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At least 721 records · Page 40Linked to original sources
USGS2025

Home ranges of economically important reef fishes at North Carolina artificial reefs

Home range is a vital component to understanding animal ecology and can vary with factors like species, body size, and habitat. Artificial reefs are increasingly used to supplement or enhance habitat for reef fish. Quantifying reef fish home range sizes and the factors affecting home ranges is thus critical to understanding the efficacy of artificial reefs to sustain communities that reflect those on natural reefs. We estimated home ranges of reef fishes at artificial reefs in the southeast United States, evaluated what factors affected those home ranges, and compared them to home ranges of similarly sized fish on natural reefs. From June–October 2021 and 2022, we deployed acoustic tags on five fishery targeted reef species, black sea bass ( Centropristis striata ), gag ( Mycteroperca microlepis ), greater amberjack ( Seriola dumerili ), almaco jack ( S. rivoliana ), and red snapper ( Lutjanus campechanus ), on four artificial reefs near Cape Lookout, North Carolina. Tagged fish were tracked using a fine-scale positioning system for ~ 120 days. Home ranges varied by species and fish size (i.e., total length). Black sea bass had the smallest home ranges (mean = 6266 m 2 ), gag and red snapper had moderate home ranges (38,265 m 2 and 53,553 m 2 , respectively), and almaco jack and greater amberjack had the largest (152,146 m 2 , and 414,107 m 2 , respectively). Black sea bass, gag, and red snapper displayed increased home range size with total length while greater amberjack and almaco jack home ranges remained relatively constant across lengths. Greater amberjack home ranges were further influenced by artificial reef complex area with an increase in reef area leading to a larger home range. Our data from artificial reefs showed considerable overlap in the relationship between home range and body size when compared to similarly sized predatory reef fish on natural reefs. This information will be vital in improving ecological understanding of how artificial reefs can influence area use of reef-associated species to help inform future artificial reef deployments. Moreover, these results provide an important comparison between artificial reefs and natural reefs as habitats for reef-associated species, a topic that will become increasingly important as the quantity of artificial structures in our oceans increases. deployments. Moreover, these results provide an important comparison between artificial reefs and natural reefs as habitats for reef-associated species, a topic that will become increasingly important as the quantity of artificial structures in our oceans increases.

North Carolina↗
USGS2005

Optimal swim speeds for traversing velocity barriers: An analysis of volitional high-speed swimming behavior of migratory fishes

Migrating fish traversing velocity barriers are often forced to swim at speeds greater than their maximum sustained speed (Ums). Failure to select an appropriate swim speed under these conditions can prevent fish from successfully negotiating otherwise passable barriers. I propose a new model of a distance-maximizing strategy for fishes traversing velocity barriers, derived from the relationships between swim speed and fatigue time in both prolonged and sprint modes. The model predicts that fish will maximize traversed distance by swimming at a constant groundspeed against a range of flow velocities, and this groundspeed is equal to the negative inverse of the slope of the swim speed-fatigue time relationship for each mode. At a predictable flow velocity, they should switch from the optimal groundspeed for prolonged mode to that for sprint mode. Data from six migratory fish species (anadromous clupeids: American shad Alosa sapidissima, alewife A. pseudoharengus and blueback herring A. aestivalis; amphidromous: striped bass Morone saxatilis; and potomodromous species: walleye (previously known as Stizostedion vitrium) and white sucker Catostomus commersonii) were used to explore the ability of fish to approximate the predicted distance-maximizing behaviors, as well as the consequences of deviating from the optima. Fish volitionally sprinted up an open-channel flume against fixed flow velocities of 1.5-4.5 m s-1, providing data on swim speeds and fatigue times, as well as their groundspeeds. Only anadromous clupeids selected the appropriate distance-maximizing groundspeed at both prolonged and sprint modes. The other three species maintained groundspeeds appropriate to the prolonged mode, even when they should have switched to the sprint optima. Because of this, these species failed to maximize distance of ascent. The observed behavioral variability has important implications both for distributional limits and fishway design.

