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USGS2011

Occurrence and distribution of Asian carps in Louisiana

In the 1970s, commercial fishers reported sightings of grass carp Ctenopharyngodon idella in large rivers and associated backwaters of Louisiana; the first specimen in Louisiana Department of Wildlife and Fisheries' fishery independent sampling was recorded in 1976. Beginning in the early 1980s, commercial fishers noted increasing populations of bighead carp Hypophthalmichthys nobilis and silver carp H. molitrix (together, the bigheaded carps). Populations of bigheaded carps appear to be increasing at a much slower rate than in the Midwest, possibly due to limited suitability of and access to backwater habitat for juvenile fish. In 2002, harvester reports of sporadic captures of "different-looking" grass carp indicated the possible presence of black carp Mylopharyngodon piceus . Because both normal diploid and triploid (in which triploidy has been induced to cause sterility) black carp have been stocked in the Mississippi basin, determination of the ploidy (number of chromosome sets) of these fishes is important. Since 2002, postmortem ploidy determinations using cells from eyeballs removed from six wild black carp captured in Louisiana showed each to be a normal diploid, indicative of breeding capability and potential reproducing populations. Although reported commercial landings of grass and bigheaded carps have been as high as 34,830 kg/year, limited market demand in past years resulted in many captures being discarded. A protocol for obtaining samples for easily determining ploidy is reported here. Accurate data on Asian carp distributions and their reproductive potential provides information to fisheries researchers that will be constructive in documenting the spread of these invasive species and in the assessment of risk to habitats.

Louisiana↗

USGS2014

Openness to the unexpected: Our Pathways to Careers in a Federal Research Laboratory.

Many fisheries professionals may not be in the job they originally envisioned for themselves when they began their undergraduate studies. Rather, their current positions could be the result of unexpected, opportunistic, or perhaps even “lucky” open doors that led them down an unexpected path. In many cases, a mentor helped facilitate the unforeseen trajectory. We offer three unique stories about joining a federal fisheries research laboratory, from the perspective of a scientist, a joint manager-scientist, and a manager. We also use our various experiences to form recommendations that should help the next generation of fisheries professionals succeed in any stop along their journey, including being open to opportunities, setting high expectations, and finding a strong and supportive team environment to work in.

Book chapter↗

USGS2011

Exploring life history characteristics of naturalized versus stocked chinook

Naturalization of stocked populations can result in divergence of life-history traits from domestic stocks. Lake Michigan supports popular Chinook (Oncorhynchus tshawytscha) Salmon fisheries that have been sustained by stocking since the late 1960s. Natural recruitment of Chinook Salmon in Lake Michigan has increased in the last few decades and currently contributes over 50% of Chinook Salmon recruits. Samples collected as part of a lakewide mass-marking of Lake Michigan Chinook Salmon, starting with the 2006 year class, indicated hatchery fish average 30-mm longer and 130 grams heavier than naturalized fish at age-1. We hypothesized that selective forces differ for naturalized and hatchery populations resulting in divergent life-history characteristics with implications for Chinook Salmon population production and the Lake Michigan fishery. Specific life-history metrics of interest include: age- and size- at maturity, spawning run timing, fecundity, and sex ratio. Objectives: We evaluated life history characteristics between naturally recruited and stocked Chinook Salmon in Lake Michigan to help discern potential changes resulting from naturalization and implications for fisheries. A. Conduct an analysis of historical data to determine if life-history parameters changed through time as the Chinook Salmon population became increasingly naturalized. B. Conduct a two-year field study of naturalized and hatchery stocked Chinook Salmon spawning populations to quantify differences in life-history metrics of adults. C. Determine if reproductive potential differs between naturalized and hatchery stocked Chinook salmon by measuring egg thiamine levels.

Michigan↗

USGS2016

Migratory routes and at-sea threats to Pink-footed Shearwaters

The Pink-footed Shearwater (Ardenna creatopus) is a seabird with a breeding range restricted to three islands in Chile and an estimated world population of approximately 56,000 breeding individuals (Muñoz 2011, Oikonos unpublished data). Due to multiple threats on breeding colonies and at-sea, Pink-footed Shearwaters are listed as Endangered by the government of Chile (Reglamento de Clasificación de Especies, 2011), Threatened by the government of Canada (Environment Canada 2008), and are listed under Appendix 1 of the Agreement on the Conservation of Albatrosses and Petrels (ACAP 2013). A principal conservation concern for the species is mortality from fisheries bycatch during the breeding and non-breeding seasons; thus, identification of areas of overlap between at-sea use by Pink-footed Shearwaters and fisheries is a high priority conservation objective (Hinojosa Sáez and Hodum 1997, Mangel et al. 2013, ACAP 2013). During the non-breeding period, Pink-footed Shearwaters range as far north as Canada, although little was known until recently about migration routes and important wintering areas where fisheries bycatch could be a risk. Additionally, Pink-footed Shearwaters face at-sea threats during the non-breeding season off the west coast of North America. Recently, areas used by wintering Pink-footed Shearwaters have been identified as areas of interest for developing alternative energy offshore in North America (e.g., floating wind generators; Trident Winds 2016). The goal of our study was to track Pink-footed Shearwater post-breeding movements with satellite tags to identify timing and routes of migration, locate important non-breeding foraging habitats, and determine population distribution among different wintering regions.

