2016-09-07 / News

Harmful algal bloom is confirmed to be present in Cannonsville Reservoir

DEP claims bloom has been contained to a small section
By Lillian Browne

A harmful algal bloom has been confirmed in the Cannonsville Reservoir at the Fish Brook Boat Launch in Walton.

According to New York City Department of Environmental Protection (DEP) spokesman Adam Bosch, the algal bloom is not widespread throughout the reservoir but contained in the upper arm.

The algae is contained in the vicinity of the Fish Brook boat launch off state Route 10 in Walton, in an area where reservoir depth is shallow and surface temperatures have been recorded near 80 degrees.

That, Bosch said, is a result of the long lasting high temperatures combined with a lack of rainfall over the past several weeks.

Not the first incident

The Cannonsville Reservoir is no stranger to algal blooms and was prone to the condition in the 1990s due to excess “nutrient load,” mainly phosphorus and nitrogen from farms and wastewater treatment plants. During that time period, he said, algal blooms were much larger and often required the DEP to shut down the intake chambers which divert water.

This instance differs, he said, because the bloom is not near an intake chamber and “there is minimal risk” of the bloom moving through the West Delaware Tunnel.

The amount of phosphorus flowing into Cannonsville Reservoir has been reduced by more than 95 percent over the past 20 years through wastewater treatment plant upgrades and by working with farmers to improve the quality of farm runoff through partnership programs with the Catskill Watershed Corporation and the Watershed Agricultural Council, Bosch said.

DEP scientists continue to monitor the bloom, which has cast a green hue over the water in that portion of the reservoir.

When asked, Bosch did not respond to questions regarding restricted recreational boating and fishing access to that portion of the reservoir.

However, he did say that people should follow the New York State Department of Environmental Conservation’s recommendations regarding contact with a bloom or discolored water. According to the DEC website, it is not easy to tell if a bloom will produce toxins or other compounds that can be harmful to human health or animals without a laboratory analysis, and therefore it is best to avoid boating or recreating in or drinking water that is discolored.

There has been no algal bloom identified on the Pepacton Reservoir, Bosch said.

Rivers and Streams

Area rivers and streams which help to support the tourism economy with recreational boating and fishing are also seeing the effects of prolonged high temperatures.

A section of the East Branch of the Delaware River, between Downsville and Corbett, is experiencing excessive vegetative growth in its streambed.

DEC research scientist Rebecca Gorney said the growths are likely not harmful algal blooms because blooms are found on the water’s surface and are not vegetative in nature. Therefore, she said, they are not likely to produce toxins.

The streambed vegetation is more noticeable this year, she said, because of the lack of “high flow,” or heavy rainstorms, which typically “cut down” the vegetation.

Contributing factors

Record high temperatures, as well as climate change, have contributed to the conditions, which favor these types of growths, Gorney said.

Bosch concurred, saying many other rivers, creeks, lakes, ponds and reservoirs are seeing algal blooms that are far more significant than what is at Cannonsville right now.

To report suspicious algae email close- up photos with location to DEC officials at habsinfo@dec.ny.gov.

The National Weather Service’s climate prediction center released charts on August 18 which reflect that Delaware County can expect to see above  average temperatures through the end of November.

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