Politics Appears To Influence Arctic Grayling Decision

This August the US Fish and Wildlife Service (FWS) reversed an earlier 2010 ruling that Arctic Grayling in the Upper Missouri River system of Montana were endangered (but precluded from listing under the Endangered Species Act due to higher priority species).

Instead the Service decided that as a result of cooperative efforts by ranchers in the Big Hole River drainage (one of the last strongholds for grayling) and other conservation measures such as efforts to restore grayling to the Ruby River, the fish no longer warranted listing under the Endangered Species Act.

But a closer reading of their listing decision demonstrates that once again it appears that political expediency triumphed over biological realities. Indeed, in some parts of their remaining range like the Big Hole River, due to very low population numbers of mature Arctic grayling, the fish may be just one prolonged drought, disease outbreak, flood or other extreme event away from extinction.

Extinction seldom happens suddenly. It’s the local extirpation of one small population after another that ultimately drives a species like the grayling over the line and extinction. With the mature grayling numbers so low in much of its existing habitat, the FWS is playing Russian Roulette with the fish’s future.

First, though grayling have been reintroduced into a few additional streams, its numbers are still precariously low.  Furthermore, the fish is still absent from 90% of its historic range. Under the ESA a species that missing from a “significant” amount of its historic habitat still deserves ESA protection. Obviously when the grayling is found in less than 10% of its former habitat, one can argue that this is a “significant” reduction in its range.

Second, with the exception of a few small populations in Red Rock Lakes and perhaps one or two other lakes in the Big Hole drainage, historically grayling were only found in rivers and streams.  It is the river dwelling fish (known as fluvial) that have declined significantly across its historic range.

In what can be considered a bait and switch to “improve” population estimates for the fish, the FWS now includes not only grayling found in historic river habitat, but fish that had been introduced into other lakes as part of its overall population estimate, in part, because lake dwelling fish are not subject to environmental problems like low flows in drought years and are typically better adapted to hatchery life.

Yet there are clear behavioral and likely genetic differences between fluvial (river dwelling) and adfluvial (lake-dwelling) fish.  Inclusion of lake-dwelling fish pumps up the population without an appreciable increase in river dwelling grayling.

This would be somewhat analogous to including all the resident hatchery-sustained populations of rainbow trout that do not migrate to the sea in estimates for steelhead populations (steelhead are a sea-run rainbow trout) to conclude that declining steelhead are not in need of protection.

Third, there is no attempt to determine the minimum viable population (MVP) for fluvial graying in rivers like the Big Hole. Even though recent population counts (taken during years of high water flows) appear to show population increases, whether the higher fish numbers are adequate for long term viability is not disclosed.

Additionally we don’t know if higher fish numbers are merely an artifact of greater survey effort. No matter, the current population estimates put adult breeding grayling at no more than a few individuals per mile of river habitat–a ridiculously low number of fish.

Keep in mind that as recently as a few years ago, there were estimated to be around 100 breeding fish in the Big Hole River and tributaries. Recent estimates (during high water years) now put the number of effective breeders at less than 400 fish in the entire 80 plus miles of the Big Hole River drainage where grayling are currently found. That’s an average of 5 fish per mile! Would any legitimate biologist argue that 2 breeding fish per mile is adequate for long term population viability?

Just because there has been an increase in fish, doesn’t mean there are enough fish to sustain them over the long haul. Until grayling numbers are high enough to be viable over the long haul, the FWS should do the prudent thing and list the species. They can always delist when they demonstrate there are sufficient fish to maintain them over the long term, as well as no new threats.

Fourth, the Service seems to be putting a lot of emphasis on the fact that there are Candidate Conservation Agreements with Assurances (CCAA) and other measures in place, suggesting these will recover the fish without federal intervention or listing. Yet CCAA are voluntary and have no force of law.

Furthermore there is not sufficient evidence at this point that these measures are actually contributing to the protection and long term survival of the fish. Recent slight improvement in fish numbers may be as much as result of higher water flow years than any consequence of the CCAA. A prudent course of action would be to list the fish, and delist if future surveys demonstrated that these measures actually were contributing to significant fish recovery.

Fifth, these agreements call for minimum flows in the Big Hole River, yet the targets have not yet been met. Worse, the targets are based on historic normal or above average snowpack and flows. Yet even an elementary school child would recognize that what determine fish population viability isn’t the normal flow years, but how many fish survive low flow years.

At present summer water temperatures, even in years of normal flow, are above the lethal temperature for grayling. Using “normal” flow years as your yardstick when clearly low flow years determine the viability of fish is like suggesting that one can grow corn or tomatoes based the “average” July day temperature, ignoring the fact that it is the night time low temperature that determines where one can reliably grow corn or tomatoes.

Water is diverted from the Big Hole River associated with irrigation use for growing hay for livestock, irrigating pastures for livestock, and watering livestock.  Return waters, are only only diminished, but are also much warmer.

Also, large expanses of riparian habitat (like downstream of Wisdom) have been virtually denuded of native vegetation that would have provided cooling shade (as well as invertebrate food and cover from predators) and instead allow the stream water to warm up in the bright sun of the Big Hole Valley.

In many cases, springs, that would naturally provide 60-degree cooling, sustaining flows to tributary streams have been “developed”, rather more properly termed kidnapped or stolen and sent for livestock needs – stock tanks, stock ponds, irrigated crops and pastures.

Livestock damage to banks and riparian areas plus diminished flows, streams have incised, simplified, and dropped water tables.  This results in much shallower, easier to heat streams and pools that are disconnect from natural riparian seeps, springs, wetlands, and eventually death of cooling springs, seeps, wetlands with alluvial water dropping and dropping.

Sixth, since the bulk of the grayling current distribution in the Big Hole River is on private lands, some biologists believe listing would have little real impact on grayling survival. ESA listings typically have much greater influence upon federal agencies than private individuals. Yet this ignores how rivers are connected.

Livestock grazing and logging on federal lands for instance, can affect downstream water quality and quantity. Trampling of riparian vegetation and streambanks by cattle can contribute to greater sedimentation and affect spawning habitat as well as fill deep pools needed for overwintering fish. Some studies even suggest that soil compaction of small first order streams, springs and seeps can reduce late season flows by up to 50%. And it is the late season flows that are critical to grayling survival.

In short, the FWS has abrogated its responsibly to protect the Arctic Grayling by using any excuse it can dream up to avoid a listing. One can’t use the excuse we think CCAAs and other conservation measures will save the grayling–the FWS has an obligation to list the fish until such measures are actually proven to be effective, and more importantly, effective enough to provide for a significant restoration of the fish across most of its historic habitat. Until then, the FWS should list the grayling.

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