Conference Paper↗

USGS2010

Elwha River dam removal: A major opportunity for salmon and steelhead recolonization

In this in-depth paper, authors George R. Pess, Gary A. Winans and Timothy J. Beechie of the NOAA Fisheries, Northwest Fisheries Science Center in Seattle, Samuel J. Brenkman of the National Park Service, Olympic National Park, Michael L. McHenry of the Lower Elwha Klallam Tribe and Jeffrey J. Duda of the U.S. Geological Survey, Western Fisheries Research Center in Seattle, provide an historical overview of the Elwha River system, and its native anadromous fish runs and the prospect of their recolonization after the Elwha and Glines Canyon dams are removed.

Washington↗

USGS1995

Nearshore distribution and abundance of Dungeness crabs in Glacier Bay National Park, Alaska

As part of an ongoing, multi-agency study to determine the effects of closure of the commercial fishery for Dungeness crabs, Cancer magister , on crab population structure we examined patterns of distribution and abundance of crabs in nearshore habitats at five locations in and near Glacier Bay National Park. Sampling was conducted in April and September 1992 and April 1993 prior to the anticipated closure of the fishery in the park. Divers censused crabs by sex and reproductive state (ovigerous/nonovigerous females) along belt transects (2m x 100m) laid perpendicular to shore in the depth range 0 m (mean lower low water) to 18 m. Preliminary results from the first three sampling periods revealed that the average densities of Dungeness crabs at the five locations ranged from 78 to 2012 crabs/ha. Crab densities differed between populations depending on sex, reproductive state of females and sampling period. Male crabs showed reduced densities at Gustavus Flats in April 1992 (P<0.01) and 1993 (P<0.001). Ovigerous females had greater density at Bartlett Cove in April 1993 (P<0.001). Sex ratios were frequently skewed toward females. At Bartlett Cove and Gustavus Flats females outnumbered males in April 1992 and 1993 (P<0.001). Most of the females at Bartlett Cove and Gustavus Flats in April 1992 and 1993 were ovigerous (P-0.001). Males tended to occupy greater depths than females in April 1992 (P<0.05) but not April 1993 (P-005). The mean depth of males shifted from deeper to shallower water between April and September 1992 (P<0.001). The depth distribution of ovigerous crabs did not differ from that of nonovigerous female crabs. Future research prior to the anticipated closure of the commercial Dungeness crab fishery in Glacier Bay will include a tagging study to determine the extent of crab movement and further study of the temporal as well as the spatial variability observed in the structure of these populations.

Alaska↗

USGS2004

Testing archival tag technology in coho salmon

Archive tags with temperature and light-geolocation sensors will be monitored for post-smolt coho salmon in Cook Inlet. Light/location relationships specific to the Gulf of Alaska developed under Project 00478 will be applied in this study of movement and migration paths for coho salmon during maturation in ocean environments in Cook Inlet. Salmon for this study will be reared in captivity (at the Alaska Department of Fish and Game hatchery at Fort Richardson) to 1+ year of age (200-250mm) and released in Cook Inlet as part of the department's Ship Creek sport-fishing hatchery release. FY 01 includes pilot studies of tag retention, behavior, and growth for coho in captivity. Ship Creek coho will be tagged mid-May. A spring release experiment in the first year will be contingent on the successful implementation and retention of these tags. Surveys for early jack recoveries will be done at the Ship Creek weir and among sport fishers. Monitoring for adult tag recoveries will be done in the coho commercial fishery in Cook Inlet and the derby sport fishery on Ship Creek. Archive tagged fish will be used to document coho salmon use of marine habitats, migration routes, contribution to the sport fishery, and hatchery/wild interactions for salmon in Cook Inlet.

Alaska↗

USGS2002

Testing pop-up satellite tags as a tool for identifying critical habitat for Pacific halibut ( Hippoglossus stenolepis ) in the Gulf of Alaska

To maintain healthy commercial and sport fisheries for Pacific halibut ( Hippoglossus stenolepis ), critical habitat must be defined by determining life history patterns on a daily and seasonal basis. Pop-up satellite archival transmitting (PSAT) tags provide a fisheries-independent method of collecting environmental preference data (depth and ambient water temperature) as well as daily geolocation estimates based on ambient light conditions. In this study, 14 adult halibut (107-165 cm FL) were tagged and released with PSAT tags in and around Resurrection Bay, Alaska. Commercial fishermen recovered two tags, while five tags transmitted data to ARGOS satellites. Horizontal migration was not consistent among fish as three halibut remained in the vicinity of release while four traveled up to 358 km from the release site. Vertical migration was not consistent among fish and over time, but they spent most their time between 150-350 m. The minimum and maximum depths reached by any of the halibut were 2m and 502m, respectively. The fish preferred water temperatures of roughly 6 °C while experiencing ambient temperatures between 4.3 °C and 12.2 °C. Light attenuation with depth prevented existing geolocation software and light sensing hardware from accurately estimating geoposition, however, information from temperature, depth, ocean bathymetry, and pop-off locations provided inference on fish movement in the study area. PSAT tags were a viable tool for determining daily and seasonal behavior and identifying critical halibut habitat, which will aid fisheries managers in future decisions regarding commercial and sport fishing regulations.

