USGS Science⌕ Search

SEARCH · USGS Science

Results for “Aquatic Sciences”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources
USGS2020

How lipid content and temperature affect American shad (Alosa sapidissima) attempt rate and sprint swimming: Implications for overcoming migration barriers

How seasonal effects such as temperature increases and reduced lipid content affect the ability of anadromous fishes to traverse high-velocity barriers and sprint swimming is poorly understood. We evaluated American shad ( Alosa sapidissima ) swimming performance in a flume against high flow velocities (2.5–3.7 m·s −1 ) during the upstream migration period (April–May; temperatures 11.1–21.4 °C) to determine how their willingness to enter a velocity barrier (attempt rate) and their swimming endurance changed during migration. American shad did not make attempts at low temperatures, and attempt rate gradually increased throughout the migration as temperatures warmed. American shad displayed two distinct, nonsustained swimming modes (prolonged and sprint swimming), and endurance was different between sexes. At warmer temperatures, females swam at prolonged speeds more often and longer females displayed a lower endurance. Males primarily swam at sprint speeds and were affected by swimming speed, fork length, and lipid content. Our results indicate that American shad motivation and swimming endurance change over the course of the migration as conditions change, potentially limiting their ability to pass barriers.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2020

Assessing the potential to mitigate climate-related expansion of largemouth bass populations using angler harvest

Climate-related changes in fish communities can present new challenges for fishery managers who must address declines in cool- and cold-water sportfish while dealing with increased abundance of warm-water sportfish. We used largemouth bass ( Micropterus salmoides ) in Wisconsin lakes as model populations to determine whether angler harvest provides a realistic method for reducing abundance of a popular warm-water sportfish that has become more prevalent and has prompted management concerns around the globe. Model results indicate largemouth bass will be resilient to increased fishing mortality. Furthermore, high rates of voluntary catch-and-release occurring in most largemouth bass fisheries likely preclude fishing mortality rates required to reduce bass abundance at meaningful levels (≥25% reductions). Increasing fishing mortality in these scenarios may require more “stimulus” than merely providing anglers with greater harvest opportunities via less stringent harvest regulations. Angler harvest could result in populations dominated by small fish, a scenario that may be undesirable to anglers, but could provide ecological benefits in certain situations.

Wisconain↗
USGS2020

Harvest–release decisions in recreational fisheries

Most fishery regulations aim to control angler harvest. Yet, we lack a basic understanding of what actually determines the angler’s decision to harvest or release fish caught. We used XGBoost, a machine learning algorithm, to develop a predictive angler harvest–release model by taking advantage of an extensive recreational fishery data set (24 water bodies, 9 years, and 193 523 fish). We were able to successfully predict the harvest–release outcome for 99% of fish caught in the training data set and 96% of fish caught in the test data set. Unsuccessful predictions were mostly attributed to predicting harvest of fish that were released. Fish length was the most essential feature examined for predicting angler harvest. Other important predictive harvest–release features included the number of individuals of the same species caught, geographic location of an angler’s residence, distance traveled, and time spent fishing. The XGBoost algorithm was able to effectively predict the harvest–release decision and revealed hidden and intricate relationships that are often unaccounted for with classical analysis techniques. Exposing and accounting for these angler–fish intricacies is critical for fisheries conservation and management.

Nebraska↗
USGS2020

Rapid early development and feeding benefits an invasive population of lake trout

Lake trout ( Salvelinus namaycush ) were discovered in Yellowstone Lake in 1994 and their population expanded dramatically despite intensive suppression. The lake is species-depauperate, with no major lake trout embryo predators. We hypothesized that without this predation threat, lake trout free embryo feeding and growth may be greater than in their native range, leading to increased survival of age-0 individuals and rapid population growth. We compared length, developmental rate, and feeding patterns of lake trout free embryos captured at a spawning site in Yellowstone Lake with free embryos captured in their native range in Lake Champlain, Vermont. More embryos were feeding, contained more food, and were significantly longer at the same developmental stages in Yellowstone Lake. With an abundance of available food and minimal threat of predation, free embryos remained on the spawning site in Yellowstone Lake later into the summer than in Lake Champlain and achieved a greater maximum length before they dispersed. Greater food consumption and associated growth likely leads to high survival of lake trout free embryos in Yellowstone Lake, contributing to rapid population growth.

