Pros and cons of lake weeds and algae

By KATHY PORTIE

Wednesday, August 22, 2007 11:01 AM PDT

Bright green algae is blooming on Big Bear Lake but there is no danger to humans, animals or plants. In fact, this strain of algae is a source of food for fish and ducks. (KATHY PORTIE/Big Bear Grizzly)

A dry winter and a hot summer made conditions ripe during Big Bear’s growing season. That may be good news for a gardener trying his luck in the backyard, but it’s been bad news for Big Bear Lake.

Eurasian milfoil has popped up in several places in the lake this summer, primarily along the North Shore. The invasive weed has been the bane of personal water craft, choking their engines. A film of green algae has also been noticeable in coves and along the shoreline. Neither pose a danger to humans or animals, according to Scott Heule, Big Bear Municipal Water District general manager.

milfoil is enemy number one for Mike Stephenson, MWD lake manager. “Eurasian milfoil is causing us the most problem,” Stephenson said. “We went out this week and treated a few of the heavier areas.”

According to Stephenson, there are about 100 acres of milfoil in the lake. That may seem like a lot, but it is not the record. “We had more than 800 acres in 2001,” Stephenson said.

According to Heule it is not just the milfoil getting tangled up in boat and personal water craft motors. “The way to go is to stay out of the shallows where there is a lot of lake vegetation,” Heule said.

Stephenson is on a crusade to eradicate the invasive weed from the lake. He earned an herbicide applicator’s license from the California Department of Pesticide Regulation in March. “My goal is to make it go away forever,” Stephenson said.

The best pesticide to use on milfoil is Renovate granular. Stephenson expects the pesticide to be approved by the California Environmental Protection Agency this winter. Heule said the state’s approval process of the pesticide is slow, but moving forward. “It’s a pesticide that has never been used in California before, so it has to go through all the committees,” Heule said.

The pesticide is expensive, costing as much as $1 million to use. But it does the job, Stephenson said. “Renovate OTF kills only milfoil in this lake,” he said, adding that it won’t harm other plant life or animals in the Big Bear Lake ecosystem. He said the high price tag will be worth it if the result is to permanently rid the lake of the invasive weed.

The weeds will slowly disappear during the fall and winter when the water gets colder, Stephenson said. In the spring, when milfoil begins to actively grow, is when he hopes to use the pesticide.

Not all lake vegetation is bad, according to Heule. “Smart or pond weed provides good cover for fish and draws nutrients out of the soil,” Heule said. Smart weed has large reddish-green leaves and often floats on the surface. The plant is blooming with pink buds and can be found in Baker Pond and in Big Bear Lake shallows, particularly around Boulder Bay, Heule said.

As for the algae, Stephenson said he can live with the bloom that is floating on the lake. “I’m happy about it,” he said. “It’s a green nonodorous algae, not like last year’s brown algae. This will keep the brown algae away.”

Allen Mielak of Los Angeles comes to Big Bear Lake twice a month for a bit of fishing. He hasn’t noticed anything different, but is concerned about what the algae will do to fishing. “I think it would impact fishing because they eat that stuff,” Mielak said.

For Stephenson the extra source of food is a favorable thing. “Fish and ducks will eat it,” Stephenson said. And if it keeps the bad algae from muddying the water, it’s a scenario Stephenson is willing to accept.

Neither the milfoil nor the algae are responsible for the brownish color of the lake. Heule said the color is the result of sediment from the bottom being stirred up on windy days, mostly on the east end of the lake. “The lake is really green once you get west of China Gardens,” Heule said.

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