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

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At least 631 records · Page 35Linked to original sources
USGS2000

Using linear models with correlated errors to analyze changes in abundance of Lake Michigan fishes: 1973-1992

We examined annual changes in relative abundance of Lake Michigan fishes using linear models with correlated errors in space and time. Abundance of bloater ( Coregonus hoyi ), deepwater sculpin ( Myoxocephalus thompsoni ), slimy sculpin ( Cottus cognatus ), alewife ( Alosa pseudoharengus ), and rainbow smelt ( Osmerus mordax ) was monitored with bottom trawls at 10 discrete depths (between 18 and 110 m) off eight fixed ports from 1973 to 1992. The model describing abundance included fixed effects of year, port, depth, and interaction terms as well as quadratic and cubic effects of year and depth because changes in abundance were not strictly linear. Observed temporal trends in abundance varied with species and depth. Additionally, trends in alewife and slimy sculpin abundances depended on port. Cubic trends in the abundance of bloater and quadratic trends in deepwater sculpin and rainbow smelt abundances were similar among ports, permitting lakewide inferences for these species. Mean bloater abundance was low throughout the 1970s, increased during the 1980s, and reached high levels by 1990. Mean abundances of deepwater sculpin and rainbow smelt increased from 1973 to the mid-1980s and declined thereafter. The linear model with correlated errors can be readily applied to repeated-measures data from other fixed-station fishery surveys and is appropriate for data exhibiting spatial and temporal autocorrelations.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2023

Riparian vegetation response amid variable climate conditions across the Upper Gila River watershed: Informing Tribal restoration priorities

Riparian systems across the Southwest United States are extremely valuable for the human and ecological communities that engage with them. However, they have experienced substantial changes and stresses over the past century, including non-native vegetation expansion, vegetation die-offs, and increased fire activity. Vegetation management approaches, such as ecological restoration, may address some of these stressors as well as reduce the risk of future impacts. We apply remote sensing to inform restoration priorities along the upper Gila River within the San Carlos Apache Reservation and Upper Gila River watershed. First, we develop a spatially and temporally explicit trend analysis across three observed climate periods (1985–1993, 1993–2014, 2014–2021) using the Landsat-derived indices to quantify changes in riparian vegetation conditions. These maps can be used to identify areas potentially more at risk for degradation. Second, we analyze changes in riparian vegetation within a climate framework to better understand trends and the potential effect of climate change. Vegetation greenness has largely increased throughout the watershed despite intensifying drought conditions across our study period, though areas within the lower watershed have shown increased stress and higher rates of wildfire and other disturbances over the past 5-years. Nevertheless, small-scale restoration activities appear to show improving vegetation conditions, suggesting efficacy of these restoration activities. Results from this study may be integrated with restoration objectives to develop a restoration plan that will help riparian vegetation communities adapt to change.

Arizona↗
USGS2020

Changing suspended sediment in United States rivers and streams: Linking sediment trends to changes in land use/cover, hydrology and climate

Sediment is one of the leading pollutants in rivers and streams across the United States (US) and the world. Between 1992 and 2012, concentrations of annual mean suspended sediment decreased at over half of the 137 stream sites assessed across the contiguous US. Increases occurred at less than 25 % of the sites, and the direction of change was uncertain at the remaining 25 %. Sediment trends were characterized using the Weighted Regressions on Time, Discharge, and Season (WRTDS) model, and decreases in sediment ranged from −95 % to −8.5 % of the 1992 concentration. To explore potential drivers of these changes, the sediment trends were (1) parsed into two broad contributors of change, changes in land management versus changes in the streamflow regime, and (2) grouped by land use of the watershed and correlated to concurrent changes in land use or land cover (land use/cover), hydrology and climate variables and static/long-term watershed characteristics. At 83 % of the sites, changes in land management (captured by changes in the concentration–streamflow relationship over time; C–Q relationship) contributed more to the change in the sediment trend than changes in the streamflow regime alone (i.e., any systematic change in the magnitude, frequency or timing of flows). However, at >50 % of the sites, changes in the streamflow regime contributed at least a 5 % change in sediment, and at 11 sites changes in the streamflow regime contributed over half the change in sediment, indicating that at many sites changes in streamflow were not the main driver of changes in sediment but were often an important supporting factor. Correlations between sediment trends and concurrent changes in land use/cover, hydrology and climate were often stronger at sites draining watersheds with more homogenous, human-related land uses (i.e., agricultural and urban lands) compared to mixed-use or undeveloped lands. At many sites, decreases in sediment occurred despite small-to-moderate increases in the amount of urban or agricultural land in the watershed, suggesting conservation efforts and best-management practices (BMPs) used to reduce sediment runoff to streams may be successful, up to a point, as lands are converted to urban and agricultural uses.

