Effects of ocean acidification on salinity tolerance and seawater growth of Atlantic salmon Salmo salar smolts.

Human activity has resulted in increasing atmospheric carbon dioxide (CO ), which will result in reduced pH and higher levels of CO in the ocean, a process known as ocean acidification. Understanding the effects of ocean acidification (OA) on fishes will be important to predicting and mitigating its consequences. Anadromous species such as salmonids may be especially at risk because of their rapid movements between fresh water and seawater, which could minimize their ability to acclimate.

A geostatistical state-space model of animal densities for stream networks.

Population dynamics are often correlated in space and time due to correlations in environmental drivers as well as synchrony induced by individual dispersal. Many statistical analyses of populations ignore potential autocorrelations and assume that survey methods (distance and time between samples) eliminate these correlations, allowing samples to be treated independently. If these assumptions are incorrect, results and therefore inference may be biased and uncertainty underestimated.

Inferring watershed hydraulics and cold-water habitat persistence using multi-year air and stream temperature signals.

Streams strongly influenced by groundwater discharge may serve as "climate refugia" for sensitive species in regions of increasingly marginal thermal conditions. The main goal of this study is to develop paired air and stream water annual temperature signal analysis techniques to elucidate the relative groundwater contribution to stream water and the effective groundwater flowpath depth. Groundwater discharge to streams attenuates surface water temperature signals, and this attenuation can be diagnostic of groundwater gaining systems.

The complete mitochondrial genome of the stalk-forming diatom .

The complete mitogenome of the stalk-forming diatom collected from Mineral County, WV, USA was sequenced on the Ion Torrent PGM and Proton sequencers. The mitogenome is 37,765 bp and encodes 35 protein coding genes, 25 tRNAs, and both large and small subunit ribosomal RNA genes. The 11 gene is split into two domains as observed in , and also lacks the large repeat region found in the mitogenome.

Canopy volume removal from oil and gas development activity in the upper Susquehanna River basin in Pennsylvania and New York (USA): An assessment using lidar data.

Oil and gas development is changing the landscape in many regions of the United States and globally. However, the nature, extent, and magnitude of landscape change and development, and precisely how this development compares to other ongoing land conversion (e.g.

A method to quantify and value floodplain sediment and nutrient retention ecosystem services.

Floodplains provide critical ecosystem services to local and downstream communities by retaining floodwaters, sediments, and nutrients. The dynamic nature of floodplains is such that these areas can both accumulate sediment and nutrients through deposition, and export material downstream through erosion. Therefore, estimating floodplain sediment and nutrient retention should consider the net flux of both depositional and erosive processes.

Linking otolith microchemistry and surface water contamination from natural gas mining.

Unconventional natural gas drilling and the use of hydraulic fracturing technology have expanded rapidly in North America. This expansion has raised concerns of surface water contamination by way of spills and leaks, which may be sporadic, small, and therefore difficult to detect. Here we explore the use of otolith microchemistry as a tool for monitoring surface water contamination from generated waters (GW) of unconventional natural gas drilling.

Shifts in the relationship between mRNA and protein abundance of gill ion-transporters during smolt development and seawater acclimation in Atlantic salmon (Salmo salar).

Smolting Atlantic salmon exhibit a seasonal increase in seawater tolerance that is associated with changes in the abundance of major gill ion-transporter transcripts and proteins. In the present study, we investigate how the transcript and protein abundance of specific ion-transporter isoforms relate to each other during smolt development and seawater acclimation, and how each correlates to seawater tolerance. We show that during smolt development both mRNA and protein abundance of gill Na/K-ATPase α1a subunit (NKAα1a) decreased but the decrease in the mRNA was five-times greater than that of the protein.

Proximate composition, lipid utilization and validation of a non-lethal method to determine lipid content in migrating American shad Alosa sapidissima.

Lipid content forms the most important energy reserve in anadromous fish and can limit survival, migration and reproductive success. A fat meter was evaluated and compared with a traditional extractive method of measuring available lipid for migrating American shad Alosa sapidissima in the Connecticut River, U.S.

