When stocking ponds with fish, stick to the process

Springtime is the right time to begin the process of stocking new ponds with fish, according to a Texas A&M AgriLife Extension Service expert.

Todd Sink, Ph.D., AgriLife Extension aquaculture specialist, College Station, said many landowners believe simply adding fish to a pond will result in a healthy and sustainable fish population. But a planned approach, starting with creating a good environment and a strong food-chain, will set the pond up for successful establishment and fishing opportunities.

A planned approach takes time – up to three years – before sportfish like largemouth bass are harvested, Sink said. But like many things in life, good things come to those who wait.

“Everyone wants their pond to be set up from the start, but doing it right takes focusing on the long game,” he said. “Rushing the process by stocking the wrong fish or stocking fish in the wrong order can result in unbalanced populations and poor fishing that can take many years of intense management to fix.”

Before stocking fish, focus on environment

Sink said setting up the pond’s environment to support the food chain from phytoplankton, the foundation for the entire food-chain, to large-mouthed bass is the first and most critical step.

Take a water sample for analyses to determine the chemistry of the pond, Sink said. This is especially important in East Texas because soils are typically acidic, which leads to low-alkalinity, acidic waters.

“Water tests can catch problems and allow you to fix them before you stock fish and are useful to determine lime and fertilizer rates to optimize fish production,”  he said.

Landowners should work toward creating alkalinity levels between 50-150 parts per million and a pH of 6-9, Sink said. This provides the best environment for the fish and the pond’s food chain.

Crushed agricultural limestone, hydrated lime, quicklime or slaked lime can be added to low-alkalinity or low pH ponds to create a more productive environment for fish and their food prior to stocking, he said. Hydrated lime, quicklime or slaked lime cannot be added to a pond with fish because the rapid pH change can cause a fish kill.

Landowners with fish in their ponds can add crushed agricultural limestone, or ag lime, to correct alkalinity or pH issues without creating adverse conditions for fish populations. Those products create a very gradual shift in pH.

Fertilize to maximize fishing

Sink also recommends a fertilization program if landowners want maximum fish production from their pond. Most ponds benefit from 5-8 pounds of liquid or powdered, not pelleted, phosphorus per acre.

“This creates a phytoplankton bloom, which produces food for baitfish, crawfish, insects and other organisms at the base of the sportfish food-chain, as well as for larval sportfish themselves,” he said. “The pond won’t produce as much food as it will when fertilized.”

The recommended fertilization programs can produce four to six times more fish than without, he said. Fertilization can also limit the establishment of nuisance rooted vegetation by blocking sunlight to the bottom of the pond.

Fertilization is optimally started in the spring when the water temperature is between 60-65 degrees, Sink said. Most phytoplankton are dormant below 60 degrees, so fertilization will be ineffective at lower temperatures.

Most undesirable submerged vegetation comes out of dormancy at water temperatures above 65 degrees, he said. Fertilizing above 65 degrees may help rooted plants and result in a dense mess in the pond.

If fertilization was not started in the spring, it can be started any time during the year, Sink said. Just make sure the water temperature is above 60 degrees. And treat any submerged rooted vegetation with an appropriate approved aquatic herbicide before starting fertilization.

Fertilization will ideally start 10-14 days before stocking juvenile fish for the first time, Sink said. This develops a strong food chain and increases the odds of establishing a good fish population.  

When adding fish, start small and be patient

One of the biggest mistakes pond owners make is stocking all their baitfish and sportfish at once, Sink said. He recommends first adding 5-15 pounds of fathead minnows per acre following the phytoplankton bloom. Minnows are easy prey that will spawn several times during early summer. They create a good food source for larger baitfish and sportfish populations added later.

In the fall, Sink recommends adding 500 bluegill or 400 bluegill and 100 redear sunfish per acre if not fertilizing. If fertilizing, add 1,000 bluegill or 800 bluegill and 200 redear sunfish per acre.

Redear can grow substantially larger than bluegill and they don’t compete for food, he said. But the pond must have a majority of bluegill to support healthy bass populations later. Redear sunfish do not have a sufficient reproductive rate to sustain bass populations on their own.

“By stocking the two species together, landowners end up with more baitfish in the pond because they don’t compete for the same resources,” he said. “This means bass have more available baitfish and there are more species available to catch when fishing.”

Landowners should ignore the impulse to add bass and/or catfish to the pond with bluegills or sunfish, Sink said.

“At this point, the impatience starts creeping in and they might think just a few bass won’t hurt,” Sink said. “But adding catfish or bass means baitfish will be eaten before they ever have a chance to spawn. This will throw the balance off because you will have too many predatory fish and too few forage fish. The result will be stunted bass and catfish populations.”

Adding bass and other sportfish

Sportfish should be added the next spring and early summer, Sink said.

Bass fingerlings should be available to add by May or June, he said. Stocking catfish should be ready to add by July or August.

Ponds should be stocked with one largemouth bass for every 10 sunfish stocked, he said. So, for the 500 fish stocked per acre, Sink would add 50 bass. 