Journal of Experimental Biology↗
USGS2012

Interbasin water transfer, riverine connectivity, and spatial controls on fish biodiversity

Background Large-scale inter-basin water transfer (IBWT) projects are commonly proposed as solutions to water distribution and supply problems. These problems are likely to intensify under future population growth and climate change scenarios. Scarce data on the distribution of freshwater fishes frequently limits the ability to assess the potential implications of an IBWT project on freshwater fish communities. Because connectivity in habitat networks is expected to be critical to species' biogeography, consideration of changes in the relative isolation of riverine networks may provide a strategy for controlling impacts of IBWTs on freshwater fish communities Methods/Principal Findings Using empirical data on the current patterns of freshwater fish biodiversity for rivers of peninsular India, we show here how the spatial changes alone under an archetypal IBWT project will (1) reduce freshwater fish biodiversity system-wide, (2) alter patterns of local species richness, (3) expand distributions of widespread species throughout peninsular rivers, and (4) decrease community richness by increasing inter-basin similarity (a mechanism for the observed decrease in biodiversity). Given the complexity of the IBWT, many paths to partial or full completion of the project are possible. We evaluate two strategies for step-wise implementation of the 11 canals, based on economic or ecological considerations. We find that for each step in the project, the impacts on freshwater fish communities are sensitive to which canal is added to the network. Conclusions/Significance Importantly, ecological impacts can be reduced by associating the sequence in which canals are added to characteristics of the links, except for the case when all 11 canals are implemented simultaneously (at which point the sequence of canal addition is inconsequential). By identifying the fundamental relationship between the geometry of riverine networks and freshwater fish biodiversity, our results will aid in assessing impacts of IBWT projects and balancing ecosystem and societal demands for freshwater, even in cases where biodiversity data are limited.

PLoS ONE↗
USGS2018

Can data from disparate long-term fish monitoring programs be used to increase our understanding of regional and continental trends in large river assemblages?

Understanding trends in the diverse resources provided by large rivers will help balance tradeoffs among stakeholders and inform strategies to mitigate the effects of landscape scale stressors such as climate change and invasive species. Absent a cohesive coordinated effort to assess trends in important large river resources, a logical starting point is to assess our ability to draw inferences from existing efforts. In this paper, we use a common analytical framework to analyze data from five disparate fish monitoring programs to better understand the nature of spatial and temporal trends in large river fish assemblages. We evaluated data from programs that monitor fishes in the Colorado, Columbia, Illinois, Mississippi, and Tallapoosa rivers using non-metric dimensional scaling ordinations and associated tests to evaluate trends in fish assemblage structure and native fish biodiversity. Our results indicate that fish assemblages exhibited significant spatial and temporal trends in all five of the rivers. We also document native species diversity trends that were variable within and between rivers and generally more evident in rivers with higher species richness and programs of longer duration. We discuss shared and basin-specific landscape level stressors. Having a basic understanding of the nature and extent of trends in fish assemblages is a necessary first step towards understanding factors affecting biodiversity and fisheries in large rivers.

PLoS ONE↗
USGS2018

Isotope niche dimension and trophic overlap between bigheaded carps and native filter-feeding fish in the lower Missouri River, USA

Stable carbon and nitrogen isotope values (δ 13 C and δ 15 N) were used to evaluate trophic niche overlap between two filter-feeding fishes (known together as bigheaded carp) native to China, silver carp ( Hypophthalmichthys molitrix ) and bighead carp ( Hypophthalmichthys nobilis ), and three native filter-feeding fish including bigmouth buffalo ( Ictiobus cyprinellus ), gizzard shad ( Dorosoma cepedianum ) and paddlefish ( Polyodon spathula ) in the lower Missouri River, USA, using the Bayesian Stable Isotope in R statistics. Results indicate that except for bigmouth buffalo, all species displayed similar trophic niche size and trophic diversity. Bigmouth buffalo occupied a small trophic niche and had the greatest trophic overlap with silver carp (93.6%) and bighead carp (94.1%) followed by gizzard shad (91.0%). Paddlefish had a trophic niche which relied on some resources different from those used by other species, and therefore had the lowest trophic overlap with bigheaded carp and other two native fish. The trophic overlap by bigheaded carp onto native fish was typically stronger than the reverse effects from native fish. Average niche overlap between silver carp and native species was as high as 71%, greater than niche overlap between bighead carp and native fish (64%). Our findings indicate that bigheaded carps are a potential threat to a diverse and stable native fish community.

