubic feet per second. The load of dissolved-solids that discharged from the Upper Floridan aquifer into the lower St. Johns River on the basis of September 1990 heads is estimated to be 47,000 tons per year. Estimated chloride and sulfate loads are 18,000 and 9,500 tons per year, respectively. Dissolved-solids, chloride, and sulfate loads discharging into the lower St. Johns River are estimated to be 81,000, 39,000, and 15,000 tons per year, respectively, on the basis of September 1991 heads.

Florida↗

USGS2015

Sources and transport of phosphorus to rivers in California and adjacent states, U.S., as determined by SPARROW modeling

The SPARROW (SPAtially Referenced Regression on Watershed attributes) model was used to simulate annual phosphorus loads and concentrations in unmonitored stream reaches in California, U.S., and portions of Nevada and Oregon. The model was calibrated using de-trended streamflow and phosphorus concentration data at 80 locations. The model explained 91% of the variability in loads and 51% of the variability in yields for a base year of 2002. Point sources, geological background, and cultivated land were significant sources. Variables used to explain delivery of phosphorus from land to water were precipitation and soil clay content. Aquatic loss of phosphorus was significant in streams of all sizes, with the greatest decay predicted in small- and intermediate-sized streams. Geological sources, including volcanic rocks and shales, were the principal control on concentrations and loads in many regions. Some localized formations such as the Monterey shale of southern California are important sources of phosphorus and may contribute to elevated stream concentrations. Many of the larger point source facilities were located in downstream areas, near the ocean, and do not affect inland streams except for a few locations. Large areas of cultivated land result in phosphorus load increases, but do not necessarily increase the loads above those of geological background in some cases because of local hydrology, which limits the potential of phosphorus transport from land to streams.

Journal of the American Water Resources Associatio↗

USGS2006

Effects of watershed land use on nitrogen concentrations and δ 15 nitrogen in groundwater

Eutrophication is a major agent of change affecting freshwater, estuarine, and marine systems. It is largely driven by transportation of nitrogen from natural and anthropogenic sources. Research is needed to quantify this nitrogen delivery and to link the delivery to specific land-derived sources. In this study we measured nitrogen concentrations and δ 15 N values in seepage water entering three freshwater ponds and six estuaries on Cape Cod, Massachusetts and assessed how they varied with different types of land use. Nitrate concentrations and δ 15 N values in groundwater reflected land use in developed and pristine watersheds. In particular, watersheds with larger populations delivered larger nitrate loads with higher δ 15 N values to receiving waters. The enriched δ 15 N values confirmed nitrogen loading model results identifying wastewater contributions from septic tanks as the major N source. Furthermore, it was apparent that N coastal sources had a relatively larger impact on the N loads and isotopic signatures than did inland N sources further upstream in the watersheds. This finding suggests that management priorities could focus on coastal sources as a first course of action. This would require management constraints on a much smaller population.

Massachusetts↗

USGS2013

Site Response and Basin Waves in the Sacramento–San Joaquin Delta, California

The Sacramento–San Joaquin Delta is an inland delta at the western extent of the Central Valley. Levees were built around swampy islands starting after the Civil War to reclaim these lands for farming. Various studies show that these levees could fail in concert from shaking from a major local or regional earthquake resulting in salty water from the San Francisco Bay contaminating the water in the Delta. We installed seismographs around the Delta and on levees to assess the contribution of site response to the seismic hazard of the levees. Cone penetrometer testing shows that the upper 10 s of meters of soil in the Delta have shear‐wave velocities of about 200 m/s, which would give a strong site response. Seismographs were sited following two strategies: pairs of stations to compare the response of the levees to nearby sites, and a more regional deployment in the Delta. Site response was determined in two different ways: a traditional spectral ratio (TSR) approach of S waves using station BDM of the Berkeley Digital Seismic Net as a reference site, and using SH / SV ratios of noise (or Nakamura’s method). Both estimates usually agree in spectral character for stations whose response is dominated by a resonant peak, but the most obvious peaks in the SH / SV ratios usually are about two‐thirds as large as the main peaks in the TSRs. Levee sites typically have large narrow resonances in the site response function compared to sites in the farmland of the Delta. These resonances, at a frequency of about 1–3 Hz, have amplitudes of about 15 with TSR and 10–12 with Nakamura’s method. Sites on farmland in the Delta also have amplifications, but these are typically broader and not as resonant in appearance. Late (slow) Rayleigh waves were recorded at stations in the Delta, have a dominant period of about one second, and are highly monochromatic. Results from a three‐station array at the Holland Marina suggest that they have a phase velocity of about 600 m/s and arrive at about the same azimuth as the straight‐line back azimuth to the source. A dispersion curve determined for the basin or valley waves yields a shallow velocity profile that increases from about 350 m/s in the upper 0.2 km to about 1.1 km/s at a depth of about 2 km.