Alaska↗

USGS2019

Diving behavior of Pink-footed Shearwaters Ardenna creatopus rearing chicks on Isla Mocha, Chile

Recent information reporting Pink-footed Shearwater Ardenna creatopus mortality from fisheries bycatch throughout its range has encouraged fisheries managers in Chile to evaluate and consider shearwater foraging behaviors to better evaluate risk. In response, we tracked six chickrearing adult Pink-footed Shearwaters from Isla Mocha, off south-central Chile, from 19 to 28 March 2015 using global positioning sensors and time-depth recorders. We recorded seven complete trips averaging 4.2 ± 2.5 d (mean ± SD). Chick-provisioning adults foraged within 334 km (i.e., 175 ± 100 km) of Isla Mocha. Dives (n = 515) occurred throughout the measured foraging range but most frequently occurred within 5–30 km from the mainland coast, in continental shelf waters north of Valdivia. Other regions with diving behavior were within ~20 km of Isla Mocha, and from Lebu to north of Talcahuano. Based on movement behavior analysis, adults spent most of their time at sea “resting/ foraging” (62% ± 6%), with the remainder spent “searching” (16% ± 4%) and “transiting” (20% ± 5%). The proportions of total number of dives associated with these three behaviors were similar. On average, dives were relatively shallow (1.6 ± 1.2 m, maximum depth = 10.1 m) and brief (4.7 ± 4.8 s, maximum duration = 25.7 s). Dives occurred during the day, at night, and at twilight, with most activity occurring at twilight and during the day. Although based on a small sample size, our results may be useful for informing modifications to fishing gear or fisheries policy to reduce the likelihood of bycatch and thus meet Chilean conservation goals for Pink-footed Shearwaters.

Isla Mocha↗

USGS2014

Offshore pelagic fish community

Lake Ontario’s offshore zone, as defined by Stewart et al. (2013), comprises all waters of the lake where the bottom depth is greater than 15 m excluding those in embayments. When the lake is thermally stratified during June-October, the offshore pelagic zone includes the upper-warm and middle-cool layers of water which serve as important habitat for Alewife and other prey fishes, and for predators like salmon and trout. Early changes in the fish community of the offshore pelagic zone are well documented elsewhere (e.g., Smith 1972; Christie 1973) as are more recent changes (e.g., Owens et al. 2003; Mills et al. 2003). Currently the offshore fish community consists of a mix of native and non-native species. Native species are those that were present prior to European colonization and for the offshore pelagic zone, include predators like Atlantic Salmon and prey fish like Cisco, Emerald Shiner, and Threespine Stickleback. Non-native species are those that were introduced unintentionally like Alewife and Rainbow Smelt, or that were introduced intentionally like Chinook Salmon, Coho Salmon, Rainbow Trout, and Brown Trout. Non-native salmon and trout were introduced originally by fisheries managers to provide fishing opportunities and later to reduce an overabundance of Alewife. Alewife is the most abundant prey fish in the offshore pelagic zone and it dominates the diets of native and introduced predators (Brandt 1986; Lantry 2001). Alewife can have direct and indirect negative effects on other fishes through competition for food and/or predation on their larvae (Madenjian et al. 2008). Alewife also contain thiaminase, an enzyme that catalyzes the breakdown of thiamine, and fish that eat mainly Alewife can become thiamine deficient which impairs their reproduction (Honeyfield et al. 2005). Except for that of the Alewife, prey fish populations in the offshore pelagic zone are depressed, and not large enough to sustain the zone’s predators. Alewife remain necessary for a functional ecosystem that is required to sustain a highly-valued, trophy sport fishery (Stewart et al. 2013). Wild production of trout and salmon occurs in Lake Ontario tributaries, contributing to in-lake populations (Rand et al. 1993; Connerton et al. 2009; Connerton et al. 2014c). Stocking hatchery-reared fish (Fig. 1), however, remains an essential tool for managing Lake Ontario’s diverse trout and salmon fisheries and achieving the Offshore Pelagic Zone Goal (Stewart et al. 2013): Maintain the offshore pelagic fish community, that is characterized by a diversity of trout and salmon species including Chinook Salmon, Coho Salmon, Rainbow Trout, Brown Trout, and Atlantic Salmon, in balance with prey-fish populations and lower trophic levels. Here we review the fish-community objectives (FCOs) for Lake Ontario’s offshore pelagic zone (Stewart et al. 2013) and evaluate whether those objectives were met during this reporting period (2008-2013) by assessing the status of the objectives’ indicators. We also compare the status of indicators in this reporting period with those in the previous reporting period (2003-2007) (Connerton et al. 2014b). Specific objectives are in italics at the start of each major section and associated indicators of progress are given in Progress and Outlook subsections.

