Egeria6We found an aggressive invasive plant in 2008. We believe eradication was successful.

The invasive plant Brazilian elodea (Egeria Densa) was found in the north cove of Lake Waccabuc during a baseline plant survey in 2008. The Brazilian Elodea Eradication Program (BEEP) started in the fall of 2008 with the Three Lakes Council’s decision to attempt to eradicate the invasive by suction harvesting.

Project management included obtaining permits, fundraising, vendor management, hand harvesting, and communications with residents.

  • Communications:  Informal and formal meetings with the community included presentations on September 19, 2008, and May 15, 2009. The council issued frequent email notices, and had newsletter articles and web postings during and after the harvesting.
  • Permits:  State and town permits were required. The Three Lakes Council representatives appeared before the planning board in January, February, and March 2009 to get the town wetland permit, which allowed suction harvesting and supplemental handpulling.
  • Fundraising: We set a target to raise at least $50,000. We pursued a series of grants but were unsuccessful. We are grateful to the many generous donors in the community who enabled us to meet and exceed our goal.
  • Suction Harvesting Vendor Management:  A scuba survey at the end of April, 2009 indicated that the cool spring weather had kept the plants from beginning to grow, and the lake was still extremely murky from the lake turnover.  We found plants beginning to grow on May 10, but not vigorously enough to accurately determine the full extent of their growth. This finding effectively disproved the widespread reports that Brazilian elodea could not overwinter under ice covered lakes. Too bad, as that would have solved our problems, but we felt that the amount we found in 2008 was more than one year of growth. We met with the vendor on May 21. Suction harvesting began with the containment curtain installation on June 8, 2009. Despite a very rainy season, the harvesting was completed on Friday July 10. The fragment curtain was removed on July 11.  The vendor removed the suction harvesting boat from the lake on July 20.

Continued monitoring and hand pulling

Unfortunately, we found some fragments of Egeria in the north cove after harvesting in 2009.  First we found a few fragments, then we found some plants.  It appears that there were several plants where the tops were pulled, but the root crowns were left intact.  When pulled, these showed new growth right next to older broken shoots. We continued monitoring, hand pulling, and tracking the areas that we had surveyed.

BEEP monitoring was paused for the season in October 2009. Brrr!  That water just got too cold, even for wet and dry suits.  The monitoring for Egeria densa in the cove ended for the season in late October.  During August, September, and October, volunteers had been swimming in the north cove generally a few days every week, monitoring the regrowth and removing any Egeria densa that they found.  The number of plants and plant fragments found in the cove got smaller as we continued to search, and the last fragments of the season were found on October 8.  Since almost any recognizable fragment can regrow, vigilance is required.

BEEP monitoring resumed in 2010.  In May, our volunteers began to search the cove for the invasive plant.  In June more intensive searches with scuba and snorkeling began.  From June 8 to July 9, searchers covered the littoral areas of the cove where the invasive plant had been seen in 2009.  Over 2 acres were searched.   No Brazilian elodea (Egeria densa) was found! Other aquatic plants were returning quickly after the suction harvesting.

BE found in new location during rake toss survey on August 23, 2010 – hand pulling continued

The Three Lakes Council hired our lake manager to do a rake toss study in Lake Waccabuc, primarily to search for Brazilian elodea (BE) in our lakes. No Brazilian elodea (BE) was found in the north cove.  Unfortunately, a fragment of BE was found on one rake toss on the north shore of the island.  Searchers began to scuba and snorkel around the island.  We found more BE plants and fragments in a dense patch of plants on one section on the north side of the island.  Our best estimate is that this area had BE plants since the prior year.  We thought that BE was growing in a relatively small area.  Scott Kishbaugh from the DEC gave us supportive perspective: “While the location is discouraging, the very small quantity of BE seems pretty encouraging. I don’t know of any EWM or other eradication efforts that have shown such strong control in the first year.”

In September 2010, scuba searches found a single plant and additional fragments of BE on the north side of the island, and they were removed.  The search area was expanded up the north shore and around the point.  We did not find any additional Brazilian elodea – very good news!

Continued monitoring suggests successful eradication

The Three Lakes Council has authorized rake toss searches of the lakes to search for Brazilian elodea each year since 2010, and through 2016 no Brazilian elodea has been found. This has been supplemented with some shoreline searches, again with no new findings.

It has been six summers since we last found Brazilian elodea (Egeria densa) in our lakes, and we’ve continued to search for it.  While it is possible that it is lurking somewhere, we have passed a milestone that allows us to consider Brazilian elodea eradicated from Lake Waccabuc.

The story of this success has been presented at the Northeast Aquatic Plant Management Society and at the NYS Federation of Lake Associations conferences.  In a world with few successful aquatic invasive eradications, this story stands out. It couldn’t have been done without community support.

We’re happy to look at suspicious plants!

This is all good news, but we need to continue to monitor.   We need you to keep helping us too!  We appreciate all the photos and  reports of unusual plants and we will gladly come look along your shores. Please report any unusual plants you find in the lake to threelakescouncil@gmail.com  Thank you!