Bull Trout

This week a survey of selected streams in northwest Montana near Glacier National Park reported an increase in Bull trout spawning beds (also called redds). Although the data is still being studied, this is encouraging news.

Bull trout (also known as Dolly Varden) are a threatened species which have been on the Endangered list since 1998. Today, they survive in only five states (Washington, Oregon, Nevada, Idaho, and in Montana west of the Continental Divide). They also survive in two Canadian provinces (Alberta and British Columbia). Bull trout were also found in Northern California at one time, but are now extinct there.

Bull trout spawn in September and early October. Adfluvial Bull trout are thought to spawn about every other year, perhaps because they need a year of rest after such a long migration journey. Most Bull trout spawners are 5 - 9 years old. The eggs hatch in the winter, and in spring the young fry emerge. Young Bull trout live among the streambed rocks for 1 - 3 years where they eat small aquatic insects, before migrating downstream to larger streams and lakes. Bull trout are predators and primarily eat other fish when adults.

These trout require very cold (usually less than 60 degrees Fahrenheit) and clean water to survive. Over the years, damaged habitat, over-fishing and the introduction of non-native fish have threatened the survival of Bull trout.

Industry is primarily blamed for damaging Bull trout habitats. Logging causes runoff into streams and rivers, sharply raising sediment levels and thus water temperature, leaving waters both too warm and too "dirty" for the fish. Sediment clogs pores in the gravel, reducing the flow of oxygen to eggs, preventing fry from emerging from the gravel.

Dams and improper culvert placement have also contributed to reducing Bull trout populations by cutting them off from reaching their natural spawning grounds.

Another threat to Bull trout are other species of fish, which compete for food and space. Young Brook and Lake trout can push out young Bull trout. Lake trout, a voracious predator, can prey on Bull trout. Brown trout, Pike, and Bass can also compete with or prey on Bull trout.

Brook trout can interbreed with Bull trout, creating mostly sterile hybrids. This interbreeding saps reproductive energy from the Bull trout population. Hybridization is also threatening the Apache and Gila trout (also on the Endangered list).

And if these weren't enough challenges for Bull trout, anglers are also a threat.

Bull trout are part of the "char" family which includes Brook and Lake trout. Bull trout look very similar to Brook trout and the two species are often confused. Anglers are responsible for being able to identify different trout species and for knowing the rules.

In Montana, it's illegal to even fish for Bull trout, let alone catch and keep one. The exception to this rule is Swan Lake. In Nevada and Idaho, you can catch Bull trout, but not keep them. They must be released back into the water immediately.

The rules are pretty similar in other states as well. Since Bull trout are often confused with other species of trout, it's important to be able to identify them. Here are some tips to help:

• Bull trout do not have black spots on their dorsal fins
• Bull trout do not have black lines following the white line on their pelvic, pectoral, or anal fins
• Remember, "No black, put it back"

When in doubt, it's better to release the fish then get caught possessing a Bull trout!

Just in case you were wondering, the recognized world record for Bull trout is 32 pounds. It was caught in Idaho's Lake Pend Oreille.

Test your knowledge of Bull trout by taking this online quiz!