Geology Reports⌕ Search

SEARCH · Geology Reports

Results for “Canadian Journal of Fisheries and 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 91 records · Page 5Linked to original sources
USGS2016

Interannual and long-term changes in the trophic state of a multibasin lake: Effects of morphology, climate, winter aeration, and beaver activity

Little St. Germain Lake (LSG), a relatively pristine multibasin lake in Wisconsin, USA, was examined to determine how morphologic (internal), climatic (external), anthropogenic (winter aeration), and natural (beaver activity) factors affect the trophic state (phosphorus, P; chlorophyll, CHL; and Secchi depth, SD) of each of its basins. Basins intercepting the main flow and external P sources had highest P and CHL and shallowest SD. Internal loading in shallow, polymictic basins caused P and CHL to increase and SD to decrease as summer progressed. Winter aeration used to eliminate winterkill increased summer internal P loading and decreased water quality, while reductions in upstream beaver impoundments had little effect on water quality. Variations in air temperature and precipitation affected each basin differently. Warmer air temperatures increased productivity throughout the lake and decreased clarity in less eutrophic basins. Increased precipitation increased P in the basins intercepting the main flow but had little effect on the isolated deep West Bay. These relations are used to project effects of future climatic changes on LSG and other temperate lakes.

Wisconsin↗
USGS2016

Prey size and availability limits maximum size of rainbow trout in a large tailwater: insights from a drift-foraging bioenergetics model

The cold and clear water conditions present below many large dams create ideal conditions for the development of economically important salmonid fisheries. Many of these tailwater fisheries have experienced declines in the abundance and condition of large trout species, yet the causes of these declines remain uncertain. Here, we develop, assess, and apply a drift-foraging bioenergetics model to identify the factors limiting rainbow trout (Oncorhynchus mykiss) growth in a large tailwater. We explored the relative importance of temperature, prey quantity, and prey size by constructing scenarios where these variables, both singly and in combination, were altered. Predicted growth matched empirical mass-at-age estimates, particularly for younger ages, demonstrating that the model accurately describes how current temperature and prey conditions interact to determine rainbow trout growth. Modeling scenarios that artificially inflated prey size and abundance demonstrate that rainbow trout growth is limited by the scarcity of large prey items and overall prey availability. For example, shifting 10% of the prey biomass to the 13 mm (large) length class, without increasing overall prey biomass, increased lifetime maximum mass of rainbow trout by 88%. Additionally, warmer temperatures resulted in lower predicted growth at current and lower levels of prey availability; however, growth was similar across all temperatures at higher levels of prey availability. Climate change will likely alter flow and temperature regimes in large rivers with corresponding changes to invertebrate prey resources used by fish. Broader application of drift-foraging bioenergetics models to build a mechanistic understanding of how changes to habitat conditions and prey resources affect growth of salmonids will benefit management of tailwater fisheries.

Arizona↗
USGS2016

Are brown trout replacing or displacing bull trout populations in a changing climate?

Understanding how climate change may facilitate species turnover is an important step in identifying potential conservation strategies. We used data from 33 sites in western Montana to quantify climate associations with native bull trout (Salvelinus confluentus) and non-native brown trout (Salmo trutta) abundance and population growth rates (λ). We estimated λ using exponential growth state space models and delineated study sites based on bull trout use for either Spawning and Rearing (SR) or Foraging, Migrating, and Overwintering (FMO) habitat. Bull trout abundance was negatively associated with mean August stream temperatures within SR habitat (r = -0.75). Brown trout abundance was generally highest at temperatures between 12 and 14°C. We found bull trout λ were generally stable at sites with mean August temperature below 10°C but significantly decreasing, rare, or extirpated at 58% of the sites with temperatures exceeding 10°C. Brown trout λ were highest in SR and sites with temperatures exceeding 12°C. Declining bull trout λs at sites where brown trout were absent suggests brown trout are likely replacing bull trout in a warming climate.

