2013 Efforts

• Cayuga Inlet Fluridone Monitoring Completed December 2
• Plant monitoring ended November 23
• Post-herbicide rake toss ended November 21
• Post-herbicide rake toss started October 22
• Fall Creek Endothall Monitoring Completed October 10
• Endothall Treatment Applied to Fall Creek Hydrilla September 26
• Sonar One "Bump" Application applied September 16
• New Hydrilla Population Found in Cayuga Lake August 21
• Fluridone Treatment Started August 14
• Sonar Treatment was Originally Scheduled to Start August 13
• Plant monitoring began August 8
• New Hydrilla Population Found in Fall Creek August 8
• One-Day Endothall Treatment on July 16

Endothall Treatment

Hydrilla growth in the Cayuga Inlet was 1-2 weeks behind in 2012, primarily due to cooler weather. Therefore, endothall treatment will began on July 16th, 2013. Cayuga Inlet closed 7/16 for 24 hours for endothall herbicide treatment. The herbicide was administered to the Cayuga Inlet, the Flood Control Channel, the Treman Marina and the lower reaches of Cascadilla Creek and Six Mile Creek. The level of endothall in the water was monitored for water quality safety and for effectiveness in knocking back hydrilla. The application was done by Allied Biological, a licensed applicator.

Additionally, endothall treatment did not take place on the weekend of July 13th as originally planned. This was due to the Salvation Army Fishing Derby and the Fingerlakes International Dragonboat Festival being scheduled for that weekend.

Fluridone Treatment

Mark Heilman of SePro, made the decision to delay fluridone treatment by a day partly based on weather/rainfall. They expected an increase in flow rate/levels mid-day due to morning rainfall Aug. 13 (flow rate is up approximately 70% since 8/12/13 from 80 cubic feet per second [cfs] to 140cfs) from the rains overnight/earlymorning. Also, during the previous week's heavy rains and increased flows, a piece of debris struck and tore off the lower half of one of the PVC shrouds running down from an injector unit into the water. SePro was planning a repair the morning of Aug 13, but with the morning rain on already-saturated soils they felt that repair could be challenged by timing it with the new pulse in stream flow. 

The fluridone treatment started on August 14. Because of the method of application, the Cayuga Inlet was not closed. Water sampling took place periodically for the duration of the treatment. The first results are now available. Two different forms (liquid and pellet) of fluridone were be used. The fluridone map shows where each form was used.

Sonar Genesis (area outlined in green on the fluridone map) is a liquid product that was be deployed by continuous-drip injectors at three locations: the upstream start of the green area on the Inlet, the upstream start on Six Mile Creek, and the upstream start on Cascadilla Creek. The injection is permitted by the DEC through November, but was terminated as soon as plant monitoring indicated that the herbicide served its purpose.

Sonar One (areas outlined in yellow in fluridone map) is a pelleted formulation of fluridone that is used in areas not effectively reached via the drip system. An application of pellets took place on August 14. The DEC permit allowed for up to 4 applications of Sonar One at the designated treatment areas. Fluridone concentrations started to decrease after a month and a "bump" application was needed to ensure that levels stayed within the target range of 3-8 ppb. Allied Biological applied the pellets. No fluridone pellets were used in the so-called donut area this year (shown on 2012 treatment map ) or in the Inlet just upstream of the donut area. This is because using pellets in those areas in 2012 did not result in sufficient concentrations of chemical to suppress plant growth. 

The Fluridone treatment to the Cayuga Inlet was a success! The amount of tubers decreased to less than 1 per square meter; down from the hundreds per square meter in 2011. The warning signs surrounding the treated areas as well as those .5 miles surrounding the treated areas have been removed.

Rake Toss Procedure

This report lists aquatic plant data collected by surveys in 2015 using the line intercept method (Madsen 1999) in Cayuga Inlet, Fall Creek and Cayuga Lake by Racine-Johnson Aquatic Ecologists of Ithaca, NY. We adapted the line intercept method of survey using the rake toss procedure of collection to determine the presence of plant species and an estimate of the species abundance (biomass) at a given location and time. We depict this 2015 information in tables, graphs, abundance maps and pie charts to provide current information of the aquatic plant community. As part of the management plan in place to eradicate hydrilla from known locations by the application of herbicides, hand removal and benthic barriers we are required to monitor the success of those efforts.

Last updated January 13, 2020