Genomic evolution, recombination, and inter-strain diversity of chelonid alphaherpesvirus 5 from Florida and Hawaii green sea turtles with fibropapillomatosis.

Chelonid alphaherpesvirus 5 (ChHV5) is a herpesvirus associated with fibropapillomatosis (FP) in sea turtles worldwide. Single-locus typing has previously shown differentiation between Atlantic and Pacific strains of this virus, with low variation within each geographic clade. However, a lack of multi-locus genomic sequence data hinders understanding of the rate and mechanisms of ChHV5 evolutionary divergence, as well as how these genomic changes may contribute to differences in disease manifestation.

Brook trout distributional response to unconventional oil and gas development: Landscape context matters.

We conducted a large-scale assessment of unconventional oil and gas (UOG) development effects on brook trout (Salvelinus fontinalis) distribution. We compiled 2231 brook trout collection records from the Upper Susquehanna River Watershed, USA. We used boosted regression tree (BRT) analysis to predict occurrence probability at the 1:24,000 stream-segment scale as a function of natural and anthropogenic landscape and climatic attributes.

Water Stress from High-Volume Hydraulic Fracturing Potentially Threatens Aquatic Biodiversity and Ecosystem Services in Arkansas, United States.

Demand for high-volume, short duration water withdrawals could create water stress to aquatic organisms in Fayetteville Shale streams sourced for hydraulic fracturing fluids. We estimated potential water stress using permitted water withdrawal volumes and actual water withdrawals compared to monthly median, low, and high streamflows. Risk for biological stress was considered at 20% of long-term median and 10% of high- and low-flow thresholds.

Reduced Swimming Performance Repeatedly Evolves on Loss of Migration in Landlocked Populations of Alewife.

Whole-organism performance tasks are accomplished by the integration of morphological traits and physiological functions. Understanding how evolutionary change in morphology and physiology influences whole-organism performance will yield insight into the factors that shape its own evolution. We demonstrate that nonmigratory populations of alewife (Alosa pseudoharengus) have evolved reduced swimming performance in parallel, compared with their migratory ancestor.

Reduced thermal tolerance during salinity acclimation in brook trout () can be rescued by prior treatment with cortisol.

The aims of this study were to assess whether thermal tolerance of brook trout () is affected during seawater (SW) acclimation and to investigate the role of cortisol in osmoregulation and thermal tolerance during SW acclimation. Freshwater (FW)-acclimated brook trout at 18°C () were exposed to SW for 16 days, whilst maintaining a FW control. Fish were examined for critical thermal maximum (CT) 0 (before), 2, 5 and 16 days after SW exposure, and sampled at and CT for analysis of plasma cortisol, glucose and Cl, gill Na/K-ATPase (NKA) activity and heat shock protein 70 (HSP70) abundance, and white muscle water content.

Molecular Detection of Avian Influenza Virus from Sediment Samples in Waterfowl Habitats on the Delmarva Peninsula, United States.

Avian influenza viruses (AIV) affect many species of birds including waterfowl and may persist in sediment in aquatic habitats. Sediment samples were collected from two areas representative of prime migration and overwintering waterfowl habitat in Dorchester County, Maryland in the fall and winter of 2013-2014. Samples were screened for the presence of AIV via reverse transcriptase-quantitative PCR targeting the matrix gene.

Microsatellite marker development from next-generation sequencing in the New England cottontail (Sylvilagus transitionalis) and cross-amplification in the eastern cottontail (S. floridanus).

Objective: The New England cottontail (Sylvilagus transitionalis) is a species of high conservation priority in the Northeastern United States, and was a candidate for federal listing under the Endangered Species Act until a recent decision determined that conservation actions were sufficient to preclude listing. The aim of this study was to develop a suite of microsatellite loci to guide future research efforts such as the analysis of population genetic structure, genetic variation, dispersal, and genetic mark-recapture population estimation.

Results: Thirty-five microsatellite markers containing tri- and tetranucleotide sequences were developed from shotgun genomic sequencing of tissue from S.