Idaho, Montana↗
USGS2015

Behavioral evidence for a role of chemoreception during reproduction in lake trout

Chemoreception is hypothesized to influence spawning site selection, mate search, and synchronization of gamete release in chars ( Salvelinus spp.), but behavioral evidence is generally lacking. Here, we provide a survey of the behavioral responses of reproductive male and female lake trout ( Salvelinus namaycush ) to natural conspecific chemosensory stimuli. A flow-through laboratory assay with side-by-side artificial spawning reefs was used to evaluate behavioral preferences of spawning-phase males and females for chemosensory stimuli from juveniles and from spawning-phase males and females. Males and females preferred male and juvenile stimuli over no stimuli, but only had weak preferences for female stimuli. Only females had a preference for male over juvenile stimuli when given a direct choice between the two. The unexpected observation of male attraction to male stimuli, even when offered female stimuli, indicates a fundamental difference from the existing models of chemical communication in fishes. We discuss our results from the perspectives of prespawning aggregation, mate evaluation, and spawning synchronization. Identification of specific components of the stimuli will allow confirmation of the function and may have management implications for native and invasive populations of lake trout that are ecologically and economically important.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2016

Principles underlying the epizootiology of viral hemorrhagic septicemia in Pacific herring and other fishes throughout the North Pacific Ocean

Although viral hemorrhagic septicemia virus (VHSV) typically occurs at low prevalence and intensity in natural populations of Pacific herring ( Clupea pallasii ) and other marine fishes in the Northeast Pacific Ocean, epizootics of the resulting disease (VHS) periodically occur, often in association with observed fish kills. Here we identify a list of principles, based on a combination of field studies, controlled laboratory experiments, and previously unpublished observations, that govern the epizootiology of VHS in Pacific herring. A thorough understanding of these principles provides the basis for identifying risk factors that predispose certain marine fish populations to VHS epizootics, including the lack of population resistance, presence of chronic viral carriers in a population, copious viral shedding by infected individuals, cool water temperatures, limited water circulation patterns, and gregarious host behavioral patterns. Further, these principles are used to define the epizootiological stages of the disease in Pacific herring, including the susceptible (where susceptible individuals predominate a school or subpopulation), enzootic (where infection prevalence and intensity are often below the limits of reasonable laboratory detection), disease amplification (where infection prevalence and intensity increase rapidly), outbreak (often accompanied by host mortalities with high virus loads and active shedding), recovery (in which the mortality rate and virus load decline owing to an active host immune response), and refractory stages (characterized by little or no susceptibility and where viral clearance occurs in most VHS survivors). In addition to providing a foundation for quantitatively assessing the potential risks of future VHS epizootics in Pacific herring, these principles provide insights into the epizootiology of VHS in other fish communities where susceptible species exist.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2016

Effects of stream-adjacent logging in fishless headwaters on downstream coastal cutthroat trout

To investigate effects of headwater logging on downstream coastal cutthroat trout ( Oncorhynchus clarkii clarkii ) populations, we monitored stream habitat and biotic indicators including biomass, abundance, growth, movement, and survival over 8 years using a paired-watershed approach. Reference and logged catchments were located on private industrial forestland on ∼60-year harvest rotation. Five clearcuts (14% of the logged catchment area) were adjacent to fishless portions of the headwater streams, and contemporary regulations did not require riparian forest buffers in the treatment catchment. Logging did not have significant negative effects on downstream coastal cutthroat trout populations for the duration of the sample period. Indeed, the only statistically significant response of fish populations following logging in fishless headwaters was an increase in late-summer biomass (g·m −2 ) of age-1+ coastal cutthroat trout in tributaries. Ultimately, the ability to make broad generalizations concerning effects of timber harvest is difficult because response to disturbance (anthropogenically influenced or not) in aquatic systems is complex and context-dependent, but our findings provide one example of environmentally compatible commercial logging in a regenerated forest setting.