Up to 50 channel or blue catfish per acre can be stocked, he said. Up to 100 catfish can be added per acre with appropriate fertilization and feeding programs. Supplemental feed should be provided two to three times per week. Catfish can be added any time after bass are stocked.

Pond owners should not stock catfish if they don’t plan to harvest catfish 2 pounds or larger, he said. Larger catfish prey on the limited baitfish in the pond and reduce the food available for preferred species like bass.

“If a pond owner stocks 100, 2-inch channel catfish, in two years there will be 200-300 pounds of catfish in the pond,” he said. “That is more than a third of the carrying capacity of most 1-acre ponds. Those 300 pounds of catfish are eating a lot of forage fish that could be growing bass and big bluegill. So, you have to ask which is more important to you, 300 additional pounds of bass and bluegill or 300 pounds of catfish? If the answer is catfish, then go ahead and stock catfish.”

Speed up the process a little

Pond owners should start experiencing quality fishing in three years once ponds are properly stocked, he said. But they can speed up the process by adding more minnows, bluegill and redear during the first two years.

But pond owners can speed up the process a full year, he said. Just stock adult 6-inch bluegill and redear sunfish along with the fathead minnows March through May. These fish will spawn the first year allowing juvenile 2-3-inch bass to be stocked in May or June.

“The numbers of fish stocked remain the same, you just start with larger sunfish that are ready to spawn,” he said. “This comes at a price though, as purchasing adult fish will likely more than triple your initial stocking cost.”

Stocking more bass will never be necessary, unless there is a fish kill, because bass typically overpopulate in ponds, he said.

“When fishing starts to decline in a pond, people think stocking more fish, especially bass, is the answer,” he said. “But you have to think of a pond like a bowl with a limited amount of food it can produce. By stocking more mouths to feed, you reduce the share of the limited food each fish gets, so growth declines. If fish in your pond are not growing as fast or getting as large as you want, the answer is to harvest more fish. Especially focus on predatory fish like bass and catfish. By removing mouths that have to be fed, more food is available for remaining fish and the faster they will grow.”

Maintain the balance

Pond management is different from large reservoir or river management because it centers around catch-and-eat plans to keep fish populations thinned out and thriving, Sink said. Catch-and-release plans normally used in large reservoirs and rivers lead to overcrowding and stunted fish in small bodies of water.

The key to stocking healthy fish populations and growing big bass is harvesting bass beginning in the third year, he said. Most ponds require harvest of at least 10 pounds of 6-10-inch large mouth bass per acre to maintain a healthy food chain.

If the goal is trophy largemouth bass, Sink said the pond owner should harvest 25 pounds or more of 6-to-14-inch bass per-acre per-year to provide more resources to growing largemouths.

Owners can also add structures to ponds to provide cover for fish, Sink said. But they are typically more beneficial to anglers because fish congregate around them.

“They’re not necessary, but they do give you a good idea where the fish will be hanging out,” he said.

Sink said structures should be made of natural materials like wood or rocks because tires and plastic pipe are petrochemically based and degrade over time. This introduces chemicals to the water and the fish. Another reason is algae and other food that attract baitfish doesn’t grow very well on plastic.

Control aquatic vegetation

Aquatic vegetation can also provide cover but is not necessary for maintaining a good environment for fish, he said. In fact, vegetation should be controlled aggressively and limited to 10%-15% of the pond’s total bottom area. In other words, limit vegetation to a ring around the edge of the pond no more than 4-8 feet from the edge of the bank.

Vegetation should be managed because coverage exceeding 25% can cause a fish kill. It can reduce the amount of dissolved oxygen at night in the water for fish to breath, he said. During the day, plants produce oxygen during photosynthesis and add oxygen to the pond. But at night when there is no sunlight, they must consume oxygen to stay alive.

“If there are too many plants in the pond, they can consume so much oxygen at night that the pond can no longer support fish, and a fish kill occurs,” he said. “This is an especially large risk during hot summer nights. because warm water holds less oxygen than cool water. And warm summer months are when vegetation growth is the greatest in the pond.”

Crappie lovers beware

Stocking crappie is not recommended for any pond less than 20 acres in size. It is very difficult to manage their numbers because they are prolific breeders.

“They are tough to manage even in ponds at the low end of that limit because predators and anglers can’t keep up with crappie spawns, he said. Eventually the ponds are overrun,” he said.

An angler might get 3-8 years of good crappie fishing, but every few years the water temperature, water level and moon phase all line up just right to get a phenomenal crappie spawn. When this happens, largemouth bass in the pond cannot remove enough small crappie from the pond to limit the population.

That means more crappie survive, and the next couple of years there are even more crappie spawning, he said. Then it snowballs out of hand. Eventually there are so many small crappie in the pond, that no fish, including juvenile bluegill, bass and catfish, can get enough food to effectively grow.

“Then the entire population starts to stunt,” Sink said. “After a few years, all the large fish in the pond will have died off or have been harvested, and the remaining fish in the pond are all stunted at a size too small for sport or food harvest. When a pond gets to this point, the most effective strategy is to start over again.”