Lower Missouri River↗
USGS2013

Spatial extent and dynamics of dam impacts on tropical island freshwater fish assemblages

Habitat connectivity is vital to the persistence of migratory fishes. Native tropical island stream fish assemblages composed of diadromous species require intact corridors between ocean and riverine habitats. High dams block fish migration, but low-head artificial barriers are more widespread and are rarely assessed for impacts. Among all 46 drainages in Puerto Rico, we identified and surveyed 335 artificial barriers that hinder fish migration to 74.5% of the upstream habitat. We also surveyed occupancy of native diadromous fishes (Anguillidae, Eleotridae, Gobiidae, and Mugilidae) in 118 river reaches. Occupancy models demonstrated that barriers 2 meters (m) high restricted nongoby fish migration and extirpated those fish upstream of 4-m barriers. Gobies are adapted to climbing and are restricted by 12-m barriers and extirpated upstream of 32-m barriers. Our findings quantitatively illustrate the extensive impact of low-head structures on island stream fauna and provide guidance for natural resource management, habitat restoration, and water development strategies.

BioScience↗
USGS2022

Relative bias in catch among long-term fish monitoring surveys within the San Francisco Estuary

Fish monitoring gears rarely capture all available fish, an inherent bias in monitoring programs referred to as catchability. Catchability is a source of bias that can be affected by numerous aspects of gear deployment (e.g., deployment speed, mesh size, and avoidance behavior). Thus, care must be taken when multiple surveys—especially those using different sampling methods—are combined to answer spatio-temporal questions about population and community dynamics. We assessed relative catchability differences among four long-term fish monitoring surveys from the San Francisco Estuary: the Bay Study Otter Trawl (BSOT), the Bay Study Midwater Trawl (BSMT), the Fall Midwater Trawl (FMWT), and the Suisun Marsh Otter Trawl (SMOT). We used generalized additive models with a spatio-temporal smoother and survey as a fixed effect to predict gear-specific estimates of catch for 45 different fish species within large and small size classes. We used estimates of the fixed effect coefficients for each survey (e.g., BSOT) relative to the reference gear (FMWT) to develop relative measures of catchability among taxa, surveys, and fish-size classes, termed the catch-ratio. We found higher relative catchability of 27%, 22%, and 57% of fish species in large size classes from the FMWT than in the BSMT, BSOT, or SMOT, respectively. In the small size class, relative catchability was higher in the FMWT than the BSMT, BSOT, or SMOT for 50%, 18%, and 25% of fish species, respectively. As expected, relative catchability of demersal species was higher in the otter trawls (BSOT, SMOT) while relative catchability of pelagic species was higher in the midwater trawls (FMWT, BSMT). Our results demonstrate that catchability is a source of bias among monitoring efforts within the San Francisco Estuary, and assuming equal catchability among surveys, species, and size classes could result in significant bias when describing spatio-temporal patterns in catch if ignored.

California↗
USGS1946

Relative toxicity of suspension and oil formulations of DDT to native fishes in Back Creek, West Virginia

On July 23, 1947, a 1‐mile section of Back Creek, treated the previous year with a DDT suspension with little damage to fish, was re‐treated with an oil spray at the same rate (1 pound per acre). The oil spray killed about six times as many fish as the suspension formula. Fish began dying within 3 to 4 hours after treatment, whereas several days elapsed before mortality began with the suspension formula in 1946. In addition to larger numbers of the minnow species, some adult game fish were killed. Losses of fish were not as great below the sprayed section as when a suspension formula was used, probably because a good part of the DDT was drifted ashore by breezes or by water currents. Some species of fish such as bluntnose minnows (Hyborhynchus notatus), chub suckers (Erimyzon oblongus), and pickerel (Esox niger), although numerous, were relatively unaffected. Considerable mortality of largemouth bass (Micropterus salmoides) and bluegill sunfish (Lepomis macrochirus) occurred in liveboxes placed in the sprayed section, particularly at the lower stations. Largemouth bass nearly 4 inches long survived at a station where 54.0 percent of the 2‐inch bass were killed. This fact supplied some positive evidence that fish of larger size are better able to withstand DDT.

