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USGS2020

Resource allocation for coastal wetland management: Confronting uncertainty about sea level rise

Coastal wetlands are rich and diverse ecosystems with a wide variety of birdlife and other natural resources. Decision making for coastal wetland management is difficult given the complex nature of these ecological systems and the frequent need to meet multiple objectives for varied resources. Management challenges in the coastal zone are exacerbated by uncertainty about sea level rise and impacts on infrastructure, particularly the levees and structures which provide managers the ability to manipulate water levels in managed wetlands and create high quality habitat for birds and other wildlife. The most challenging decisions in coastal wetland management involve resource allocation for habitat manipulations and longer-term investments to maintain management control in wetlands that are increasingly compromised by sea level rise and increasing storm frequency and intensity associated with a changing climate. We used multi-criteria decision analysis to create a resource allocation framework for managed wetlands that identifies the most effective and efficient management strategies that are robust to uncertainty about sea level rise. The prototype framework includes a small number of managed wetlands, for which subject matter experts articulated potential management and restoration actions. The consequences of these actions were predicted using expert elicitation with the subject matter experts; furthermore, expert judgment was used to articulate expected outcomes with two hypotheses about the rate of sea level rise. We used a constrained optimization (integer linear programming) to find optimal resource allocation strategies given a range of budget constraints; we also used a Pareto efficiency analysis for a graphical solution to the problem if the exact budget constraint is not known. Finally, given the importance of preference weights in a multi-criteria decision analysis, we also evaluated sensitivity to objective weights. With this resource allocation framework, we showed how to identify optimal combinations of management and restoration actions to maximize benefits in terms of stated objectives. We show how multiple working hypotheses about sea level rise can be incorporated into decisions for coastal wetland management. Our resource allocation approach can be modified for a wide variety of natural resource management settings.

Book chapter↗

USGS2026

A tool to monitor hydrologic conditions on tree islands in the Everglades

Tree islands are patchy upland forested habitats in Florida's Everglades that face degradation and disappearance due to altered hydrologic patterns. The U.S. Geological Survey coordinated with the Miccosukee Tribe of Indians of Florida and the Seminole Tribe of Florida to co-develop a decision-support tool based on tree-island hydrologic conditions. Everglades managers can use this tool to help with restoration planning and water operations decisions that affect tree-island conditions. After a series of organized workshops and meetings, a list of hydrologic metrics was selected as indicators of tree-island health, including hydroperiod, number of days since last dry, and maximum water depth at the head of the island. As a result, a web application tool, called ETree, has been developed and is publicly available online. This web application provides data on daily metrics for the current Everglades water year and annual summaries for past years, beginning in 2000.

Florida↗

USGS2025

Failure to meet the exchangeability assumption in Bayesian multispecies occupancy models: Implications for study design

Bayesian hierarchical models are ubiquitous in ecology. Random effect model structures are often employed that treat individual effects as deviations from larger population-level effects. In this way individuals are assumed to be "exchangeable" samples. Ecologists may address this exchangeability assumption intuitively, but might in certain modeling contexts ignore it altogether, including in situations where it may have large implications for study design. Multispecies occupancy models based on detection/non-detection data are an approach that can be utilized by those tasked with monitoring rare and endangered species because most literature suggests that, compared to single species occupancy models, improved parameter estimates are assured. Yet, we illustrate through a power analysis how sampling requirements to detect experimental treatment effects vary tremendously depending on whether the species exchangeability assumption is met. The degree to which species in a community respond similarly to covariates governs the ability to accurately estimate parameters using multispecies occupancy models. Detecting small or moderate changes in occupancy resulting from habitat restoration treatments may be impossible for small datasets (e.g., < 36 sampling locations, each surveyed < 8 times) even with a paired treatment-control design if the exchangeability assumption is violated. By contrast, when the assumption is met, small effects may be confidently estimated with as few as 12 sampling locations (6 pairs) and 6-8 survey events. Often, it may be impossible to know whether the exchangeability assumption is met. The statistical power needed to accurately estimate species-specific effects using detection/non-detection multispecies occupancy models depends on the unknown values of treatment effects and whether responses by species in the community diverge. When the species exchangeability assumption is violated, and at lower levels of sampling effort, multispecies occupancy models may provide worse inference than single species occupancy models.