Oregon↗
USGS2017

Responses of invasive silver and bighead carp to a carbon dioxide barrier in outdoor ponds

Resource managers need for effective methods to prevent the movement of silver ( Hypophthalmichthys molitrix ) and bighead carp ( H. nobilis ) from the Mississippi River basin into the Laurentian Great Lakes. In this study, we evaluated dissolved carbon dioxide (CO 2 ) as a barrier and deterrent to silver (278 ± 30.5 mm) and bighead (212 ± 7.7 mm) carp movement in continuous-flow outdoor ponds. As a barrier, CO 2 significantly reduced upstream movement but was not 100% effective at blocking fish passage. As a deterrent, we observed a significant shift away from areas of high CO 2 relative to normal movement before and after injection. Carbon dioxide concentrations varied across the pond during injection and reached maximum concentrations of 74.5±1.9 mg/L CO 2 ; 29 532 – 41 393 µatm at the site of injection during three independent trials. We conclude that CO 2 altered silver and bighead carp movement in outdoor ponds and recommend further research to determine barrier effectiveness during field applications.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2017

Hard choices in assessing survival past dams — a comparison of single- and paired-release strategies

Mark–recapture models are widely used to estimate survival of salmon smolts migrating past dams. Paired releases have been used to improve estimate accuracy by removing components of mortality not attributable to the dam. This method is accompanied by reduced precision because ( i ) sample size is reduced relative to a single, large release; and ( ii ) variance calculations inflate error. We modeled an idealized system with a single dam to assess trade-offs between accuracy and precision and compared methods using root mean squared error (RMSE). Simulations were run under predefined conditions (dam mortality, background mortality, detection probability, and sample size) to determine scenarios when the paired release was preferable to a single release. We demonstrate that a paired-release design provides a theoretical advantage over a single-release design only at large sample sizes and high probabilities of detection. At release numbers typical of many survival studies, paired release can result in overestimation of dam survival. Failures to meet model assumptions of a paired release may result in further overestimation of dam-related survival. Under most conditions, a single-release strategy was preferable.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2016

Sea lamprey carcasses exert local and variable food web effects in a nutrient-limited Atlantic coastal stream

Resource flows from adjacent ecosystems are critical in maintaining structure and function of freshwater food webs. Migrating sea lamprey ( Petromyzon marinus ) deliver a pulsed marine-derived nutrient subsidy to rivers in spring when the metabolic demand of producers and consumers are increasing. However, the spatial and temporal dynamics of these nutrient subsidies are not well characterized. We used sea lamprey carcass additions in a small stream to examine changes in nutrients, primary productivity, and nutrient assimilation among consumers. Algal biomass increased 57%–71% immediately adjacent to carcasses; however, broader spatial changes from multiple-site carcass addition may have been influenced by canopy cover. We detected assimilation of nutrients (via δ 13 C and δ 15 N) among several macroinvertebrate families including Heptageniidae, Hydropsychidae, and Perlidae. Our research suggests that subsidies may evoke localized patch-scale effects on food webs, and the pathways of assimilation in streams are likely coupled to adjacent terrestrial systems. This research underscores the importance of connectivity in streams, which may influence sea lamprey spawning and elicit varying food web responses from carcass subsidies due to fine-scale habitat variables.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2016

Reply to comments by Riley and Dunlop on He et al. (2015)

He et al. (2015) described piscivory patterns in the main basin of Lake Huron 1984-2010, during which there was also a pattern of stepwise declines in the abundance of dominant prey fish species. The approach of He et al. (2015) was to couple age-structured stock assessment and fish bioenergetics models to estimate prey fish consumption, and to compare these patterns with prey fish biomass from a bottom trawl survey. Riley and Dunlop (2015) were highly critical of the methods and conclusions reached by He et al. (2015). They claimed that we incorrectly interpreted the bottom trawl survey data, and did not account for uncertainty. We respond to these and other criticisms below, which we find do not undermine our findings.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2017

Testing for synchrony in recruitment among four Lake Michigan fish species

In the Great Lakes region, multiple fish species display intra-specific spatial synchrony in 28 recruitment success, with inter-annual climate variation hypothesized as the most likely driver. 29 In Lake Michigan, we evaluated whether climatic or other physical variables could also induce 30 spatial synchrony across multiple species, including bloater ( Coregonus hoyi ), rainbow smelt 31 ( Osmerus mordax ), yellow perch ( Perca flavescens ), and alewife ( Alosa pseudoharengus ). The 32 residuals from stock-recruitment relationships revealed yellow perch recruitment to be correlated 33 with recruitment of both rainbow smelt (r = 0.37) and alewife (r = 0.36). Across all four species, 34 higher than expected recruitment occurred in 5 years between 1978 and 1987 and then switched 35 to lower than expected recruitment in 5 years between 1996 and 2004. Generalized additive 36 models revealed warmer spring and summer water temperatures and lower wind speeds 37 corresponded to higher than expected recruitment for the nearshore-spawning species, and 38 overall variance explained ranged from 14% (yellow perch) to 61% (alewife). For all species 39 but rainbow smelt, higher recruitment also occurred in extremely high or low years of the North 40 Atlantic Oscillation index. Future development of indices that describe the physical Great Lakes 41 environment could improve understanding of how climate can synchronize fish populations 42 within and across species.

