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Key elements of the 2015 national assessment of stream fish habitats follow the 2010 assessment, including: 1) the idea that distributions and numbers fishes reflect the quality of habitat in which they live; and 2) human landscape factors pose a risk to the condition of stream habitat, and indirectly, to fishes. The 2015 inland stream assessments for the contiguous United States, Alaska, and Hawaii all followed five broad steps (Figure 1) that are described in detail below for the inland stream assessment for Alaska. Note that analytical details for the Alaska assessment differed in southeast Alaska as compared to the remainder of the state (referred to as greater Alaska) due to differences in the resolution of...
Tags: 2015, Alaska, Method
Accounting for natural variation With the exception of differences in spatial units, assessments for greater Alaska and southeast Alaska were conducted similarly across regions. Because stream fish assemblage data were not available for the state, no steps were taken to account for natural variation in stream habitats for either southeast or greater Alaska. This represents an important need for future work.
Tags: 2015, Alaska, Method
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State-wide data on fish populations were limited in Alaska for use in this assessment, as was a detailed spatial (mapping) framework that fully characterizes watersheds throughout the state at the time this assessment was conducted. Because of these factors, we modified our assessment methods to account for these limitations. Twenty-one landscape disturbance variables were assembled from medium-sized watersheds throughout the state (i.e., 12-digit hydrologic unit code watersheds). Variables were then assigned to one of six categories based on their disturbances to stream habitats. Categories include: urban land use, agricultural land use, point source pollution and water quality, barriers to fish movement, human...
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The habitats of the Southeast Atlantic states range from the mountains and uplands in the Blue Ridge and Piedmont areas in the western portion of this region to the Southeastern and Coastal Plains. Fish habitats in the higher elevation regions are typically fast-moving, clear, coldwater streams originating from seeps and springs, while warmwater rivers of the plains carry more organic material and sediment. This diversity of habitats along a very long period of stable geologic activity produces one of the most diverse assemblages of aquatic species in the nation. The Altamaha, Chattahoochee, Flint, Savannah, Catawba, Pee Dee, Broad, and Neuse are major rivers of the region. There are a large number of dams on waterways...
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Partnerships - Atlantic Coastal Fish Habitat Partnership, Eastern Brook Trout Joint Venture, Reservoir Fisheries Habitat Partnership, and Southeast Aquatic Resources Partnership Removed four barriers that opened access to six mile of streams and restored 21 miles of streams to improve habitat for Eastern Brook Trout and other fish species. A shoreline restoration demonstration area was constructed near the U.S. Army Corps of Engineers Visitors Center in North Carolina. Native vegetation was used to stabilize 175’ of shoreline to be used as a showcase for other lakeshore property owners. Planted 0.2 acres of tidal marsh and installed 0.1 acres of oyster reefs in Stump Sound, North Carolina. Also planted 0.15 acres...
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Available data for the American Eel (Anguilla rostrata) indicate that, overall, there have been declines in recruitment, population, and escapement during three generations (36 years). A recent report indicated that barriers to migration (dams and weirs), passage through turbines at hydropower dams, habitat degradation or loss, and overharvest were likely the greatest threats by humans across the species’ range. Although eels are able to ascend many smaller barriers, recent studies have documented a tenfold reduction in eel density above each potentially passable barrier. For example, the number of juvenile eels migrating to Lake Ontario passing over hydropower dams fell from 935,000 in 1985 to approximately 8,000...
The Bering Cisco (Coregonus laurettae) is endemic to Alaska and is present primarily along the State’s west and north coasts. It is known to spawn in only three river systems – the Yukon, Kuskokwim, and Susitna Rivers. Genetic research indicates that each of these populations is distinct. The Bering Cisco has been observed to migrate more than 1,200 miles into freshwater streams to spawn. Unlike salmon, some of these fish survive spawning runs. Since this species is slow-growing but short-lived, it is highly vulnerable to alterations in stream flow or water quality and large-scale environmental disasters.
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The Ironcolor Shiner (Notropis chalybaeus) is found in deep pool areas of creeks and small rivers and is often associated with aquatic vegetation. This species needs clear sandy areas for spawning. Populations of Ironcolor Shiner are in decline due to increased turbidity, siltation, and pollution.