New York, Quebec, Vermont, Wyoming↗
USGS2019

Predicting fish species richness and habitat relationships using Bayesian hierarchical multispecies occupancy models

Understanding how stream fishes respond to changes in habitat availability is complicated by low occurrence rates of many species, which in turn reduces the ability to quantify species–habitat relationships and account for imperfect detection in estimates of species richness. Multispecies occupancy models have been used sparingly in the analysis of fisheries data, but address the aforementioned deficiencies by allowing information to be shared among ecologically similar species, thereby enabling species–habitat relationships to be estimated for entire fish communities, including rare species. Here, we highlight the utility of hierarchical multispecies occupancy models for the analysis of fish community data and demonstrate the modeling framework on a stream fish community dataset collected in the Delaware Water Gap National Recreation Area, USA. In particular, we demonstrate the ability of the modeling framework to make inferences at the species-, guild-, and community-levels, thereby making it a powerful tool for understanding and predicting how environmental variables influence species occupancy probabilities and structure fish assemblages.

New York New Jersey, Pennsylvania↗
USGS2020

Spatiotemporal patterns in trophic niche overlap among five salmonines in Lake Michigan, USA

Native lake trout and introduced Chinook salmon, coho salmon, steelhead, and brown trout are major predators in Lake Michigan’s complex ecosystem and collectively support a valuable recreational fishery, but declines in their primary prey, alewife, have raised ecological and management concerns about competition and prey allocation. We applied niche overlap analysis to evaluate competition among salmonine predators during rapid forage base change in Lake Michigan. δ13C and δ15N stable isotope ratios indicated that lake trout had a unique trophic niche from inclusion of offshore and benthic prey, with <29% lakewide niche overlap with Chinook salmon, coho salmon and steelhead. Brown trout had moderate overlap with other species (45 – 91%), while Chinook salmon, coho salmon, and steelhead had high overlap (71 – 98%). Regional differences in isotopic signatures highlighted the potential importance of sub-system differences in fish diets in large aquatic systems. The uniqueness of the lake trout niche, and broadness of brown trout and steelhead niches, suggest these species may be resilient to forage base changes. This study demonstrates how niche overlap analysis can be applied to tease apart competitive interactions and their response to ecosystem change.

Lake Michigan↗
USGS2021

A framework for assessing the ability to detect macroscale effects on fish growth

Various abiotic and biotic factors affect fish and their habitats at macroscales. For example, changes in global temperatures will likely alter demographic rates, including growth. However, to date, there is no statistical framework for assessing the ability to detect macroscale effects on fish growth under different sampling scenarios. We provide a generalized framework for calculating the frequentist and Bayesian power of detecting macroscale effects on fish growth. We illustrate this framework for a range of sampling scenarios that varied in the number of fish sampled per lake, the number of lakes sampled, and the magnitude of the temperature effect on growth for two case study species. However, the framework can be adapted to investigate other species, sampling scenarios, and environmental drivers. The ability to detect macroscale effects was more affected by the number of lakes sampled rather than the number of fish sampled from each lake. Confidently detecting macroscale effects likely requires sampling hundreds of lakes. This was true for both case study species, despite different life histories and extents of spatial variability in growth.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2021

Could ecological release buffer suppression efforts for non-native lake trout (Salvelinus namaycush) in Yellowstone Lake, Yellowstone National Park?

