Kohler A.E.,Shoshone Bannock Tribes |
Kusnierz P.C.,Shoshone Bannock Tribes |
Copeland T.,Fisheries Research |
Venditti D.A.,Fisheries Research |
And 6 more authors.
Canadian Journal of Fisheries and Aquatic Sciences | Year: 2013
Salmon provide an important resource subsidy and linkage between marine and land-based ecosystems. This flow of energy and nutrients is not unidirectional (i.e., upstream only); in addition to passive nutrient export via stream flow, juvenile emigrants actively export nutrients from freshwater environments. In some cases, nutrient export can exceed import. We evaluated nutrient fluxes in streams across central Idaho, USA, using Chinook salmon (Oncorhynchus tshawytscha) adult escapement and juvenile production data from 1998 to 2008. We found in the majority of stream-years evaluated, adults imported more nutrients than progeny exported; however, in 3% of the years, juveniles exported more nutrients than their parents imported. On average, juvenile emigrants exported 22% ± 3% of the nitrogen and 30% ± 4% of the phosphorus their parents imported. This relationship was density-dependent and nonlinear; during periods of low adult abundance, juveniles were larger and exported up to 194% and 268% of parental nitrogen and phosphorus inputs, respectively. We highlight minimum escapement thresholds that appear to (i) maintain consistently positive net nutrient flux and (ii) reduce the average proportional rate of export across study streams. Our results suggest a state shift occurs when adult spawner abundance falls below a threshold to a point where the probability of juvenile nutrient exports exceeding adult imports becomes increasingly likely.
Ebel J.D.,Michigan Technological University |
Marcarelli A.M.,Michigan Technological University |
Kohler A.E.,Shoshone Bannock Tribes |
Ebel J.D.,Memorial University of Newfoundland
Canadian Journal of Fisheries and Aquatic Sciences | Year: 2014
Dramatic declines of Pacific salmon (Oncorhynchus spp.) populations have decreased delivery of marine-derived material to Pacific Northwest streams where juvenile salmon reside. Managers use artificial nutrient additions to increase juvenile salmon growth and survival and typically assume nutrient-driven increases in biofilm production are an important pathway by which nutrients become available to higher trophic levels. To evaluate how biofilms respond to additions of salmon carcass analog, a pasteurized, processed form of nutrient mitigation materials, we quantified biofilm nutrient limitation, benthic and whole-stream metabolism, and biofilm standing crops before and following experimental additions in tributaries of the Salmon River, Idaho, USA. Biofilm nutrient limitation did not change and standing crop did not increase in response to analog additions at two different levels (low, 30 g·m-2; or high, 150 g·m-2) within 1 month of addition. In contrast, whole-stream and benthic primary productivity and respiration increased in a high-analog treated segment, but did not increase in a low-analog treated segment. Together, our results suggest that metabolism may be a more appropriate tool for assessing the ecosystem effects of nutrient additions than biofilm standing crop or nutrient limitation, which are constrained by a variety of abiotic and biotic factors like hydrology and grazing. © 2014, National Research Council of Canada. All rights received.
Griswold R.G.,Biolines Environmental Consulting |
Kohler A.E.,Shoshone Bannock Tribes |
Taki D.,Shoshone Bannock Tribes
North American Journal of Fisheries Management | Year: 2011
In 1991, Snake River sockeye salmon Oncorhynchus nerka were listed as endangered. The Sawtooth Valley Project was initiated to conserve and rebuild sockeye salmon populations that historically spawned and reared in five Sawtooth Valley lakes designated as critical habitat in central Idaho. We evaluated smolt survival of sockeye salmon that were stocked as parr into Redfish, Pettit, and Alturas lakes. Smolt travel time, residuals of Salmon River discharge and smolt travel time, and specific growth rate of parr explained 58% of the variation in smolt survival in a multipleregression model. Smolt survival was inversely related to smolt travel time, and travel time was negatively correlated with mean May discharge in the Salmon River at Salmon, Idaho.We were particularly interested in the relationships between smolt survival and parr size at release, smolt size at migration, and parr growth rate. Smolt survival from nursery lakes to Lower Granite Dam was negatively correlated with mean parr size at release and mean smolt size at emigration. Smaller parr and smolts survived better. Smolt survival to the dam was correlated with parr growth rates in the three lakes combined; the relationship was nonlinear. Smolt survival increased as specific growth rate increased up to 0.06% per day, but further increases in growth rate were associated with reductions in survival. Absolute growth rates of parr were negatively related to parr weight at release. Smaller individuals grew faster than larger individuals, apparently as a result of size-dependent metabolic demand and prey availability. The relationships between smolt survival and parr size, smolt size, and parr growth rate differed among lakes. These data suggest that successful migrants must at least maintain weight during the winter preceding migration and that the stocking of smaller parr with lower metabolic demand may be preferable to stocking larger parr when forage is limited. © American Fisheries Society 2011.
