Fish kills are common in the spring or fall seasons when the water inverts or turns over.  The mixing of highly oxygenated rich water suddenly is gone when the water mixes and dilutes the oxygen.  Stress is the number one cause of fish death.  Sudden temperature fluxes when the water turns over add to stress of fish in your pond.

Sometimes if caught earlier enough and depending on the size of your pond trash pumps can be used to infuse the water with oxygen to stop the fish kill from proceeding.  Be careful not to pull water from too deep when pumping as this can only help the inverting of the pond.

Floating fountains typically circulate water on the top 3 feet of the pond and are helpful during a fish kill.  However, because most pond fountains do not have draft tubes they do little to stop your pond from having a fish kill caused by stratification and pond water turning over.

When of the best methods to prevent a fish kill is bottom aeration.  If designed and installed properly it can be prove the most useful tool in keeping the pond healthy and free of inversions.  These systems bubble up from the pond with the power of 4 or 5 fire hydrants, mixing up the pond, and creating a larger ecosystem that is better at absorbing what nature throws at it.

However, not all fish kills are because of inversions.  Some fish kills are caused by the decaying of plant material such as grass clippings, treating of algae, or aquatic herbicides.   The first signs of a fish kill are typically the larger fish dying or floating sideways near the water’s surface.

Because the hottest days of the year create the least amount of oxygen saturation levels of pond water, combined with the most stress for fish this can set the stage for a fish kill with small amounts of rotting plant material or an outside force like an herbicide.

One or two fish of different sizes found dead in a pond can be from genetics, stress or even predators like turtles, diving or wading birds.  So don’t run out and start pumping water just because of a couple dead fish.  If your pond has grass carp over a few years old these are the typically the first to die and would be the best warning sign of a fish kill beginning.

Now serving Greenville SC, Spartanburg SC, Asheville NC, Charlotte NC, Winston-Salem NC, & Greensboro NC areas.

Get started. Become a member today!