Hydrology and Earth System Sciences↗
USGS2019

Decline of the North American avifauna

Species extinctions have defined the global biodiversity crisis, but extinction begins with loss in abundance of organisms that can result in extreme compositional and functional changes of ecosystems. Using multiple and independent monitoring networks, we report major population losses across much of the North American avifauna, including in once common species and from nearly every biome. Integration of trend and population size estimates indicates a net loss approaching three billion birds, or 29% of 1970 abundance. Continent-wide weather radar also reveals a comparable decline in biomass passage of migrating birds over a recent 10-year period. Our estimates of abundance and biodiversity loss signals an urgent need to address ongoing threats, in order to avert future avifaunal collapse and associated loss of ecosystem integrity and function.

Science↗
USGS1993

Cycling of sulfur in subduction zones: The geochemistry of sulfur in the Mariana Island Arc and back-arc trough

The sulfur contents and sulfur isotopic compositions of 24 glassy submarine volcanics from the Mariana Island Arc and back-arc Mariana Trough were determined in order to investigate the hypothesis that subducted seawater sulfur (δ 34 S= 21‰) is recycled through arc volcanism. Our results for sulfur are similar to those for subaerial arc volcanics: Mariana Arc glasses are enriched in 34 S (δ 34 S=up to10.3‰,mean= 3.8‰) and depleted in S (20–290 ppm, mean = 100 ppm) relative to MORB (850 ppm S,δ 34 S= 0.1 ± 0.5‰). The back-arc trough basalts contain 200–930 ppm S and haveδ 34 S values of1.1 ± 0.5‰, which overlap those for the arc and MORB. The low sulfur contents of the arc and some of the trough glasses are attributed to (1) early loss of small amounts of sulfur through separation of immiscible sulfide and (2) later vapor-melt equilibrium control of sulfur contents and loss of sulfur in a vapor phase from sulfide-undersaturated melts near the minimum in sulfur solubility atƒO 2 ≈NNO (nickel-nickel oxide). Although these processes removed sulfur from the melts their effects on the sulfur isotopic compositions of the melts were minimal. Positive trends ofδ 34 S with 87 Sr/ 86 Sr, LILE and LREE contents of the arc volcanics are consistent with a metasomatic seawater sulfur component in the depleted sub-arc mantle source. The lack of a 34 S-rich slab signature in the trough lavas may be attributed to equilibration of metasomatic fluid with mantle material along the longer pathway from the slab to the source of the trough volcanics. Sulfur is likely to have been transported into the mantle wedge by metasomatic fluid derived from subducted sediments and pore fluids.

Earth and Planetary Science Letters↗
USGS2018

Toxicity assessment of groundwater contaminated by petroleum hydrocarbons at a well-characterized, aged, crude oil release site

Management of petroleum-impacted waters by monitored natural attenuation requires an understanding of the toxicology of both the original compounds released and the transformation products formed during natural breakdown. Here, we report data from a groundwater plume consisting of a mixture of crude oil compounds and transformation products in an effort to bridge the gap between groundwater quality information and potential biological effects of human exposures. Groundwater samples were characterized for redox processes, concentrations of nonvolatile dissolved organic carbon (NVDOC) and total petroleum hydrocarbons in the diesel range, as well as for activation of human nuclear receptors (hNR) and toxicologically relevant transcriptional pathways. Results show upregulation of several biological pathways, including peroxisome proliferator-activated receptor gamma and alpha, estrogen receptor alpha, and pregnane X receptor (PXR) with higher levels of hNR activity observed in more contaminated samples. Our study of affected groundwater contaminated by a crude-oil release 39 years ago shows these types of waters may have the potential to cause adverse impacts on development, endocrine, and liver functioning in exposed populations. Additionally, positive trends in activation of some of the molecular targets (e.g., PXR) with increasing NVDOC concentrations (including polar transformation products) demonstrate the importance of improving our understanding of the toxicity associated with the unknown transformation products present in hydrocarbon-impacted waters. Our results begin to provide insight into the potential toxicity of petroleum-impacted waters, which is particularly timely given the ubiquitous nature of waters impacted by petroleum contamination not only recently but also in the past and the need to protect drinking-water quality.