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The Waccamaw Silverside (Menidia extensa) has a very limited distribution confined to Lake Waccamaw in North Carolina, a lake with neutral pH levels from underlying limestone formations in an area of acidic natural waters. This species is found in large schools and often over dark-colored substrates. Its limited habitat is threatened by nutrient loading caused by the runoff of organic matter and agricultural chemicals.
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The Northeastern States contain over 17,000 dams with most built before 1910 for agricultural and industrial water power uses. A few have been built more recently for flood control, recreation, water supply, and energy generation. In many cases, the dams have outlived their expected life expectancy and use, but continue to block the passage of migratory fish species, such as American Shad, river herring, American Eel, Rainbow Smelt, and Atlantic Salmon, to and from their historic upstream spawning grounds. Additionally, the fragmentation of stream systems by dams have reduced Brook Trout populations in some locations. Progress is being made on this impairment as over 67 dams were removed during 2010 to 2014 in...
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A. Pervasive disturbances: The most common disturbances based on total stream length in a given region. Top five overall most pervasive disturbances to all stream reaches, regardless of stream size and across all spatial scales (ranked highest first): Total excessive (anthropogenic or man caused) sediment yield Impervious surface cover Road crossing density Population density Pasture and hay land use Top three most pervasive disturbances to creeks (<100 km 2 watersheds) across all spatial scales : Total excessive sediment yield Impervious (hard) surface cover Road crossing density Top three most pervasive disturbances to rivers (>100 km 2 watersheds) across all spatial scales: Upstream dam density...
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Lands within the watersheds of the Great Plains streams that are not used for crops are often used for cattle grazing and hay production. Northern Plains States are one of the nation’s top producers of cattle, which outnumber people almost three to one in North Dakota. Cattle can have direct habitat impacts by trampling stream banks, which destroys beneficial vegetation and increases sedimentation and nutrient loads. Hofmann and Ries (1991) found that livestock increased sediment runoff in North Dakota streams. Schepers and Francis (1982) reported that runoff from a Nebraska cattle farm increased total phosphorus levels in runoff by 37%. In addition, cattle watering ponds, often constructed by diverting streams,...
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Southern Plains States Fish Habitat Partnerships’ 2010 - 2015 Actions to Make a Difference Partnerships - Reservoir Fisheries Habitat Partnership, Southeast Aquatic Resources Partnership, Great Plains Fish Habitat Partnership, Desert Fishes Habitat Partnership, and Western Native Trout Initiative Funded a project to stabilized 3,050 feet of shoreline on Olpe City Lake, Kansas. Assisted partners in installation of a fish barrier on Lovewell Reservoir, Kansas to prevent fish loss during irrigation releases. Evaluation is ongoing but preliminary results show a large increase in the forage base. Provided funding for 400 plastic fish attractors that were installed in six Texas reservoirs: Sam Rayburn, Toledo Bend,...
Map of the risk of current fish habitat degradation of Northern Gulf of Mexico estuaries.
The United States is home to more than 3,000 fish species and over 322 million people, and they all depend on the same water. Healthy aquatic resources are vital to the integrity of the United States and essential for sustainable fish populations. Unfortunately, in many places around the United States, fish and the habitats on which they depend are degraded or in decline. Almost 40 percent of the nation’s freshwater fish species are considered at risk or vulnerable to extinction. Habitat loss is the most common cause for extinction of freshwater fish in the United States over the past century, and many saltwater fish are also in decline due to habitat degradation. In 1997, Congress declared that one of the greatest...
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The Crystal Darter (Crystallaria asprella) requires large, clear-water streams with clean sand and gravel bottoms and moderate to swift currents. It is intolerant of siltation and other forms of pollution from various land use practices. Direct habitat degradation from damming, channelization, and dredging has also reduced habitat for this species. Remaining populations have become isolated from one another by dams and impoundments. The Mississippi River most likely no longer serves as a usable corridor for the Crystal Darter because of the silt load. The isolated local populations are then vulnerable to single destructive events such as toxic chemical spills.
