How to Care for Ponds
Ponds are a wonderful addition to a forest or tree farm, providing a source of water for animal, crops and people, as well as a place to swim, observe wildlife and, of course, fish.
The quality of a sportfishing pond is affected by the pond’s location, size and water quality, as well as by the availability of spawning areas and food supplies. Remember that ponds don’t exist in isolation. They are part of the surrounding watershed, and reflect that way nearby land is being used. A pond that is situated in a woodland or grassland benefits from their ability to absorb sediment and improve water quality.
Although one pond is never the same as the next, there are some management principles that apply to all of them. So follow these pointers on assessing, stocking and harvesting to get the best fishing out of it.
Caring for ponds
Assessing your pond
Before stocking a fish pond, measure its depth and volume, temperature and water quality. Your state’s department of natural resources can connect you to a consultant who can advise you on managing aquatic plants and ponds, as well as to conservation incentive programs that may help reduce your costs.
- Depth and volume: In general, sportfishing ponds should be at least one acre in size and have a depth of 8- to 12-feet in at least 25 percent of the pond basin. The ideal depth and volume depends on climate: in the north, more depth and volume may be required to avoid winter fish kills.
- Temperature: Water temperature will determine what type of fish will survive in a pond. There are three general categories: coldwater fish, such as trout, that thrive when the average surface temperature is below 70 °F; warmwater fish such as largemouth bass, bluegill and channel catfish (up to 90 °F or warmer); and coolwater fish such as walleye and northern pike that prefer average surface temperatures somewhere in between (70 to 80 °F).
- Water quality: Runoff and water temperature affect water quality but so do many other factors, including turbidity (the cloudiness or muddiness of water due to phytoplankton, clay particles in suspension, bacteria and more), pH, carbon dioxide levels, alkalinity and hardness.
Stocking your pond
To establish a balanced sportfish population, any existing fish must be removed from the pond or they will outcompete newcomers for food, cover and nesting sites. Next, select the best fish for your pond, and determine how many to stock and at what age or size, using the guide below.
- Coldwater fish: What to stock: Brook and rainbow trout are the most common coldwater sportfish; brown trout are can also be stocked but they are a more aggressive species and therefore less popular. When: Trout are best introduced in the fall when the water is cool. It’s generally advised to stock fingerlings (2-4 inches) into new or renovated ponds that are free of other fish. (If you’re planning to add fish to an established pond, consult a fisheries biologist.) How much: How many you stock (the “stocking density”) depends on the size of the pond; a good rule of thumb is 600 fingerlings per acre of surface area.
- Warmwater fish: What to stock: The most popular freshwater sportfish is the largemouth bass. It’s a predator and must be stocked with forage fish, most commonly bluegill (also known as bream or blue sunfish) or redear sunfish, both of which are also great to harvest. Channel catfish can be stocked alongside the bass and bluegill without affecting their populations. When: Bluegill is usually stocked in the fall or winter; and largemouth bass the following spring to give its prey time to mature. How much: To sustain the fish, you need to strike the right balance between predator and prey. The recommended stocking density is 100 bass fingerlings and 500 sunfish fingerlings per acre. Stock channel catfish at a density of 70 catfish fingerlings per acre.
- What not to stock: In small fish ponds, black and white crappies (speckled perch), yellow perch, pumpkinseed and green sunfish, bullheads (yellow and black) and gizzard shad are not recommended because they can become overpopulated, outcompeting your species of interest. Common carp and suckers tend to stir up the bottom, muddying pond water.
Ensure you’re stocking your pond with healthy fish by purchasing them from a licensed commercial fish hatchery (not by transferring them from local streams, rivers or lakes). Follow the hatchery’s advice on how to introduce fish to the pond because they are sensitive to new environments.
Before you stock, seek the advice of a fisheries expert in your state or county. They can help you determine what’s native to your region. Stocking non-native fish poses a threat to waterways that are connected to your pond or close enough to be affected by a flood.
Lastly, don’t overstock--overcrowding will actually reduce the overall fish population.
Enhancing the catch
Fertilizing and liming, artificial feeding, adding structure and establishing aquatic plants are all ways of managing fish populations in a pond.
- Fertilizing and liming: Inorganic fertilizers can be used to boost the supply of phytoplankton and zooplankton at the bottom of the food chain. But they can also have undesirable consequences, such as boosting the growth vegetation and algae. Liming -- the addition of limestone (calcite) -- increases the alkalinity and hardness of pond water. By neutralizing and reducing the levels of toxic metal dissolved in water, it helps promote healthy fish populations.
- Artificial feeding: Fish food, in the form of pellets, is the most direct way of increasing fish size without affecting the whole ecosystem. Feeding works best in ponds under five acres.
- Structures: Fish shelters help concentrate swimmers but they also provide much-needed cover, resting spots and feeding areas. They can be natural or man-made, including sunken Christmas trees, logs, pipes and concrete blocks.
- Aquatic plants: They’re essential to ecosystem, providing vital food and cover, but they can quickly get of hand. They can be managed mechanically, chemically or biologically. Grass carp are a common means of noxious weeds in ponds. These herbivores are sterile so they must be restocked.
Harvesting your pond
Pond fish are a renewable resource if the populations of predatory and forage fish are kept in balance by proper harvesting. But the importance of harvesting is often overlooked. Basically, your goal should be to fish enough to keep populations in check. Recreational fish ponds are usually underfished, leading to overpopulation and a host of related problems, such small, stunted fish.
A balanced ponds is one in which the fish are of a harvestable size, reproduce annually and coexist with other species, including a predator species. Regular harvesting, sampling of the fish population by angling or seining, and recording the catch (weight and size) are all helpful management practices.
When to harvest: In a pond stocked with largemouth bass and bluegill, you can begin harvesting the following summer, once the fish have had a chance to reproduce. (Largemouth bass reproduce once a year in spring; bluegill reproduce several times per year.) However, you may wish to wait until the third year, or until bass have grown to 12 to 14 inches in length. Spread the harvest throughout the year.
How much to harvest: Follow these guidelines for unfertilized and fertilized ponds.
- Bluegill: unfertilized: 40-50 lbs/acre/year; fertilized: 100-125 lbs/acre/year.
- Largemouth bass: unfertilized: 10 lbs/acre/year; fertilized: 25 lbs/acre/year.
- Channel catfish: harvest and restock as needed; they reproduce poorly in fish ponds.
Trout may not survive the summer, when water temperatures rise above 70 degrees, so harvest them through the winter and spring.
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