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Steve Crawford

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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
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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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...
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