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As the SEAK Hydro database evolves, so to will the metadata for this dataset. Until noted otherwise, please reference this dataset's metadata for an older version of the source data.This map service contains two barrier layers, one from the USFS and one from the AWC. The USFS barriers layer contains points representing bedrock waterfalls in Southeast Alaska that are potential barriers to fish passage on the Tongass National Forest. Waterfalls less than 1 meter are not mapped nor are those caused only by wood or debris jams. Channel types considered to be de facto barriers to fish passage HC5, HC6, & MC3 (Channel Type Users Guide, USFS 1992) were not included in the layer. The AWC layer is undocumented at this time.
Locks and dams are possible management points to block the spread of invasive Asian carps in the United States. Infusion of carbon dioxide (CO2) into water is one deterrent strategy being considered at navigational structures to reduce upstream fish passage that would not directly interfere with lock and dam operations. The goal of this study was to determine the efficacy of CO2 as a behavioral deterrent to free-swimming fishes. Telemetered bighead carp (Hypophthalmichthys nobilis) and grass carp (Ctenopharyngodon idella) were monitored within a U-shaped pond (30.5 m long x 13.7 m wide x 1 m deep) using a two-dimensional acoustic telemetry array. Gaseous CO2 was administered to one-half of the pond at 30, 75, or...
Recent studies have shown the potential of acoustic deterrents against invasive silver carp (Hypophthalmichthys molitrix). This study examined the phonotaxic response of the bighead carp (H. nobilis) to pure tones (500– 2000 Hz) and playbacks of broadband sound from an underwater recording of a 100 hp outboard motor (0.06–10 kHz) in an outdoor concrete pond (10 × 5 × 1.2 m) at the U.S. Geological Survey Upper Midwest Environmental Science Center in La Crosse, WI. The number of consecutive times the fish reacted to sound from alter- nating locations at each end of the pond was assessed. Bighead carp were relatively indifferent to the pure tones with median consecutive responses ranging from 0 to 2 reactions away...
Dams create barriers to fish migration and dispersal in drainage basins, and the removal of dams is often viewed as a means of increasing habitat availability and restoring migratory routes of several fish species. However, these barriers can also isolate and protect native taxa from aggressive downstream invaders.We examined fish community composition two years prior to and two years after the removal of a pair of low-head dams from Boulder Creek,Wisconsin, U.S.A. in 2003 to determine if removal of these potential barriers affected the resident population of native brook trout (Salvelinus fontinalis). Despite the presence of other taxa in the downstream reaches, and in other similar streams adjacent to the Boulder...
The effectiveness of an acoustic barrier to deter the movement of silver carp, Hypophthalmichthys molitrix, and bighead carp, H. noblis, was evaluated. A pond (10 m, x 5 m x 1.2 m) was divided in half by a concrete-block barrier with a channel (1 m across) allowing fish access to each side. Underwater speakers were placed on each side of the barrier opening and an outboard motor noise (broadband sound; 0.06 – 10 kHz) was broadcast to repel carp that approached within 1 m of the channel. Broadband sound was effective at reducing the number of successful crossings in schools of silver carp, bighead carp and a combined school. Repulsion rates were 82.5% (silver carp), 93.7% (bighead carp) and 90.5% (combined). This...
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Rivers and streams are comprised of flowlines selected from the National Hydrography Flowline Dataset Medium. These data are provided by Bureau of Land Management (BLM) "as is" and may contain errors or omissions. The User assumes the entire risk associated with its use of these data and bears all responsibility in determining whether these data are fit for the User's intended use. These data may not have the accuracy, resolution, completeness, timeliness, or other characteristics appropriate for applications that potential users of the data may contemplate. The User is encouraged to carefully consider the content of the metadata file associated with these data. The BLM should be cited as the data source in any...
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Rivers and streams are comprised of flowlines selected from the National Hydrography Flowline Dataset Medium. These data are provided by Bureau of Land Management (BLM) "as is" and may contain errors or omissions. The User assumes the entire risk associated with its use of these data and bears all responsibility in determining whether these data are fit for the User's intended use. These data may not have the accuracy, resolution, completeness, timeliness, or other characteristics appropriate for applications that potential users of the data may contemplate. The User is encouraged to carefully consider the content of the metadata file associated with these data. The BLM should be cited as the data source in any...
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Barriers to upstream fish movement (either long-term geologic, natural short-term, or anthropogenic barriers) will be used to assess whether individual stream segments are currently occupied by bull trout, for assessing risk of genetic introgression or disease to existing bull trout populations, or whether existing subpopulations are connected with other subpopulations. Only those barriers that are believed to have a significant influence bull trout distribution or population integrity will be identified.


    map background search result map search result map Southeast Alaska Hydro Barriers BLM REA NGB 2011 Bull Trout Fish Barriers BLM REA WYB 2011 Ch08 Streams and Rivers Distribution Figs 10 to 17 BLM REA WYB 2011 Ch08 Streams and Rivers Distribution Figs 01 to 09 BLM REA NGB 2011 Bull Trout Fish Barriers Southeast Alaska Hydro Barriers BLM REA WYB 2011 Ch08 Streams and Rivers Distribution Figs 01 to 09 BLM REA WYB 2011 Ch08 Streams and Rivers Distribution Figs 10 to 17