Environmental Science & Technology↗
USGS2011

Quantifying differences in the impact of variable chemistry on equilibrium uranium(VI) adsorption properties of aquifer sediments

Uranium adsorption-desorption on sediment samples collected from the Hanford 300-Area, Richland, WA varied extensively over a range of field-relevant chemical conditions, complicating assessment of possible differences in equilibrium adsorption properties. Adsorption equilibrium was achieved in 500-1000 h although dissolved uranium concentrations increased over thousands of hours owing to changes in aqueous chemical composition driven by sediment-water reactions. A nonelectrostatic surface complexation reaction, >SOH + UO 2 2+ + 2CO 3 2- = >SOUO 2 (CO 3 HCO 3 ) 2- , provided the best fit to experimental data for each sediment sample resulting in a range of conditional equilibrium constants (log K c ) from 21.49 to 21.76. Potential differences in uranium adsorption properties could be assessed in plots based on the generalized mass-action expressions yielding linear trends displaced vertically by differences in log K c values. Using this approach, log K c values for seven sediment samples were not significantly different. However, a significant difference in adsorption properties between one sediment sample and the fines (<0.063 mm) of another could be demonstrated despite the fines requiring a different reaction stoichiometry. Estimates of log K c uncertainty were improved by capturing all data points within experimental errors. The mass-action expression plots demonstrate that applying models outside the range of conditions used in model calibration greatly increases potential errors.

Washington↗
USGS2022

Aquatic vegetation dynamics in the Upper Mississippi River over 2 decades spanning vegetation recovery

Macrophytes have recovered in rivers across the world, but long-term data and studies are lacking regarding community assembly and diversity changes coincident with macrophyte recovery. We investigated patterns of aquatic vegetation species composition and diversity in thousands of sites in the Upper Mississippi River, USA, spanning 21 y of monitoring and a period of vegetation recovery. We analyzed site-level compositional dissimilarity and environmental associations using non-metric multidimensional scaling, compared stability of lake-level assemblages over time with convex hulls, and assessed shared trends in assemblage dissimilarity at the pool scale using dynamic factor analysis. Site-level differences in aquatic vegetation assemblage structure were associated with water depth and substrate, and a gradient of species abundance and diversity was apparent. A common trend in assemblage dissimilarity over time and across contiguous floodplain lakes indicate that assemblage composition changed and diversity increased with considerable synchrony within the past 21 y. Shared trends across the 400-km study reach are indicative of 1 or more widespread, common drivers; however, neither hydrologic extremes nor turbidity explained vegetation assemblage patterns. Following several years of strong changes in composition and increased diversity, the vegetation assemblage displayed signs of increasing stability in some pools but not others. Further research is needed to identify drivers and mechanisms of aquatic vegetation assemblage expansion, assembly, and resilience, all of which will be applicable to the recovery of aquatic vegetation in floodplain systems worldwide.

Illinois, Iowa, Minnesota, Wisconsin↗
USGS2024

Range-wide genetic analysis of an endangered bumble bee (Bombus affinis, Hymenoptera: Apidae) reveals population structure, isolation by distance, and low colony abundance

Declines in bumble bee species range and abundances are documented across multiple continents and have prompted the need for research to aid species recovery and conservation. The rusty patched bumble bee ( Bombus affinis ) is the first federally listed bumble bee species in North America. We conducted a range-wide population genetics study of B. affinis from across all extant conservation units to inform conservation efforts. To understand the species’ vulnerability and help establish recovery targets, we examined population structure, patterns of genetic diversity, and population differentiation. Additionally, we conducted a site-level analysis of colony abundance to inform prioritizing areas for conservation, translocation, and other recovery actions. We find substantial evidence of population structuring along an east-to-west gradient. Putative populations show evidence of isolation by distance, high inbreeding coefficients, and a range-wide male diploidy rate of ~15%. Our results suggest the Appalachians represent a genetically distinct cluster with high levels of private alleles and substantial differentiation from the rest of the extant range. Site-level analyses suggest low colony abundance estimates for B. affinis compared to similar datasets of stable, co-occurring species. These results lend genetic support to trends from observational studies, suggesting that B. affinis has undergone a recent decline and exhibit substantial spatial structure. The low colony abundances observed here suggest caution in overinterpreting the stability of populations even where B. affinis is reliably detected interannually. These results help delineate informed management units, provide context for the potential risks of translocation programs, and help set clear recovery targets for this and other threatened bumble bee species.