Yellowstone Lake in Yellowstone National Park, USA, has the longest ongoing suppression program for non-native lake trout ( Salvelinus namaycush ) in the western USA. Harvest data from the suppression program, along with data from an assessment program initiated in 2011, was used to estimate lake trout abundance and mortality rates. Abundance and biomass estimates were used to estimate stock–recruitment dynamics, which were inputs to a simulation model forecasting responses to continued suppression. Abundance increased during 1998–2012 when total annual mortality exceeded 0.59 and declined thereafter. The fishing mortality rate required to reduce abundance was 67% greater than predicted by models that used prerecruit survival estimates from the lake trout’s native range. Prerecruit survival in Yellowstone Lake was estimated at four to six times greater than native range survival rates. Simulated abundance continued to decline if recent suppression efforts were maintained. High prerecruit survival in Yellowstone Lake likely illustrates ecological release for an invasive species in an ecosystem containing few predators or competitors and demonstrates the potential pitfalls of assuming equal demographic rates for native and non-native populations.

Wyoming↗
USGS2020

A flexible survey design for monitoring spatiotemporal fish richness in nonwadeable rivers: optimizing efficiency by integrating gears

We designed a flexible protocol for monitoring fish species richness in nonwadeable rivers. Nine sites were sampled seasonally with six gears in two physiographic regions in Missouri (USA). Using resampling procedures and mixed-effects modeling, we quantified richness and compositional overlap among gears, identified efficient gear combinations, and evaluated protocol performance across regions and seasons. We detected 25–75 species per sample and 89 185 fish. On average, no single gear detected >62% of observed species, but an optimized, integrated-gear protocol with four complementary gears on average detected 90% of species while only requiring 51.9% of initial sampling effort. Neither season nor physiographic region explained low spatiotemporal variation in percent richness detected by the integrated-gear protocol. In contrast, equivalent effort with an electrofishing-only protocol was 53.5% less efficient, seasonally biased and imprecise (36.1%–82.3% of richness), and on average detected 15.9% less of observed richness. Altogether, riverine fish richness is likely underestimated with single-gear survey designs. When paired with existing wadeable-stream inventories, our customizable approach could benefit regional monitoring by comprehensively documenting riverine contributions to riverscape biodiversity.

Missouri↗
USGS2020

Estimating population abundance with a mixture of physical capture and passive PIT tag antenna detection data

The inclusion of passive interrogation antenna (PIA) detection data has promise to increase precision of population abundance estimates ( ). However, encounter probabilities are often higher for PIAs than for physical capture. If the difference is not accounted for, may be biased. Using simulations, we estimated the magnitude of bias resulting from mixed capture and detection probabilities and evaluated potential solutions for removing the bias for closed capture models. Mixing physical capture and PIA detections ( p det ) resulted in negative biases in . However, using an individual covariate to model differences removed bias and improved precision. From a case study of fish making spawning migrations across a stream-wide PIA ( p det ≤ 0.9), the coefficient of variation (CV) of declined 39%–82% when PIA data were included, and there was a dramatic reduction in time to detect a significant change in . For a second case study, with modest p det (≤0.2) using smaller PIAs, CV ( ) declined 4%–18%. Our method is applicable for estimating abundance for any situation where data are collected with methods having different capture–detection probabilities.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2020

Dietary versus nondietary fatty acid profiles of lake trout ecotypes from Lake Superior and Great Bear Lake: Are fish really what they eat?

Fatty acids are well-established biomarkers used to characterize trophic ecology, food-web linkages, and the ecological niche of many different taxa. Most often, fatty acids that are examined include only those previously identified as “dietary” or “extended dietary” biomarkers. Fatty acids considered as nondietary biomarkers, however, represent numerous fatty acids that can be extracted. Some studies may include nondietary fatty acids (i.e., combined with dietary fatty acids), but do not specifically assess them, whereas in other studies, these data are discarded. In this study, we explored whether nondietary biomarker fatty acids can provide worthwhile information by assessing their ability to discriminate intraspecific diversity within and between lakes. Nondietary fatty acids used as biomarkers delineated variation among regions, among locations within a lake, and among ecotypes within a species. Physiological differences that arise from differences in energy processing can be adaptive and linked to habitat use by a species’ ecotype and likely explains why nondietary fatty acid biomarkers can be a relevant tool to delineate intraspecific diversity. Little is known about the nondietary-mediated differences in fatty acid composition, but our results showed that nondietary fatty acid biomarkers can be useful tool in identifying variation.