West Virginia↗
USGS1953

Therapy of bacterial fish diseases

During the past decade considerable progress has been made in the therapy of bacterial fish diseases. This progress was possible largely because of the introduction of powerful chemotherapeutic agents such as sulfonamides and antibiotics. Fish furunculosis can be treated with very good results with sulfamerazine, sulfamethazine, and sulfaguanidine as well as by chloramphenicol and terramycin. Ulcer disease caused by Hemophilus piscium resists treatment with sulfonamides but responds well to the above mentioned antibiotics. Chemotherapy of fish diseases caused by pseudomonads is possible with chloramphenicol, but sanitary measures are preferred. External disinfections with Roccal and pyridylmercuric acetate (PMA) are satisfactory in treatment and prophylaxis of gill diseases which are probably caused by superficial infections with myxobacteria. Sulfonamides are helpful in systemic infections with myxobacteria and are also being used with some success for the control of a recently described kidney disease of salmonold fishes. Also described are methods of control of other fish diseases and of immunity in cold‐blooded animals and fishes. Most of the drugs in the described treatments may be toxic to fishes, and therefore should be used with caution.

Transactions of the American Fisheries Society↗
USGS1968

Some effects of mirex on two warm-water fishes

The effects of mirex on two species of warm-water fishes were studied in three experiments in which the fish were exposed either by feeding a mirex-treated diet, or by treating the holding ponds with a mirex formulation. Bluegills were used in the feeding experiment, where three different levels of mirex were incorporated into the diet and fed to fish held in plastic pools, and in the first pond-exposure experiment, in which the fish were held in earthen ponds treated once with a mirex-corncob grit formulation. The third experiment used goldfish held in earthen ponds which also were treated once with the mirex-corncob grit formulation. In general, higher rates of exposure produced higher whole-body residues of mirex in the fish, and, except in bluegills from the lower-treatment ponds of the first contact experiment and in control fish, whole-body residues increased throughout the terms of these experiments. Soil, water, and vegetation samples from the two contact experiments, although subject to large differences between individual samples, contained relatively unchanging mirex concentrations, illustrating that this chemical is highly resistant to degradation or removal. No mortality or tissue pathology in the bluegills could be ascribed to mirex exposure, but the gills and kidneys of mirex-exposed goldfish showed reactions beginning with the samples taken 56 days after treatment, and the numbers of these fish surviving until termination of this experiment were inversely related to treatment level. Total serum protein and hematocrit percentages had no apparent relationship to treatment levels, nor was mirex exposure a demonstrable factor in growth rates in the contact experiments. However, growth of the bluegills in the highest treatment groups of the feeding experiment was adversely affected. Invertebrate populations seemed not to be affected by the mirex treatment in either of the earthen pond experiments.

Transactions of the American Fisheries Society↗
USGS1986

Does pH affect fish species richness when lake area is considered?

Numerous surveys have shown that fish species richness (number of species) is positively correlated with lake pH. However, species richness of fish communities is also correlated with lake size, and low‐pH lakes are often small. Thus, conclusions drawn from examination of fish community structure relative to spatial (among‐lake) variation in pH have been limited by uncertainties regarding the confounded effects of lake area. We used two statistical methods, analysis of covariance and a nonparametric blocked comparison test, to remove effects of lake area and compare fish species richness in low‐pH and high‐pH lakes. Data from six previous surveys of water chemistry and fish communities in lakes of Ontario and northern Wisconsin were examined. Lakes with low pH (≤6.0) contained significantly fewer fish species than lakes with high pH (>6.0) when the effect of lake area was considered. A simple probabilistic model showed that the ability to detect differences in species richness is low when lake areas and the pool of potential colonizing species are small. We recommend the blocked comparison test for separating the effects of lake area and pH on species richness and urge critical examination of inferences based on analyses of fish communities in small lakes.

Ontario, Wisconsin↗
USGS1996

Establishment of a fish community in the Hayden-Rhodes and Salt-Gila aqueducts, Arizona

Fish populations were studied in the Central Arizona Projectˈs canal system during the first 4 years of aqueduct operation (1986–1989). Ichthyoplankton entering the canal from Lake Havasu averaged 1 larva/m 3 during April–June 1987 and 1988. Larval fish densities increased significantly in downstream samples, substantiating diver observations that fish were spawning in the canal system. Of the 16 fish species collected, 14 were assumed to have originated from Lake Havasu and 2 were introduced by anglers from their bait buckets. Initially, the fish community was dominated numerically by threadfin shad Dorosoma petenense (>88%), centrarchids (< 10%), cyprinids (<2%), and striped bass Morone saxatilis (<I%). However, as annual water diversions increased from 1.3 × 10 8 m 3 in 1986 to 9.4 × 10 8 m 3 in 1989, community composition shifted from clupeids to centrarchids (70%). Fish densities dropped from an estimated 1,260 fish/ha in 1986 to 17 fish/ha in 1989, and biomass dropped from 116 to 73 kg/ha. Declines were attributed to higher operational velocities, associated scour, deprivation, and predation. Although initial populations adjusted downward to planned operational conditions, the fish community continued to represent a potentially valuable, but as yet unused, resource.

