Monday, June 23, 2008

Week of June 22

Officials Unsure What Is Causing Absence Of Weeds

By Patrick Fanelli

Nobody knows why, but there is something conspicuously absent from the waters of Chautauqua Lake, New York.

Drive past places like Burtis Bay, and the red tint and still water that is normally a symptom of the lake’s Eurasian milfoil epidemic are gone. So, too, are the weed clippings that clog up the shoreline.

For the past few years, the invasive weeds were in full bloom by this time of the year. While one can’t say for sure what is hindering weed growth all over Chautauqua Lake, county lake officials only hope it stays this way into the busy summer season.

‘‘The weeds, I’m guessing, are probably two weeks behind, and that’s a good thing,’’ said Bill Evans, Chautauqua Lake Management Commission chairman. ‘‘So something is going on. As a matter of fact, we’ve been having quite a bit of discussions about it.’’

While Evans jokes about how tempting it is to credit the efforts of the variety of lake organizations that comprise the CLMC, he believes Mother Nature deserves the credit.‘‘Mother Nature has certainly been good to us so far,’’ said Evans, who owns a lakeside home on Summit Street in Lakewood. ‘‘It’s not hard to see. (The weeds) are not nearly as high as they should be as we approach the end of June.’’

In recent years, relatively warm winters resulted in an ice cover that was unusually thin and broke an abnormally high number of times, allowing a greater amount of sunshine into the water — and this was sometimes blamed for the explosive growth in 2006 and 2007. While no one can say for sure whether this really was one of the causes, an inadequate ice cover wasn’t a factor this past winter.

‘‘That deterred the weeds somewhat, but then when it got warm in April, I got nervous,’’ said Karen Rine, who heads the Chautauqua Lake Partnership, a group that advocates for the spraying of herbicides in certain parts of the lake to hinder weed growth.

For the most part, though, the weeds still haven’t grown to the surface of the water. ‘‘I really don’t know why, because the conditions were optimum in the spring — but there was an awful lot of wave action on the lake. That’s my take,’’ said Mrs. Rine, who lives along the shore of Burtis Bay in Celoron.

While the region may have enjoyed some pleasant days this past spring, temperatures across the board were lower than normal, says Evans — a factor that may also have contributed to the slow weed growth.In addition, Robert Johnson — who manages Cornell University’s Research Ponds Facility and studies Chautauqua Lake’s weed infestation — is exploring the possibility that weed-eating insects are slowing down the weed growth, according to CLMC officials. Article


Invasion of alien snails: what to do about them

The gummy-looking, droplet- like clusters of pink eggs that clung to the bank of the pond appeared harmless enough, but S.C. nature officials are worried the snails that hatch from those eggs could pose a health risk and cause widespread ecologi cal damage.

The island apple snail has been found for the first time in South Carolina in about a dozen ponds in the Laurel Woods subdivision and the Heron Point Golf Club off S.C. 707.

Now, offi cials are trying to eradicate them before they spread to the Waccamaw River, which would make containment efforts much harder.

"Ideally, they would be exterminated," said David Knott, a marine biologist with the S.C. Department of Natural Resources. "If it's feasible, and we can do it without causing environmental damage, that's what we'd like to do.''

The snail could eat just about all the plants in a pond, and displace and even feed on native snail populations, Knott said.

The snail also carries a parasite that could cause fatal menin gitis and can transfer to people if it is handled without gloves, although Knott said he was unaware of a case in the U.S.

The island apple snail, indi genous to South America, is one of several apple snail species. Of greater concern to biologists is the channeled apple snail, which can devour rice and taro crops and is the 73rd worst invasive species in the world, according to the Global Invasive Species Database.

The channeled apple snail has been found in Arizona, California, Hawaii and maybe Alabama, according to a DNR press release.

The island apple snail as been introduced in Texas, Florida and Georgia, the press release said.
The island apple snail cannot survive for long in water below 50 degrees, but it can burrow into the ground if the temperatures drop. Overall, South Carolina appears to be just warm enough for the snails, Knott said.

To get rid of the snail, the DNR is spraying copper sulfate, a federally approved pesticide, in the infested ponds. The blue, granular substance will also kill algae but should not have any other detrimental effects.

Michael Hook, a field supervisor with the DNR's aquatic nuisance species program, said he sprays about 10 feet from the edge of the pond, where most of the snails live. The DNR plans to treat the infested ponds once a month throughout the summer, he said.

SC Dept. of Natural Resources. (803) 734-9100 Article


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