Monday, August 30, 2010

Big Hole Watershed Committee: Low Flows Imperil Grayling

The US Fish & Wildlife Service is under a legal agreement to make a decision regarding Endangered Species Act status for the Montana fluvial Arctic grayling (aka Big Hole River grayling).

The agency may try to weasel out of this based on conservation agreeements ("CCAA") with local irrigators (ranchers use Big Hole River water to grow hay for cattle). When it comes to minimum instream flows, however, the CCAA is a failure: flows are well below what is needed for grayling survival. And when it comes to restoring grayling, the CCAA is a failure: grayling population estimates have declined continually despite US FWS agreements with irrigators.
Today's Grayling Survival Index = -40. An index of "zero" marks the minimum sustainability point. Below that, recruitment and survival are likely to be so low that the population is in decline. Montana's Big Hole River is home to a rapidly declining population of fluvial Arctic grayling--the last such population in the lower 48 states.


Despite an exceptionally wet, cool summer, Big Hole ranchers in the upper river basin (from Wisdom upstream) are seriouly dewatering the river. Current flows at Wisdom are hovering around 40 cubic feet per second (cfs)--well below the lower wetted perimeter of 60 cfs, the level at which the carrying capacity of the river channel habitat rapidly falls off. According to fisheries biologists, the lower wetted perimeter is the rock-bottom minimum flow needed to sustain a species.

The Big Hole Watershed Committee has a so-called "Drought Management Plan." Given the low flows, why has the Committee not implemented this Plan? Does the Committee actually desire to exterminate the few remaining grayling before the U.S. Fish & Wildlife Service can impose Endangered Species status?

Furthermore, where are "conservation" groups such as the George Grant Chapter of Trout Unlimited and the Big Hole River Foundation in this process? Though the Watershed Committee is dominated by agricultural interests, the participation of TU and the Foundation legitimates the destruction of Big Hole River grayling.

Support groups such as the Center for Biological Diversity and the Federation of Fly Fishers--instead of fiddling while Rome burns, these groups are doing everything they can to stop this madness.