MOSQUITO PROBLEMS

Fish ponds can become major producers of biting mosquitoes. The most common mosquito produced in fish ponds is the Fish Pond Mosquito, Culiseta incidens. Although this mosquito is not known to transmit disease, it can be a pest in the early evening or during the day in the shade. It is moderately aggressive and very noticeable.

MOSQUITO PREVENTION

• Most mosquito problems can be prevented by taking appropriate steps.
• Plant goldfish and/or mosquito fish in pond. (Mosquito fish supplied free by District).
• Keep landscape plants trimmed away from pond edge.
• Remove excess organic material such as leaves, plants, or fallen fruit from pond.
• Trim or prune landscaping plants to allow pond to receive sunlight.
• Avoid getting pesticides and herbicides into pond (may kill your fish).
• Do not over feed fish. Hungry fish make better mosquito predators.
• Provide fish with rocks, cinder blocks, tile pipes, etc. for shelter from predators.
• If you have any special problems preventing mosquitoes, call the District for advice.

FISH POND CONSTRUCTION

If you are considering building a pond, here are some considerations which will minimize future mosquito problems.

• Construct from plastic, vinyl, concrete or other suitable material. (See your local nursery for advice. There are also excellent books available.)
• Choose a sunny, sheltered location.
• Avoid locating under or near trees or large shrubs. Especially avoid pines, redwood, eucalyptus, fruit trees, acacia, or pittosporum.
• Construct pond large enough to support fish and resist rapid temperature changes. The greater the volume the less maintenance required.
• Construct pond at least 18" deep to provide protection to the fish from temperature changes and predators.
• Construct the sides of the pond to be as steep as possible.
• Avoid constructing too much shallow area in the pond.
• Provide for drainage or removal of the water for future cleaning.
• Avoid metal to water contact. Use plastic pipe or coat exposed pipe to prevent contact with the water.
• The personnel of the Alameda County Mosquito Abatement District will be glad to provide preconstruction advice to minimize mosquito problems.

FISH POND REMOVAL

If you have a fishpond you no longer use or want, it may be permanently removed to prevent mosquito problems.

COMPLETE REMOVAL

To completely remove a fish pond, break up and remove the bottom and edge material. Fill the hole with soil.

DRAINAGE

A pond may be prevented from causing a problem by breaking holes in the bottom or removing the bottom. Drainage is successful if water does not stand for more than a few days.

FILLING

Provide drainage as above then fill pond with good soil and landscape. If you desire to grow plants that prefer continuously wet soils, leave pond intact and fill with soil. Allow for shrinkage of the soil and fill above the edges of the pond so that water will not stand on surface. Use plants preferring these soil conditions. Consult a horticulturist at your local nursery for advice.

A FISH POND CAN BE AN ENJOYABLE ADDITION TO YOUR LANDSCAPING. WITH PROPER CONSTRUCTION AND CARE IT CAN BE KEPT MOSQUITO FREE.



ALAMEDA COUNTY MOSQUITO ABATEMENT DISTRICT
23187 Connecticut Street
Hayward, CA 94545
Phone: (510) 783 - 7744
Fax: (510) 783 - 3903
E-mail: enspec@mosquitoes.org