BioRxiv↗

USGS2022

Optimization of salt marsh management at the Petit Manan National Wildlife Refuge of the Maine Coastal Islands National Wildlife Refuge Complex, Maine, through use of structured decision making

Structured decision making is a systematic, transparent process for improving the quality of complex decisions by identifying measurable management objectives and feasible management actions; predicting the potential consequences of management actions relative to the stated objectives; and selecting a course of action that maximizes the total benefit achieved and balances tradeoffs among objectives. The U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, applied an existing, regional framework for structured decision making to develop a prototype tool for optimizing tidal marsh management decisions at the Petit Manan National Wildlife Refuge of the Maine Coastal Islands National Wildlife Refuge Complex in Maine. Refuge biologists, refuge managers, and research scientists identified multiple potential management actions to improve the ecological integrity of two marsh management units within the refuge complex, totaling about 47 hectares, and estimated the outcomes of each action in terms of performance metrics associated with each management objective. Value functions previously developed at the regional level were used to transform metric scores to a common utility scale, and utilities were summed to produce a single score representing the total management benefit that could be accrued from each potential management action. Constrained optimization was used to identify the set of management actions, one per marsh management unit, that could maximize total management benefits at different cost constraints at the refuge scale. Results indicated that, for the objectives and actions considered here, total management benefits may increase consistently up to $ 9,545, and may continue to increase at a lower rate with further expenditures. Potential management actions in optimal portfolios at total costs less than or equal to $ 9,545 included removing dikes to restore tidal flow in the Gouldsboro Bay management unit and installing runnels to improve surface-water drainage in the Sawyers Marsh management unit. The potential management benefits were derived from expected increases in the numbers of tidal marsh obligate breeding birds and density of spiders (as an indicator of trophic health), reduced duration of flooding, and increased capacity of marsh elevation to keep pace with sea-level rise. The prototype presented here does not resolve management decisions; rather, it provides a framework for decision making at the Maine Coastal Islands National Wildlife Refuge Complex that can be updated for implementation as new data and information become available. Insights from this process may also be useful to inform future habitat management planning at the refuge complex.

Maine↗

USGS2003

Effects of abandoned coal-mine drainage on streamflow and water quality in the Shamokin Creek Basin, Northumberland and Columbia Counties, Pennsylvania, 1999-2001

