 |
|
|
|
|
|
Find your county office Publications About us News Events Programs Partners & other resources UMaine |
|
Pond Troubleshooting John M. Jemison, Jr., Extension water
quality and soil specialist This fact sheet will guide you, the small pond
owner, through an outline of several common pond problems. We will also
offer some alternatives that you might try to alleviate pond problems. Muddy Water Muddy water can cause several problems for the
small pond owner. In addition to reducing the beauty of the pond, silting
of gravel beds after spawning can cause mortality of fish eggs and damage
aquatic insect larvae. Silt may also clog the gills of fish, reduce light
penetration and make it difficult for plants to survive. This can reduce oxygen
production and further harm fish populations. Soil type, erosion, and animal or
human activity can all contribute to muddy water problems. Soil Type Very small soil particles, like clay, can become suspended in the water during construction of a pond. If these are primarily clay-sized particles, the soil may not settle out. Applying gypsum, powdered alum, slaked lime, organic material or other non-hazardous material may help clear the water. To be effective, enough material should be applied so that your hand can be seen at 12 inches below the surface one week after application. Here are the rates for the most common additives: Gypsum: 12 pounds per 1000 cubic feet of water, or 5.25 pounds per acre-foot of water.
Erosion Soil disturbance in the pond's watershed from
agricultural, home garden, forestry or construction activities can cause soil
erosion into the pond. Also, bare banks and weedless shallow areas are
susceptible to erosion. Establishment of weeds in the shallow end of the pond
can reduce erosion by wave action, and pondside plantings will help stabilize
pond banks. Best Management Practices (BMPS) applied to land in the watershed
can reduce erosion from agriculture and forestry practices. Animal or Human Activity Livestock who have access to the pond will trample shoreline vegetation and wade into the water, stirring up sediment. To protect water quality, livestock can be fenced out of the pond. Water can be supplied to livestock with a pasture pump or a gravity water pipe system. If a water system is not practical, a section of the bank can be graveled to reduce erosion. Aquatic Weeds Nutrient-rich water, relatively high water
temperature, and shallow depth characterize many ponds. These conditions
encourage excessive plant growth of both desirable and undesirable algae and
submerged weeds. Refer to bulletin #2375, Managing
Aquatic Plants in Ponds, for details on coping with algae and weeds.
Fish Kills Predation, Disease and Parasites Some wildlife will prey on fish. Common
fish-eating birds include heron and kingfishers. However, seldom will the small
number of fish taken by birds or other wildlife be harmful to the total
population of fish in your pond. In addition, many pond owners enjoy the sight
of wildlife using their pond. Fish are affected by a wide variety of diseases
and parasites. However, parasitism and disease are usually not much of a problem
in the private small pond as long as water quality is good and overpopulation is
prevented. They are a greater problem where fish are crowded, as in hatcheries
and commercial operations. Most diseases and parasites are not harmful to
humans, especially if the fish flesh is properly cooked before being eaten. Winter Kills Snow cover on the ice limits the oxygen
production by plants. Over the winter, there is a steady decline in oxygen due
to the decay of organic matter and respiration by bacteria and other organisms.
Shallow ponds are most susceptible to winter kill. Suggested minimum depth of
water for ponds in Maine is six to seven feet if fish will overwinter in the
pond. Controlling aquatic vegetation (see bulletin
#2375, Managing Aquatic Plants in Ponds) and reducing the
amount of livestock or other wastes entering the pond will help reduce
decomposition and respiration and will help prevent winter kill. If you believe
that your pond is susceptible to winter kill, there are a few steps you can
take. These actions include: removing snow from the ice so that plants will
receive enough light to photosynthesize; using an aeration device; and
installing a water circulator to keep an area free of ice. Summer Kills Massive fish mortality may be observed during the
summer and may be the result of excessive vegetation. Nutrient runoff into your
pond can trigger an explosion of plants, especially algae. Periodic die-off of
this dense vegetation can occur during the summer. Oxygen is consumed by
bacteria as they decompose the dead plants, and can lead to large fish kills.
Usually, large fish are the first to be affected; frogs, turtles and other
air-breathing animals will not be affected. Summer kills can be prevented by keeping aquatic vegetation from becoming too abundant. (For more information, see bulletin #2375, Managing Aquatic Plants in Ponds.) Excess nutrients should also be prevented from entering the pond. This will help prevent heavy algae blooms. An aeration device or “bleeder hose” may also help prevent fish kills. Improper Use of Pesticides Most herbicides used today have a very low
toxicity to fish. Many insecticides are short-lived, especially when exposed to
water, and are usually broken down and non-toxic by the time they get into
ponds. But problems can occur when someone carelessly sprays a pond while
applying a pesticide to a lawn, garden or field near a pond, or when heavy rains
wash pesticide-loaded silt into a pond immediately following application. The pattern of mortality with chemical misuse may
include small fish dying sooner than large fish. All species of vertebrates,
including turtles and frogs, can be affected. Use caution when applying pesticides in your
pond’s watershed. Never rinse out a sprayer tank in your pond. Also, be careful
that other household and automotive chemicals are not dumped on the ground.
Waste oil, battery acid, radiator fluid and other household toxic materials will
contaminate ground water and will leach into your pond. Dispose of these
materials properly. Leaking Ponds A leaking pond can be a serious problem for a pond owner. However, sometimes it can be difficult to determine if your pond is leaking. For example, it is normal for new ponds to leak to some degree. As the pond ages, this leaking should subside. Also, evaporation during the hottest part of the summer can be expected to remove one-half an inch of water per day. To determine if your pond is leaking, measure the water level in your pond over several days with a marked stick. For the most accurate measurements, this should be done during a period of cold or very humid weather when evaporation is low. If you believe that your pond is losing too much water to evaporation, you can plant trees and shrubs near the pond to provide shade and reduce water temperature in the shallow areas. Remember, never plant trees on the dam of a pond. Leaks in ponds can be caused by
Although techniques are available to seal leaky
ponds, they are expensive and require considerable work. These techniques
include: addition of soil layers, bentonite clay applied to bottom of basin,
trampling of basin, gleization (organic matter used for sealing), plastic liners
or resinous polymers. Wildlife Damage to Pond Banks Muskrat can damage ponds by burrowing into dams
and banks to make dens. Den openings are about four to six inches in diameter.
Beaver can burrow into the dams and banks, cut trees and plug outlet tubes. Bank
dens are 12 to 18 inches in diameter. Nuisance wildlife can be trapped and removed from
the area. Contact the Maine Department of Inland Fisheries and Wildlife at (207)
287-3371 for information on trapping or a list of trappers who remove nuisance
animals. Health Concerns Fecal
Contamination Swimmer’s
Itch The adult worms are parasitic and live within some birds and mammals. Some snails act as an intermediate host. Chemical treatments have been effective; however, the aquatic environment is affected by disrupting the food chain of some fish, and some fish may be killed by a direct toxic effect. Sunfish will prey on snails, and are also effective in controlling swimmer's itch. References
© 2002 Published and distributed in furtherance of Acts of Congress of May 8 and June 30, 1914, by the University of Maine Cooperative Extension, the Land Grant University of the state of Maine and the U.S. Department of Agriculture cooperating. Cooperative Extension and other agencies of the U.S.D.A. provide equal opportunities in programs and employment. Call 800-287-0274 or TDD 800-287-8957 (in Maine), or 207-581-3188, for information on publications and program offerings from University of Maine Cooperative Extension, or visit www.extension.umaine.edu.
A Member of the University of Maine System |
Last
Modified:
05/15/08
|