Most ponds fit within one of two categories, “balanced” or “unbalanced”. Ponds that are unbalanced are often plagued with significant algae and vegetation growth. Those ponds are at high risk of a fish kill (aka fish die-off) on an annual basis. Low Dissolved Oxygen (DO) levels are often responsible for killing fish, but the low oxygen levels are simply a symptom of the real problem, which is excess nutrients, such as Phosphorus and Nitrogen, and high water temperatures. Until unstable ponds strike a balance with their nutrient load they will continue to experience undesired plant and algae growth and face the risk of a fish kill.
Even when professionally managed, ponds can suffer from an unbalanced fate. Pond management must include more than just weed and algae treatments if it is to be truly successful. We observe a few ponds every year that experience fish kills. Each of these ponds falls within the category of being unbalanced.
Plants and algae require proper temperature, nutrients and sunlight to grow. As favorable weather conditions allow plant matter to thrive, unbalanced ponds increasingly become more and more unstable. In addition to this, the need for oxygen in ponds is highest when water temperatures reach the 80’s. During these warm temperatures, waters ability to hold oxygen is at its lowest. These two factors team together to reduce the stability of the ponds oxygen supply, making the scenario of a fish kill more probable in the summer months.
If a pond is continually in need of management to keep algae and vegetation at an acceptable level, it is naturally unbalanced and is susceptible to fish kills. Many algae species can grow very rapidly under the correct conditions and as result the biomass of algae can rapidly shift to a very dense population. Unbalanced ponds often require frequent algae and vegetation treatments. Even with treatments every couple weeks, unbalanced ponds can have algae densities reach the point where a fish kill is probable. This high risk of a fish kill is likely to reoccur over the years unless steps are taken by the property owner to break this cycle.
Nuisance vegetation and algae growth are a symptom of the problem, not the problem. Nutrients are the problem. For water bodies that have difficulty maintaining balance, it is critical that other steps are taken to manage the nutrient load other than just treating undesired plant and algae growth. Simply treating the growth is only putting a band-aid on the actual issue. It is important to find ways to remediate the existing in water nutrient load while preventing future nutrient accumulations.
Lake and pond owners and managers whose water bodies experience excessive plant and algae growth should strongly consider the use of an integrated approach that utilizes many of these tools to aid in the overall pond management strategy. The results of your efforts will improve the aesthetics and the health of the pond, while providing your fish with a much less stressful life and lessening chances of a fish kill.
By David Beasley, Fisheries Biologist
In support of our belief that lakes and ponds are a precious natural resource requiring protection, SOLitude is committed to providing sustainable and renewable solutions that maintain ecological balance in the workplace and beyond.
When you partner with SOLitude, a dedicated field technician visits your lake or pond twice a month, leveraging extensive knowledge and training to carefully maintain ecological balance and preserve the appearance of your aquatic property.
Utilizing the latest GPS aquatic mapping technology and our own proprietary lake and pond management software, the experts at SOLitude collect all the data necessary to provide comprehensive analysis and in-depth solutions.