This report assesses the contaminant loading, effects to receiving streams, and possible remedial alternatives for abandoned mine drainage (AMD) within the upper Shamokin Creek Basin in east-central Pennsylvania. The upper Shamokin Creek Basin encompasses an area of 54 square miles (140 square kilometers) within the Western Middle Anthracite Field, including and upstream of the city of Shamokin. Elevated concentrations of acidity, metals, and sulfate in the AMD from flooded underground anthracite coal mines and (or) unreclaimed culm (waste rock) piles degrade the aquatic ecosystem and water quality of Shamokin Creek to its mouth and along many of its tributaries within the upper basin. Despite dilution by unpolluted streams that more than doubles the streamflow of Shamokin Creek in the lower basin, AMD contamination and ecological impairment persist to its mouth on the Susquehanna River at Sunbury, 20 miles (32 kilometers) downstream from the mined area. Aquatic ecological surveys were conducted by the U.S. Geological Survey (USGS) in cooperation with Bucknell University (BU) and the Northumberland County Conservation District (NCCD) at six stream sites in October 1999 and repeated in 2000 and 2001 on Shamokin Creek below Shamokin and at Sunbury. In 1999, fish were absent from Quaker Run and Shamokin Creek upstream of its confluence with Carbon Run; however, creek chub ( Semotilus atromaculatus ) were present within three sampled reaches of Carbon Run. During 1999, 2000, and 2001, six or more species of fish were identified in Shamokin Creek below Shamokin and at Sunbury despite ph as low as 4.2 at Sunbury and elevated concentrations of dissolved iron and iron-encrusted streambeds at these sites. Data on the flow rate and chemistry for 46 AMD sources and 22 stream sites throughout the upper basin plus 1 stream site at Sunbury were collected by the USGS with assistance from BU and the Shamokin Creek Restoration Alliance (SCRA) during low base-flow conditions in August 1999 and high baseflow conditions in March 2000. The water-quality data were used to determine priority ranks of the AMD sources on the basis of loadings of iron, manganese, and aluminum and to identify possible remedial alternatives, including passive-treatment options, for consideration by water-resource managers. The ranking sequence for the top AMD sources based on the high base-flow data generally matched that based on the low base-flow data. The contaminant loadings generally increased with flow, and 10 previously identified intermittent AMD sources were not discharging during the low base-flow sampling period. The top 3 AMD sources (SR19, SR12, and SR49) on the basis of dissolved metals loading in March 2000 accounted for more than 50 percent of the metals loading to Shamokin Creek, whereas the top 15 AMD sources accounted for more than 98 percent of the metals loading. When sampled in March 2000, these AMD sources had flow rates ranging from 0.7 to 19 cubic feet per second (1,138 to 32,285 liters per minute) and pH from 3.5 to 6.4 standard units. Only 1 of the top 15 AMD sources (SR21) was net alkaline (alkalinity > acidity); the others were net acidic and will require additional alkalinity to facilitate metals removal and maintain near-neutral pH. For the top 15 AMD sources, dissolved iron was the principal source of acidity and metals loading; concentrations of iron ranged from 3.7 to 57 milligrams per liter. Dissolved manganese ranged from 1.8 to 7.1 milligrams per liter. Dissolved aluminum exceeded 3.8 milligrams per liter at six of the sites but was less than 0.2 milligram per liter at six others. Alkalinity can be acquired by the dissolution of limestone and (or) bacterial sulfate reduction within various passive-treatment systems including anoxic or oxic limestone drains, limestone- lined channels, or compost wetlands. Subsequently, the gradual oxidation and consequent precipitation of iron and manganese can be accommodated within settling ponds or aerobic wetlands. Assuming an iron removal rate of 180 pounds per acre per day (20 grams per square meter per day), constructed treatment wetlands at the top 15 AMD sites would require a minimum area ranging from 0.1 to 17.8 acres (405 to 71,670 square meters). Implementation of passive treatment would not be feasible at most of the top 15 and many lower priority AMD sites considering the proximity of many discharges to streams, roads, or railroads, and the limited availability or access to land at the discharge location. The reduction of infiltration and removal of culm waste and (or) the relocation of the discharge to nearby areas could decrease the AMD quantities and facilitate treatment at some of the priority AMD sites.

Water-Resources Investigations Report↗

USGS2025

Public support for puma reintroduction in the eastern United States

Pumas ( Puma concolor ) are among the species identified as having the potential to enhance ecosystem function. Previous research highlights sufficient ecological habitat to support pumas in the eastern United States; however, their reintroduction requires social and institutional support as well. To this end, we conducted research to assess attitudes about puma reintroduction among key constituencies like hunters, rural residents, and young people. We sampled 2756 respondents across seven states (Massachusetts, Maine, New Hampshire, New York, Pennsylvania, Vermont, and West Virginia). Ratios of strong support (for puma reintroduction) to strong opposition across states ranged from 4:1 to 13:1, and support outweighed opposition in every state. Our results contrasted with common assumptions that hunters, rural residents, and people who identify as politically conservative oppose carnivore conservation and reintroduction. We found marginal differences among categories of people, but overall little variation in support exhibited by different groups. People who identified very strongly as hunters were more supportive of reintroduction than those who did not identify as hunters at all. Taken together, the presence of quality habitat and support for puma restoration warrant further exploration. However, federal funding for state-based restoration efforts likely requires the inclusion of pumas in State Wildlife Action Plans (SWAPs), which are currently under a 10-year revision due to be published this year (2025).