Great Lakes↗
USGS2016

Invasive European bird cherry disrupts stream-riparian linkages: effects on terrestrial invertebrate prey subsidies for juvenile coho salmon

The spread of invasive species in riparian forests has the potential to affect both terrestrial and aquatic organisms linked through cross-ecosystem resource subsidies. However, this potential had not been explored in regards to terrestrial prey subsidies for stream fishes. To address this, we examined the effects of an invasive riparian tree, European bird cherry (EBC, Prunus padus ), spreading along urban Alaskan salmon streams, by collecting terrestrial invertebrates present on the foliage of riparian trees, their subsidies to streams, and their consumption by juvenile coho salmon ( Oncorhynchus kisutch ). Riparian EBC supported four to six times less terrestrial invertebrate biomass on its foliage and contributed two to three times lower subsidies relative to native deciduous trees. This reduction in terrestrial invertebrate biomass was consistent between two watersheds over 2 years. In spite of this reduction in terrestrial prey resource input, juvenile coho salmon consumed similar levels of terrestrial invertebrates in stream reaches bordered by EBC. Although we did not see ecological effects extending to stream salmonids, reduced terrestrial prey subsidies to streams are likely to have negative consequences as EBC continues to spread.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2016

Trophic pathways supporting juvenile Chinook and Coho salmon in the glacial Susitna River, Alaska: patterns of freshwater, marine, and terrestrial resource use across a seasonally dynamic habitat mosaic

Contributions of terrestrial-, freshwater-, and marine-derived prey resources to stream fishes vary over time and space, altering the energy pathways that regulate production. In this study, we determined large-scale use of these resources by juvenile Chinook and coho salmon ( Oncorhynchus tshawytscha and Oncorhynchus kisutch , respectively) in the glacial Susitna River, Alaska. We resolved spatial and temporal trophic patterns among multiple macrohabitat types along a 97 km segment of the river corridor via stable isotope and stomach content analyses. Juvenile salmon were supported primarily by freshwater-derived resources and secondarily by marine and terrestrial sources. The relative contribution of marine-derived prey to rearing salmon was greatest in the fall within off-channel macrohabitats, whereas the contributions of terrestrial invertebrate prey were generally greatest during midsummer, across all macrohabitats. No longitudinal (upstream–downstream) diet pattern was discernable. These results highlight large-scale spatial and seasonal patterns of energy flow and the dynamic interplay of pulsed marine and terrestrial prey subsidies to juvenile Chinook and coho salmon in a large, complex, and relatively pristine glacial river.

Alaska↗
USGS2016

Development and assessment of a new method for combining catch per unit effort data from different fish sampling gears: Multigear mean standardization (MGMS)

Fish community assessments are often based on sampling with multiple gear types. However, multivariate methods used to assess fish community structure and composition are sensitive to differences in the relative scale of indices or measures of abundance produced by different sampling methods. This makes combining data from different sampling gears and methods a serious challenge. We developed a method of combining catch per unit effort data that standardizes catch per unit effort data across gear types, which we call multigear mean standardization (MGMS). We evaluated how well MGMS and other types of standardization reflect underlying community structure through a computer simulation that generated model riverine-fish communities and simulated sampling data for two gears. In these simulations, combining sampling observations from two gears with MGMS produced community structure estimates that were highly correlated with true community structure under a variety of conditions that are common in large rivers. Our simulation results indicate that the use of MGMS to combine data from different sampling gears is an effective data manipulation method for the analysis of fish community structure.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2017

Measuring fish and their physical habitats: Versatile 2D and 3D video techniques with user-friendly software

