Taylor Creek fish kill update
I spent the day with Corps fisheries biologist Doug Harter in Taylor creek and adjoining canals. After several hours of fact finding and interviewing residents in the area, it appears the kill was confined to about 5 short dead end canals in a housing development. Taylor Creek has current in it and didn't appear to be effected.
It was discovered that the water quality at the time of spraying was very low in oxygen content (See item below). When the contractor sprayed the grass in the approximately 50 foot wide canal it depleted the oxygen even lower. There appears to be several elements contributing to the low water quality in the area. Another contributing factor is the water level has risen almost 5 feet in a short period of time and flooded grass that had grown on exposed areas. The dying plants also lower oxygen levels as the plants decompose.
Mr. Harter has decided to implement several new precautions for the Corps contractors in their methods of spraying, ranging from using dissolved oxygen meters to check water quality and oxygen content before spraying begins, to avoiding spraying in confined areas during heavy overcast days which limit the ability of plants to bring the level of DO up to where it is safe for spraying.
I will work closely with Mr. Harter to monitor the areas being sprayed and hopefully to help develop a safe way to treat grass that produces blockage to navigation in canals and trails without any damage to the fish in the area.
September 27, 2001
FWC EXPECTS FISH KILLS TO
INCREASE IN ST. JOHNS RIVER
CONTACT: Sam McKinney or Joy M. Hill (352) 732-1225
or Joe Jenkins (386) 985-7880
The recent rains and cloudy skies in Central Florida are causing more than
just flooding problems along the St. Johns River and associated waterways.
Fisheries biologists with the Florida Fish and Wildlife Conservation
Commission (FWC) are concerned that the number and severity of fish kills
will increase over the next several weeks.
"We have already seen fish kills resulting from low dissolved oxygen (DO)
levels from Lake Washington (Brevard County) to Palatka (Putnam County), but
conditions are prime for a major kill," said Sam McKinney, regional
biological administrator for the FWC's Division of Freshwater Fisheries in
Why do heavy rains and cloudy skies sometimes result in fish kills? The
heavy rains wash organic debris, such as plant and animal material, into the
waterways, and stir up the bottom sediments. As the debris decays the
process uses the dissolved oxygen in the water faster than it can be
replenished. At the same time, the overcast skies reduce sunlight so algae
does not produce oxygen, and the result is that there is not enough
dissolved oxygen in the water for the fish to breathe.
"That is when fish begin coming to the surface and gulping air," said
McKinney. "Ultimately the fish die and float to the surface. How low and
widespread the DO levels are, determine the size of the fish kills which can
range from only a few individuals being affected, to massive kills where
hundreds of thousands of fish become victims."
For the past month biologists have recorded DO levels of less than one part
per million (ppm) in many portions of the St. Johns River. Fish need DO
levels of about five parts per million, and can begin gasping and dying when
levels reach one or two ppm.
In Lake Dexter for example, FWC biologists recently recorded DO levels of
between 0.2 to 1.0, which has resulted in a minor fish kill involving
approximately 600 fish, so far, including largemouth bass, bluegill, black
crappie and catfish. On Thursday, biologists recorded DO levels in Lake
Woodruff between 0.2 and 1.0, and counted several hundred dead fish there.
Conditions on Rodman Reservoir are prime for a major fish kill, as well,
with DO levels well below optimum levels.
Please report fish kills to the FWC at (352) 732-1225, and the Department of
Environmental Protection in Orlando at (407) 894-7555.