Lake Ontario↗

USGS1999

The ecological condition of estuaries in the Gulf of Mexico

The Gulf of Mexico is a vast natural resource encompassing the coastal areas of western Florida, Alabama, Mississippi, Louisiana, and Texas, as well as a portion of Mexico. Many estuaries flow into the Gulf of Mexico and serve as nursery grounds for fish, habitat for a wide variety of wildlife, shipping routes, and a source of recreation. Estuarine-dependent species constitute more than 95 percent of the commercial fishery harvests from the Gulf of Mexico, and many important recreational fishery species depend on estuaries during some part of their life cycle. Gulf estuaries are diverse and productive ecosystems that provide a variety of valuable resources, including fish and shellfish, recreation, transportation, and water supply. Assessing the overall condition of Gulf of Mexico estuaries required incorporating data from other federal, state, and local monitoring programs to augment the information on ecological indicators collected by the U.S. Environmental Protection Agency’s (USEPA) Environmental Monitoring and Assessment Program (EMAP). The resulting document would provide a synthesis of the available knowledge about the condition of Gulf of Mexico estuaries. This document is intended for use by scientists and other citizens concerned with the ecological condition of estuaries, as well as by managers and lawmakers interested in the sustained use of estuaries for commercial and recreational purposes. It also addresses public concerns about the aesthetic quality of coastal areas vital to tourism and recreation. By producing this report on the ecological condition of estuaries in the Gulf of Mexico, we have taken one step in assessing the health of this environmental resource. We have produced an environmental “report card” to be used as a guide in the evaluation of management decisions and research directions. This report is organized in three parts: (1) an introduction that gives background information on the Gulf of Mexico, estuarine ecology, and the factors that impact estuaries in the gulf, (2) the main section on priority ecological indicators used to measure the condition of estuaries in the gulf and (3) an ecological report card that summarizes the data on ecological indicators and provides a rating of the condition of estuaries in each gulf state and for gulf estuaries overall. Many of the ratings were based on the percent area of estuaries in each state exhibiting degraded or adverse levels of an indicator. Eutrophication, a condition of high nutrients often resulting in low oxygen levels and other adverse effects, is an important water quality concern for estuaries along the gulf coast. The National Oceanic and Atmospheric Administration (NOAA) has compared the Gulf of Mexico to other coastal regions like the middle Atlantic and has ranked the Gulf of Mexico as having the highest number of point sources of nutrients and the highest percentage of land use devoted to agriculture. We evaluated monitoring data for nitrogen, chlorophyll, and dissolved oxygen as indicators of eutrophication. Although most of the estuaries exhibited high nitrogen or chlorophyll or low dissolved oxygen concentrations at least once during a survey, many times these conditions were observed in small rivers or bayous rather than in the entire estuary. Often, the percent area affected was low. The gulf estuaries had moderate conditions overall for nutrients and dissolved oxygen. Definite nutrient problems were observed in >25% of the estuarine area in Louisiana and Texas and definite dissolved oxygen problems were observed in Alabama. Contaminants in estuarine sediments provide evidence of the accumulation of chemicals from anthropogenic sources. We compared the concentrations of sediment contaminants to established guideline values to determine the proportion of estuarine area that could have potential adverse effects on living organisms. Although detectable levels of contaminants were measured in almost every estuary in the Gulf of Mexico, <25% of the estuarine area in all states had contaminant concentrations that exceeded these guidelines. Wetlands are integral parts of estuarine systems. Declining acreage means habitat loss that may be the result of commercial and residential development, hydrologic alterations, or dredge and fill operations. The Gulf of Mexico region contains more than 50% of the coastal wetland acreage in the U.S. and yet it also has the highest rate of coastal wetland loss. Nine of the top ten estuarine drainage areas ranked by total wetland area are in the Gulf of Mexico region. The most current estimates of total wetland loss over the past 200 years range from 41% to 54% for the gulf states. Although coastal wetlands continue to be altered or destroyed, some estimates indicate that the rate of loss has slowed. All gulf states were rated as having severe problems with wetland loss. The condition of benthic (bottom-dwelling) invertebrates, fish and shellfish, birds, and threatened and endangered species was used to evaluate the health of estuarine fauna. Degraded benthic communities inhabited <25% of the estuarine area in all gulf states except for Texas. Commercial fish and shellfish landings may be used as an indicator of population stability while fish biomarkers are used to measure the health of individuals in the population. Commercial landings of the top four fisheries (shrimp, menhaden, blue crab, and oyster) are stable in the gulf states while fish biomarkers indicate fair to poor fish health in Alabama and Texas and good fish health elsewhere. Coastal and marine bird populations appear to be in good condition throughout the gulf. Four threatened or endangered species inhabit coastal areas in the Gulf of Mexico: brown pelican, Gulf sturgeon, manatee, and Kemp’s ridley sea turtle. In general, populations of these species are in good to fair condition in the gulf states. Public health indicators include shellfish bed closures and chemicals found in edible fish tissue. Harvest of shellfish (primarily oyster in the Gulf of Mexico) is restricted or prohibited when concentrations of bacteria or other pathogens reach levels that could impair human health. The gulf states contain the most acreage of shellfish-growing waters in the U.S. but also have the most acreage restricted for harvest. All gulf states except Mississippi have >25% of their shellfish-growing waters restricted for harvest, mostly due to pollution from wastewater treatment plants or other upstream sources. Advisories may be issued that limit consumption when the concentrations of chemicals in fish tissue exceed levels known to be harmful to humans. Although seafood consumption advisories have been issued in all gulf states, the percent of the fish population with high concentrations of contaminants is relatively low in the gulf overall.