Arizona↗
USGS2009

Dietary segregation of pelagic and littoral fish assemblages in a highly modified tidal freshwater estuary

Estuarine food webs are highly variable and complex, making identification of their trophic pathways difficult. Energy for the food web of the San Francisco Estuary is thought to be based largely on in situ phytoplankton production, but little attention has been paid to littoral habitats, where other energy sources may be important. We analyzed the stomach contents of over 960 juvenile fishes and the stable carbon and nitrogen isotope ratios of these fishes and their potential food resources in pelagic and littoral habitats from the tidal freshwater area of the estuary. The mixing model IsoSource was used to examine energy sources important to consumers. Our results show evidence of two predominant food web pathways. Pelagic fishes and some littoral fishes showed strong dependence on a zooplankton–phytoplankton trophic pathway. However, the majority of fishes in littoral habitats had diets and carbon isotope ratios consistent with energy arising from submerged aquatic vegetation and epiphytic macroalgae. IsoSource revealed that the overall majority of nutrition of littoral fishes originated from consumption of grazer amphipods. Examining both stable isotopes and stomach contents allowed us to identify a food web with contributions to resident fishes that had been previously underestimated in the estuary. This study provides insight to how estuarine food webs have changed over the last few decades and highlights why the functions of habitats must be understood for effective restoration planning.

Marine and Coastal Fisheries: Dynamics, Management↗
USGS2011

Variable responses of fish assemblages, habitat, and stability to natural-channel-design restoration in Catskill Mountain streams

Natural-channel-design (NCD) restorations were recently implemented within large segments of five first- and second-order streams in the Catskill Mountains of New York in an attempt to increase channel stability, reduce bed and bank erosion, and sustain water quality. In conjunction with these efforts, 54 fish and habitat surveys were done from 1999 to 2007 at six restored reaches and five stable control reaches to evaluate the effects of NCD restoration on fish assemblages, habitat, and bank stability. A before–after–control–impact study design and two-factor analysis of variance were used to quantify the net changes in habitat and fish population and community indices at treatment reaches relative to those at unaltered control reaches. The density and biomass of fish communities were often dominated by one or two small prey species and no or few predator species before restoration and by one or more trout (Salmonidae) species after restoration. Significant increases in community richness (30%), diversity (40%), species or biomass equitability (32%), and total biomass (up to 52%) in at least four of the six restored reaches demonstrate that NCD restorations can improve the health and sustainability of fish communities in geomorphically unstable Catskill Mountain streams over the short to marginally long term. Bank stability, stream habitat, and trout habitat suitability indices (HSIs) generally improved significantly at the restored reaches, but key habitat features and trout HSIs did not change or decreased at two of them. Fish communities and trout populations at these two reaches were not positively affected by NCD restorations. Though NCD restorations often had a positive effect on habitat and fish communities, our results show that the initial habitat conditions limit the relative improvements than can be achieved, habitat quality and stability do not necessarily respond in unison, and biotic and abiotic responses cannot always be generalized.

New York↗
USGS2011

Application of a multistate model to estimate culvert effects on movement of small fishes

While it is widely acknowledged that culverted road-stream crossings may impede fish passage, effects of culverts on movement of nongame and small-bodied fishes have not been extensively studied and studies generally have not accounted for spatial variation in capture probabilities. We estimated probabilities for upstream and downstream movement of small (30-120 mm standard length) benthic and water column fishes across stream reaches with and without culverts at four road-stream crossings over a 4-6-week period. Movement and reach-specific capture probabilities were estimated using multistate capture-recapture models. Although none of the culverts were complete barriers to passage, only a bottomless-box culvert appeared to permit unrestricted upstream and downstream movements by benthic fishes based on model estimates of movement probabilities. At two box culverts that were perched above the water surface at base flow, observed movements were limited to water column fishes and to intervals when runoff from storm events raised water levels above the perched level. Only a single fish was observed to move through a partially embedded pipe culvert. Estimates for probabilities of movement over distances equal to at least the length of one culvert were low (e.g., generally ???0.03, estimated for 1-2-week intervals) and had wide 95% confidence intervals as a consequence of few observed movements to nonadjacent reaches. Estimates of capture probabilities varied among reaches by a factor of 2 to over 10, illustrating the importance of accounting for spatially variable capture rates when estimating movement probabilities with capture-recapture data. Longer-term studies are needed to evaluate temporal variability in stream fish passage at culverts (e.g., in relation to streamflow variability) and to thereby better quantify the degree of population fragmentation caused by road-stream crossings with culverts. ?? American Fisheries Society 2009.

