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USGS2003

Photographic techniques for characterizing streambed particle sizes

We developed photographic techniques to characterize coarse (>2-mm) and fine (≤2-mm) streambed particle sizes in 12 streams in Anchorage, Alaska. Results were compared with current sampling techniques to assess which provided greater sampling efficiency and accuracy. The streams sampled were wadeable and contained gravel—cobble streambeds. Gradients ranged from about 5% at the upstream sites to about 0.25% at the downstream sites. Mean particle sizes and size-frequency distributions resulting from digitized photographs differed significantly from those resulting from Wolman pebble counts for five sites in the analysis. Wolman counts were biased toward selecting larger particles. Photographic analysis also yielded a greater number of measured particles (mean = 989) than did the Wolman counts (mean = 328). Stream embeddedness ratings assigned from field and photographic observations were significantly different at 5 of the 12 sites, although both types of ratings showed a positive relationship with digitized surface fines. Visual estimates of embeddedness and digitized surface fines may both be useful indicators of benthic conditions, but digitizing surface fines produces quantitative rather than qualitative data. Benefits of the photographic techniques include reduced field time, minimal streambed disturbance, convenience of postfield processing, easy sample archiving, and improved accuracy and replication potential.

Transactions of the American Fisheries Society↗

USGS1985

Accretion tectonics and crustal structure in Alaska

The entire width of the North American Cordillera in Alaska is made up of "suspect terranes". Pre-Late Cretaceous paleogeography is poorly constrained and the ultimate origins of the many fragments which make up the state are unclear. The Prince William and Chugach terranes accreted since Late Cretaceous time and represent the collapse of much of the northeast Pacific Ocean swept into what today is southern Alaska. Greater Wrangellia, a composite terrane now dispersed into fragments scattered from Idaho to southern Alaska, apparently accreted into Alaska in Late Cretaceous time crushing an enormous deep-marine flysch basin on its inboard side. Most of interior eastern Alaska is the Yukon Tanana terrane, a very large entirely fault-bounded metamorphic-plutonic assemblage covering thousands of square kilometers in Canada as well as Alaska. The original stratigraphy and relationship to North America of the Yukon-Tanana terrane are both obscure. A collapsed Mesozoic flysch basin, similar to the one inboard of Wrangellia, lies along the northern margin. Much of Arctic Alaska was apparently a vast expanse of upper Paleozoic to Early Mesozoic deep marine sediments and mafic volcanic and plutonic rocks now scattered widely as large telescoped sheets and Klippen thrust over the Ruby geanticline and the Brooks Range, and probably underlying the Yukon-Koyukuk basin and the Yukon flats. The Brooks Range itself is a stack of north vergent nappes, the telescoping of which began in Early Cretaceous time. Despite compelling evidence for thousands of kilometers of relative displacement between the accreted terranes, and large amounts of telescoping, translation, and rotation since accretion, the resulting new continental crust added to North America in Alaska carries few obvious signatures that allow application of currently popular simple plate tectonic models. Intraplate telescoping and strike-slip translations, delamination at mid-crustal levels, and large-scale lithospheric wedging were important processes in northern Cordilleran tectonic evolution.

Alaska↗

USGS2000

Growth and invasive potential of Sapium sebiferum (Euphorbiaceae) within the coastal prairie region: the effects of soil and moisture regime

The introduced tree Sapium sebiferum (Euphorbiaceae) is considered a serious threat to the preservation of the coastal prairie region of Louisiana and Texas, although it is currently uncommon in the western part of the region. The objective of this study was to evaluate the potential effects of location, soils, and available moisture on the growth and survival of S. sebiferum in coastal prairie. In a field experiment, S. sebiferum mortality was significantly greater at a western site than at central and eastern sites. The greatest mortality and least growth of surviving plants occurred on a soil from the western region, regardless of site. A greenhouse study also found that S. sebiferum growth was lowest on the western soil. Watering frequency significantly affected S. sebiferum growth, except on the western soil. Sapium sebiferum growth responded to both nitrogen and phosphorum additions for all soils. Soil analyses revealed the highest sand, sodium, and phosphorus contents, and much higher electrical conductivity in the western soil. It is concluded that the soil examined from the western region is unfavorable for S. sebiferum growth, though not to the extent to preclude S. sebiferum completely. Evidence suggests that soil salinity may be the primary cause of the poor S. sebiferum growth at the western site.