Alabama, Florida, Louisiana, Mississippi, Texas↗

USGS2020

Smallmouth buffalo (Ictiobus bubalus) growth across a 1200km human use and ecological disturbance gradient in the Upper Mississippi River System

Smallmouth buffalo (Ictiobus bubalus) is a common and widely distributed large-bodied species of the family Catostomidae. It inhabits large rivers and reservoirs of the eastern continental United States (east of the continental Divide) and is most abundant and common in the large rivers of the Midwest and Central Plains, though it does occur as far north and east as the Hudson Bay drainage and as far south and west as Arizona (Edwards and Twoney 1982). Historically, smallmouth buffalo were an important component of commercial fisheries on both the Mississippi and Illinois Rivers. However, following the introduction of common carp (Cyprinus carpio) in the mid-1800s (Carlander 1954), the construction of a system of navigation dams on Upper Mississippi and Illinois River in the 1930s (USGS 1999), and water quality/pollution issues through the 1980s (Weiner 2010), the role of smallmouth buffalo in the overall UMRS fish community and commercial fishery has generally diminished relative to historical standards. Still, smallmouth buffalo remains an important and valued component of the UMRS commercial fishery. The study area is represented by three study reaches on the Illinois River and three study reaches on the Upper Mississippi River (Figure 1). Collectively, these study reaches represent nearly 1200 river km and exist across strong and pronounced ecological and disturbance gradients. For example, habitat composition, water quality, commercial navigation intensity, aquatic plant prominence, and the number and abundance of nonnative fish species vary strongly across the study domain, with northern Mississippi River reaches exhibiting less navigation traffic, better water quality, markedly greater aquatic plant prominence, more diverse habitat composition, and comparably much smaller numbers of nonnative species than the lower Mississippi River study reach and those on the Illinois River (USGS 1999; Johnson and Hagerty [eds] 2008; Irons et al. 2009). Long term monitoring efforts conducted under the auspices of the Upper Mississippi River Restoration program over the past 27 years have provided tremendous insights into shifts and changes of the overall UMRS fish community (Ickes et al. 2005; Garvey et al. 2010; Schramm and Ickes 2016). However, these monitoring efforts observe only the most basic aspects of the UMRS fish community (i.e., catch, length, weight, distribution, and occurrence). To gain a greater understanding of forces driving community level shifts and changes, more directed study is needed on the functional attributes of fish populations (i.e., growth, mortality, recruitment). Collectively, these functional attributes of populations are termed population dynamics and/or vital rates. It is important to note, the population dynamics of fishes in large rivers is generally poorly understood, especially for non-game species (Ickes 2018). The prevailing view is that abiotic factors largely govern inter-annual population dynamics, typically based upon rather short-term observations and correlations with assorted abiotic river attributes that vary on a seasonal or annual basis (for example, Risotto and Turner 1985). However, the role that longer-term abiotic factors play in regulating population abundance, or that biotic factors internal to the population (e.g., spawner-recruit dynamics, growth dynamics) or external to the population (e.g., predator-prey dynamics, sympatric competitors, disease) remain poorly understood. Achieving a greater understanding of these dynamics is important for stock, game, and invasive species management. In 2017, as part of a larger study designed to gain vital population rate information for smallmouth buffalo in the Upper Mississippi and Illinois Rivers (“Smallmouth Buffalo population demographics of the Upper Mississippi River System”; UMRR LTRM 2018SOW project items 2018MMBF1-2018MMBF6) annual growth patterns in smallmouth buffalo were determined and evaluated. This was accomplished by measuring growth histories recorded in annual growth increments on hard bony parts (here otoliths), a method known generically as biochronology, and somewhat analogous to dendrochronology practiced by foresters. These methods allow one to generate time-series of annual growth histories that depend upon age, year class (i.e., cohort), and annual environmental conditions experienced by the population over time (Weisberg, 1993). Biochronology methods were used to develop a 36-year time series of smallmouth buffalo growth in the Upper Mississippi and Illinois Rivers across a 1200 km ecological and human use disturbance gradient. Annual growth intervals were identified and measured from otoliths to determine fish age and growth history. A mixed model that parses the growth increment into age and year effects was fit to these data. Given the pronounced ecological and disturbance gradients inherent to the UMRS and the study domain, an a priori expectation of differing patterns in growth is accepted as a null hypothesis to test. The goal of this study was to model smallmouth buffalo growth as a function of the age of the fish and the growth year in which the growth was gained. The primary modeling objective was to parse growth observed on each annulus into a portion attributable to the age of the fish and the portion attributable to the year in which the growth was gained. In effect, this modeling approach removes the somewhat trivial age effects on growth so that a non-confounded growth year effect can be gained. Results attributable to growth year provide a time series of growth information that is of the same duration as the oldest fish observed and solely reflects environmental influences on growth. These model responses can then be investigated relative to environmental covariate time-series suspected of influencing growth of smallmouth buffalo in the Upper Mississippi and Illinois Rivers (e.g., temperature, discharge, population density, population mortality, forage availability, sympatric competition, habitat composition, navigation intensity, nonnative fish prominence, etc.). Thus, the primary scientific objective was to investigate if and how smallmouth buffalo growth varies in accordance with innate ecological and disturbance gradients across the study domain.

