A question frequently asked by clients is why their pond seems to have a mosquito problem. Mosquitoes, like many other insects, undergo their juvenile development in water. Adults lay their eggs on aquatic vegetation, and when the eggs hatch, they enter the water to begin their growth. However, unlike many animals which breath through their mouths, juvenile mosquitoes instead breathe through a tube which extends from their rear. Hanging upside down in the water, mosquito juveniles effectively use the tube as a snorkel. Because of this, juvenile mosquitoes require a fairly still water surface in order to breathe, otherwise the “snorkel” is forced underwater. This is what makes ponds ideal habitats for mosquito breeding—their water is often sheltered and still. The presence of mosquitoes can be a concern for pond owners, not only for the annoyance, but also for the concern of spreading disease. So what can be done to prevent or mitigate their breeding?

The key to limiting mosquito presence lies in making the pond into a habitat which is not ideal for their breeding. This can be accomplished in a few ways: agitation of the water, reducing aquatic vegetation, biological factors, and chemical treatments. Let’s explore each of these!

Agitation of the water: As we learned, juvenile mosquitoes need still water in order to properly use their breathing tubes. If the surface of the water is kept in motion, the mosquitoes should be unable to keep their breathing tubes above water. Adding a fountain can be enough to keep the surface of the water moving. One can also purchase surface agitators and surface aerators which will serve the same purpose. Surface aerators have the added benefit of helping to ensure your fish have enough oxygen in the water!

Reducing aquatic vegetation: Although aquatic vegetation is considered healthy for ponds, it is possible to have too much of a good thing. Apart from the other problems which too much vegetation can present, heavy growth of underwater plants can prevent water from being naturally circulated by wind action. When the water is kept still by too much plant growth, mosquitoes are once again presented with an ideal spot for breeding. Responsible management of aquatic vegetation can help to mitigate this problem.

Biological factors: Although mosquitoes like to feed on humans, they themselves are prey items for many other animals. In order to deal with existing mosquito problems, it can be beneficial to add predator fish to your pond’s ecosystem. Fish feed on mosquito larvae, thus creating a natural remedy to an irritating problem. Other aquatic insects can also act as predators to mosquito larvae, so leaving enough vegetation for healthy development of predator insects can be beneficial. A third option is buying products like Mosquito Dunks, which release bacteria onto the water’s surface which are toxic to many forms of juvenile mosquitoes.

Chemical treatments: Many companies provide mosquito fogging to discourage the presence of adult mosquitoes in your yard. By removing the adults, you are effectively eliminating the possibility of mosquitoes breeding in your pond.

Here we’ve outlined a handful of solutions to mosquito problems in and around your pond. It should be kept in mind that where there is still water, mosquitoes will attempt to congregate, and no solution is going to be 100% effective. However, combining a few methods should help to return your pond to a comfortable state, with limited irritation from mosquitoes!

Emily Huber

Field Biologist and Aquatic Specialist

Q & A with: Elizabeth Hiser - Watershed Program Manager at Cuyahoga Soil & Water Conservation District

Written by: Alex Boskovic

Hello pond lovers out there in this wild world! I was fortunate enough to sit down recently with Elizabeth Hiser for a quick Q & A interview to discuss winter stormwater and road salts. Elizabeth has been with Cuyahoga Soil & Water Conservation District since 2014 and is currently the Watershed Program Manager.  Prior to Soil & Water, Elizabeth was an Environmental Scientist for a private company for over 11 years.  She has also been a volunteer for Cleveland Metroparks and Friends of Euclid Creek for the past decade.

1) We have all lived in NE Ohio long enough to understand the necessity for deicing our roads, but what type of negative environmental impacts can road salt have on our stormwater basins?

As salt levels rise we see plant life struggle. Most plants will have issues growing and reproducing with high salt levels. Increased salt can also increase mobility of metals leading to lower water quality in the basin. Newer water quality basins may settle some of this out, but older flood control basins will pass this pollution on downstream where it can impact our drinking water sources. Salt can affect soil structure allowing soil to erode more easily creating areas that will need               stabilization in your basin.

2) What are some alternatives available for deicing that would leave less of an environmental impact on our basins and are any of these alternatives being used here in NE Ohio?

While there are alternatives, none of them come with zero environmental impacts. The best practice with salt is to make sure not to over apply, and to only apply when it will actually work. Apply right before snow falls or right after snow is removed - and never apply when rain is in the forecast. Rock salt does not work  below 15 degrees F.  Some alternatives that may work in the residential landscape include Sugar Beet Juice, Calcium Magnesium Acetate, or Sand.

3) In your experience, besides road salt, what are some of the other issues you have seen with stormwater basins in the winter months?

One big winter issue with stormwater control measures is improperly plowing snow into practices like bioretention that will be negatively impacted by the compaction that snow can create. With wet basins - safety is a concern. Be sure to have signage for your basin indicating that no skating is allowed. Be sure to check your outlets just like the rest of the year, a clogged outlet in winter can cause even more issues if the frozen conditions cause a pipe to break.

4) What actions can a homeowner take that may live in a HOA with stormwater basins to help keep the basins healthy and functioning?

Remember that what you do on your property ends up in the basin. By keeping your yard stabilized, you will keep excess sediment out of the basin (and prevent costly dredging projects). Minimize your use of fertilizers and test your soil before fertilizing. Excess nutrients from fertilizer can cause unsightly algal blooms in basins. Pick up after your pets! Bacteria from pet waste ends up in your basin and then in our local waterways untreated.

5) What normal routine maintenance would you recommend for stormwater basins in winter months?

