You build a beautiful pond that settles down nicely into sparkling clear water. Then the next spring arrives and you find the water is completely covered with tiny bits of vegetation. Or maybe you discover that the pond liner is leaking, even though you know it was installed correctly. Nuisance plants and animals can ruin the water quality, kill off fish and chosen plants, and damage a pond liner with sharp claws.
Identifying pond weeds is the first step to controlling them. Duckweed is one of the most common and easily spread aquatic weeds in the country, as it mimics algae blooms by covering the surface in green growth. However, you’ll notice that tiny leaf-like structures are actually floating there, not the slime or strings of algae.
There are dozens of types of algae that infest farm ponds, most of which lower the oxygen levels to accidentally kill fish and other water plants. Farm ponds are particularly prone to algae blooms due to ready supplies of fertilizer and animal waste that get washed into the water. Since there is a variety of water weeds to deal with, call your local extension office and schedule a consultation before applying a particular pond-safe herbicide or algaecide.
Some of the most common nuisance animals attracted to farm ponds include:
- Beavers: Since the beaver wants to build his own dam, he may destroy your dams and levees in the process. If beavers leave your dam alone, they may dam up your inlet instead and cause the pond to dry out. You may also find your banks collapsing after a beaver burrows into the ground below it. Trapping and shooting are both viable options, but poison baits should be avoided due to their impact on unrelated predators. Covering your dam in riprap and fencing the banks with hog wire panels will keep them from returning.
- Muskrats: Muskrats also burrow under banks and can collapse dams, but they are most hated by pond owners for their damage to pond liners. With sharp claws and a desire to dig, they can cause serious leaks that drain most or all of a pond’s water before a problem is noticed. Docks, especially floating ones, also tend to get infested and damaged by muskrats looking for new burrows. They also have a desire to eat your prized pond fish or plants. Most areas greatly limit trapping and shooting of muskrats due to their important status as a valued fur animal, but you can get permission from your local conservation authority after showing them proof of damage. You can keep muskrats away with the same riprap and fencing techniques used for beavers.
- Cranes, herons, and other wild birds: Unlike water-loving rodents, wild birds attracted to ponds tend to do damage to fish and plants alone. These birds also tend to enjoy far more protection than other pond pests. You can’t simply shoot or trap most of them because they’re under protected or endangered status. Focus on outsmarting cranes and herons that steal your fish instead. Covering the surface in a stretchy netting is an expensive solution, but it’s very reliable as long as the material is properly anchored around the bank edges. Making the banks hard to access with tightly strung stretches of fishing line between poles can keep cranes and herons from strolling up to the water’s edge, which they prefer to landing in water. Solar and battery powered water splashing and spraying devices scare birds away, while heron decoys make the birds think the pond is occupied.
- Geese and ducks: Geese and ducks don’t directly catch many fish, but they can damage valuable pond plants. They’re also a source of high nitrogen and phosphorus droppings, up to two pounds per day from a single mature goose, that kill off fish and plants while promoting algae growth. Lost nests of eggs spoil and then surprise you or your guests months later. Unless you’re building a pond specifically to attract geese and ducks for pest control or hunting opportunities, discourage them from settling in your pond for cleaner water. Hiring waterfowl trained dogs, especially breeds like border collies, can scare flocks and individual birds away for the season. Many states also allow farm owners to shoot most geese and duck varieties during any season with a permit, or during open waterfowl seasons with hunting licenses.
- Alligators: Only a limited number of farmers need to worry about alligators in their ponds, but states like Florida and Louisiana do feature plenty of agriculture and farm ponds. An alligator is one of the most dangerous nuisance animals your body of water can attract onto your farm. Even the smallest ones can cause serious injury or death when you try to handle the animal on your own. Call your local animal control or natural resources office to find out who’s qualified in your area to remove an alligator. These removed animals go to farms that raise them for meat in most cases, making your pond’s nuisance a valuable addition to another farm’s income.
- Flower and koi pond owners tend to consider turtles a pest or threat, but these animals have basically no effect on a farm pond. Farm pond liners are thick enough that the claws of anything smaller than a snapping turtle won’t scratch them, and water stocked with fish generally has more than enough fry to feed a population of turtles without creating a significant an impact. Snapping turtles are the main exception because these turtles are large and aggressive enough to damage or eliminate fish stocks, rip open pond liners, and cause serious injuries to swimmers. Thankfully, these turtles are primarily limited to areas where waters don’t freeze on the surface over the winter.