Applications of video in fisheries research range from simple biodiversity surveys to three-dimensional (3D) measurement of complex swimming, schooling, feeding, and territorial behaviors. However, researchers lack a transparently developed, easy-to-use, general purpose tool for 3D video measurement and event logging. Thus, we developed a new measurement system, with freely available, user-friendly software, easily obtained hardware, and flexible underlying mathematical methods capable of high precision and accuracy. The software, VidSync, allows users to efficiently record, organize, and navigate complex 2D or 3D measurements of fish and their physical habitats. Laboratory tests showed submillimetre accuracy in length measurements of 50.8 mm targets at close range, with increasing errors (mostly <1%) at longer range and for longer targets. A field test on juvenile Chinook salmon ( Oncorhynchus tshawytscha ) feeding behavior in Alaska streams found that individuals within aggregations avoided the immediate proximity of their competitors, out to a distance of 1.0 to 2.9 body lengths. This system makes 3D video measurement a practical tool for laboratory and field studies of aquatic or terrestrial animal behavior and ecology.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2016

Using thermal limits to assess establishment of fish dispersing to high-latitude and high-elevation watersheds

Distributional shifts of biota to higher latitudes and elevations are presumably influenced by species-specific physiological tolerances related to warming temperatures. However, it is establishment rather than dispersal that may be limiting colonizations in these cold frontier areas. In freshwater ecosystems, perennial groundwater springs provide critical winter thermal refugia in these extreme environments. By reconciling the thermal characteristics of these refugia with the minimum thermal tolerances of life stages critical for establishment, we develop a strategy to focus broad projections of northward and upward range shifts to the specific habitats that are likely for establishments. We evaluate this strategy using chum salmon ( Oncorhynchus keta ) and pink salmon ( Oncorhynchus gorbuscha ) that seem poised to colonize Arctic watersheds. Stream habitats with a minimum temperature of 4 °C during spawning and temperatures above 2 °C during egg incubation were most vulnerable to establishments by chum and pink salmon. This strategy will improve modelling forecasts of range shifts for cold freshwater habitats and focus proactive efforts to conserve both newly emerging fisheries and native species at northern and upper distributional extremes.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2017

Incorporating temporal heterogeneity in environmental conditions into a somatic growth model

Evaluating environmental effects on fish growth can be challenging because environmental conditions may vary at relatively fine temporal scales compared to sampling occasions. Here we develop a Bayesian state-space growth model to evaluate effects of monthly environmental data on growth of fish that are observed less frequently (e.g., from mark-recapture data where time between captures can range from months to years). We assess effects of temperature, turbidity duration, food availability, flow variability, and trout abundance on subadult humpback chub (Gila cypha) growth in two rivers, the Colorado River (CR) and the Little Colorado River (LCR), and we use out-of-sample prediction to rank competing models. Environmental covariates explained a high proportion of the variation in growth in both rivers; however, the best growth models were river-specific and included either positive temperature and turbidity duration effects (CR) or positive temperature and food availability effects (LCR). Our approach to analyzing environmental controls on growth should be applicable in other systems where environmental data vary over relatively short time scales compared to animal observations.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2017

Migratory behavior of adult sea lamprey and cumulative passage performance through four fishways

This article describes a study of PIT-tagged sea lamprey ( Petromyzon marinus ) ascending four fishways comprising three designs at two dams on the Connecticut River, USA. Migration between dams was rapid (median migration rate = 23 km·day −1 ). Movement through the fishways was much slower, however (median = 0.02–0.33 km·day −1 ). Overall delay at dams was substantial (median = 13.6–14.6 days); many fish failed to pass (percent passage ranged from 29% to 55%, depending on fishway), and repeated passage attempts compounded delay for both passers and failers. Cox regression revealed that fishway entry rates were influenced by flow, temperature, and diel cycle, with most lampreys entering at night and at elevated flows, but with no apparent effect of sex or length. Overall delay was influenced by slow movement through the fishways, but repeated failures were the primary factor determining delay. These data suggest that although some lamprey were able to pass fishways, they did so with difficulty, and delays incurred as they attempted to pass may act to limit their distribution within their native range.

Canadian Journal of Fisheries and Aquatic Sciences↗