Winter is a good time for invasive cutback and/or removal. B. Good time to plan for the spring native seeding/planting and clean up. C. Keep snow piles out of away from basins (extra nutrients). D. Erosion issues can enhance from excess runoff (with freeze and thaw). E. Check pipes/water quality orifice for clogging during freeze and thaw periods (sometimes we can get a rain between snow events - or lots of snow melt runoff)

DID YOU KNOW THAT AQUADOC OFFERS A MONTHLY PREVENTATIVE WINTER STORMWATER BASIN MANAGEMENT PROGRAM? WE INCLUDE REGULAR MONTHLY CHECKS ON THE BASIN TO HELP KEEP GARBAGE CLEANED UP, CHECK ON BOTTOM AERATION SYSTEMS, AND CHECK ON THE  INFLOWS AND OUTFLOW STRUCTURES TO MAKE SURE THERE IS NO CLOGGING. FEEL FREE TO CONTACT OUR OFFICE ANYTIME TO DISCUSS OUR WINTER STORMWATER PROGRAM FOR YOUR BASIN.

Measuring the surface acreage of your pond is going to differ depending on the shape. Use the following formulas to help you.

Rectangular or Square Pond - Length x Width / 43,560

Example: for a pond that is 100 feet long by 50 feet wide - 100 x 50 = 5000 sq. ft. 5000/43,560=.115 surface acres

Circular pond - Circumference Squared / 547,390

Example: for a pond with a 300' circumference (shoreline in feet around the entire pond) - 300 squared = 90,000; 90,000/547,390= 0.16 surface acres

Irregular Shaped Ponds - There are many methods to calculate irregularly shaped ponds. A common method is using the formula to calculate the area of a trapezoid.

Example: a pond is 500 feet long but 200 feet wide at one end and 400 feet wide at the other. This shape can be calculated like a trapezoid using the average width to find the area

(Width 1 + Width 2)/2 * Length/43,560

(200+400)/2*500=75,000 sq. ft. 75,000/43560=1.72 surface acres

For ponds that are very irregular in shape you may need to divide into sections, or multiple trapezoids, then add the totals together

If you are still unsure, AQUA DOC can assist, in most cases, by mapping the pond. Please feel free to contact us!

In harsher, colder climates where ice and snow may build up on your pond, it is important to remove floating fountains for the winter. The ice and snow build-up may damage your float and/or motor and may void your warranty. AQUA DOC offers a fountain winterization program where we will remove your unit for in the fall, store it over the winter, wash and test it, and return it to your pond in the spring (limited area). However, have fish in your pond, it is good to keep some open water to ensure exchange of gasses and help mitigate the chance of winter fish loss. With the fountain removed for winter, AQUA DOC suggests using a bottom diffused-air aeration system to maintain some open water. The boil over each diffuser will keep up to a 16′ diameter circle of open water in the ice. For more information please contact us for a consultation.

Cattails are best treated in the late summer and early fall with glyphosate, a systemic herbicide.  Glyphosate, when applied correctly, will travel from the leaves to the root system of the plant decreasing the amount of regrowth the following year.  AQUA DOC offers cattail treatment as well as cut and removal services.  If you prefer to do-it-yourself, we recommend Shoreline Defense in combination with Cide-Kick II or Cygnet Plus. If you have questions about managing your cattails our experts are ready to help, contact us for a free consultation (800)689-5253.

When a fountain is clogged, the spray may appear weak, uneven, or go up and down. Unfortunately, occasional clogging of a fountain is unavoidable. Even when managed well, a body of water will likely have some amount of algae growth and/or vegetation which can get sucked up against the screen causing the fountain to clog. Debris from the surrounding area, both man-made and natural, such as plastic trash bags, grass clippings and leaves from surrounding trees can also contribute to clogging.

Invasive aquatic plants are generally defined as nonnative plant species that cause ecological and/or economic harm to natural or managed ecosystem. Invasive plants can greatly reduce the desired native plant growth. They can form dense canopies on the surface of the water which will result in a dramatic change in the quality of habitat for fish as well as interfering with desired use of the water (ex; boating, swimming, fishing, irrigation, fire suppression systems which are tied to the body of water).

Any restrictions such as swimming, fishing and irrigation, that my be associated with an algaecide or aquatic herbicide, can be found on the product label.  All products should be used only as directed.  The algaecides and aquatic herbicides featured on our website have a link to the product label and safety data sheet embedded in the product description for your convenience.

A good rule of thumb for floating fountain size is 1-2 horsepower per surface acre.  For example, if you have a half acre pond, the minimum fountain size would be a 1/2 horsepower, but 1 horsepower is recommended.

It is important to know the volume of water in your pond or waterfeature for many reasons including properly sizing pumps and calculating application rates.

Here is the formula for calculating the volume, in gallons, of your pond or watergarden: Length X Width X Average Depth in Feet X 7.5 = Gallons

For example, your watergarden is 10’x20′ and has a depth of 3′: 10x20x3x7.5=4,500 gallons.

If your watergarden or pond has different depths use the average depth or section off the waterbody.  For example, if your feature is 30’x20′ with 10’x10′ section with 1′ depth and a 20’x10′ section with 3′ depth, calculate the gallons in each section and add together.  (10×10’x1x7.5) + (20x10x3x7.5)= 750+4500=5,250 total gallons.  If you have a larger body of water with several depths, use the average.  For example your 50’x50′ pond has depths of 2′, 4′, 6′, and 8′, the average is 2+4+6+8=20/4=5′ so your volume in gallons would be 50x50x5x7.5=93,750 gallons.