California↗

USGS2026

Coastal barrier resilience and resistance: Analysis and metrics for characterizing coastal state

Barrier islands are shaped by a variety of short- and long-term environmental processes such as storms and relative sea-level rise. These islands, found along the estuarine-marine interface, provide ecosystem services including storm surge and wave attenuation, erosion protection to inland marshes, habitat for fish and wildlife, and recreation. Natural resource managers require actionable information on how barrier island resilience and resistance changes over time to understand how an island’s current state relates to past conditions and to inform restoration prioritization and implementation. The U.S. Geological Survey and The Water Institute collaborated on a study to develop indicators of resilience and resistance for barrier islands in Louisiana. Here, resilience captures island persistence on yearly to decadal time scales, and resistance captures persistence on event time scales of days to weeks. The indicators fall in two categories: Tier 1 Screening Metrics, that can be readily calculated from available data, are easily interpretable as an evaluation of barrier condition, and provide a high-level snapshot of overall barrier resilience and resistance; and Tier 2 Analysis Metrics, which are detailed metrics that required specialized analysis and interpretation and are more applicable to answering specific questions managers may have about barrier state. The research team derived Tier 1 resilience indicators from subaerial land and vegetation cover calculated from publicly available maps and products based on satellite imagery. By benchmarking the total land and vegetation extent against their respective historical maxima, this metric provides a snapshot of an island’s current state in the context of its long-term trajectory. The research team developed Tier 1 resistance indicators based on subaerial island configuration and water level recurrence as a proxy for evaluating island resistance to storms, which are the primary driver of short-term change. These Tier 1 metrics can be analyzed over time to provide a high-level assessment of how an island’s resistance decreases because of elevation loss or sea-level rise or increases due to restoration or natural recovery. The research team developed Tier 2 resilience and resistance indicators and associated analyses to provide detailed information for specific time periods or applications (e.g., wildlife management). These metrics include habitat coverage from high-resolution maps, which show composition changes over time to capture the evolving resilience of specific habitat types; high tide flooding analysis, which evaluate island area relative to specified flooding thresholds to characterize resistance in the short-term or, if analyzed over time, indicate changes in resilience; and hypsometric curve analysis, which allows managers to evaluate island area changes above their own elevation benchmarks of interest and similarly characterize resistance in the short-term or indicate changes in resilience if assessed over time. The research team calculated Tier 1 metrics of the barrier islands and headlands along the coast of Louisiana for the period of 1984 through 2021 and Tier 2 metrics for select times during that period depending on data available and quality. The results were captured in a report card for each barrier, which also includes an overview of the metrics and their interpretation; a restoration and storm history; and Tier 1 and Tier 2 metric analysis, including benchmarking against coastwide and regional values as well as to an island’s pre-restoration trajectory. These report cards provide a readily digestible synthesis of barrier condition and trajectory that coastal managers can use to support restoration prioritization and other decisions.