Bingham D.M.,Rogue Biological Consultants |
Buckskin P.,Shoshone Bannock Tribes |
Osborne H.,Shoshone Bannock Tribes
North American Journal of Fisheries Management | Year: 2016
We analyzed 67 SNPs to describe the genetics of Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri in seven tributaries near American Falls Reservoir, Idaho. We detected Yellowstone Cutthroat Trout in all but one site despite significant historical stocking of Rainbow Trout O. mykiss. Three of four relatively low-elevation sites near the reservoir contained Yellowstone Cutthroat Trout in sympatry with early-generation hybrids and Rainbow Trout yet contained no physical barriers to admixture. A posteriori assignment tests suggested that migrants from a nearby headwater population in Ross Fork Creek and possibly recruitment by local-origin Yellowstone Cutthroat Trout with fluvial or adfluvial life histories drive persistence in these sites. In contrast, hybridization was rare or absent in headwater populations and was associated with complete or apparent physical isolation. We also compared genetic diversity of our samples with Yellowstone basin Yellowstone Cutthroat Trout and Bear River Bonneville Cutthroat Trout O. c. utah to examine possible historical gene flow resulting from hydrogeological connections during the Pleistocene. Multivariate analysis showed that most genetic variation among individuals was explained by divergence of Yellowstone basin Yellowstone Cutthroat Trout from our samples and Bear River Bonneville Cutthroat Trout, which supports recent mtDNA studies and a possible change in taxonomic nomenclature. Our results indicate that, due to relative isolation and downstream emigration, headwater populations are critical to the persistence of Yellowstone Cutthroat Trout and thus loss of such populations would likely threaten the subspecies throughout the region. Management actions to reduce threats from established, nonnative Rainbow Trout populations will likely have to be multifaceted and may include a combination of targeted removal of Rainbow Trout and hybrids and the use of physical barriers to prevent further dispersal. © American Fisheries Society 2016.
News Article | November 13, 2015
The tribes' opposition marks the latest turn in the saga of a massive, ferocious predator driven to widespread extermination by overhunting and trapping early last century. It also adds a new, cultural dimension to a wildlife controversy that previously centered on disagreements over science and how many bears are enough. A former chairman of Arizona's Hopi Tribe, Ben Nuvamsa, says his people regard the grizzly as an "uncle" who possesses strong healing powers and plays a central role in traditional ceremonies. He said tribes want to "keep it from being a trophy animal and prevent the industrialization of bear habitat." "We regard him as part of our family, and it's really important to all of us natives to keep him around," Nuvamsa added. "It doesn't matter where the bears are. We pray to them when we see them." U.S. wildlife officials and their state counterparts in Montana, Idaho and Wyoming contend the region's 700 to 1,000 bears are biologically recovered. They've been pushing for almost a decade to revoke the animal's threatened status, a step that was taken in 2007 only to be reversed by a federal judge two years later. Removing federal protections would put the animals under state management and open the door to limited trophy hunting. Wildlife officials in Montana, Idaho and Wyoming have advocated future hunts as a way to help them deal with problem bears. Since the 2009 court ruling, government biologists have sought to bolster with new research their conclusions that bear food supplies are not threatened by climate change and other factors. They've also pledged that some habitat protections would remain in place regardless of the animal's legal status. A decision on whether to propose a rule to lift protections is expected in the next several months. No such proposal is pending for the only other large concentration of grizzlies in the Lower 48, an area around Glacier National Park in northwest Montana and southern Canada with an estimated 1,000 bears. Rising numbers of conflicts between bears and humans have further complicated the upcoming decision on bears in the 19,000-square-mile Yellowstone region. Since 2010, grizzlies have killed six people in and around Yellowstone and regularly maul hunters and domestic livestock outside the park. Such occurrences have fueled opposition to continued protections within the ranching industry and among state officials. U.S. Fish and Wildlife spokeswoman Serena Baker says the agency will try to balance the tribes' concerns against science that shows the grizzly bear population has rebounded in the Yellowstone region since protections were imposed in 1975. Endangered Species Act decisions typically are guided by what's known under the law as the "best available science," but Baker said the tribes' views also would be taken into consideration. "They have a very deep connection to the land and the animals and the environment," she said. "We certainly want to respect that." But leaders of dozens of tribes across the U.S, most of them west of the Mississippi River, have called for a halt to the process. They said they have been denied formal consultations over an animal that was once widespread across their ancestral homelands. Consultations on matters affecting tribes are required under treaty obligations and prior White House executive orders. Grizzly bears lived across much of the West until hunting and trapping eliminated them from more than 98 percent of their historic range in the Lower 48 states. "These are our treaty lands, our ancestral homelands," said Shoshone Bannock Tribes Vice Chairman Lee Juan Tyler. "Too many times in our relationship with the federal government we have surprises. ... We want the grizzly bear protected with those lands, and the grizzly bear returned to areas where we can co-manage them." Federal officials said they've consulted with five tribes to date in Montana, Idaho and Wyoming. Discussions with two others are planned, and Baker said letters have been sent to more than 50 tribes inviting them to join the process. "We need to hear from them on when and where we can meet, because we are ready to meet at any time," Baker said. Explore further: Fed judge says grizzlies still threatened