Illinois, Iowa, Minnesota, Missouri, Wisconsin↗

USGS2020

North Atlantic right whale (Eubalaena glacialis) scenario planning summary report

Scenario planning provides a structured framework that can be used in strategic planning to help manage risk and prioritize actions (Schwartz 1996; Peterson et al. 2003). By providing a mechanism to communicate about complex situations, scenario planning encourages “out-of-the-box” thinking to help groups assess the impacts of plausible future scenarios on a target or resource. The outcomes from scenario planning can be used to improve management decisions, highlight data gaps, and/or identify future science priorities (Star et al. 2015; Borggaard et al. 2019). The application of scenario planning by resource management organizations (e.g., Borggaard et al. 2019; Runyon et al. 2020; Star et al. 2015) and the urgency surrounding the recovery of the critically endangered North Atlantic right whale (Eubalaena glacialis), led to a 2018 NOAA Fisheries scenario planning initiative for the species. In addition to complementing the many management and conservation efforts already underway, this initiative was designed to address the uncertainties around future anthropogenic and environmental changes and how these uncertainties may impact species recovery. We used a scenario planning framework to explore plausible future conditions for North Atlantic right whales and to develop possible options to address those conditions and improve recovery. Specific objectives were to: 1) better understand the challenges of right whale management in a changing climate; 2) identify potential research activities and recovery needs across the species’ range; 3) increase coordination and collaboration related to recovery efforts; and 4) explore how scenario planning can be used to support decisions. Using projected changes in ocean conditions coupled with anthropogenic stressors, we built four plausible future scenarios for right whales. These scenarios helped identify priority research and management actions that NOAA Fisheries and our partners can undertake to improve right whale recovery. We identified priority actions related to science, management, and partnerships including, but not limited to, 1) research on shifting spatial and temporal distributions of right whales and prey in a changing climate; 2) development of technology to further reduce impacts from human activities; 3) continuation of ongoing management efforts related to vessel traffic and fishing; and 4) continued maintenance of existing and development of new partnerships (e.g., industry engagement in problem solving). This scenario planning exercise helped prioritize North Atlantic right whale management and science needs in light of changing ocean conditions and anthropogenic impacts. It can also serve as a reference for how NOAA Fisheries and its partners can better prepare for multiple plausible futures while complementing other on-going initiatives. Priorities identified here can be considered in conjunction with implementation and monitoring actions such as with the Atlantic Large Whale Take Reduction Team (ALWTRT) and/or regional Right Whale U.S. Implementation Teams. The framework can also be repeated and improved upon as additional information becomes available to support future exercises.

Technical Memorandum↗

USGS2019

Atlantic Salmon (Salmo salar) climate scenario planning pilot report

Scenario planning is a structured process that embraces uncertainty and explores plausible alternative future conditions under different assumptions to help manage risk and prioritize actions ( Schwartz 1996, Peterson et al . 2003). It has been used by a variety of organizations to explore and help prepare for the future, lends itself well to exploring the uncertainty surrounding changing environmental conditions, and is widely applicable to natural resource management issues. The conservation and management of protected resources for example, can be particularly challenging when the rate and magnitude of climate-related changes, and the response of species to those changes, are uncertain (NMFS 2016). The structured process of scenario planning can help resource managers navigate through potentially paralyzing uncertainties, manage risk, and evaluate/prioritize management actions associated with adapting to, and managing for, climate change (Moore et al . 2013). Atlantic salmon ( Salmo salar ) is a species highly vulnerable to climate change in the Northeast Atlantic (Hare et al . 2016a). Based on this and the above reasons, a scenario planning initiative was piloted by NOAA Fisheries to explore what the agency can do to improve U.S.Atlantic salmon population resilience to changing climate conditions in riverine, estuarine(transition), and marine environments across its current range (U.S. headwaters to Greenland). Project objectives were: 1) to better understand the challenges of managing Atlantic salmon in a changing climate; 2) to identify and discuss potential management actions and research activities that can be undertaken to increase our understanding of the drivers of Atlantic salmon productivity and resilience; 3) to increase collaborations and coordination related to the speciesrecovery; and 4) to explore how scenario planning can be used to support decisions. Outcomes from this initiative included, but were not limited to, the identification of high priority research and management actions to further collaborations and efforts to recover this species. The identified high priority actions were those that could be undertaken in the near-term(1-5 years) using current resources and in consideration of potential future conditions. Examples of identified actions by habitat (not in order of priority) included: 1) synthesize and refine range-wide life stage specific quantitative environmental thresholds for temperature, flow, etc.; 2) assess watershed habitat productivity; 3) assess forage fish and survival connection and options for marine migration monitoring; and 4) reduce dam-associated indirect estuarine mortality rate. In addition, a number of high priority climate-related actions were included in the revised Atlantic Salmon Recovery Plan (USFWS and NMFS 2019, Appendix 16) and at least two newly NOAA Fisheries funded projects are now underway (1. conduct range-wide habitat analysis and synthesize life stage specific quantitative thresholds and 2. identify locations of cold water refugia under a changing climate). This is the first use of the scenario planning process (NPS 2013) by NOAA Fisheries. This report documents an important example of applying scenario planning to marine species/environments and may serve as a useful reference for other case studies.

