Bob Johnson (of Racine-Johnson Aquatic Ecologists) and Angel Hinickle (of the Tompkins County Soil & Water Conservation District) are currently working on finalizing a map delineating the new hydrilla infestation in the Fall Creek area. Before making a formal announcement to the public and stakeholders, the Task Force wanted to understand the full extent of the new infestation. Severe storms directly following the initial discovery on August 8th prevented completion of our delineation until early this week (due to excessively high water levels, flow rates, and turbidity). The Task Force also wanted to survey as much of the mouth of Fall Creek as possible, including the adjacent section of Cayuga Lake. Survey efforts are still ongoing, but at this time NO hydrilla has been found rooted or growing in Cayuga Lake.
In both 2011 and 2012, floating fragments of hydrilla were observed in the inlet, meaning some fragments could have floated into the lake. A prevailing northwest wind on Cayuga Lake pushes the surface waters back into the inlet, toward Stewart Park and into Fall Creek. It is possible fragments may have been blown back into Fall Creek and become rooted. It is also possible that hydrilla fragments could have been transported via watercraft (boats, canoes, kayaks, etc.) from an area of the Cayuga Inlet that was infested to the Fall Creek area. The potential does exist for water fowl to carry fragments as well. The hydrilla in Fall Creek was likely there last year, but was not detected by our surveys due to growth being too low for detection. The Task Force believes that we have caught this growth very early, making eradication possible and confirming the importance of ongoing monitoring/sampling.
At the same time that the extent of hydrilla growth in Fall Creek is being delineated, the Hydrilla Task Force has been considering the possible treatment options. The current plan is to apply to NYS Dept. of Environmental Conservation for a pesticide permit to treat this new discovery with a contact herbicide to prevent any further growth of plants this fall. The herbicide Aquathol-K (active ingredient endothall), which has been used in 2011, 2012 and 2013 in Cayuga Inlet, is the standard and recommended treatment for a new infestation, though all possible responses are being considered. Herbicide treatment in the Fall Creek will not affect ongoing herbicide treatment in Cayuga Inlet and will not necessitate closing the inlet. Signs are being placed in the areas of new infestations to keep out boaters.
Long-term decisions will be made based on our observations following any herbicide treatment and continued monitoring from now into winter. Since our current efforts to eradicate hydrilla in the Cayuga Inlet are on track and working well, it is likely that we will consider a similar approach in the Fall Creek area in the coming years. The Task Force will develop a comprehensive treatment plan (including area to be treated, quantity of herbicides to be used, monitoring/sampling plans, and associated costs). We will continue to consult our state and national hydrilla experts who guide our hydrilla eradication plans for the Cayuga Lake Watershed.
The Task Force is committed to providing up to date information regarding eradication activities and developments to as broad an audience as possible. This includes notifying the public and stakeholders as soon as possible when changes occur. Full public notification for the discovery of hydrilla in Fall Creek will occur on Wednesday August 21, 2013 through the Ithaca Journal and the Task Force website. To ensure widespread notification is achieved, additional publications, interviews, and outreach will be conducted throughout the coming days and weeks.
Although this notification is primarily to address the recently discovered hydrilla growth in Fall Creek, I also wanted to provide a quick update on the hydrilla eradication efforts in the Cayuga Inlet. In 2012 a combination treatment utilizing Aquathol-K and the systemic herbicide Sonar (active ingredient fluridone) was used to eliminate hydrilla biomass (above the sediment) and prevent further growth and tuber production (tubers being a specialized root structure that allows hydrilla to remain viable in the sediment for years at a time, only to sprout new plants). By reducing the overall tuber population in the inlet, we are effectively eliminating the potential seed bank for hydrilla growth in the future. In 2012, the hydrilla biomass was reduced by 95% and the tuber population was reduced to a tenth of what it was in 2011.
For the 2013 season, a combination treatment utilizing both Aquathol-K and Sonar is being utilized again in the Cayuga Inlet. The initial Aquathol treatment was applied on July 16th, with effective results; eliminating almost all hydrilla biomass above the sediment. The secondary Sonar treatment was initiated this past week (on August 14th), and we look to review the water sampling results and adjust the herbicide treatment as necessary. The Task Force has obtained permits to apply Sonar through the end of November 2013, but we hope to finish Sonar treatments after a 60 day time period (mid-October). This, of course, will be dependent on in-field observations and sampling results (more information to come as the season and Sonar treatments progress*).
While the newly discovered hydrilla growth in Fall Creek is a setback, the Task Force believes that we have caught this growth very early, and both the Task Force and our national advisors stress that we must push forward with the eradication plan. The fact that this new area of infestation was discovered early supports the vital role that early detection and ongoing monitoring/sampling plays in our Project efforts. On a broader scale, ongoing monitoring/sampling for hydrilla and other invasive species needs to be a statewide initiative, which will help lead to earlier detection and greater rapid response if/when new infestations are discovered.
The Hydrilla Task Force of the Cayuga Lake Watershed greatly appreciates the support that everyone has provided to us in our efforts! We will be working diligently to address this newly discovered area of hydrilla growth in Fall Creek, while at the same time continuing our eradication efforts in the Cayuga Inlet uninterrupted.