Many people living in rural Indiana have farm ponds, and the management of ponds spawns a few questions that are directed my way each year. (Yes, that pun was intentional).
I must give credit for much of the following information to my colleagues Jonathan Farris and David Osborne, Extension Educators in Wayne and Ripley Counties, respectively. Additionally, former Purdue Extension pond specialist, Mitchell Zischke, co-authored some of Purdue Extension’s current publications on pond and fish management.
First of all, this subject is much more extensive than can be covered in a single news article, so we’ll just hit a few high points.
Let’s start with your goals. Most rural people construct a pond for fishing. If it is next to a house, aesthetics or natural character may also play a role. You’ll soon run into conflicting management strategies if your goal is to have a fishing and swimming pond.
Pond size plays a role in potential long-term success. Smaller ponds are more difficult to manage for fish. About an acre pond with an average depth of eight feet is a good minimum goal to consider.
After a few short years, algae or weeds may begin to interfere with your enjoyment and use of the pond.
Key management considerations for preventing excessive plant growth include:
1) Minimize plant dispersal through seeds, fragmentation, or via waterfowl,
2) Prevent the spread of invasive species, such as purple loosestrife or phragmites,
3) Reduce fertilizer application to surrounding land if possible,
4) Plant and maintain buffer strips of vegetation around the pond, and
5) Don’t directly add nutrients to your pond, including fertilizer and fish food.
When weed control tactics are needed, you may choose from a number of options.
1) Habitat alteration, such as increasing the depth of a pond, drawing down water in winter to control shallow water shore weeds, or using dyes to shade rooted plants,
2) Mechanical control, which involves the physical removal of plants by various means,
3) Biological control by using grass carp or tilapia (strict attention to protocols must be exercised), and
4) Chemical control using aquatic herbicides and following all label directions. (See Purdue Extension publication, Identifying and Managing Aquatic Vegetation, at https://www.extension.purdue.edu/extmedia/APM/APM_3_W.pdf).
After a pond is built, most pond owners stock their ponds with fish. You may wish to refer to guidelines from the Indiana Department of Natural Resources or Purdue Extension on this aspect of pond management. A general guideline shared by my colleagues was that an acre pond at an average depth of 8 feet would support about 320 total pounds of fish. For such a pond, a simple initial stocking rate would be 1000 bluegill and 200 largemouth bass (5:1 ratio), with an option for an additional 200 channel catfish. Subsequent restocking may be needed, but continuing to fish the pond and paying attention to pond ecology is more important. Don’t fish from other water sources and add the fish to your pond, as you may inadvertently be introducing diseases or parasites to your pond.
For more information, visit Purdue Extension’s website on pond and wildlife management at https://extension.purdue.edu/pondwildlife/, which includes links to relevant Purdue Extension publications. Also, visit Indiana DNR’s website on private pond and lake management at https://www.in.gov/dnr/fish-and-wildlife/fishing/private-pond-and-lake-management/.