Iowa, Illinois, Indiana, Kentucky, Michigan, Minne↗
USGS2023

Using geospatial analysis to guide marsh restoration in Chesapeake Bay and beyond

Coastal managers are facing imminent decisions regarding the fate of coastal wetlands, given ongoing threats to their persistence. There is a need for objective methods to identify which wetland parcels are candidates for restoration, monitoring, protection, or acquisition due to limited resources and restoration techniques. Here, we describe a new spatially comprehensive data set for Chesapeake Bay salt marshes, which includes the unvegetated-vegetated marsh ratio, elevation metrics, and sediment-based lifespan. Spatial aggregation across regions of the Bay shows a trend of increasing deterioration with proximity to the seaward boundary, coherent with conceptual models of coastal landscape response to sea-level rise. On a smaller scale, the signature of deterioration is highly variable within subsections of the Bay: fringing, peninsular, and tidal river marsh complexes each exhibit different spatial patterns with regards to proximity to the seaward edge. We then demonstrate objective methods to use these data for mapping potential management options on to the landscape, and then provide methods to estimate lifespan and potential changes in lifespan in response to restoration actions as well as future sea level rise. We account for actions that aim to increase sediment inventories, revegetate barren areas, restore hydrology, and facilitate salt marsh migration into upland areas. The distillation of robust geospatial data into simple decision-making metrics, as well as the use of those metrics to map decisions on the landscape, represents an important step towards science-based coastal management.

Chesapeake Bay area↗
USGS2016

Global trends in satellite-based emergency mapping

Over the past 15 years, scientists and disaster responders have increasingly used satellite-based Earth observations for global rapid assessment of disaster situations. We review global trends in satellite rapid response and emergency mapping from 2000 to 2014, analyzing more than 1000 incidents in which satellite monitoring was used for assessing major disaster situations. We provide a synthesis of spatial patterns and temporal trends in global satellite emergency mapping efforts and show that satellite-based emergency mapping is most intensively deployed in Asia and Europe and follows well the geographic, physical, and temporal distributions of global natural disasters. We present an outlook on the future use of Earth observation technology for disaster response and mitigation by putting past and current developments into context and perspective.

Science↗
USGS2010

Trends and transformation of nutrients and pesticides in a Coastal Plain aquifer system, United States

Four local-scale sites in areas with similar corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] agriculture were studied to determine the effects of different hydrogeologic settings of the Northern Atlantic Coastal Plain (NACP) on the transport of nutrients and pesticides in groundwater. Settings ranged from predominantly well-drained soils overlying thick, sandy surficial aquifers to predominantly poorly drained soils with complex aquifer stratigraphy and high organic matter content. Apparent age of groundwater, dissolved gases, N isotopes, major ions, selected pesticides and degradates, and geochemical environments in groundwater were studied. Agricultural chemicals were the source of most dissolved ions in groundwater. Specific conductance was strongly correlated with reconstructed nitrate (the sum of N in nitrate and N gas) (R 2 = 0.81, p < 0.0001), and is indicative of the relative degree of agricultural effects on groundwater. Trends in nitrate were primarily related to changes in manure and fertilizer use at the well-drained sites where aquifer conditions were consistently oxic. Nitrate was present in young groundwater but completely removed over time through denitrification at the poorly drained sites where there were variations in chemical input and in geochemical environment. Median concentrations of atrazine (6-chloro-N-ethyl-N'-(1- methylethyl)-1,3,5-triazine-2,4-diamine), metolachlor (2-chloro-N-(2-ethyl-6- methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide), and some of their common degradates were higher at well-drained sites than at poorly drained sites, with concentrations of degradates generally higher than those of the parent compounds at all sites. An increase in the percentage of deethylatrazine to total atrazine over time at one well-drained site may be related to changes in manure application. Copyright ?? 2010 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

Journal of Environmental Quality↗
USGS1990

Magnetic and bathymetric data from R/V FARNELLA cruises FRNL87-1, 87-2, 87-3, 87-4 and 87-5 in the U.S. Atlantic Margin EEZ, southern Blake Escarpment, and Nova Scotia continental rise