Upper thermal limits of growth in brook trout and their relationship to stress physiology.

Despite the threat of climate change, the physiological mechanisms responsible for reduced performance at high temperatures remain unclear for most species. Elevated but sublethal temperatures may act via endocrine and cellular stress responses to limit performance in important life-history traits such as growth. Here, brook trout () subjected to chronically elevated or daily oscillating temperatures were monitored for growth and physiological stress responses.

Draft Genome Sequence of a Picorna-Like Virus Associated with Gill Tissue in Clinically Normal Brook Trout, .

Here, we report a draft genome sequence of a picorna-like virus associated with brook trout, , gill tissue. The draft genome comprises 8,681 nucleotides, excluding the poly(A) tract, and contains two open reading frames. It is most similar to picorna-like viruses that infect invertebrates.

Micronuclei and other erythrocyte nuclear abnormalities in fishes from the Great Lakes Basin, USA.

Biological markers (biomarkers) sensitive to genotoxic and mutagenic contamination in fishes are widely used to identify exposure effects in aquatic environments. The micronucleus assay was incorporated into a suite of indicators to assess exposure to genotoxic and mutagenic contamination at five Great Lakes Areas of Concern (AOCs), as well as one non-AOC (reference) site. The assay allowed enumeration of micronuclei as well as other nuclear abnormalities for both site and species comparisons.

A detailed risk assessment of shale gas development on headwater streams in the Pennsylvania portion of the Upper Susquehanna River Basin, U.S.A.

The development of unconventional oil and gas (UOG) involves infrastructure development (well pads, roads and pipelines), well drilling and stimulation (hydraulic fracturing), and production; all of which have the potential to affect stream ecosystems. Here, we developed a fine-scaled (1:24,000) catchment-level disturbance intensity index (DII) that included 17 measures of UOG capturing all steps in the development process (infrastructure, water withdrawals, probabilistic spills) that could affect headwater streams (<200km in upstream catchment) in the Upper Susquehanna River Basin in Pennsylvania, U.S.

Cambrian origin of the CYP27C1-mediated vitamin A-to-A switch, a key mechanism of vertebrate sensory plasticity.

The spectral composition of ambient light varies across both space and time. Many species of jawed vertebrates adapt to this variation by tuning the sensitivity of their photoreceptors via the expression of CYP27C1, an enzyme that converts vitamin A into vitamin A, thereby shifting the ratio of vitamin A-based rhodopsin to red-shifted vitamin A-based porphyropsin in the eye. Here, we show that the sea lamprey (), a jawless vertebrate that diverged from jawed vertebrates during the Cambrian period (approx.

Experimental test of genetic rescue in isolated populations of brook trout.

Genetic rescue is an increasingly considered conservation measure to address genetic erosion associated with habitat loss and fragmentation. The resulting gene flow from facilitating migration may improve fitness and adaptive potential, but is not without risks (e.g.

Highlighting the complexities of a groundwater pilot study during an avian influenza outbreak: Methods, lessons learned, and select contaminant results.

The highly pathogenic avian influenza (H5N2) outbreak in the Midwestern United States (US) in 2015 was historic due to the number of birds and poultry operations impacted and the corresponding economic loss to the poultry industry and was the largest animal health emergency in US history. The U.S.

Widespread occurrence and potential for biodegradation of bioactive contaminants in Congaree National Park, USA.

Organic contaminants with designed molecular bioactivity, such as pesticides and pharmaceuticals, originate from human and agricultural sources, occur frequently in surface waters, and threaten the structure and function of aquatic and terrestrial ecosystems. Congaree National Park in South Carolina (USA) is a vulnerable park unit due to its location downstream of multiple urban and agricultural contaminant sources and its hydrologic setting, being composed almost entirely of floodplain and aquatic environments. Seventy-two water and sediment samples were collected from 16 sites in Congaree National Park during 2013 to 2015, and analyzed for 199 and 81 targeted organic contaminants, respectively.