Louisiana, Texas↗

USGS2020

Canada goose survival and recovery rates in urban and rural areas of Iowa, USA

Once extirpated from much of their North American range, temperate-breeding Canada geese ( Branta canadensis maxima ) have reached high abundance. As a result, focus has shifted from restoration to managing harvest and addressing human-goose conflict. Conflict persists or is increasing in urban areas throughout the Mississippi Flyway. Managers need more information regarding demographic rates to determine how hunting affects geese breeding in urban areas and what management actions may be required to achieve management goals. We estimated survival, dead recovery, live recapture, and fidelity probabilities using data from 77,872 Canada geese banded in Iowa, USA, during 1999–2019 using Burnham joint live-dead band recovery models. Factors predicted to affect parameters in candidate models included age (juvenile, subadult, adult), banding site (urban, rural), time, trend, harvest regulation index, and winter severity index. We predicted Canada geese banded in urban areas would have higher survival and lower dead recovery rates than geese banded at rural sites. The top model indicated support for age and banding site effects, and trends in survival and recovery rate (Brownie parameterization). Adult survival was similar for urban (0.75; range = 0.60–0.92) and rural (0.75; range = 0.66–0.82) geese and relatively constant across years. Mean juvenile survival was lower in urban (0.74; range = 0.48–0.93) than rural (0.85; range = 0.68–0.92) areas. Survival increased for urban-banded juveniles and recovery rates increased during liberalization of harvest regulations and decreased after regulations stabilized. Recovery rates of subadults increased for the urban and rural groups. Our results suggest Canada geese breeding in urban areas contribute to harvest and specialized regulations can affect these populations. Harvest regulations in place during our analysis may not have reached a threshold required to observe substantial changes in survival. Current human-goose conflict in urban areas suggests survival has not decreased to a level required to completely address conflict via reduction in goose abundance. Managers may consider additional liberalization of harvest regulations and monitoring via banding to determine to what degree hunter harvest contributes to reducing human-goose conflict and what additional management actions will be required to achieve goals. © 2020 The Wildlife Society.

Iowa↗

USGS2010

Comparison of aquifer characterization approaches through steady state groundwater model validation: A controlled laboratory sandbox study

Groundwater modeling has become a vital component to water supply and contaminant transport investigations. An important component of groundwater modeling under steady state conditions is selecting a representative hydraulic conductivity (K) estimate or set of estimates which defines the K field of the studied region. Currently, there are a number of characterization approaches to obtain K at various scales and in varying degrees of detail, but there is a paucity of information in terms of which characterization approach best predicts flow through aquifers or drawdowns caused by some drawdown inducing events. The main objective of this paper is to assess K estimates obtained by various approaches by predicting drawdowns from independent cross-hole pumping tests and total flow rates through a synthetic heterogeneous aquifer from flow-through tests. Specifically, we (1) characterize a synthetic heterogeneous aquifer built in the sandbox through various techniques (permeameter analyses of core samples, single-hole, cross-hole, and flow-through testing), (2) obtain mean K fields through traditional analysis of test data by treating the medium to be homogeneous, (3) obtain heterogeneous K fields through kriging and steady state hydraulic tomography, and (4) conduct forward simulations of 16 independent pumping tests and six flowthrough tests using these homogeneous and heterogeneous K fields and comparing them to actual data. Results show that the mean K and heterogeneous K fields estimated through kriging of small-scale K data (core and single-hole tests) yield biased predictions of drawdowns and flow rates in this synthetic heterogeneous aquifer. In contrast, the heterogeneous K distribution or ?K tomogram? estimated via steady state hydraulic tomography yields excellent predictions of drawdowns of pumping tests not used in the construction of the tomogram and very good estimates of total flow rates from the flowthrough tests. These results suggest that steady state groundwater model validation is possible in this laboratory sandbox aquifer if the heterogeneous K distribution and forcing functions (boundary conditions and source/sink terms) are characterized sufficiently. ?? 2010 by the American Geophysical Union.

