number 10 Pond

As many may have noticed we have had several fish die in our pond on 10 over the weekend. We will be cleaning these up first thing Tuesday. All personnel were busy today with other work best done on Mondays when we are closed.

 The reason behind the fish dying is most likely a natural occurrence common this time of year.

Pond Turn Over triggered by the low water levels and cold rain this weekend. Here is a pretty good description of pond turnover by the Virginia Game Fish Department.

Turnover

During summer, the heat and relatively calm weather causes pond water to stratify into layers (Figure 5). There is a less dense, warm, upper layer that is exposed to the sun and atmospheric oxygen (epilimnion), a very thin layer where temperature and density changes rapidly (metalimnion), and a cold, denser, lower layer that receives little sunlight and does not mix with the upper layers (hypolimnion). Because it does not mix, the hypolimnion has no incoming oxygen to replace what is used by bacteria that are decomposing dead animals and plants on the bottom of the pond. As the summer progresses, the hypolimnion usually loses its oxygen. If a storm carrying cold rains causes the pond to turn over (mix suddenly), the de-oxygenated water in the hypolimnion can reduce the oxygen level of the pond enough to cause a fish kill. Ponds with the proper maximum depth (6-12 feet) are less likely to have this kind of kill because they have a smaller hypolimnion.

Another less likely factor is disease brought on by over crowding due to low water levels. Either way the fish kill is a natural occurrence and happens to many ponds each year. We will do our best to have it cleaned up quickly.