Trout Fishing Tips

Biologist have been watching the number of Yellowstone Cutthroat trout decrease for years, but each year the numbers are more alarming.

Yellowstone Cutthroat trout are a subspecies of Cutthroat trout and are native to Yellowstone Lake (where they get their name). Originally, they were found throughout northwest of Wyoming and sub-central Montana, but today 91% of the remaining trout are found in Yellowstone Lake and River.

Like other threatened trout species, hybridization and competition pose the biggest threat to Yellowstone Cutthroat trout - and Lake trout are believed to the major the culprit threatening the survival of these native Cutthroat trout.

Lake trout are not native to their area. They were first discovered in Yellowstone in 1994, although some believe they may have been there since 1989. Who brought them there is unknown - but authorities do believe that somebody planted Lake trout in Yellowstone illegally.

Despite the state's efforts to control Lake trout populations, these trout continue to populate at a high rate and thrive. This story offers further evidence of what can happen when non-native trout are introduced in other water systems, and why it can be a bad thing.

For more information about the problem and recovery effort for Yellowstone Cutthroat, click here.

Labels: Cutthroat Trout, hybridization, Lake Trout, Yellowstone Cutthroat trout

As mentioned yesterday, hybridization is the interbreeding of trout species. Many fish (especially trout) interbreed with other species. Over time, this can lead to a species' survival being threatened.

Arizona is home to the Apache and Gila trout. With the exception of the Gila trout (which can also be found in New Mexico), these twp species don’t exist anywhere else in the world. Due to hybridization, their survival has been threatened and they’ve been on the Endangered list since 1967.

But thanks to the Arizona Fish and Game Department teaming up with other organizations, these two species not only survive today, but are making a comeback!

These agencies have been sterilizing certain rivers and lakes to kill off unwanted fish and plant Apache and Gila trout into these waters. In doing so, these trout species have an opportunity to survive and repopulate the waters.

In 2006 the Arizona Fish and Game Department sterilized the West Fork of the Little Colorado River to remove Rainbow and Brook trout which were threatening Apache trout. Once it's been confirmed that Rainbow and Brook trout have been successfully removed, the river will be restocked with Apache trout.

The process of sterilization is very safe and interesting. A very small concentration of an EPA approved chemical (Antimycin) is introduced into the river. Antimycin is actually an antibiotic developed for human use. In this case, it interferes with the fish's ability to exchange oxygen within its cells; thereby removing unwanted fish from the stream. At specific doses, it can remove some fish without affecting others.

Antimycin is neutralized by applying potassium permanganate, which oxidizes the Antimycin. After a couple days, fish can be restocked.

One of the biologists involved in the project told me that they hope to take Apache trout off the Engendered list by next January.

If you'd like to read more about the Apache trout recovery project, click here.

Labels: Hybrid Trout, hybridization