Maine, Massachusetts, New Hampshire, New York, Pen↗

USGS2015

Portfolio theory as a management tool to guide conservation and restoration of multi-stock fish populations

Habitat degradation and harvest have upset the natural buffering mechanism (i.e., portfolio effects) of many large-scale multi-stock fisheries by reducing spawning stock diversity that is vital for generating population stability and resilience. The application of portfolio theory offers a means to guide management activities by quantifying the importance of multi-stock dynamics and suggesting conservation and restoration strategies to improve naturally occurring portfolio effects. Our application of portfolio theory to Lake Erie Sander vitreus (walleye), a large population that is supported by riverine and open-lake reef spawning stocks, has shown that portfolio effects generated by annual inter-stock larval fish production are currently suboptimal when compared to potential buffering capacity. Reduced production from riverine stocks has resulted in a single open-lake reef stock dominating larval production, and in turn, high inter-annual recruitment variability during recent years. Our analyses have shown (1) a weak average correlation between annual river and reef larval production (ρ̄ = 0.24), suggesting that a natural buffering capacity exists in the population, and (2) expanded annual production of larvae (potential recruits) from riverine stocks could stabilize the fishery by dampening inter-annual recruitment variation. Ultimately, our results demonstrate how portfolio theory can be used to quantify the importance of spawning stock diversity and guide management on ecologically relevant scales (i.e., spawning stocks) leading to greater stability and resilience of multi-stock populations and fisheries.

Lake Erie↗

USGS2009

Application of the Hydroecological Integrity Assessment Process for Missouri Streams

Natural flow regime concepts and theories have established the justification for maintaining or restoring the range of natural hydrologic variability so that physiochemical processes, native biodiversity, and the evolutionary potential of aquatic and riparian assemblages can be sustained. A synthesis of recent research advances in hydroecology, coupled with stream classification using hydroecologically relevant indices, has produced the Hydroecological Integrity Assessment Process (HIP). HIP consists of (1) a regional classification of streams into hydrologic stream types based on flow data from long-term gaging-station records for relatively unmodified streams, (2) an identification of stream-type specific indices that address 11 subcomponents of the flow regime, (3) an ability to establish environmental flow standards, (4) an evaluation of hydrologic alteration, and (5) a capacity to conduct alternative analyses. The process starts with the identification of a hydrologic baseline (reference condition) for selected locations, uses flow data from a stream-gage network, and proceeds to classify streams into hydrologic stream types. Concurrently, the analysis identifies a set of non-redundant and ecologically relevant hydrologic indices for 11 subcomponents of flow for each stream type. Furthermore, regional hydrologic models for synthesizing flow conditions across a region and the development of flow-ecology response relations for each stream type can be added to further enhance the process. The application of HIP to Missouri streams identified five stream types ((1) intermittent, (2) perennial runoff-flashy, (3) perennial runoff-moderate baseflow, (4) perennial groundwater-stable, and (5) perennial groundwater-super stable). Two Missouri-specific computer software programs were developed: (1) a Missouri Hydrologic Assessment Tool (MOHAT) which is used to establish a hydrologic baseline, provide options for setting environmental flow standards, and compare past and proposed hydrologic alterations; and (2) a Missouri Stream Classification Tool (MOSCT) designed for placing previously unclassified streams into one of the five pre-defined stream types.

Open-File Report↗

USGS2023

Using eDNA metabarcoding to establish targets for freshwater fish composition following river restoration

