April 12, 2012

Herbicides ‘Only Choice’ in Tackling Hydrilla, Experts Say

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In conjunction with Cornell Plantations, a panel of local environmental experts led a discussion on Thursday to update community members on current efforts to combat hydrilla –– an invasive weed that is threatening the survival of other species in local waters by both blocking their access to sunlight and removing oxygen from the water.

First spotted last August in the Cayuga Inlet, hydrilla is suspected to have been introduced to Ithaca’s waters by cross-water contamination from an unknown source and is now threatening to spread deeper into the Great Lakes’ water networks.

Identified by its toothy leaves, the aquatic weed is known for its resistance to eradication measures due to the resilient, underground part of its stem. In one of the first effective measures to contain the invasive species, the inlet was closed off to boaters in October, according to Roxy Johnson, the City of Ithaca watershed coordinator.

According to Johnston, hydrilla was observed in 2011 to be spreading in the waters around the Farmers Market, Cascadilla Creek and the Cornell Crew Boathouse, among other locations. After confirming the spread of hydrilla in areas around the Inlet, the Department of Ecological Conservation allocated $800,000 for measures to protect Ithaca’s ecosystem from invasive species.

Early in its response, the Hydrilla Task Force –– the primary action group formed to combat the ecological crisis –– emphasized that pesticide would only be used in limited circumstances. However, an unsuccessful attempt in October to send divers to manually remove the aquatic plant through specialized vacuum tubes is suspected to have worsened the situation by allowing the hydrilla to further propagate.

According to Johnston, after the ineffective efforts to manually remove the material, there is “only one choice left,” which is the use of herbicides, namely Fluridon.

“We are expecting an herbicide treatment maybe sometime mid-May to mid-June,” said Sharon Anderson, a member of the Hydrilla Task Force.

During the event, the panel assuaged fears of human health dangers of Fluridon, citing successful results in the handling of hydrilla in other states. However, the panel stressed the importance of funding to fully research the specific impacts of both the hydrilla and herbicide on Ithaca’s ecosystem.

“This is probably an eight-year battle. The timeline to try to eradicate this is long,” Anderson said. “We’ll be trying to monitor [the hydrilla] all throughout this summer and throughout this fall … For all we know, last year, it could have gotten into Seneca Lake.”

Anderson explained the rapid spread of hydrilla.

“[Johnston] used the analogy of cancer,” Anderson said. “You have cancer, you treat it, you hopefully get it, but you always keep looking and testing if it comes back. Hydrilla will be like that.”

Additionally, Mayor Svante Myrick ’09 stressed hydrilla’s disastrous ecological consequences.

“We can’t allow this thing to keep growing,” he said. “The future is at stake.”

Along with environmental procedures by the local agencies to control the infestation with herbicide, the panel highlighted proposed measures to engage the entire community in the effort.

These efforts will include workshops to train individuals to spot hydrilla and 12 boat stewards to educate boaters in the lake. Johnston stressed the need to “tell every individual possible” about hydrilla.

Additionally, a group of Cornell students enrolled in an independent study communications class are working with the task force on a strategy to tackle the hydrilla project.

“I’m really thrilled with their involvement,” said Anderson, who works to involve Cornell students in various environmental projects in the community, including the hydrilla project.

Johnston emphasized the importance of the task force’s efforts.

“We are the gateway to the Great Lakes, so it is important that we win the battle,” Johnston said.

Original Author: Sophie Lin