Water Resources Research↗

USGS2005

Introduction [to Issue 3]

Artificial propagation of aquatic organisms is increasing globally and currently accounts for approximately 32% of total world fishery production (Vannuccini, 2004). Between 1970 and 2000, aquaculture production of salmonids has grown from less than 200,000 metric tons per year to over 1.5 million metric tons (Tacon, 2003). In 1995, the number of Atlantic salmon (Salmo salar) far exceeded the carrying capacity of salmon in the wild but over 94% of all adult Atlantic salmon were in aquaculture environments (Gross, 1998). Since the 1970’s, concerns have arisen about interactions of hatchery and wild produced salmonids in native habitats. In response, research has addressed concerns about domestication and genetic impacts (Reisenbichler and McIntyre, 1977; Hindar et al., 1991; Waples, 1991; Clifford et al., 1998a; Fleming et al., 2000, 2002; Hard et al., 2000), transfer of disease and parasites (Johnsen and Jensen, 1994; Bakke and Harris, 1998), behavior of spawning adults (Fleming and Gross, 1992; Fleming et al., 1994; Økland et al., 1995; Youngston et al., 1998), differences in fitness traits and life history (Jonsson et al., 1991; Thodesen et al., 1999; McGinnity et al., 2003), and behavioral interactions between hatchery and wild juvenile salmon (Swain and Riddell, 1990; Johnsson et al., 1996; Clifford et al., 1998b). Much of this research has been driven by concerns about the impacts of escaped farmed Atlantic salmon in the North Atlantic Ocean (Hansen et al., 1991). Studies of the interactions between hatchery and wild salmonids, with few exceptions (see Myers et al., 2000), have primarily focused on interactions in freshwater environments. Interactions between hatchery and wild fishes in estuarine and marine environments have not received the same attention, but may have signifi- cant impacts on wild populations. To address this issue, we organized a symposium held at the 2003 annual meeting of the Western Division of the American Fisheries Society in San Diego, California. The session was titled Interactions of Hatchery and Wild Fishes in Marine and Estuarine Environments and included nine presentations. All but one presentation focused on salmonids. This Special Issue of Reviews in Fish Biology and Fisheries includes five papers that were submitted to the symposium.

Reviews in Fish Biology and Fisheries↗

USGS2016

Genetic status and conservation of Westslope Cutthroat Trout in Glacier National Park

Invasive hybridization is one of the greatest threats to the persistence of Westslope Cutthroat Trout Oncorhynchus clarkii lewisi . Large protected areas, where nonhybridized populations are interconnected and express historical life history and genetic diversity, provide some of the last ecological and evolutionary strongholds for conserving this species. Here, we describe the genetic status and distribution of Westslope Cutthroat Trout throughout Glacier National Park, Montana. Admixture between Westslope Cutthroat Trout and introduced Rainbow Trout O. mykiss and Yellowstone Cutthroat Trout O. clarkii bouvieri was estimated by genotyping 1,622 fish collected at 115 sites distributed throughout the Columbia, Missouri, and South Saskatchewan River drainages. Currently, Westslope Cutthroat Trout occupy an estimated 1,465 km of stream habitat and 45 lakes (9,218 ha) in Glacier National Park. There was no evidence of introgression in samples from 32 sites along 587 km of stream length (40% of the stream kilometers currently occupied) and 17 lakes (2,555 ha; 46% of the lake area currently occupied). However, nearly all (97%) of the streams and lakes that were occupied by nonhybridized populations occurred in the Columbia River basin. Based on genetic status (nonnative genetic admixture ≤ 10%), 36 Westslope Cutthroat Trout populations occupying 821 km of stream and 5,482 ha of lakes were identified as “conservation populations.” Most of the conservation populations ( N = 27; 736 km of stream habitat) occurred in the Columbia River basin, whereas only a few geographically restricted populations were found in the South Saskatchewan River ( N = 7; 55 km) and Missouri River ( N = 2; 30 km) basins. Westslope Cutthroat Trout appear to be at imminent risk of genomic extinction in the South Saskatchewan and Missouri River basins, whereas populations in the Columbia River basin are widely distributed and conservation efforts are actively addressing threats from hybridization and other stressors. A diverse set of pro-active management approaches will be required to conserve, protect, and restore Westslope Cutthroat Trout populations in Glacier National Park throughout the 21st century.

Glacier National Park↗

USGS2007

Enhancements of nonpoint source monitoring of volatile organic compounds in ground water