Transactions of the American Fisheries Society↗
USGS2002

How often do fishes "run on empty"?

We used a large data set of African, Neotropical, and North American fishes to examine the frequency with which fishes have empty stomachs ( n species = 254; n individuals = 36 875). Mean percentage of empty stomachs was low across all fishes (16.2 ± 1.2%) but varied from 0% to 79.4% among individual species. Nocturnal fishes had empty stomachs more frequently than diurnal fishes. Trophic classification was strongly associated with the percentage of empty stomachs, a pattern also revealed from an intraspecific analysis. Fishes appear to adjust their feeding intervals relative to the energy density, conversion efficiency, and particle size of their food. Piscivorous fishes seem to be the only trophic group that regularly experience long periods of empty stomachs, with species that consume prey whole and those that provide extended parental care having the highest proportions of empty stomachs. Activity patterns and life histories of some piscivorous species probably have evolved in partial response to energetic benefits of large, energy-rich food resources.

Ecology↗
USGS2011

Role of the fish astyanax aeneus (Characidae) as a keystone nutrient recycler in low-nutrient neotropical streams

Nutrient recycling by animals is a potentially important biogeochemical process in both terrestrial and aquatic ecosystems. Stoichiometric traits of individual species may result in some taxa playing disproportionately important roles in the recycling of nutrients relative to their biomass, acting as keystone nutrient recyclers. We examined factors controlling the relative contribution of 12 Neotropical fish species to nutrient recycling in four streams spanning a range of phosphorus (P) levels. In high‐P conditions (135 μg/L soluble reactive phosphorus, SRP), most species fed on P‐enriched diets and P excretion rates were high across species. In low‐P conditions (3 μg/L SRP), aquatic food resources were depleted in P, and species with higher body P content showed low rates of P recycling. However, fishes that were subsidized by terrestrial inputs were decoupled from aquatic P availability and therefore excreted P at disproportionately high rates. One of these species, Astyanax aeneus (Characidae), represented 12% of the total population and 18% of the total biomass of the fish assemblage in our focal low‐P study stream but had P excretion rates >10‐fold higher than other abundant fishes. As a result, we estimated that P excretion by A. aeneus accounted for 90% of the P recycled by this fish assemblage and also supplied ∼90% of the stream P demand in this P‐limited ecosystem. Nitrogen excretion rates showed little variation among species, and the contribution of a given species to ecosystem N recycling was largely dependent upon the total biomass of that species. Because of the high variability in P excretion rates among fish species, ecosystem‐level P recycling could be particularly sensitive to changes in fish community structure in P‐limited systems.

Ecology↗
USGS2015

Fish assemblage shifts in the Powder River of Wyoming: an unregulated prairie river system previously considered to be relatively pristine.

W y oming &rsquo; s P owder River is considered an example of a pristine prairie river system. While the river hosts a largely native fish assemblage and remains unimpounded over its 1,146-km course to the Y ellowstone River confluence, the hydrologic regime has been altered through w ater dive rsion for agriculture and natural gas extraction and there has been limited study of fish assemblage structure. W e analyzed fish data collected from the mainstem P owder River in W yoming between 1896 and 2008. Shifts in presence/absence and relative abundance of fish species, as well as fish assemblage composition, were assessed among historical and recent samples. The recent P owder Rive r fish assemblage w as characterized by increased relative abundances of sand shiner Notr opis stramineus and plains killifish Fundulus zebrinus , and decreases in sturgeon chub Macrhybopsis gelida . Shifts in fish species relative abundance are linked to their reproductive ecology with species with adhesive eggs generally increasing in relative abundance while those with buoy ant drifting eggs are decreasing. Assemblage shifts could be the result of landscape level changes, such as the loss of extreme high and low flow events and changing land use practices.

Montana, Wyoming↗