Storms brew over crawfish
January 11, 2013
Tahoe Lobster Co., the first commercial fishing operation to come to Lake Tahoe since the 1930s, drew national attention, but it’s also worried some regional outfitters who say fish like the trout and mackinaw rely on the crawfish for food.
Gene St. Denis, operator of Blue Ribbon Fishing Charters, started fishing Lake Tahoe in 1981. A trophy trout and light tackle specialist, St. Denis said 50 to 70 percent of the fish he reels in have crawfish in their stomachs.
“They’re a significant food source for the freshwater fish of Tahoe. Saying the crawdads aren’t a primary food source for the fish isn’t good science,” St. Denis said.
But stomach content can sometimes be misleading, according to University of Nevada, Reno limnologist Sudeep Chandra.
The food located in a stomach offers only a snapshot of a diet and not necessarily the animal’s long-term energy source. The scientific data Chandra’s seen indicates that while the trout and mackinaw do feed on crawfish, Mysid shrimp compose the bulk of their caloric intake.
To dive into Lake Tahoe is to get ensnared in a web of non-native versus invasive species. It’s a question of semantics that ultimately comes down to whether or not an introduced species is harmful to the environment and what sort of values society places on the animal.
Mysid shrimp were introduced to the ecosystem in the 1960s to help improve fishing in the mountain lake. The animals, which are about the size of a quarter, proliferated and now number in the tens of millions. Though the shrimp are dubbed a non-native species, Chandra said that could be argued from a scientific perspective since the animals affect carbon dynamics in the lake.
The trout and mackinaw that feed on both the crawfish – another invasive that’s been linked to water-clarity issues – and the shrimp were also introduced.
Chandra estimates that there are about 7 million pounds of crawfish crawling in Lake Tahoe. Tahoe Lobster Co. has brought in about 4,500 pounds since they started hauling in traps last summer, according to TRPA senior fisheries and wildlife biologist Patrick Stone. That’s not even 1 percent of the total number of crawdads.
“Unless the commercial operations really ramp up, there’s pretty much no way you could eliminate the crawfish population in the lake,” Chandra said.
St. Denis agrees that Tahoe Lobster Co. won’t make much of a dent in Tahoe crawfish populations. But since the Tahoe Regional Planning Agency approved permits for four more crawfish-harvesting start-ups last month, St. Denis said he’s worried that might change.
Tahoe fishermen have posted on the fishing forum website, ImHooked.com, to express their concerns about the crawfish harvest. Some writers were worried about snagging the submerged traps or about currents that would shift the traps to deeper water and make them unrecoverable.
Tahoe Lobster Co. Owner Fred Jackson knows there are a lot of questions circulating the community. That’s why he’s scheduled a February meeting in Carson City where he plans to address some of the concerns raised by sports fishermen. Jackson said he can only talk about his business, but he hopes the meeting will spark more collaboration between the parties.
“I don’t know how to approach it. It’s almost like a ‘kill Frankenstein’ mentality. Pitchforks and flames. The trout-fishing community has their way of doing things and we have ours. But science is on our side, and myths on theirs,” Jackson said.