The U.S. Geological Survey (USGS) has compiled a national retrospective data set of analyses of volatile organic compounds (VOCs) in ground water of the United States. The data are from Federal, State, and local nonpoint-source monitoring programs, collected between 1985–95. This data set is being used to augment data collected by the USGS National Water-Quality Assessment (NAWQA) Program to ascertain the occurrence of VOCs in ground water nationwide. Eleven attributes of the retrospective data set were evaluated to determine the suitability of the data to augment NAWQA data in answering occurrence questions of varying complexity. These 11 attributes are the VOC analyte list and the associated reporting levels for each VOC, well type, well-casing material, type of openings in the interval (screened interval or open hole), well depth, depth to the top and bottom of the open interval(s), depth to water level in the well, aquifer type (confined or unconfined), and aquifer lithology. VOCs frequently analyzed included solvents, industrial reagents, and refrigerants, but other VOCs of current interest were not frequently analyzed. About 70 percent of the sampled wells have the type of well documented in the data set, and about 74 percent have well depth documented. However, the data set generally lacks documentation of other characteristics, such as well-casing material, information about the screened or open interval(s), depth to water level in the well, and aquifer type and lithology. For example, only about 20 percent of the wells include information on depth to water level in the well and only about 14 percent of the wells include information about aquifer type. The three most important enhancements to VOC data collected in nonpoint-source monitoring programs for use in a national assessment of VOC occurrence in ground water would be an expanded VOC analyte list, recording the reporting level for each analyte for every analysis, and recording key ancillary information about each well. These enhancements would greatly increase the usefulness of VOC data in addressing complex occurrence questions, such as those that seek to explain the reasons for VOC occurrence and nonoccurrence in ground water of the United States.

Journal of the American Water Resources Associatio↗

USGS2015

Modeling the present and future geographic distribution of the Lone star tick, Amblyomma americanum (Ixodida: Ixodidae ), in the continental United States

The Lone star tick ( Amblyomma americanum L.) is the primary vector for pathogens of significant public health importance in North America, yet relatively little is known about its current and potential future distribution. Building on a published summary of tick collection records, we used an ensemble modeling approach to predict the present-day and future distribution of climatically suitable habitat for establishment of the Lone star tick within the continental United States. Of the nine climatic predictor variables included in our five present-day models, average vapor pressure in July was by far the most important determinant of suitable habitat. The present-day ensemble model predicted an essentially contiguous distribution of suitable habitat extending to the Atlantic coast east of the 100th western meridian and south of the 40th northern parallel, but excluding a high elevation region associated with the Appalachian Mountains. Future ensemble predictions for 2061–2080 forecasted a stable western range limit, northward expansion of suitable habitat into the Upper Midwest and western Pennsylvania, and range contraction along portions of the Gulf coast and the lower Mississippi river valley. These findings are informative for raising awareness of A. americanum -transmitted pathogens in areas where the Lone Star tick has recently or may become established.

American Journal of Tropical Medicine and Hygiene↗

USGS2017

Between hot rocks and dry places: The status of the Dixie Valley toad

In Dixie Valley, Nevada, an isolated population of toads has been the subject of proactive conservation measures by the Nevada Department of Wildlife and the U.S. Fish and Wildlife Service since 2008 due to concerns about potential habitat degradation resulting from exploitation of nearby geothermal energy resources. These toads appear to belong within the Anaxyrus boreas species group but are commonly referred to as Dixie Valley toads (DVTs). The DVT is currently confined to an extremely narrow habitat range (370 ha) that is geographically isolated from any other A. boreas population. In this study, genetic variations in mitochondrial genes and 11 microsatellite loci were used to assess the affinities of DVTs in relation to members of the A. boreas species group. We compared results from DVTs with previously published data spanning much of the range of A. boreas in the United States and new data from a nearby toad population within Dixie Valley. Data from both mitochondrial DNA and microsatellites placed DVTs inside the A. boreas species group. In particular, DVTs fell into a cluster of A. boreas from Washington and California, along with other species from the A. boreas species group, namely A. nelsoni, A. canorus, and A. exsul. Genetic differentiation of DVTs was lowest between A. boreas populations in Washington and California. However, allele frequencies were significantly different between DVTs and all other populations, including a nearby locality within Dixie Valley. This genetic differentiation, along with the DVT's geographical isolation and restricted habitat, warrants recognition of the DVT as a distinct management unit.