During the winter and spring of 1987, the U.S. Geological Survey, in cooperation with the Institute of Oceanographic Sciences of the United Kingdom, collected approximately 31,350 line kilometers (km) of magnetic data and approximately 32,280 line km of bathymetric data in the U.S. Atlantic Margin Exclusive Economic Zone (EEZ), Southern Blake Escarpment, and Nova Scotia Rise (Fig. 1). Collected simultaneously with the magnetic and bathymetric data was a suite of geophysical data. These geophysical datasets will be released at a later date and include GLORIA (Geological LOng-Range Inclined Asdic) sidescan-sonar digital image data, 3.5 kilohertz (kHz) high-resolution sub-bottom profiler records, 10 kHz bottom profiler records from which bathymetric data were derived, and two channel seismic-reflection profiles. Survey line spacing was about 25 km in water depths exceeding 3,000 meters (m) and gradually decreased to less than 5 km in 200 m water depths. No areas were surveyed with depths shallower than 200 m. Orientation of the tracklines varies with respect to the trend of the bathymetric contours for each of the five legs (Fig.l).

Open-File Report↗
USGS2016

Trace elements at the intersection of marine biological and geochemical evolution

Life requires a wide variety of bioessential trace elements to act as structural components and reactive centers in metalloenzymes. These requirements differ between organisms and have evolved over geological time, likely guided in some part by environmental conditions. Until recently, most of what was understood regarding trace element concentrations in the Precambrian oceans was inferred by extrapolation, geochemical modeling, and/or genomic studies. However, in the past decade, the increasing availability of trace element and isotopic data for sedimentary rocks of all ages has yielded new, and potentially more direct, insights into secular changes in seawater composition – and ultimately the evolution of the marine biosphere. Compiled records of many bioessential trace elements (including Ni, Mo, P, Zn, Co, Cr, Se, and I) provide new insight into how trace element abundance in Earth's ancient oceans may have been linked to biological evolution. Several of these trace elements display redox-sensitive behavior, while others are redox-sensitive but not bioessential (e.g., Cr, U). Their temporal trends in sedimentary archives provide useful constraints on changes in atmosphere-ocean redox conditions that are linked to biological evolution, for example, the activity of oxygen-producing, photosynthetic cyanobacteria. In this review, we summarize available Precambrian trace element proxy data, and discuss how temporal trends in the seawater concentrations of specific trace elements may be linked to the evolution of both simple and complex life. We also examine several biologically relevant and/or redox-sensitive trace elements that have yet to be fully examined in the sedimentary rock record (e.g., Cu, Cd, W) and suggest several directions for future studies.

Earth-Science Reviews↗
USGS2010

Growth, condition factor, and bioenergetics modeling link warmer stream temperatures below a small dam to reduced performance of juvenile steelhead

We investigated the growth and feeding performance of juvenile steelhead Oncorhynchus mykiss using field measures and bioenergetics modeling. Juvenile steelhead populations were sampled from mid-June through August 2004 at study sites upstream and downstream of Hemlock Dam. The growth and diet of juvenile steelhead were determined for a warm (summer) and subsequent (late summer) transitional period at each study site. Empirical data on the growth and diet of juvenile steelhead and mean daily temperatures were used in a bioenergetics model to estimate the proportion of maximum consumption achieved by juvenile steelhead by site and period. Modeled estimates of feeding performance were better for juvenile steelhead at the upstream compared to the downstream site during both periods. The median condition factor of juvenile steelhead did not change over the summer at the upstream site, but showed a significant decline over time at the downstream site. A negative trend in median condition factor at the downstream site supported bioenergetics modeling results that suggested the warmer stream temperatures had a negative impact on juvenile steelhead. Bioenergetics modeling predicted a lower feeding performance for juvenile steelhead rearing downstream compared to upstream of Hemlock Dam although food availability appeared to be limited at both study sites during the warm period. Warmer water temperatures, greater diel variation, and change in diel pattern likely led to the reduced feeding performance and reduced growth, which could have affected the overall survival of juvenile steelhead downstream of Hemlock Dam. ?? 2010 by the Northwest Scientific Association.

