At Yellowstone Lake, there's a new fishing regulation: No matter how many lake trout you catch, you can keep them. In fact, you have to. The compulsory open season is part of a desperate attempt by the Park Service to curb lake trout, a species dumped illegally in the lake (HCN, 9/19/94).
trout are bad news because they prey on cutthroat trout, one of
just two native fish species in Yellowstone Lake. Cutthroats are a
nutritional staple for 43 animal species, including the threatened
grizzly bear. The cutthroat also supports a fishing industry valued
at $36 million annually.
Anglers confirmed the
existence of lake trout in 1994, but netting indicates that the
species has been present much longer: Park staffers recently caught
a 20-year-old female weighing 21 pounds. In contrast, cutthroat
trout rarely exceed 4 pounds.
This summer, the
Park Service has been probing for lake trout hot spots and
experimenting with different kinds of nets. Large-scale
gill-netting will begin next year, and may continue in perpetuity.
On the advice of fish biologists, the park has given up its initial
goal to eradicate the trout invaders. Now, officials say, they hope
only to keep the invaders under control.