City advises caution with Corby Pond algal bloom

ST. JOSEPH, Mo. (KQTV) -- The City of St. Joseph is asking people and animals to stay out of the water and avoid fishing at Corby Pond after it found a harmful algal bloom.

According to the Missouri Department of Natural Resources, cyanobacteria, which is often referred to as "blue-green algae," are responsible for harmful algal blooms. Some types can produce toxins that may affect the health of people and animals.

The city said signage will be placed at the pond to warn visitors and will remain in place until 14 days after the bloom has completely disappeared.

The additional 14-day period is in place as a precaution in case toxins were produced during the bloom.

Although the blooms occur naturally, excess nutrients in a pond can cause them to develop more frequently or become more severe. Nutrients can build up over time through atmospheric deposition, decomposition and runoff from the surrounding watershed during rainfall.

Eventually, the blooms disappear on their own; however, the city said it had its contracted pond management company treat the Pond and the Krug Park lagoon for algae Tuesday.

According to a news release from the city, a few dead fish have been observed in Corby Pond. Department of Natural Resources official said the fish deaths are likely a result of low dissolved oxygen in the water rather than cyanotoxins, if toxins are present.

The city said visitors are asked to follow the posted warning and keep themselves, children and pets out of the water until the signs have been removed.