Establishing realistic targets for fish community composition is needed to assess the effectiveness of river restoration projects. We used environmental DNA (eDNA) metabarcoding with MiFish primers to obtain estimates of fish community composition across 17 sites upstream, downstream and within a restoration mitigation project area (Kaihotsu–Kasumi) located in the Shigenobu River system, Ehime Prefecture, Japan. We evaluate the benefits of using eDNA to quickly, sensitively, and extensively gather data to establish existing fish community composition in the restoration area, as well as potential future short-term, medium-term, and long-term targets of species assemblages that could realistically emerge following dispersal into the project area from upstream and downstream populations. We compare results from eDNA metabarcoding with species lists obtained from contemporaneous capture surveys and historical information. Nonmetric multidimensional scaling plots of community composition obtained from eDNA surveys showed that the Kaihotsu–Kasumi restoration area and surrounding river reaches were divided into three clusters: upper reaches, middle and lower reaches, and estuarine reaches. The Kaihotsu–Kasumi restoration area sites were included in the group containing the middle and lower reaches of the inflow and outflow rivers that were near the restoration area. We detected a total of twenty-six species in this group, twenty-one native species and five non-native species. Therefore, these native species were considered suitable as short-term target species with high potential for dispersal into Kaihotsu–Kasumi restoration area. By comparison, only 14 species would have been selected as target species based on capture surveys and historical literature. One factor increasing the resolution of our eDNA surveys was our ability to identify the presence of intraspecific lineages of Misgurnus anguillicaudatus (Clades A and B), which were missed by the capture surveys. These results indicate that the eDNA metabarcoding method can provide more comprehensive and realistic short-term target species estimates than capture surveys, as well as provide higher resolution monitoring through intraspecific lineage detection.

Global Ecology and Conservation↗

USGS2021

Optimization of salt marsh management at the Moosehorn National Wildlife Refuge, Maine, through use of structured decision making

Structured decision making is a systematic, transparent process for improving the quality of complex decisions by identifying measurable management objectives and feasible management actions; predicting the potential consequences of management actions relative to the stated objectives; and selecting a course of action that maximizes the total benefit achieved and balances tradeoffs among objectives. The U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, applied an existing, regional framework for structured decision making to develop a prototype tool for optimizing tidal marsh management decisions at the Moosehorn National Wildlife Refuge in Maine. Refuge biologists, refuge managers, and research scientists identified multiple potential management actions to improve the ecological integrity of four marsh management units within the refuge, totaling about 13 hectares, and estimated the outcomes of each action in terms of performance metrics associated with each management objective. Value functions previously developed at the regional level were used to transform metric scores to a common utility scale, and utilities were summed to produce a single score representing the total management benefit that could be accrued from each potential management action. Constrained optimization was used to identify the set of management actions, one per marsh management unit, that could maximize total management benefits at different cost constraints at the refuge scale. Results indicated that, for the objectives and actions considered here, total management benefits may increase consistently up to $ 1,000, and may continue to increase at a lower rate with further expenditures. Potential management actions in optimal portfolios at total costs less than or equal to $ 1,000 included improving nesting habitat for Ammodramus nelsoni (Nelson’s sparrow) or restoring hydrologic connections to the upper marsh in one marsh management unit (Hobart Stream West). The potential management benefits were derived from expected increases in the density of nekton and of spiders (as an indicator of trophic health). The prototype presented here does not resolve management decisions; rather, it provides a framework for decision making at the Moosehorn National Wildlife Refuge that can be updated for implementation as new data and information become available. Insights from this process may also be useful to inform future habitat management planning at the refuge.

Maine↗

USGS2010

Fire helps restore natural disturbance regime to benefit rare and endangered marsh birds endemic to the Colorado River

Large flood events were part of the historical disturbance regime within the lower basin of most large river systems around the world. Large flood events are now rare in the lower basins of most large river systems due to flood control structures. Endemic organisms that are adapted to this historical disturbance regime have become less abundant due to these dramatic changes in the hydrology and the resultant changes in vegetation structure. The Yuma Clapper Rail is a federally endangered bird that breeds in emergent marshes within the lower Colorado River basin in the southwestern United States and northwestern Mexico. We evaluated whether prescribed fire could be used as a surrogate disturbance event to help restore historical conditions for the benefit of Yuma Clapper Rails and four sympatric marsh-dependent birds. We conducted call-broadcast surveys for marsh birds within burned and unburned (control) plots both pre-and post-burn. Fire increased the numbers of Yuma Clapper Rails and Virginia Rails, and did not affect the numbers of Black Rails, Soras, and Least Bitterns. We found no evidence that detection probability of any of the five species differed between burn and control plots. Our results suggest that prescribed fire can be used to set back succession of emergent marshlands and help mimic the natural disturbance regime in the lower Colorado River basin. Hence, prescribed fire can be used to help increase Yuma Clapper Rail populations without adversely affecting sympatric species. Implementing a coordinated long-term fire management plan within marshes of the lower Colorado River may allow regulatory agencies to remove the Yuma Clapper Rail from the endangered species list. ?? 2010 by the Ecological Society of America.