Nevada↗

USGS2016

Geometric quality assessment of lidar data based on swath overlap

This paper provides guidelines on quantifying the relative horizontal and vertical errors observed between conjugate features in the overlapping regions of lidar data. The quantification of these errors is important because their presence quantifies the geometric quality of the data. A data set can be said to have good geometric quality if measurements of identical features, regardless of their position or orientation, yield identical results. Good geometric quality indicates that the data are produced using sensor models that are working as they are mathematically designed, and data acquisition processes are not introducing any unforeseen distortion in the data. High geometric quality also leads to high geolocation accuracy of the data when the data acquisition process includes coupling the sensor with geopositioning systems. Current specifications (e.g. Heidemann 2014) do not provide adequate means to quantitatively measure these errors, even though they are required to be reported. Current accuracy measurement and reporting practices followed in the industry and as recommended by data specification documents also potentially underestimate the inter-swath errors, including the presence of systematic errors in lidar data. Hence they pose a risk to the user in terms of data acceptance (i.e. a higher potential for Type II error indicating risk of accepting potentially unsuitable data). For example, if the overlap area is too small or if the sampled locations are close to the center of overlap, or if the errors are sampled in flat regions when there are residual pitch errors in the data, the resultant Root Mean Square Differences (RMSD) can still be small. To avoid this, the following are suggested to be used as criteria for defining the inter-swath quality of data: a) Median Discrepancy Angle b) Mean and RMSD of Horizontal Errors using DQM measured on sloping surfaces c) RMSD for sampled locations from flat areas (defined as areas with less than 5 degrees of slope) It is suggested that 4000-5000 points are uniformly sampled in the overlapping regions of the point cloud, and depending on the surface roughness, to measure the discrepancy between swaths. Care must be taken to sample only areas of single return points only. Point-to-Plane distance based data quality measures are determined for each sample point. These measurements are used to determine the above mentioned parameters. This paper details the measurements and analysis of measurements required to determine these metrics, i.e. Discrepancy Angle, Mean and RMSD of errors in flat regions and horizontal errors obtained using measurements extracted from sloping regions (slope greater than 10 degrees). The research is a result of an ad-hoc joint working group of the US Geological Survey and the American Society for Photogrammetry and Remote Sensing (ASPRS) Airborne Lidar Committee.

Conference Paper↗

USGS2019

Assessment of the American woodcock singing-ground survey zone timing and coverage

The American woodcock ( Scolopax minor ; hereafter, woodcock) Singing-Ground Survey (SGS) was developed to inform management decisions by monitoring changes in the relative abundance of woodcock. The timing of the designated survey windows was designed to count resident woodcock while minimizing counting of migrating woodcock. Since the implementation of the SGS in 1968, concerns over survey protocols that may bias data have been raised and investigated; however, the extent of survey coverage and the timing of the survey window zones have not been critically investigated. We used 3 years of data collected from male and female woodcock marked with satellite tags to assess the extent of survey coverage and the timing of the SGS survey windows relative to presence of woodcock. SGS coverage encompassed the majority of woodcock breeding-period sites (locations where marked woodcock returned to in spring) within the U.S. (n = 17, 92%) and approximately half of the breeding-period sites in Canada (n = 6, 43%). Thirteen of the 37 monitored woodcock with known breeding-period site arrival dates (35%) were migrating through a survey zone during an active survey window, all in the northernmost 4 of 5 SGS zones. Thirteen woodcock arrived at breeding-period sites after the start of surveys, and all but one of these was located in the northernmost 2 zones. The combination of migration through a SGS zone during the survey window and arrival at breeding-period sites after the beginning of the survey window in northern zones may result in the SGS weighing too heavily the contribution of routes in the southern portion of the primary breeding range, while weighing too lightly the routes in the northern portion of the primary breeding range. We suggest that additional information is necessary to evaluate whether current survey windows are sufficient, or whether they need to be changed.

Conference Paper↗

USGS2000

Habitats used by shortnose sturgeon two Massachusetts rivers, with notes on estuarine Atlantic sturgeon: A hierarchical approach

Biotelemetry of shortnose sturgeon Acipenser brevirostrum and Atlantic sturgeon A. oxyrinchus oxyrinchus was used to study fish uses of habitat in several hierarchical classes in the Connecticut and Merrimack rivers. Hierarchical classes were geomorphological region (straight river run, run with an island, and river curve), river cross section (channel or shoal), and microhabitat (water depth, bottom current, substrate, and illumination). Coastal wandering juvenile Atlantic sturgeon were summer visitors to the Merrimack River, where they used a narrow range of habitat on all spatial scales, e.g., run-with-island, the channel portion of the cross section, and sand substrate. Shortnose sturgeon, year-round residents in both rivers, showed great individual variation in habitat use, and all ages selected a broad range of habitats on all spatial scales. However, shortnose sturgeon in both rivers preferred curves with sand or cobble substrate and avoided runs regardless of substrate. Individuals used channel or shoal at rates ranging from 0 to 100% on a weekly time scale in an unpredictable manner. Connecticut River shortnose sturgeon increased their use of curves, channels (deep water), and sand substrate in the fall. This strategy may conserve energy because these conditions usually reflect slow water velocity. Winter habitat selection continued the fall pattern, but was less variable because habitat affinity was highest among wintering fish. Documenting individual fish use of large-scale habitat revealed habitat relationships that would not have been discovered if only fish use of microhabitat had been studied.

