Although it is not an issue during the time of drought, terrestrial plant growth on the newly exposed shoreline sediments of a pond during the time of drought will impact management once rains return. Some species more adapted to aquatic life may persist for some time, but many of the grasses and broadleaves that take advantage of the newly exposed soil will die off once flooded with winter rains.
As they die and decompose the nutrients released can create an excessive growth of filamentous algae, particularly as temperatures rise above 50°F in the spring. However, this algae growth can be limited by maintaining water clarity at 18”-24” by applying pond dye or through proper fertilization. In addition, stocking grass carp at a rate of 10-20 per acre can do well to control algae, however, delay stocking until ponds return to at least ¾ pool.
Still, be prepared to control excess algae by use of herbicides, namely diquat and copper-based products. Both of these may be purchased or ordered through farm supply stores or on-line vendors. However, know that copper can be toxic to fish if over-applied, particularly in ponds with low alkalinity.
An alkalinity test can be conducted by your regional Extension agent to guide you towards the amount of copper that can be safely applied.
Resources:
Weed Management in Lakes and Ponds
Using Grass Carp to Control Weeds in Ponds
Grass Carp Producer and Dealer List
Alabama Extension Video – Measuring Water Clarity
Alabama Extension Video – Filamentous Algae Control
Prepared by Norm Haley, Forestry, Wildlife, and Natural Resource Management Regional Agent