Ecological Applications↗

USGS2021

Optimization of salt marsh management at the Eastern Shore of Virginia and Fisherman Island National Wildlife Refuges, Virginia, through use of structured decision making

Structured decision making is a systematic, transparent process for improving the quality of complex decisions by identifying measurable management objectives and feasible management actions; predicting the potential consequences of management actions relative to the stated objectives; and selecting a course of action that maximizes the total benefit achieved and balances tradeoffs among objectives. The U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, applied an existing, regional framework for structured decision making to develop a prototype tool for optimizing tidal marsh management decisions at the Eastern Shore of Virginia and Fisherman Island National Wildlife Refuges in Virginia. Refuge biologists, refuge managers, and research scientists identified multiple potential management actions to improve the ecological integrity of six marsh management units within the refuges, totaling about 575 hectares, and estimated the outcomes of each action in terms of performance metrics associated with each management objective. Value functions previously developed at the regional level were used to transform metric scores to a common utility scale, and utilities were summed to produce a single score representing the total management benefit that could be accrued from each potential management action. Constrained optimization was used to identify the set of management actions, one per marsh management unit, that could maximize total management benefits at different cost constraints at the refuge scale. Results indicated that, for the objectives and actions considered here, total management benefits may increase consistently up to approximately $ 143,000, but that further expenditures may yield diminishing return on investment. Potential management actions in optimal portfolios at total costs less than $ 143,000 included digging runnels by hand to improve drainage from the marsh surface, breaching a road to restore natural hydrology, trapping predators to enhance nest success of tidal marsh birds, and reducing the abundance of Odocoileus virginianus (white-tailed deer) to minimize their effects on marsh vegetation. The potential management benefits were derived from expected increases in number of tidal marsh obligate breeding birds, species richness of nekton, and density of spiders (as an indicator of trophic health); and an expected decrease in duration of surface flooding. The prototype presented here does not resolve management decisions; rather, it provides a framework for decision making at the Eastern Shore of Virginia and Fisherman Island National Wildlife Refuges that can be updated as new data and information become available. Insights from this process may also be useful to inform future habitat management planning at the refuges.

Virginia↗

USGS2003

Sustainable Land Use Requires Attention to Ecological Signals

This case study details the difficulties of landscape management, highlighting the challenges inherent in managing natural resources when multiple agencies are involved, when the land users have no incentive for conservation, and when government agencies have too few resources for effective management. Pumping of groundwater from the aquifer of La Costa de Hermosillo in the state of Sonora, Mexico, began in 1945 and developed so quickly that by the late 1950s salinity intrusion from the Gulf of California was occurring in the wells. In the 1970s, the irrigatable land in La Costa peaked at 132,516 ha and the extracted volume of water from the aquifer peaked at around 1.14 billion cubic meters annually. By the 1980s, 105 wells of the total of 498 were contaminated with seawater and, therefore, identified for closure. At present La Costa de Hermosillo still represents 15% of the total harvested land, 16% of the total annual production, and 23% of the gross agricultural production of the state of Sonora. However, there are approximately 80,000 ha of abandoned fields due to salt water intension, lack of water and/or lack of credit available to individual farmers. This unstable situation resulted from the interplay of water management policies and practices, and farm-land policies and practices. While government agencies have been able to enforce better water use for agricultural production, there remains a significant area that requires restoration from its degraded state. For this piece of the ecosystem management puzzle, government agencies have thus far been unable to affect a solution.