Massachusetts↗

USGS2006

Using on-site bioassays to determine selenium risk to propagated endangered fishes

The Utah Reclamation, Mitigation and Conservation Commission is determining the feasibility of establishing a hatchery and grow-out facility for endangered June suckers Chasmistes liorus at Goshen Warm Springs, Utah. A survey of water quality indicated that selenium and other contaminants may be of concern at Goshen Warm Springs. We conducted an ecotoxicological study with three objectives: (1) to determine the growth rates of juvenile June suckers in two ponds (Lily Pond and North Pond) at Goshen Warm Springs and in Utah Lake, (2) to determine the uptake and depuration rates of selenium in juvenile June suckers, and (3) to evaluate limnological factors that may influence growth and selenium accumulation in June suckers. Fish growth was significantly greater at Utah Lake and North Pond than at Lily Pond or under current hatchery conditions. At the end of the uptake phase of the study (day 87), selenium concentrations in June suckers from Lily Pond, North Pond, and Utah Lake were 1.62, 1.90, and 1.32 μg /g of dry weight, respectively. Selenium uptake in June suckers was statistically significant at Lily Pond ( 0.005 μg · g −1 · d −1 ), North Pond (0.010 μg · g −1 · d −1 ), and Utah Lake (0.003 μg · g −1 · d −1 ). At day 87, the fish were transferred to well water for selenium depuration. Significant selenium depuration occurred after the transfer of June suckers to clean water. Results indicated that selenium bioaccumulated to statistically significant levels at both Lily and North ponds. However, these concentrations are not likely to be of concern because they are not known to cause chronic toxicity. Depuration experiments indicated that June suckers stocked into Utah Lake would eliminate accumulated selenium residues within 3 months. Results indicated that Goshen Warm Springs could be used for fish propagation. In addition, further evaluation of Utah Lake as an interim hatchery site for June suckers should be considered.

North American Journal of Fisheries Management↗

USGS2014

Spawning patterns of Pacific Lamprey in tributaries to the Willamette River, Oregon

Addressing the ongoing decline of Pacific Lamprey Entosphenus tridentatus across its range along the west coast of North America requires an understanding of all life history phases. Currently, spawning surveys (redd counts) are a common tool used to monitor returning adult salmonids, but the methods are in their infancy for Pacific Lamprey. To better understand the spawning phase, our objective was to assess temporal spawning trends, redd abundance, habitat use, and spatial patterns of spawning at multiple spatial scales for Pacific Lamprey in the Willamette River basin, Oregon. Although redd density varied considerably across surveyed reaches, the observed temporal patterns of spawning were related to physical habitat and hydrologic conditions. As has been documented in studies in other basins in the Pacific Northwest, we found that redds were often constructed in pool tailouts dominated by gravel, similar to habitat used by spawning salmonids. Across the entire Willamette Basin, Pacific Lampreys appeared to select reaches with alluvial geology, likely because this is where gravel suitable for spawning accumulated. At the tributary scale, spawning patterns were not as strong, and in reaches with nonalluvial geology redds were more spatially clumped than in reaches with alluvial geology. These results can be used to help identify and conserve Pacific Lamprey spawning habitat across the Pacific Northwest.

Oregon↗

USGS2011

Patterns of hybridization of nonnative cutthroat trout and hatchery rainbow trout with native redband trout in the Boise River, Idaho

Hybridization is one of the greatest threats to native fishes. Threats from hybridization are particularly important for native trout species as stocking of nonnative trout has been widespread within the ranges of native species, thus increasing the potential for hybridization. While many studies have documented hybridization between native cutthroat trout Oncorhynchus clarkii and nonnative rainbow trout O. mykiss , fewer have focused on this issue in native rainbow trout despite widespread threats from introductions of both nonnative cutthroat trout and hatchery rainbow trout. Here, we describe the current genetic (i.e., hybridization) status of native redband trout O. mykiss gairdneri populations in the upper Boise River, Idaho. Interspecific hybridization was widespread (detected at 14 of the 41 sampled locations), but high levels of hybridization between nonnative cutthroat trout and redband trout were detected in only a few streams. Intraspecific hybridization was considerably more widespread (almost 40% of sampled locations), and several local populations of native redband trout have been almost completely replaced with hatchery coastal rainbow trout O. mykiss irideus ; other populations exist as hybrid swarms, some are in the process of being actively invaded, and some are maintaining genetic characteristics of native populations. The persistence of some redband trout populations with high genetic integrity provides some opportunity to conserve native genomes, but our findings also highlight the complex decisions facing managers today. Effective management strategies in this system may include analysis of the specific attributes of each site and population to evaluate the relative risks posed by isolation versus maintaining connectivity, identifying potential sites for control or eradication of nonnative trout, and long-term monitoring of the genetic integrity of remaining redband trout populations to track changes in their status.

