Pinedale fisheries managers for the Wyoming Game and Fish Department have begun the final phase of the Dollar Lake restoration project, stocking fish! Last week approximately 2000 rainbow trout and 250 tiger trout were stocked into the lake that had to be cleaned out this past August as it had become dominated by non-native white suckers. The fish stocked were 6-8 inches in length. The plan is to stock the same number and size of fish each year beginning next May. With little competition, fish managers expect the fish just stocked to double in size by next summer. Dollar Lake is adjacent to the Green River approximately 35 miles north of Pinedale.
The non-native and invasive white sucker has a history of taking over many fish populations by out-competing other fish, in this case rainbow trout. In 2007, Pinedale fish biologists first discovered white suckers in Dollar Lake. Since then, white sucker numbers had grown exponentially to where they accounted for 99 percent of the fish population in the lake.
The best means of dealing with such a situation is to completely eradicate the suckers through the application of a fish toxicant, such as rotenone, that will remove all the fish. Rotenone has been successfully used by fish managers for decades to remove undesirable fish species in many places. While rotenone is toxic to fish, it is not harmful to humans or other wildlife.
In addition to restocking rainbow trout, tiger trout, a brown trout – brook trout hybrid, have been introduced into the lake this time. Tiger trout are known to prey on other fish and will be used to prevent the future establishment of another white sucker population. The rainbow trout that have been stocked in Dollar Lake are too large for most tiger trout to eat.
Given the popularity of suckers as a live baitfish in other parts of the state, it is suspected that the white suckers may have been introduced into Dollar Lake by illegal bait fisherman. Anglers are reminded that the dumping of bait buckets or the intentional translocation of fish is strictly prohibited for this reason.