Environmental Management↗

USGS2017

California Gull population growth and ecological impacts in the San Francisco Bay estuary, 1980–2016

The breeding population of California Gulls (Larus californicus) in the San Francisco Bay estuary increased from 24 individuals in 1980 to a peak of over 53,000 in 2014, then declined to 38,040 in 2016. The expansion of the breeding population may be related to the availability of suitable nesting sites in close proximity to anthropogenic food subsidies at landfills. Telemetry data indicate that California Gull movements are largely dictated by the two primary landfills in South San Francisco Bay. The large population of California Gulls has had negative effects on locally breeding shorebirds and terns, especially the Forster’s Tern (Sterna forsteri), American Avocet (Recurvirostra americana), and Western Snowy Plover (Charadrius nivosus nivosus). In South San Francisco Bay, California Gulls were responsible for 13% and 38% of egg predation events at nests of American Avocets and Snowy Plovers, respectively, and 55% and 54% of chick predation events of American Avocets and Forster’s Terns, respectively. The forced relocation of the largest gull colony (~24,000) at Pond A6 in 2010 resulted in increased survival of Forster’s Tern chicks at the adjacent colony at Pond A7 in 2011. The California Gull population and its effects on locally breeding shorebirds and terns are among the most pressing concerns for wetland managers within the San Francisco Bay estuary, especially for the South Bay Salt Pond Restoration Project. Further research is needed to evaluate the gull’s reproductive rates, habitat use, and annual movements and so to clarify its demographics and to quantify its effects on other breeding birds.

Book chapter↗

USGS2005

Gulf of Mexico Integrated Science - Tampa Bay Study: Examining the Impact of Urbanization on Seafloor Habitats

Seafloor habitats, such as seagrass beds, provide essential habitat for fish and marine mammals. For many years, the study of seagrass vitality has been a priority for scientists and resource managers working in Tampa Bay. Seafloor habitats are extremely sensitive to changes in water quality. Like a canary in a coal mine, seagrass can serve as an ecological indicator of estuary health. Between the 1940s and the 1970s, seagrass gradually died in Tampa Bay. This loss has been attributed to a rise in urbanization and an increase in nutrient loading into the bay. Better treatment of industrial wastewater and runoff beginning in the 1980s resulted in the continuous recovery of seagrass beds. However, in the mid-1990s, the recovery began to level off in areas where good water quality was expected to support continued seagrass recovery, demonstrating that nutrient loading may be only one factor impacting seagrass health. Researchers now are trying to determine what might be affecting the recovery of seagrass in these areas. Currently, little is understood about the effects that other aspects of urbanization and natural change, such as groundwater and sediment quality, might have on seagrass vitality. This segment of the Tampa Bay integrated science study is intended to identify, quantify, and develop models that illustrate the impact that urbanization may have on seafloor habitat distribution, health, and restoration.

Open-File Report↗

USGS2019

Identifying characteristics of actionable science for drought planning and adaptation: Final report to the North Central Climate Adaptation Science Center

Changing climate conditions can make water management planning and drought preparedness decisions more complicated than ever before. Resource managers can no longer rely solely on historical data and trends to base their actions, and are in need of science that is relevant to their specific needs and can directly inform important planning decisions. Questions remain, however, regarding the most effective and efficient methods for extending scientific knowledge and products into management and decision-making. This study analyzed two unique cases of water management to better understand how science can be translated into resource management actions and decision-making. In particular, this project sought to understand 1) the characteristics that make science actionable and useful for water resource management and drought preparedness, and 2) the ideal types of scientific knowledge or science products that facilitate the use of science in management and decision-making. The first case study focused on beaver mimicry, an emerging nature-based solution that increases the presence of wood and woody debris in rivers and streams to mimic the actions of beavers. This technique has been rapidly adopted by natural resource managers as a way to restore riparian areas, increase groundwater infiltration, and slow surface water flow so that more water is available later in the year during hotter and dryer months. The second case study focused on an established research program, Colorado Dust on Snow, that provides water managers with scientific information explaining how the movement of dust particles from the Colorado Plateau influences hydrology and the timing and intensity of snow melt and water runoff into critical water sources. This program has support from and is being used by several water conservation districts in the state. Understanding how scientific knowledge translates into action and decision-making in these cases is expected to strengthen our knowledge of actionable science in the context of drought and its impacts on ecosystems. The project team gathered qualitative data through stakeholder interviews and will conduct an extensive literature review. Findings from these efforts will also be incorporated into a broader Intermountain West synthesis effort to determine and assess commonalities and differences among socio-ecological aspects of drought adaptation and planning.