Lake Superior↗
USGS2020

Modelling grass carp egg transport using a 3-D hydrodynamic river model: The role of egg retention in dead zones on spawning success

Invasive grass carp (Ctenopharyngodon idella) are known to spawn in the Sandusky River, Ohio, USA, within the Great Lakes Basin, and are threatening to expand throughout the Great Lakes. Successful spawning is thought to require that eggs remain in suspension until hatching, which depends on river hydrodynamics and temperature-dependent egg development. Previous modelling efforts used one-dimensional hydrodynamic models that simplify egg movement by not simulating low-velocity zones within the river. To examine the effect of low-velocity zones on egg transit times and hatching rates, we developed a novel coupling of a biophysical Lagrangian particle tracker and three-dimensional hydrodynamic model on the Sandusky River during a high-flow event. The model successfully predicted egg-capture data for a range of developmental stages and revealed a mechanism that resuspends eggs trapped in low-velocity zones. The resuspension mechanism increases the residence time of grass carp eggs in spawning tributaries and can lead to successful hatching occurring in shorter distances than previously estimated. Grass carp potentially spawning in shorter tributary lengths has widespread implications for efforts preventing establishment in the Great Lakes Basin.

Ohio↗
USGS2020

Integrating side-scan sonar and acoustic telemetry to estimate the annual spawning run size of Atlantic sturgeon in the Hudson River

There is considerable interest in evaluating the status and trends of sturgeon populations, yet many traditional approaches to estimating the abundance of fishes are intractable due to their biology and rarity. Side-scan sonar has recently emerged as an effective tool for censusing sturgeon in rivers, yet challenges remain for censusing open populations that may visit specific habitats over periods of time (e.g., spawning runs). We use a hierarchical model to integrate side-scan sonar with acoustic telemetry, to estimate the proportion of a spawning run fitted with acoustic tags (12%; 95% CRI = 8-16%) and extrapolate to the total run size in 2014. Our investigation represents a novel approach to generating run size estimates in a large river and provides the first estimate of Atlantic sturgeon spawning run size for the Hudson River (N ̂ = 466; 95% CRI = 310-745) since the fishery moratorium in the 1990’s. Our estimate suggests that the Hudson River holds one of the largest contemporary populations of Atlantic sturgeon, but also indicates that it remains sharply depleted relative to virgin conditions.

Hudson River↗
USGS2020

Keeping it classy: Classification of live fish and ghost PIT tags detected with a mobile PIT tag interrogation system using an innovative analytical approach

The ability of passive integrated transponder (PIT) tag data to improve demographic parameter estimates has led to the rapid advancement of PIT tag systems. However, ghost tags create uncertainty about detected tag status (i.e., live fish or ghost tag) when using mobile interrogation systems. We developed a method to differentiate between live fish and ghost tags using a random forest classification model with a novel data input structure based on known fate PIT tag detections in the San Juan River (New Mexico, Colorado, and Utah, USA). We used our model to classify detected tags with an overall error rate of 6.8% (1.6% ghost tags error rate and 21.8% live fish error rate). The important variables for classification were related to distance moved and response to monsoonal flood flows; however, habitat variables did not appear to influence model accuracy. Our results and approach allow the use of mobile detection data with confidence and allow for greater accuracy in movement, distribution, and habitat use studies, potentially helping identify influential management actions that would improve our ability to conserve and recover endangered fish.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2020

Can nutrient additions facilitate recovery of Pacific salmon?

