But that appears to be the conclusion of this story from the San Francisco Chronicle.
In recent decades, Lake Tahoe has grown murkier and murkier, with people quick to blame obvious culprits: a rise in tourism and development, along with fluctuations in drought conditions and rainfall.
But an unlikely crustacean culprit may also play a role in the story of the lake’s decreasing clarity, some researchers now believe, according to the annual State of the Lake report from the Tahoe Environmental Research Center at UC Davis.
Mysis shrimp were introduced to Lake Tahoe in the mid-20th century by what was then called the California Department of Fish and Game, with the hope they would provide a food source for the mid-sized fish that lake goers enjoyed catching on fishing trips, like the Tahoe angler.
“It was a deliberate introduction,” said Professor Geoffrey Schladow, director of the Tahoe Environmental Research Center.
But things didn’t go according to plan once the shrimp, which measure about a half inch-long, were in the water.
“So the net result was that the food supply for the fish went down, the fish got smaller and Tahoe was left with an invasive species,” Schladow explained.
Changes in the water at Emerald Bay, about 12 miles north of South Lake Tahoe, were a surprising clue that the shrimp might have an effect not just on the fish, but also on the clarity of the water. For some reason that researchers don’t fully understand, several years ago the Mysis shrimp disappeared from Emerald Bay. In the time that followed, populations of bosmina and daphnia zooplankton started to come back.
“What took us by surprise is once we had the daphnia back there, the clarity of Emerald Bay improved by something like 40 feet in a year, which is a huge change,” said Schladow.
“The hypothesis this brought to mind for us is that maybe these native zooplankton that had been removed by the Mysis had been serving this role of keeping Tahoe’s water clean by the way they feed,” he said.
Retrieved August 4, 2018 from https://www.sfgate.com/science/article/mysis-shrimp-zooplankton-key-clearer-Lake-Tahoe-13121278.php