Identifying disturbances to fish habitat The approach for identifying disturbances to fish habitat was based on the assumption that greater intensities and types of human landscape disturbances would most likely lead to more disturbed stream fish habitat (e.g., Danz et al. 2007, Esselman et al. 2011). Twenty-two human landscape variables were identified for the Alaska assessment, with 21 variables used in the southeast and 19 in greater Alaska. We grouped variables into six sub-indices representing specific types of disturbances including: urban land use, agricultural land use, stream fragmentation, point source pollution, infrastructure, and active mines. Each sub-index of disturbance was represented by 2 to...
Tags: 2015, Alaska, Method
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Integrating data into a spatial framework Greater Alaska For most of Alaska excluding the southeast portion of the state, watershed boundaries for individual stream reaches were unavailable, and the highest resolution spatial units available for assessment were 12-digit USGS hydrological units (HUC-12s). Greater Alaska includes 12,824 HUC-12s that partially follow watershed boundaries; however, boundaries are also intended to capture roughly similarly-sized regions vs. entire upstream landscape areas draining to streams (Figure 11). After acquiring data, variables were attributed to HUC-12s for the greater Alaska assessment. Southeast Alaska For the southeast portion of Alaska, watersheds were delineated from...
Tags: 2015, Alaska, Method
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Partnerships - California Fish Passage Forum, Pacific Marine and Estuarine Fish Habitat Partnership, Western Native Trout Initiative, and Desert Fish Habitat Partnership Partnerships supported the removal of 59 barriers that reconnected 114 miles of native trout habitat and 14.5 miles of coastal streams to be used by threatened and endangered anadromous species. Funded estuarine restoration of 500 acres in Washington and 519 acres in Oregon. Sponsored the installation of one barrier to protect native trout from introduced species. Partnerships funded 24 population assessments of inland stream native trout species and three assessments of fish assemblages in habitats of Coos estuary, Oregon. Assessments provide...
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Integrating data into a spatial framework After acquiring data, variables were attributed to a national stream coverage for use in assessment following Wang et al. (2011). The National Hydrography Dataset Version 1 (NHDV1) is a 1:100,000 scale representation of streams from throughout the conterminous United States. The NHDV1 identifies stream reaches as sections of streams occurring between confluences (Figure 2). We attributed all data to stream reaches (i.e., fish data, fragmentation metrics by dams) or to local catchments and 90m buffers draining to stream reaches (i.e., human land uses, mining activities, impervious surfaces, etc.). Local catchments (watersheds) and buffers are the land areas draining directly...
Tags: 2015, CONUS, Method


map background search result map search result map Description of dams and other barriers as a human activity affecting fish habitat in Northeastern States Habitat Trouble for Ironcolor Shiner in Upper Midwest States Habitat Trouble for Crystal Darters in Central Midwest States Fish Habitat Partnership Activities for the Pacific Coast States Generalized Methodology for Stream Assessments of Alaska and Hawaii Most Pervasive and Severe Disturbances for the Eastern Gulf of Mexico States Summary of Scientific Findings for Southeast Atlantic States Habitat Trouble for American Eel in Northeastern States Description of Pasture as a Human Activity Affecting Fish Habitat in Northern Plains States Fish Habitat Partnership Activities for the Southeast Atlantic States Habitat Trouble for Waccamaw Silverside in Southeast Atlantic States Fish Habitat Partnership Activities for the Southern Plains States Summary of Scientific Findings for Southeast Atlantic States Fish Habitat Partnership Activities for the Southeast Atlantic States Habitat Trouble for Waccamaw Silverside in Southeast Atlantic States Description of Pasture as a Human Activity Affecting Fish Habitat in Northern Plains States Description of dams and other barriers as a human activity affecting fish habitat in Northeastern States Habitat Trouble for American Eel in Northeastern States Habitat Trouble for Crystal Darters in Central Midwest States Habitat Trouble for Ironcolor Shiner in Upper Midwest States Most Pervasive and Severe Disturbances for the Eastern Gulf of Mexico States Fish Habitat Partnership Activities for the Pacific Coast States Fish Habitat Partnership Activities for the Southern Plains States Generalized Methodology for Stream Assessments of Alaska and Hawaii