scholarly journals White Sturgeon Management Plan in the Snake River between Lower Granite and Hells Canyon Dams; Nez Perce Tribe, 1997-2005 Final Report.

2005 ◽  
Author(s):  
Keyword(s):  
Management Plan ◽  
White Sturgeon ◽  
Snake River ◽  
Nez Perce ◽  
Final Report ◽  
Hells Canyon

Biology, Management, and Protection of North American Sturgeon

2002 ◽  
Keyword(s):  
Population Dynamics ◽  
Population Structure ◽  
White Sturgeon ◽  
Acipenser Transmontanus ◽  
Snake River ◽  
Nez Perce ◽  
River Section ◽  
Catch And Release ◽  
Research Population ◽  
Hells Canyon

<em>Abstract.</em>—White sturgeon <em>Acipenser transmontanus</em> in the Hells Canyon reach of the Snake River have been under sport catch-and-release regulations for almost thirty years. Three states, Idaho, Oregon, and Washington bound this river section, and each imposed catchand-release regulations in 1970s. Nez Perce Tribe tribal members can harvest sturgeon throughout the year in this Snake River section. The population structure at the initiation of catch-and-release regulations showed a deficit in the 92–183 cm (TL) length range as white sturgeon within this group were harvested before 1972. The population composition was 86% between 55 and 92 cm, 4% between 92 and 183 cm, and 10% greater than 183 cm. Information collected during 1982–85 and in 1998 shows increasing abundance in the mid-sized length-group (92–183 cm TL). Because of the positive response of this population to a reduction in legal sport harvest, there have been discussions regarding the elimination of catchand-release fishing. Because of the longevity of white sturgeon, it may take another 25–30 years for the older age-class segment (>183 cm TL) to show a response to catch and release. For the interim, I suggest that strong consideration be given for retaining the Hells Canyon population as a conservation research population. This designation would allow for better understanding of population dynamics for future managers, but still allow present activities of catch-and-release sport fishing and tribal harvest.

Historical Changes in Large River Fish Assemblages of the Americas

2005 ◽  
Keyword(s):  
Alien Species ◽  
Fish Species ◽  
Agricultural Land ◽  
Fish Assemblages ◽  
Index Of Biotic Integrity ◽  
White Sturgeon ◽  
Biotic Integrity ◽  
Snake River ◽  
Elevated Water ◽  
Hells Canyon

<em>Abstract.</em>—The Snake River is the tenth longest river in the United States, extending 1,667 km from its origin in Yellowstone National Park in western Wyoming to its union with the Columbia River at Pasco, Washington. Historically, the main-stem Snake River upstream from the Hells Canyon Complex supported at least 26 native fish species, including anadromous stocks of Chinook salmon <em>Oncorhynchus tshawytscha</em>, steelhead <em>O. mykiss</em>, Pacific lamprey <em>Lampetra tridentata</em>, and white sturgeon <em>Acipenser transmontanus</em>. Of these anadromous species, only the white sturgeon remains in the Snake River between the Hells Canyon Complex and Shoshone Falls. Today, much of the Snake River has been transformed into a river with numerous impoundments and flow diversions, increased pollutant loads, and elevated water temperatures. Current (1993–2002) fish assemblage collections from 15 sites along the Snake River and Henrys Fork contained 35 fish species, including 16 alien species. Many of these alien species such as catfish (Ictaluridae), carp (Cyprinidae), and sunfish (Centrarchidae) are adapted for warmwater impounded habitats. Currently, the Snake River supports 19 native species. An index of biotic integrity (IBI), developed to evaluate large rivers in the Northwest, was used to evaluate recent (1993– 2002) fish collections from the Snake River and Henrys Fork in southern Idaho and western Wyoming. Index of biotic integrity site scores and component metrics revealed a decline in biotic integrity from upstream to downstream in both the Snake River and Henrys Fork. Two distinct groups of sites were evident that correspond to a range of IBI scores—an upper Snake River and Henrys Fork group with relatively high biotic integrity (mean IBI scores of 46–84) and a lower Snake River group with low biotic integrity (mean IBI scores of 10–29). Sites located in the lower Snake River exhibited fish assemblages that reflect poor-quality habitat where coldwater and sensitive species are rare or absent, and where tolerant, less desirable species predominate. Increases in percentages of agricultural land, total number of diversions, and number of constructed channels were strongly associated with these decreasing IBI scores.

Anadromous Sturgeons: Habitats, Threats, and Management

2007 ◽  
Keyword(s):  
Density Dependence ◽  
Simulation Study ◽  
White Sturgeon ◽  
Acipenser Transmontanus ◽  
Snake River ◽  
Spawning Habitat ◽  
Density Dependent ◽  
Hydrologic Conditions ◽  
Genetic Results ◽  
New Alleles

<em>Abstract.</em>— This paper describes a simulation study of reconnection options for white sturgeon <em>Acipenser transmontanus</em> subpopulations in adjacent river segments above and below CJ Strike Dam on the Snake River, Idaho, USA. In contrast to the downstream river segment, the upstream river segment is long and has areas that are suitable for spawning during normal and wet hydrologic conditions. We evaluated demographic and genetic consequences of upstream and downstream passage using different model assumptions about trashrack spacing and density-dependent effects on the spawning interval. Our genetic results predict that, although reconnection would introduce new alleles to the upstream subpopulation, it would also preserve alleles from the downstream subpopulation by propagating them in the larger subpopulation above the dam. Our demographic results predict that halving the space between trashracks would have large and unequivocal benefits, whereas the predicted effects of reconnection were smaller and more sensitive to model assumptions. Simulated upstream passage tended to benefit both subpopulations only in the absence of density-dependent limitation. In the presence of density dependence, the combination of halved trashrack spacing and upstream and downstream passage produced the best results. Narrower trashracks kept spawning adults in the upstream segment with spawning habitat, while allowing their progeny to migrate downstream. Screening appears to be the best option for such a species in this configuration of a long river segment acting as a demographic source above a short one acting as a demographic sink.

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