Dead Fish in Summer? Low Dissolved Oxygen Is Usually the Culprit

One of the most common calls we get during late summer regarding pond management is about a pond full of dead fish, and the owner wants to know what happened. People are worried the water has been poisoned and is unsafe. The vast majority of time, the fish kill is a result of low dissolved oxygen levels in the pond.

A Secchi Disk is Used to Measure Water Clarity

Appropriate water quality is fundamentally important for fish and aquatic plants, and muddy water limits production of both. Ideal clarity for largemouth bass and bluegill production in ponds without substantial vegetation is 12- to 30-inch visibility, with primarily phytoplankton turbidity. Turbidity is cloudiness caused by suspended or dissolved material. Sport fish also perform well in clearer water when substantial aquatic vegetation is present. Ideal clarity for aquatic plant production is generally greater than 36-inch visibility.