Northwest Science↗
USGS2021

Characterizing downstream migration timing of American Eels using commercial catch data in the Penobscot and Delaware rivers

Adult “silver-phase” American Eels Anguilla rostrata were a focus of commercial fisheries in the 1970s and 1980s, but stocks have been depleted due to many anthropogenic factors. One significant source of mortality occurs during the downstream migration of eels when passing through turbines at hydroelectric facilities. We sought to construct a model to predict eel migration timing to inform optimization of mitigation actions that might reduce mortality. We utilized commercial catch collected from 16 tributaries in the Penobscot River watershed, Maine (2–10 years), and the Delaware River, New York (31 years). A Bayesian hierarchical approach was used to model the relationship between the timing of silver eel capture and environmental conditions that are known to be related to their movements (i.e., river discharge, water temperature, and lunar cycle). Among river systems, daily catch was associated with higher-than-average flows, temperatures of 7–22°C, and new lunar phase cycles. A cross-validation approach to evaluate the ability of the models to make predictions for new data demonstrated a greater ability (higher R 2 values) to predict weekly eel catch (0.01–0.92) compared to daily eel catch (0.00–0.42). In addition, we examined the model’s ability to forecast migration events by applying posterior simulations to make predictions of eel catch by ordinal date. Predicted daily eel catch generally followed the trend of observed daily catch and was stronger for the Delaware River ( R 2 = 0.67) than for Souadabscook Stream, Maine ( R 2 = 0.07). Sharp pulses in observed catch were not reflected by the predicted catch. Additionally, variability observed among rivers suggests that site-specific modeling may be advantageous (and necessary) to capture local conditions, thereby improving predictive power. More broadly, our work highlights a novel use of fishery-dependent data in a Bayesian modeling framework to predict intervals of risk for migrating fish.

Maine, New York↗
USGS1989

High velocity anomaly beneath the Deccan volcanic province: Evidence from seismic tomography

Analysis of teleseismic P-wave residuals observed at 15 seismograph stations operated in the Deccan volcanic province (DVP) in west central India points to the existence of a large, deep anomalous region in the upper mantle where the velocity is a few per cent higher than in the surrounding region. The seismic stations were operated in three deployments together with a reference station on precambrian granite at Hyderabad and another common station at Poona. The first group of stations lay along a west-northwesterly profile from Hyderabad through Poona to Bhatsa. The second group roughly formed an L-shaped profile from Poona to Hyderabad through Dharwar and Hospet. The third group of stations lay along a northwesterly profile from Hyderabad to Dhule through Aurangabad and Latur. Relative residuals computed with respect to Hyderabad at all the stations showed two basic features: a large almost linear variation from approximately +1s for teleseisms from the north to-1s for those from the southeast at the western stations, and persistance of the pattern with diminishing magnitudes towards the east. Preliminary ray-plotting and three-dimensional inversion of the P-wave residual data delineate the presence of a 600 km long approximately N-S trending anomalous region of high velocity (1-4% contrast) from a depth of about 100 km in the upper mantle encompassing almost the whole width of the DVP. Inversion of P-wave relative residuals reveal the existence of two prominent features beneath the DVP. The first is a thick high velocity zone (1-4% faster) extending from a depth of about 100 km directly beneath most of the DVP. The second feature is a prominent low velocity region which coincides with the westernmost part of the DVP. A possible explanation for the observed coherent high velocity anomaly is that it forms the root of the lithosphere which coherently translates with the continents during plate motions, an architecture characteristic of precambrian shields. The low velocity zone appears to be related to the rift systems (anomaly 28, 65 Ma) which provided the channel for the outpouring of Deccan basalts at the close of the Cretaceous period. ?? 1989 Indian Academy of Sciences.

Proceedings of the Indian Academy of Sciences - Ea↗
USGS2018

Corresponding long-term shifts in stream temperature and invasive fish migration

By investigating historic trapping records of invasive sea lamprey ( Petromyzon mari nus) throughout tributaries to the Laurentian Great Lakes, we found that upstream spawning migration timing was highly correlated with stream temperatures over large spatial and temporal scales. Furthermore, several streams in our study exceeded a critical spring thermal threshold (i.e., 15°C) and experienced peak spawning migration up to 30 days earlier since the 1980s, whereas others were relatively unchanged. Streams exhibiting warming trends and earlier migration were spatially clustered and generally found on the leeward side of the Great Lakes where the lakes most affect local climate. These findings highlight that all streams are not equally impacted by climate change and represent, to our knowledge, the first observation linking long-term changes in stream temperatures to shifts in migration timing of an invasive fish. Earlier sea lamprey migration in Great Lakes tributaries may improve young of the year growth and survival, but not limit their spatial distribution, making sea lamprey control more challenging.

Laurentian Great Lakes↗