Louisiana↗

USGS2021

Genomic and environmental influences on resilience in a cold-water fish near the edge of its range

Small, isolated populations present a challenge for conservation. The dueling effects of selection and drift in a limited pool of genetic diversity make the responses of small populations to environmental perturbations erratic and difficult to predict. This is particularly true at the edge of a species range, where populations often persist at the limits of their environmental tolerances. Populations of cisco, Coregonus artedi , in inland lakes have experienced numerous extirpations along the southern edge of their range in recent decades, which are thought to result from environmental degradation and loss of cold, well-oxygenated habitat as lakes warm. Yet, cisco extirpations do not show a clear latitudinal pattern, suggesting that local environmental factors and potentially local adaptation may influence resilience. Here, we used genomic tools to investigate the nature of this pattern of resilience. We used restriction site-associated DNA capture (Rapture) sequencing to survey genomic diversity and differentiation in southern inland lake cisco populations and compared the frequency of deleterious mutations that potentially influence fitness across lakes. We also examined haplotype diversity in a region of the major histocompatibility complex involved in stress and immune system response. We correlated these metrics to spatial and environmental factors including latitude, lake size, and measures of oxythermal habitat and found significant relationships between genetic metrics and broad and local factors. High levels of genetic differentiation among populations were punctuated by a phylogeographic break and residual patterns of isolation-by-distance. Although the prevalence of deleterious mutations and inbreeding coefficients was significantly correlated with latitude, neutral and non-neutral genetic diversity were most strongly correlated with lake surface area. Notably, differences among lakes in the availability of estimated oxythermal habitat left no clear population genomic signature. Our results shed light on the complex dynamics influencing these isolated populations and provide valuable information for their conservation.

Wisconsin↗

USGS2007

Climate change: Potential impacts and interactions in wetlands of the United States

Wetlands exist in a transition zone between aquatic and terrestrial environments which can be altered by subtle changes in hydrology. Twentieth century climate records show that the United States is generally experiencing a trend towards a wetter, warmer climate; some climate models suggest that his trend will continue and possibly intensify over the next 100 years. Wetlands that are most likely to be affected by these and other potential changes (e.g., sea-level rise) associated with atmospheric carbon enrichment include permafrost wetlands, coastal and estuarine wetlands, peatlands, alpine wetlands, and prairie pothote wetlands. Potential impacts range from changes in community structure to changes in ecological function, and from extirpation to enhancement. Wetlands (particularly boreal peatlands) play an important role in the global carbon cycle, generally sequestering carbon in the form of biomass, methane, dissolved organic material and organic sediment. Wetlands that are drained or partially dried can become a net source of methane and carbon dioxide to the atmosphere, serving as a positive biotic feedback to global warming. Policy options for minimizing the adverse impacts of climate change on wetland ecosystems include the reduction of current anthropogenic stresses, allowing for inland migration of coastal wetlands as sea-level rises, active management to preserve wetland hydrology, and a wide range of other management and restoration options.

Journal of the American Water Resources Associatio↗

USGS2018

Effects of temperature and exposure duration on four potential rapid-response tools for zebra mussel (Dreissena polymorpha) eradication

Zebra mussels (Dreissena polymorpha) have continued their spread within inland lakes and rivers in North America despite diligent containment and decontamination efforts by natural resource agencies and other stakeholders. Identification of newly infested waterways by early detection surveillance programs allows for rapid response zebra mussel eradication treatments in some situations. Previous eradication treatments have occurred over a broad range of water temperatures which have influenced the efficacy of molluscicides. Natural resource managers will benefit from knowledge regarding the impacts of water temperature and exposure duration on the toxicity of molluscicides to zebra mussels. In particular, temperature specific data are needed to inform the selection of an effective molluscicide and the proper dose that will induce 100% zebra mussel mortality. We evaluated the influences of temperature and exposure duration on the toxicity of two U.S. EPA-registered (EarthTec QZ and Zequanox) and two nonregistered (niclosamide and potassium chloride) molluscicides to zebra mussels at water temperatures of 7, 12, 17, and 22 °C. Our results indicate that treatment options for the eradication of zebra mussels in waters ≤ 12 °C include 336 h or longer treatments with EarthTec QZ and KCl as well as treatments with niclosamide ≥ 24 h in duration. In waters ≥ 17 °C, multiple toxicant and exposure duration combinations are potentially effective for zebra mussel eradication. On-site or in situ zebra mussel bioassays are a useful tool for the evaluation of treatment efficacy.