Multiple restoration actions have been implemented in response to declining salmon populations. Among these is the addition of salmon carcasses or artificial nutrients to mimic marine-derived nutrients historically provided by large spawning runs of salmon. A key assumption in this approach is that increased nutrients will catalyze salmon population growth. Although effects on aquatic ecosystems have been observed during treatments, it is unclear whether permanent population increases for salmon will occur. To test this assumption and address associated uncertainties, we linked a food web model with a salmon life cycle model to examine whether carcass additions in a river reach would improve conditions for salmon in the long term. Model results confirmed immediate increases in the biomass of periphyton, macroinvertebrates, and fish during carcass additions. In turn, juvenile salmon grew larger and experienced improved freshwater and smolt survival, which translated to a greater number of adults returning to spawn. However, once additions ceased, salmon abundance returned to pretreatment levels, which, based on our model, is owing to a combination of instream and out-of-basin factors. Overall, results of this work suggest that benefits during carcass and nutrient additions may not translate into persistent productivity of salmon unless additions are sustained indefinitely or other limiting factors are addressed.

Alberta, British Columbia, Idaho, Montana, Nevada,↗
USGS2021

Considerations of variability and power for long-term monitoring of stream fish assemblages

Little attention has been given to optimizing statistical power for monitoring stream fish assemblages. We explored the relationship between temporal variability and statistical power using 34 metrics from fish community data collected annually at six sites over 10 years via electrofishing. Metric variability differed by the life stage and group of species considered, use of abundance or mass data, and data standardization technique. Lower variability was associated with community data, abundance data, and time-based standardizations, while greater variability was associated with young-of-the-year data, mass data, and area-based standardizations. Simulation-based power analysis indicated metric choice, and to a lesser degree, monitoring design (annual, biennial, endpoints, or haphazard sampling) influenced power to detect change. Across a fixed number of surveys (N = 60), endpoints sampling performed best. The N needed to detect change was heavily dependent upon metric choice for all monitoring designs, with the most biologically specific metrics requiring greater N. Large savings in effort and resource expenditure can be obtained utilizing biologically relevant metrics that are robust to temporal noise within an appropriate sampling design.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2020

Remarkable response of native fishes to invasive trout suppression varies with trout density, temperature, and annual hydrology

Recovery of imperiled fishes can be achieved through suppression of invasives, but outcomes may vary with environmental conditions. We studied the response of imperiled desert fishes to an invasive brown ( Salmo trutta ) and rainbow trout ( Oncorhynchus mykiss ) suppression program in a Colorado River tributary, with natural flow and longitudinal variation in thermal characteristics. We investigated trends in fish populations related to suppression and tested hypotheses about the impacts of salmonid densities, hydrologic variation, and spatial–thermal gradients on the distribution and abundance of native fish species using zero-inflated generalized linear mixed effects models. Between 2012 and 2018, salmonids declined 89%, and native fishes increased dramatically (∼480%) once trout suppression surpassed ∼60%. Temperature and trout density were consistently retained in the top models predicting the abundance and distribution of native fishes. The greatest increases occurred in warmer reaches and in years with spring flooding. Surprisingly, given the evolution of native fishes in disturbance-prone systems, intense, monsoon-driven flooding limited native fish recruitment. Applied concertedly, invasive species suppression and efforts to mimic natural flow and thermal regimes may allow rapid and widespread native fish recovery.

Arizona↗
USGS2021

The genetic composition of wild recruits in a recovering lake trout population in Lake Michigan

Strain performance evaluations are vital for developing successful fishery management and restoration strategies. Here, we utilized genotypes from 36 microsatellites to investigate hatchery strain contribution to collections of naturally produced lake trout ( Salvelinus namaycush ) sampled across Lake Michigan. Strain composition varied by area, with recoveries of Seneca Lake strain exceeding expectations based on stocking records in northern Lake Michigan but performing similarly to other strains in southern Lake Michigan. Interstrain hybrids were present at moderate frequencies similar to expectations based on simulations, suggesting that strains are interbreeding randomly. We hypothesize that the superior performance of the Seneca Lake strain in northern Lake Michigan is partially due to adaptive advantages that facilitate increased survival in areas with high mortality from sea lamprey ( Petromyzon marinus ) predation, such as northern Lake Michigan. However, when this selective pressure is lessened, the Seneca Lake strain performs similarly to other strains. Our study demonstrates that strain performance can vary across small spatial scales and illustrates the importance of conducting thorough strain evaluations to inform management and conservation.

Lake Michigan↗