Atlantic Ocean↗

USGS2020

Gear comparison study for sampling nekton in Barataria Basin marshes

This project was funded by the Louisiana Trustee Implementation Group (LA TIG) to support decisions related to investments in long-term monitoring. The LA TIG seeks to ensure long-term monitoring informs coastal restoration activities with the goal of sustaining and improving fisheries impacted by the Deepwater Horizon (DWH) Oil Spill. The project objective was to compare nekton catch across an estuarine gradient using different sampling gear with the goal of identifying trade-offs among nekton sampling approaches. To accomplish this objective, Louisiana Department of Wildlife and Fisheries (LDWF), The Water Institute of the Gulf (the Institute), Dynamic Solutions, LLC, Louisiana State University Agricultural Center (LSU AgCenter), and the U.S. Geological Survey (USGS) completed a field gear comparison study from 2018 to 2019. This work compared electrofisher and seine sampling at 12 fixed stations in Barataria Basin using data collected by LDWF. In addition, and in conjunction with LDWF monthly sampling, the same 12 fixed stations were sampled in May 2019 using a throw trap to compare nekton catch and assemblages collected with the throw trap, seine and electrofisher. LDWF has been conducting seine sampling since 1986, and seine data are used by the State of Louisiana to assess juvenile shrimp, crab and fish abundances, sizes and overall assemblages. In 2018, LDWF began conducting electrofisher sampling at 12 Barataria Basin seine stations in order to determine if the two gear types sample similar species and assemblages for potential future replacement of long-term seine sampling with electrofishing. Throw traps were included as they provide density estimates, which are ultimately the desired statistic used in modeling trophic webs, and are used in assessing habitat restoration outcomes. The project compared the nekton catch and assemblages collected using seine, electrofisher, and throw trap data from marsh edge habitats located across the estuarine gradient in Barataria Basin. Specifically, catch per unit effort (CPUE), species richness, species-specific total length (mm) distribution and nekton assemblages were compared between gear types. The first dataset was collected in May 2019 with throw trap (Appendix A), seine (LDWF data), and electrofisher (LDWF data) gear, and the second dataset (collected by LDWF) spanned 14 months of seine and electrofisher monthly sampling occurring from May 2018 through June 2019 at 12 stations in Barataria Basin. Key findings include that gear bias was not evident across the range of water quality conditions (salinity, temperature, o C, dissolved oxygen, mg L-1 , turbidity, NTU; Appendix B: scatter plots) captured during this pilot study, but differences in nekton catch per unit effort (CPUE) and assemblages were evident between gear types. However, those differences largely depended on the parameter examined. For example, the overall CPUE was highest for electrofishing, followed by seine, and then throw trap. When grass shrimp (the most abundant taxon collected) were removed from CPUE, the electrofisher and seine results were similar in CPUE. When CPUE was corrected for gear efficiency and total area sampled, the throw trap had the highest reported density of nekton sampled, followed by electrofisher and seine results. Electrofishing captured the highest number of species, which included more unique species compared to seine or throw trap catches, though all gear types captured at least one unique species. These highlight a need for caution in interpreting assemblage and density data when comparing datasets derived from different sampling methodologies. These key findings can help inform implementation and interpretation of long-term monitoring data in Louisiana as management decisions are made about coastal restoration projects to sustain and improve fisheries. There are trade-offs in selecting gear types for estuarine nekton monitoring of density, abundance, species richness, and assemblages. The table below (Table 1) summarizes some considerations when selecting gear types for long-term monitoring of estuarine nekton. In addition to biological and ecological considerations, other important considerations include cost, the labor required to conduct sampling, logistics, and potential uncertainties related to how effective each gear type is for sampling the wide variety of conditions found across Louisiana’s coastal habitats. For example, although electrofishing may capture higher CPUE, the equipment is more expensive to obtain and maintain compared to the other gear types. Most importantly, this table highlights differences in the nekton assemblages sampled by each gear type; this consideration is critical when designing the goals of a long-term monitoring program as it will inform how the data can be used and interpreted in the future. This report provides caveats, assumptions, and recommendations that can help support the Louisiana Coastal Protection and Restoration Authority (CPRA), LDWF and the LA TIG in comparing data from different gear types, and in making decisions for future monitoring. Findings from this study are limited to the range of water quality conditions occurring during these data collection events; these data and analyses could benefit from sampling across a wider range of water quality conditions, and collection of habitat structure and bottom type data which are not routinely collected but critically influence nekton. Further investigation examining how relative differences detected in key species abundances between gear types might impact ecosystem indicators and energetics in a modeled food web would provide valuable input to understand outputs of the Comprehensive Aquatic System Model for Barataria Basin, including the potential impacts of nekton monitoring decisions on food web models.

Louisiana↗

USGS2021

Estimating detection and occupancy coefficients for the Pacific Islands coral reef fish species

The data-limited stock assessment models used to monitor the status of coral reef fish species in the Western Pacific region are dependent upon accurate estimates of standing stock biomass generated from underwater visual surveys of reefs. However, the imperfect detection of and variable occupancy of habitat by reef fishes are not currently accounted for in these estimates. Therefore, the objective of this project was to estimate detection and occupancy coefficients for the species listed in the Western Pacific Regional Fishery Management Council’s Fishery Ecosystem Plans by analyzing the Pacific Island Fishery Science Center-Coral Reef Ecosystem Program Reef Fish Dataset. These detection and occupancy coefficients would then be applied to refine standing stock biomass estimates. In general, species with higher detection probabilities and/or lower occupancy rates tended to exhibit the greatest differences in the estimates of standing stock biomass calculated with and without accounting for detection and occupancy. The standing stock biomass of most reef fish species seem to be underestimated when detection and occupancy are not accounted for. However, the standing stock biomass of larger-bodied targeted species, such as jacks, snappers, and groupers, seem to be over-estimated relative to the estimates generated when accounting for occupancy and detection. While there are still issues to resolve regarding how well the current data collection methods meet the underlying assumptions of the detection and occupancy modeling approach, the inclusion of detection and occupancy coefficients seems likely to improve estimates of standing stock biomass of coral reef fish species.