Idaho↗

USGS2015

Forecasting sagebrush ecosystem components and greater sage-grouse habitat for 2050: learning from past climate patterns and Landsat imagery to predict the future

Sagebrush ( Artemisia spp.) ecosystems constitute the largest single North American shrub ecosystem and provide vital ecological, hydrological, biological, agricultural, and recreational ecosystem services. Disturbances have altered and reduced this ecosystem historically, but climate change may ultimately represent the greatest future risk. Improved ways to quantify, monitor, and predict climate-driven gradual change in this ecosystem is vital to its future management. We examined the annual change of Daymet precipitation (daily gridded climate data) and five remote sensing ecosystem sagebrush vegetation and soil components (bare ground, herbaceous, litter, sagebrush, and shrub) from 1984 to 2011 in southwestern Wyoming. Bare ground displayed an increasing trend in abundance over time, and herbaceous, litter, shrub, and sagebrush showed a decreasing trend. Total precipitation amounts show a downward trend during the same period. We established statistically significant correlations between each sagebrush component and historical precipitation records using a simple least squares linear regression. Using the historical relationship between sagebrush component abundance and precipitation in a linear model, we forecasted the abundance of the sagebrush components in 2050 using Intergovernmental Panel on Climate Change (IPCC) precipitation scenarios A1B and A2. Bare ground was the only component that increased under both future scenarios, with a net increase of 48.98 km 2 (1.1%) across the study area under the A1B scenario and 41.15 km 2 (0.9%) under the A2 scenario. The remaining components decreased under both future scenarios: litter had the highest net reductions with 49.82 km 2 (4.1%) under A1B and 50.8 km 2 (4.2%) under A2, and herbaceous had the smallest net reductions with 39.95 km 2 (3.8%) under A1B and 40.59 km 2 (3.3%) under A2. We applied the 2050 forecast sagebrush component values to contemporary (circa 2006) greater sage-grouse ( Centrocercus urophasianus ) habitat models to evaluate the effects of potential climate-induced habitat change. Under the 2050 IPCC A1B scenario, 11.6% of currently identified nesting habitat was lost, and 0.002% of new potential habitat was gained, with 4% of summer habitat lost and 0.039% gained. Our results demonstrate the successful ability of remote sensing based sagebrush components, when coupled with precipitation, to forecast future component response using IPCC precipitation scenarios. Our approach also enables future quantification of greater sage-grouse habitat under different precipitation scenarios, and provides additional capability to identify regional precipitation influence on sagebrush component response.

