Controlling Mosquitoes on Ponds and Lakes
- What attracts mosquitoes to a particular pond or lake?
- How do fluctuating water levels favor mosquitoes?
- How does low or no dissolved oxygen attract mosquitoes to a habitat?
- What to watch out for in pond designs to prevent mosquitoes
- Methods the pond or lake can prevent mosquitoes
- What are the best animals in or around a pond to control mosquitoes?
- What is the simple water quality criteria to prevent mosquitoes?
Mosquitoes on ponds and lakes: living with and without them!
With the fear of mosquito transmitted pathogens such as zika virus, it is time we offered some guidance to pond and lake owners to clarify
management of mosquitoes. As with so many issues in life we have the choice of proactive prevention or reactive treatment. Today we focus on the best solution:
prevention of mosquitoes. There are two types of water to avoid in your ponds and lakes: 1) water surfaces that frequently fluctuate
in elevation and 2) acidic water which usually presents itself as brown stained / tea color swampy type of water.
Mosquitoes have the ability to avoid the oxygen-rich healthy and stable water that supports all the animals ( and a few plants) that prey
on them. Most of these predators need water with sufficient oxygen to live out life cycles that usually span more than a year.
Eliminating predators via temporary or fluctuating water levels gives the mosquito a safe habitat in which to thrive. The strategy is
simple: no permanent water = no predators.
The second method a mosquito utilizes is selecting acidic water that very often experiences low/no dissolved oxygen that will not support
the predators or competitors for food. Very generally, acidic waters are the most likely to be lacking in dissolved oxygen due to
decaying vegetation and other biota. Again, generally speaking the most visible indicator of acidic water is the color. As water becomes
more acid due to rotting plants etc, the more brown or tea color stain the water will appear. Even if a small garden pond or water
feature is well circulated and oxygen-rich, the mosquitoes will sense the acidity of the water and deposit eggs. Yes this is complex and
full of exceptions because natural waters are not often acidic and full of oxygen.
The indicators of healthy water are more simple. The water should either be clear and colorless or have a greenish hue. These indicate
neutral or basic pH water with sufficient oxygen to support a healthy population of predators such as dragonflies and damselflies which
are our favorite predators since they prey on mosquitoes both as immature nymphs and colorful adult dragonflies.
Soft mud/sand pond bottom substrate and submerged aquatic plants will provide habitat for a range of mosquito predators. Either habitat
will work; both are better together. If you build it, they will come.
Of course there are more mosquito assassins around the pond such as fish, bats, birds and frogs, all of which should be encouraged.
Predatory aquatic insects are simply ubiquitous, abundant and eager to volunteer to move into your ponds and lakes. Dragonflies and
damselflies just happen to be very colorful and beautiful.
Since maintaining water level in the pond or lake has a straight forward fix, we will describe methods to avoid acidic water. In most
cases tea colored acidic water is caused by great amounts of vegetation in and around the water. Some vegetation is virtually required,
but a preponderance of plants will cause stained water due to periods of dead or decaying plants. Ponds that rely heavily on plants and
are not designed to efficiently break down dead plants will need to be more intensively managed. Thus too much reliance on plants may be a
sign of sub-optimum design. Relying on the addition of straw or dead plants in an attempt to limit algae also adds to brownish stained
water if treated to excess. Eventually the stain in the water will diminish if the inputs are removed. Water can be exchanged for
cleaner water, but again this is not a desirable practice. Note that there are times when water may appear brown, but it is caused by a
brown colored algae on the pond / lake bottom.
The best time to address all of these issues is before a pond or lake is built. Look for images of waters built using methods that
render either green or colorless clear water. Perhaps the most frequent occurrence of the mosquito question arises during the discussion
of natural swimming ponds or natural pools. Pre-construction is the time to assess the quality of water around your future landscape or
Well designed lakes ponds and waterfront property should have very few if any mosquitoes in order for carefree enjoyment of the outdoors. Yes mosquitoes are a natural part of the landscape, but they are not required for a healthy pond or lake.
Creating a quality pond, riverfront, stream or lakefront property requires careful planning due unforeseen factors such as mosquitoes.
Few waterfront properties are ever purchased without an inspection or evaluation, yet possibly due to emotionally charged buyers, waterfront properties are virtually purchased on a hope and a prayer because of their beauty and the lack of available qualified counsel to evaluate issues with waterfront property value such as mosquitoes.
images of waters designed by Spring Creek
As Aquatic Biologists with over 30 years of dealing with all of these issues across North America, we help clients analyze their situations to achieve their goals of clean safe streams ponds and lakes.
We invite you to further explore our website for study and consideration. We suggest these topics:
Waterfront property buyers guide
Cost to build a lake, pond or stream
Pond Building Guide
Lake and Pond Design
images of waters designed by Spring Creek
IN THE NEWS: Our Senior Fishery Biologist was the Technical Advisor for an important new trophy trout fishing book titled: Big Trout. This book will not only change the way you think of chasing trophy fish, it will cause you to replace those old photos of trophy trout with new photos of even bigger trout.