Colorado, Kansas, Montana, Nebraska, North Dakota,↗

USGS2019

Fish assemblages in a Mississippi reservoir mudflat with low structural complexity

In shallow reservoirs, seasonal water drawdowns expose littoral areas and over time produce barren mudflats. When flooded, mudflats provide homogeneous substrates, turbid water, and eroding shorelines of limited ecological value. We hypothesized that in mudflats structurally complex habitats are occupied by more fish, smaller fish of a larger range in sizes, more species, and fish assemblages that are different from those in simpler habitats. We tested these hypotheses over two consecutive years with fish collections made in sites with varying structural complexity. Results indicated that structural complexity harbors more fish in transects and enclosures. Structural complexity did not influence median length, but length range increased with structural complexity. Average species richness increased with structural complexity. Fish assemblage composition changed as structural complexity increased. The ability of cover to provide survival, growth, and carrying capacity benefits is fundamental to programs aimed at increasing structural complexity. Results suggest observed effects on fish assemblages can lead to such benefits. Considering mudflats are a major component of reservoirs, expand as reservoirs age, and there is a potential to exert meaningful change on fish assemblages of impounded rivers by managing mudflats, we suggest additional attention is needed to develop practical habitat restoration options.

Mississippi↗

USGS2018

Status of selenium in south San Francisco Bay—A basis for modeling potential guidelines to meet National tissue criteria for fish and a proposed wildlife criterion for birds

The U.S. Environmental Protection Agency (EPA) proposed Aquatic Life and AquaticDependent Wildlife Criteria for Selenium (Se) in California’s San Francisco Bay and Delta (Bay-Delta) in June 2016. Here we apply the same modeling methodology—Ecosystem-Scale Selenium Modeling— to an assessment of conditions and documentation of food webs of south San Francisco Bay (South Bay) as an exploratory framework in support of site-specific Se criteria development. Long-term datasets contribute to the basis for modeling, especially the 21-year collection of the clam Macoma petalum from a mudflat at the lower end of South Bay (Lower South Bay). As such, this is a working document that may serve as a basis to establish an understanding of the specifics of Se biodynamics within the estuary and reduce uncertainties about how to protect it. This approach brings together the main factors involved in toxicity: likelihood of high exposure, inherent species sensitivity, and the behavioral ecology (for example, demographics and life history) of an organism in terms of susceptibility to a reproductive toxicant. Species sensitivity is represented here by use of the EPA’s current national tissue Se criterion for fish or that proposed to protect the eggs of aquatic birds for the Bay-Delta (U.S. Environmental Protection Agency, 2016a, 2016b, 2016c). This report also strives to bring together findings and field data across a body of literature for South Bay to provide an integrative assessment. We find an assemblage of site-specific conditions that could affect modeling: associated urban processes such as discharges from municipal wastewater treatment plants and drainage from mercury (Hg) mining and limestone extraction are sources of Se that characterize the Lower South Bay as the location of interest for Se exposure; • hydrodynamics are lagoon-like (that is, less flushing), which sustains elevated nutrients and phytoplankton blooms; • managed freshwater sources are a major hydrodynamic component; • birds, in addition to fish, are prominent predators in South Bay; • wetland restoration has recently intervened to play a significant role in ecosystem function that may include uptake of both Hg and Se; • the dietary food web of surficial-sediment to M. petalum is important because of the dominance of this clam species and its elevated Se bioaccumulation potential compared to other local food webs; and 2 • maximal Se concentrations may be limited by transitory or annually renewed food webs (for example, migratory shorebirds and decimation of clams from marshes). We also find that the constructed mechanistic model: • spatially connects to the Palo Alto mudflat site because of data availability; • accurately predicts average observed Se concentrations in M. petalum and in predator species of fish and birds; and • is able to bracket a range of potential protective water-column Se concentrations specific to predator species based on the EPA’s national Se criterion for whole-body fish tissue and a proposed site-specific criterion for bird eggs in the Bay-Delta.

California↗