Hawaii↗

USGS2023

FishPass baseline assessment of fish community assemblage and migratory patterns in in the Boardman River, Traverse City, Michigan, USA

This report on baseline assessment of fish community assemblage and migratory patterns of fishes in the lower Boardman River (LBR; Traverse City, MI (USA)) is one of four assessment projects conceived circa 2017 after the Boardman (Ottaway) River was selected by the Great Lakes Fishery Commission (GLFC) and collaborating agencies as the future site of the Selective Bi-directional Fish Passage (FishPass) project. This report describes the results from fisheries community sampling from 2017-2021 and the concurrent bio-telemetry project aimed at understanding phenological changes in the fish community and movement and space-use of a variety of large-bodied fishes in the LBR against which selective fish passage treatments will be developed and evaluated. Fish migration in riverine environments is a growing area of concern as mounting anthropogenic influences, particularly fragmentation from dams and barriers, constitute a major threat to global river species diversity. Specifically, In the Laurentian Great Lakes basin, more than 250,000 dams, weirs, culverts, and other significant obstructions prevent the movement of species both between the Great Lakes and rivers, and within rivers. Barriers impede the movement of fishes between areas critical to the completion of their lifecycle, affecting both population and ecosystem viability. However, a conundrum arises in that the same barriers can also prevent the upstream invasion of non-native or undesirable species (most notably the sea lamprey Petromyzon marinus in the Great Lakes),prevent the transfer of contaminants and diseases, halt deleterious genes, provide recreational opportunities, or generate power. As a result, fish passage solutions with the capability of selectively passing desirable taxa while restricting the dispersal of undesirable taxa (selective connectivity) are sought to solve this connectivity conundrum. FishPass is a multi-agency initiative planned to replace the Union Street Dam on the Boardman River in Traverse City,MI (USA), aimed at developing and implementing automatic or semiautomatic selective bi-directional fish guidance, sorting, and passage techniques and technologies. Pivotal to both the successful development of selective connectivity and assessment of its effects is a more complete understanding of the Boardman River’s fishery. Specifically, understanding the species and size composition of the fish community, fish movement phenology and the associated abiotic conditions. Fish community sampling confirmed the presence of 28 unique species in the LBR (Boardman River reach below Union Street Dam). Passive Integrated Transponder (PIT) tag telemetry increased the resolution of phenological shifts in the fish community that could not have been captured from periodic fish sampling. This data demonstrates large variation within species and overlap between species presence. However, discrete periods of presence were identified across most species when considering the central tendencies in the distribution of their presence. Rainbow trout Oncorhynchus mykiss were found to be omni-present in the river while brown trout Salmo trutta and smallmouth bass Micropterus dolomieu also persisted throughout a majority of the year; all of which will require continually sorting at FishPass. PIT tag telemetry also provided the important understanding that individuals (3-64%) of all species return to the LBR across multiple years. Radio telemetry (RT) proved useful in refining the entry and exit timing and in evaluating the proportion of individuals that encountered the current Union Street Dam and Kid’s Creek (the only tributary confluence below the Union Street Dam) across six species (common white sucker Catostomus commersonii, rainbow trout, smallmouth bass, walleye Sander vitreus, brown trout, and common carp Cyprinus carpio). The RT results show that these species are present in FishPass Research Publication: baseline assessment of fish community assemblage and migratory pattern in the Boardman River, Traverse City, Michigan, USA November 2023 7 between April and August. Our analysis also demonstrated that not all fish that entered the river proceeded to the Union Street Dam, but those that did, did so prior to being detected encountering Kid’s Creek. Common white sucker and rainbow trout were the only species to be detected encountering Kid’s Creek. Collectively, the results of this study provide a baseline understanding of the seasonal fish diversity and relative abundance of fishes in the LBR, and a basic description of observed movement patterns of a subset of species in the context of seasonal phenology, entry and exit behavior within the LBR, and the propensity at which telemetered individuals encounter the Union Street dam and/or Kid’s Creek.

Michigan↗

USGS2023

Updated decision analysis to inform multi-species salmonine management in Lake Michigan

The recreational fishery for salmonine species in Lake Michigan (lake trout, Chinook salmon, coho salmon, steelhead, and brown trout) is largely maintained through stocking. Decisions about how many of each species to stock require an understanding of how to maintain a sustainable balance of predators (salmonine species) to prey (alewife) in the lake. The current models used to make these decisions can estimate the ratio of Chinook salmon to alewife in the lake. However, the Lake Michigan Committee’s new stocking strategy aims to incorporate the other salmonine species into this predator-prey ratio. We used structured decision making to evaluate potential stocking strategies. We worked with fishery stakeholders and members of the Lake Michigan Committee, conducted participatory modeling to forecast outcomes of stocking scenarios using updated information on fish movement and feeding, and evaluated the risk of these stocking strategies. Most of the stocking practices we evaluated resulted in a high risk of large declines in alewife abundance, negatively affecting future salmon fisheries. The forecasts were substantially more pessimistic than those resulting from a similar analysis conducted a decade earlier, apparently due to more recent alewife assessments indicating lower alewife productivity (recruits per spawner). Alewife recruitment dynamics is an area of substantial uncertainty, with apparently large consequences for management; decision makers on Lake Michigan would benefit from greater understanding of alewife recruitment dynamics to reduce this uncertainty when accounting for risks.

Lake Michigan↗