Conservation Issues
Both Whirling Disease and Acid Rain are critical issues that should concern anyone interested in trout conservation across North America, and particularly in pristine Jackson Hole.
Whirling Disease
Whirling disease is a parasitic infection which attacks juvenile trout and salmon, but does not infect warm water species. All species of trout and salmon may be susceptible to whirling disease. Other members of the trout and salmon family, such as mountain whitefish are also at risk. Rainbow trout and cutthroat trout appear to be more susceptible than other trout species. Brown trout become infected with the parasite, but they appear to have an immunity to the infection and have not been as greatly impacted as rainbow trout. Studies in Montana and at the University of California-Davis have demonstrated that grayling and bull trout are very resistant to infection. Learn more about whirling disease at the Whirling Disease Foundation.
Acid Rain
Acid rain is rain, snow or fog that is polluted by acid in the atmosphere and damages the environment. Two common air pollutants acidify rain: sulphur dioxide (SO2) and nitrogen oxide (NOX). When these substances are released into the atmosphere, they can be carried over long distances by prevailing winds before returning to earth as acidic rain, snow, fog or dust. When the environment cannot neutralize the acid being deposited, damage occurs. Learn more about acid rain at this website.
New Zealand Mud Snails
Stories abound of adventuresome trekkers hitchhiking across New Zealand,
however adventuresome New Zealand mud snails hitchhiking their way across
Wyoming is no story -- it's fact.
Several brown BB-sized snails were collected from the Bighorn River near Thermopolis in September during a routine fish management survey. The snails were thought to be mud snails. Ecologist and snail expert Dr. Dan Gustafson, Montana State University, confirmed local managers suspicions. The snails were New Zealand mud snails, an aquatic nuisance species invading western waters.
New Zealand mud snails are tiny, growing to only 5mm in length. However, their size can be deceiving. "The mud snail reproduces rapidly to form colonies which can sometimes cover the habitat of important native trout food like may, stone and caddis flies," said the Game and Fish Department's Cody Region Fisheries Supervisor Steve Yekel. Although trout eat mud snails, they are very indigestible and are a poor food source.
The exact impact mud snails will have on trout populations is not known. What is known is that mud snails are appearing in rivers that are popular with anglers. The Cody region is a popular fishing destination, and Yekel is concerned that the snails could become established in other drainages within the Bighorn Basin.
According to Yekel, snails can survive for long periods of time on waders, in live-wells, and when carried on boats and trailers. "Mud snails, like many aquatic nuisance animals are true hitchhikers. They cannot move great distances by themselves--they are transported. Anglers are encouraged to clean their equipment when moving from one fishing area to another," Yekel said. "The best precaution anglers can take is to use a solution of three-quarter cup of chlorine bleach per gallon of water to disinfect their equipment; a thorough rinsing is recommended."
New Zealand mud snails were first detected in central Idaho's Snake River in 1987. They spread rapidly into Yellowstone National Park's Firehole, Gibbon, Nez Perce, Madison, Upper Snake and Gardiner rivers. New Zealand mud snails are now established in rivers in seven western states, three national parks and Lake Ontario. (reprint from Wyoming Game and Fish Department)