Management of Biological Invasions↗

USGS2024

Asymmetric impacts of climate change on thermal habitat suitability for inland lake fishes

Climate change is altering the thermal habitats of freshwater fish species. We analyze modeled daily temperature profiles from 12,688 lakes in the US to track changes in thermal habitat of 60 lake fish species from different thermal guilds during 1980-2021. We quantify changes in each species’ preferred days, defined as the number of days per year when a lake contains the species’ preferred temperature. We find that cooler-water species are losing preferred days more rapidly than warmer-water species are gaining them. This asymmetric impact cannot be attributed to differences in geographic distribution among species; instead, it is linked to the seasonal dynamics of lake temperatures and increased thermal homogenization of the water column. The potential advantages of an increase in warmer-water species may not fully compensate for the losses in cooler-water species as warming continues, emphasizing the importance of mitigating climate change to support effective freshwater fisheries management.

Arkansas, Illinois, Indiana, Iowa, Michigan, Minne↗

USGS2012

The role of mangroves in attenuating storm surges

Field observations and numerical simulations indicate that the 6-to-30-km-wide mangrove forest along the Gulf Coast of South Florida effectively attenuated stormsurges from a Category 3 hurricane, Wilma, and protected the inland wetland by reducing an inundation area of 1800 km 2 and restricting surge inundation inside the mangrove zone. The surge amplitude decreases at a rate of 40–50 cm/km across the mangrove forest and at a rate of 20 cm/km across the areas with a mixture of mangrove islands with open water. In contrast, the amplitudes of stormsurges at the front of the mangrove zone increase by about 10–30% because of the "blockage" of mangroves to surge water, which can cause greater impacts on structures at the front of mangroves than the case without mangroves. The mangrove forest can also protect the wetlands behind the mangrove zone against surge inundation from a Category 5 hurricane with a fast forward speed of 11.2 m/s (25 mph). However, the forest cannot fully attenuate stormsurges from a Category 5 hurricane with a slow forward speed of 2.2 m/s (5 mph) and reduced surges can still affect the wetlands behind the mangrove zone. The effects of widths of mangrove zones on reducing surge amplitudes are nonlinear with large reduction rates (15–30%) for initial width increments and small rates (<5%) for subsequent width increments.

Florida↗

USGS2010

A Seamless, High-Resolution, Coastal Digital Elevation Model (DEM) for Southern California

A seamless, 3-meter digital elevation model (DEM) was constructed for the entire Southern California coastal zone, extending 473 km from Point Conception to the Mexican border. The goal was to integrate the most recent, high-resolution datasets available (for example, Light Detection and Ranging (Lidar) topography, multibeam and single beam sonar bathymetry, and Interferometric Synthetic Aperture Radar (IfSAR) topography) into a continuous surface from at least the 20-m isobath to the 20-m elevation contour. This dataset was produced to provide critical boundary conditions (bathymetry and topography) for a modeling effort designed to predict the impacts of severe winter storms on the Southern California coast (Barnard and others, 2009). The hazards model, run in real-time or with prescribed scenarios, incorporates atmospheric information (wind and pressure fields) with a suite of state-of-the-art physical process models (tide, surge, and wave) to enable detailed prediction of water levels, run-up, wave heights, and currents. Research-grade predictions of coastal flooding, inundation, erosion, and cliff failure are also included. The DEM was constructed to define the general shape of nearshore, beach and cliff surfaces as accurately as possible, with less emphasis on the detailed variations in elevation inland of the coast and on bathymetry inside harbors. As a result this DEM should not be used for navigation purposes.

Data Series↗