Are Lake Tahoe’s aquatic invasive species edible?
April 16, 2017
Invasive species have found their way into Lake Tahoe through motorized and man-powered watercrafts, fishing gear, waders, construction machinery and rafts. Mandatory watercraft inspections are critical to preventing further transportation of non-native species into Lake Tahoe.
Inspection stations are slated to open May 1 this year. The Meyers Inspection Station is located at 2175 Keetak Street, and the Spooner Summit Inspection Station is located at the intersection of Highway 28 and U.S. 50.
For more information, visit http://www.tahoeboatinspections.com.
Aquatic invasive species pose a significant threat to Lake Tahoe. The establishment of non-native species impacts the lake's clarity and can result in the loss of important habitat for native species.
While agencies like the Tahoe Regional Planning Agency and the UC Davis Tahoe Environmental Research Center are working to monitor, study and eradicate invasive species, some might wonder, "what can I do?" Well, for starters, you can eat them — or at least some of them.
Crayfish were first introduced into Marlette Lake, which feeds into Lake Tahoe, in 1895. More introductions followed, and today scientists estimate there are roughly 300 million crayfish in Lake Tahoe.
Though the crustaceans graze on algae at the bottom of the lake, they stimulate further algal production due to the nutrients they excrete.
Commercial harvesting of crayfish on the Nevada side of the lake has been allowed since 2012. In 2013 California followed suit, but the permitting process has still not been developed.
"They are at a level where we think we will never get a handle on them, so we allow the commercial harvesting of them," said Dennis Zabaglo, aquatic resources program manager at the TRPA.
Fishing for personal consumption is allowed on both sides of the state line.
In California, a fishing license is required to trap crayfish, but not in Nevada. Crayfish baskets can be found at sporting good stores and filled with bait like raw chicken to attract the crustaceans. There is no catch limit.
The Asian clam was first discovered in Lake Tahoe in 2002. In 2010, the clams also found their way to the entrance of Emerald Bay.
"They outcompete native species, and they potentially create these algal blooms because they are excreting nutrients in a concentrated format," explained Zabaglo.
So can you eat them?
"I think it does happen in other places that have them, but they are so small here that I don't think it's viable," said Zabaglo.
For divers not deterred by the small size of the catch, harvesting of the clams from Lake Tahoe is allowed in both California (with a fishing license) and Nevada.
The freshwater clam is a popular base ingredient in Asian soups and broths. It can also be pan seared and served over noodles.
Since a surge in the popularity of minute Asian clams for diners is unlikely, researchers are instead banking on the success of a pilot project involving 5 acres of rubber bottom barriers placed over the clam beds in Emerald Bay in 2012. The barriers, designed to cut the clams off from food, were removed in 2014.
CURLYLEAF PONDWEED AND EURASIAN WATERMILFOIL
Before you consider harvesting the curlyleaf pondweed and Eurasian watermilfoil taking over the lagoons of the Tahoe Keys to create a fresh-water version of a seaweed salad, think again.
"I've never heard of anybody doing that," said Zabaglo with a laugh. "You could clean them off I suppose, but they get pretty covered in algae so it's not something you'd want to eat."
Between 13,400 and 18,600 cubic yards of these weeds have been removed from the Tahoe Keys annually since 2011.
Stakeholders have been combating the issue for more than 25 years, using a variety of plant-fighting methods, including harvesting and fragment collection, dredging, bottom barrier mats, rotovating, dewatering, nutrient reduction and other biological controls.
The popular catch for Lake Tahoe's anglers is the mackinaw or lake trout, which is actually not native to the lake.
"It's a managed game species. They were introduced decades ago. It doesn't mean they don't have an impact, but they are not categorized as an invasive species," explained Zabaglo.
"The invasive fish species that we are more interested in are some of the warm water fish species like bass, blue gill, sunfish. They are mainly in areas like marinas, the Keys, and potentially tributaries where the water is a little bit warmer, a little more stagnant."
With a fishing license, these fish are available for catching and consuming in Lake Tahoe.
"We've done some electrofishing in the past, which basically you have a boat that puts out a current. We've mainly done it in the Keys' lagoons and channels. It stuns the fish, we collect them, put the natives back and introduced managed species back, and remove the invasives," explained Zabaglo.
"The fish have gone to soup kitchens, wildlife feeding, fertilizers and things like that. We haven't done that in a few years because we haven't had the funding."