Wyoming↗

USGS2016

California State Waters map series — Offshore of Aptos, California

Introduction In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP), designed to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats, and geology within California’s State Waters. The CSMP approach is to create highly detailed seafloor maps through collection, integration, interpretation, and visualization of swath sonar bathymetric data (the undersea equivalent of satellite remote-sensing data in terrestrial mapping), acoustic backscatter, seafloor video, seafloor photography, high-resolution seismic-reflection profiles, and bottom-sediment sampling data. The map products display seafloor morphology and character, identify potential marine benthic habitats, and illustrate both the surficial seafloor geology and shallow subsurface geology. The Offshore of Aptos map area is located on the Pacific Coast, on the north side of Monterey Bay, about 105 km southeast of San Francisco. The largest incorporated city in the map area, Capitola, and numerous unincorporated towns including Aptos, lie on uplifted marine terraces between the shoreline, and the northwest-trending Santa Cruz Mountains, part of California’s Coast Ranges. The map area includes the northernmost part of Santa Cruz Harbor, and Moss Landing Harbor is located about 10 km south of the map area. The offshore part of the map area is entirely within California’s State Waters and is also part of the Monterey Bay National Marine Sanctuary. In the southern part of the map area, the Soquel Canyon State Marine Conservation Area extends eastward from the limit of California’s State Waters across Soquel Canyon. The Offshore of Aptos map area is on the western margin of North American Plate—the only continental margin in the world delineated largely by transform faults. The San Andreas Fault Zone cuts through the Santa Cruz Mountains just 3.5 km northeast of the map area. The San Gregorio Fault Zone, another major plate-boundary structure, cuts through Monterey Canyon about 13 km southwest of the map area. Ongoing deformation associated with and between these major fault zones has uplifted the Santa Cruz Mountains and formed well-developed sets of marine terraces that characterize almost the entire coastal zone of the map area. The offshore part of the map area consists of relatively flat and shallow continental shelf which is underlain by variable amounts (0 to 30 m) of upper Quaternary shelf, estuarine, and fluvial sediments deposited as sea level fluctuated in the late Pleistocene. Along the southern edge of the map area, the shelf is incised by the head of Soquel Canyon, a northeast-trending tributary to the west-trending Monterey Canyon. During the last sea-level lowstand (the Last Glacial Maximum [LGM], about 21,000 years ago) Soquel Creek flowed through a paleochannel across the emergent shelf into the head of Soquel Canyon. This canyon was disconnected from its onshore watershed during the post-LGM sea-level rise of about 125 m; the abandoned paleochannel was subsequently filled with marine sediment. Coastal sediment in the Offshore of Aptos map area is supplied by coastal watersheds and bluff erosion. Sediment transport in this part of the Santa Cruz littoral cell is primarily from the northwest to the southeast and terminates in the submarine Monterey Canyon. Longshore drift is impeded by jetties at Santa Cruz Harbor, resulting in high beach erosion rates east of the harbor. Sediment dredged from the harbor mouth (estimated 300,000 yds 3 /yr) is currently being used to nourish beaches directly to the east. Farther downcoast, the rapidly eroding beach at Capitola was stabilized by construction of an about 75-m-long groin. This part of central California is exposed to large North Pacific swells from the northwest throughout the year. North Pacific swell heights range from 2 to 10 meters, with larger swells occurring from October to May. During El Niño-Southern Oscillation (ENSO) events, winter storms track farther south than they do in normal (non-ENSO) years, thereby impacting the map area more frequently and with waves of larger heights. Bedrock exposed in coastal cliffs is relatively erosion-resistant, and significant erosional events primarily are restricted to storm-wave activity that also erodes the overlying unconsolidated marine-terrace sediments. The Offshore of Aptos map area lies within the cold-temperate biogeographic zone that is called either the “Oregonian” province or the “northern California ecoregion.” This biogeographic province is maintained by the long-term stability of the southward-flowing California Current, the eastern limb of the North Pacific subtropical gyre that flows from southern British Columbia to Baja California. At its midpoint off central California, the California Current transports subarctic surface (0–500 m deep) waters southward, about 150 to 1,300 km from shore. Seasonal northwesterly winds that are, in part, responsible for the California Current, generate coastal upwelling. The south end of the Oregonian province is at Point Conception (about 310 km southeast of the map area), although its associated phylogeographic group of marine fauna may extend beyond to the area offshore of Los Angeles in southern California. The ocean off of central California has experienced a warming over the last 50 years that is driving an ecosystem shift away from the productive subarctic regime towards a depopulated subtropical environment. Seafloor habitats in the Offshore of Aptos map area lie within the “Shelf” Megahabitat class and include patchy rocky habitats, gravel-rich scour depressions, minor bedrock habitat, and predominantly sandy inner shelf. Sandy shelf habitats grade offshore to mud-dominated habitats on the midshelf in deeper water. Biological productivity resulting from coastal upwelling supports populations of Sooty Shearwater, Western Gull, Common Murre, Cassin’s Auklet, and many other less populous bird species. In addition, an observable recovery of Humpback and Blue Whales has occurred in the area; both species are dependent on coastal upwelling to provide nutrients. California sea lions and Pacific harbor seals are abundant in the map area. Common bottlenose dolphins are often observed very close to shore and in the surf zone. The large extent of exposed inner shelf bedrock supports large forests of “bull kelp,” which is well adapted for high-wave-energy environments. The kelp beds are the northernmost known habitat for the population of southern sea otters. Common fish species found in the kelp beds and rocky reefs include blue rockfish, black rockfish, olive rockfish, kelp rockfish, gopher rockfish, black-and-yellow rockfish, painted greenling, kelp greenling, and lingcod.

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