Impacts of Endothall Applications on Largemouth Bass Spawning Behavior and Reproductive Success

This research paper states the research behind certain aquatic herbicides and their effects on fish spawning and reproductive success. The aquatic herbicide being examined is Aquathol K and the fish species corresponding with the research is that of the Largemouth Bass.

Aquatic herbicides are used in the eradication process of many different types of aquatic invasive plant species. Hydrilla is an example of one of these invasive aquatic plant species where the use of certain aquatic herbicides are very effective if done properly. The main goal of the research being mentioned is to address the concerns of anglers and the public about the effects of aquatic herbicides on different aquatic species such as fish rather than the targeted specie that it is meant for.

Endothall was applied to achieve a concentration of 3 mg/L for an entire pond were it was directly applied to largemouth bass nests in three ponds in the month of March for three consecutive years which were 2005, 2006, and 2007. This same procedure was done using water instead of Endothall within another three ponds in order to create a controlled group. The applications were all applied at the time of the initial spawning of the largemouth bass.

Spawning activity was monitored throughout the 3 years and results were gathered. The findings showed that endothall did not affect nest guarding by the bass. Nest fidelity was also similar to that of the controlled ponds even after endothall concentrations declined but were still present. Examinations of young largemouth bass, 2-3 months after spawning, that had been in contact with endothall showed that the relative abundance and size was similar to that of the controlled groups. These findings provide evidence to the anglers and public that the application of this type of aquatic herbicide did not directly affect the spawning behavior and reproductive success of largemouth bass.

Michael J. Maceina, Matthew D. Marshall, And Steven M. Sammons. "Impacts of Endothall Applications on Largemouth Bass Spawning Behavior and Reproductive Success". Department of Fisheries, Auburn University, Auburn, Alabama 36849 USA. 2008.

Last updated October 20, 2016