Environmentalists Sue Governmental Agencies in an Effort to Help Pallid Sturgeon in Montana Rivers

by Trevor Smith

The Bozeman Daily Chronicle reports that two environmental activist groups have filed a lawsuit early this week against the U.S. Army Corps of Engineers, the Fish and Wildlife Service, and the Bureau of Reclamation (Lundquist 2015). The Natural Resources Defense Council and the Defenders of Wildlife’s suit claims that these agencies’ operation of dams on the Montana and Yellowstone Rivers threatens the life of pallid sturgeon. The suit hopes both to stop the agencies’ current actions, which it claims will be ineffective in helping the fish survive, and to force the agencies to create a new dam modification plan.

Pallid sturgeon have been listed as endangered since 1990, and although their population is estimated to have increased somewhat since then (Brown 2015), biologists assert that the upper Missouri River pallid sturgeon fish population rests at approximately 125 fish, almost all of whom are older—younger fish are not surviving (Lundquist 2015).

The problem comes from the way the two dams in question work. A study published by the American Fisheries Society in Fisheries last month makes the novel claim that one of the main reasons the dams threaten pallid sturgeon is not because of their difficulty passing through the dams, but because the dams slow the speed of the water, creating anoxic “dead zones” that lack enough oxygen for the fish to survive (Guy et al. 2015). The study is notable in that it focuses on the effects of dams on fish survival upriver of the dams, noting that dams make life more difficult for pallid sturgeon miles before they attempt to cross the dam.

The lawsuit cites this evidence to argue that the U.S. Army Corps of Engineer’s current plan to aid pallid sturgeon survival—increasing the width of side channels for fish to navigate through dams—is unlikely to be particularly effective at increasing the size of the sturgeon population (Brown 2015).The lawsuit seeks both to block this current plan and to require governmental agencies overseeing the dams to make different modifications to improve the health of the rivers for the pallid sturgeon.

Tags:

Pallid Sturgeon, Endangered Species, Dams, Lawsuits, Natural Resources Defense Council, Defenders of Wildlife, U.S. Army Corps of Engineers

Brown, Matthew. “Advocates: Dams Put Dinosaur-Like River Fish at Risk.” ABC News. February 2, 2015. http://abcnews.go.com/Technology/wireStory/advocates-dams-put-dinosaur-river-fish-risk-28673490

Guy, Christopher S., Treanor, Hilary B., Kappenman, Kevin M., Scholl, Eric A., Ilgen, Jason E., Webb, Molly A. H. “Broadening the Regulated-River Management Paradigm: A Case Study of the Forgotten Dead Zone Hindering Pallid Sturgeon Recovery”. Fisheries. http://news.fisheries.org/broadening-the-regulated-river-management-paradigm-a-case-study-of-the-forgotten-dead-zone-hindering-pallid-sturgeon-recovery/

Lundquist, Laura. “Groups sue to save endangered pallid sturgeon”. The Bozeman Daily Chronicle. February 2, 2015. http://www.bozemandailychronicle.com/news/environment/groups-sue-to-save-endangered-pallid-sturgeon/article_38667c30-9954-5d29-83c2-18a6bff32634.html

Can Pacific Salmon Adapt to Climate Change?

by Emil Morhardt

Chinook (king) salmon deposit their eggs in the cobbles of Pacific Coast streambeds, where they, and the subsequent developing juveniles spend months before heading out to sea. Some of these streams can get quite warm by salmon standards, and more than one major run has been heavily depleted by temperatures higher than 24 °C which seems to be generally lethal to this species. As global warming progresses we can expect more salmon streams to reach this temperature, so an important question is whether these fish have either the developmental plasticity or the genetic variability that will allow them to adapt. Muñoz et al. (2015) crossbred 16 wild chinook salmon caught at Canada’s Quinsam River Hatchery so as to get 64 different genotypes, then reared half of them at the hatchery ambient water temperatures and the other half at temperatures 4 °C higher. They then looked to see if cardiac function, the apparent limiting factor in high temperature mortality, was shifted to higher temperatures. Continue reading

Western Australian fish populations Response to Climate Change

Population distribution changes for Australian fish could provide scientists with a useful tool in predicting the effects of climate change.  Bond et al. (2011) examined 43 species of Australian freshwater fish and quantified their results into species distribution models (SDMs).  The SDMs provided a useful approach for examining predicted range shifts and provided a clear way of describing the types of environment in which these species of fish will be encountered. When SDMs were combined with future climate scenarios the models predicted future population and range shifts that in some cases described total population loss. In conclusion the author’s remark on their ability to predict current and future distributions using statistical models but that the models are just a step and future efforts in mechanistic modeling and in climate scenarios will be needed to further understand the effects of climate change on fish species.
Bond, N., Thomson, J., Reich, P., Stein, J., 2011. Using species distribution models to infer potential climate change-induced range shifts of freshwater fish in south-eastern Australia. Marine and Freshwater Research 62, 1043—1061.    

            Bond et al. used fish distribution data from survey records drawn from the Victorian Department of Sustainability and Environment’s Aquatic Fauna Database (AFD). In gathering these data they excluded sites below large impoundments because of markedly atypical behavior created by those sites.  They gathered their environmental data from a digital elevation model (DEM), which characterized stream networks all across Victoria. To enhance model sensitivity they restricted the environment data to areas that fish had been officially surveyed and recorded. For the data characterizing river flows, they used gauge data from 120 unregulated sites around Victoria that had significant records to quantify water flow patterns. Although high flow events couldn’t be modeled, they predicted that this would be offset in their model by the large effect that low flow events have on fish distribution. Their climate scenarios came from changes in temperature, precipitation, and evapotranspiration (the water put back into the atmosphere by plant respiration and evaporation). These scenarios corresponded to low, median, and high estimates for 2030, and were run in tandem with hydrologic model data. The statistic modeling was based on a system of boosted regression trees, a form of model averaging; model fit was based on residual error (R2).
            Their results showed only five of their water flow models (hydrologic models) could be confidently predicted, with high water flow characteristics showing very poor residual error (R2<0.4). The SDMs for the current fish populations were extremely accurate, with only two species with inaccurate predictions. They ran the climate scenario prediction for domestic and exotic fish species and found the results differed, but overall the species showed strong and consistent range patterning.
Their overall goal of making SDM’s to describe historical distributions of the 43 specifies of fish was accomplished successfully. The climate scenarios that were found could provide a useful approach to examine future range shifts. BRTs (Boosted Regression Trees) successfully carried out the model’s predictions and their capacity to fit non-linear response functions helped describe species response to environmental changes. Bond et al.analysis suggests that the non-linear associations of water flow/climate variables is common, thus why the BRTs are such an extremely useful modeling tool.
SDMs showed the combined impacts of altered temperature and water flow patterns rising from climate change in south-eastern Australia caused distribution and population changes in freshwater fish.   One of the main findings was that the fish shifted up along an elevation gradient, and also south in direction in response to the climate change scenarios. Although the results are just models the authors suggested they represent an important step in finding the long-term understanding of finding climate change impacts and their response strategies.