Hot, still cloudy days result in farm pond fish kills
Writer: Robert Burns, 903-834-6191, email@example.com
COLLEGE STATION – A combination of weather patterns is causing wholesale die-offs of fish in many East and North Texas farm ponds and lakes, according to Dr. Billy Higginbotham, Texas A&M AgriLife Extension Service wildlife specialist, Overton.
Most of the calls Higginbotham has received have been from East and North Texas, he said. However, the same confluence of weather conditions– high temperatures and cloudy days followed by cool thunderstorms – could likely be causing fish kills in other areas as well. The conditions are causing oxygen depletion in farm ponds and lakes.
“The weather conditions we’ve experienced over the northern part of Texas have been conducive for farm pond oxygen-depletion fish kills,” he said. “Many pond owners have lost all or part of their fish populations.”
There is always a risk of oxygen depletion in farm ponds during hot summer weather, Higginbotham said. This is because warm water holds less oxygen than cooler water.
However, several hot, still cloudy days in a row will raise the risk of oxygen depletion much higher, he said. Normally, photosynthesis by aquatic plants, mostly single-celled algae, produce enough oxygen to help maintain oxygen levels in ponds even during hot weather. But cloudy skies result in less sunlight reaching the pond, and photosynthesis is reduced.
Windy weather causes waves and also helps to aerate pond water, so hot, still and cloudy conditions are a triple whammy for oxygen production, he said. And the coupe de grace for many farm pond fish in northern Texas in the last week was the cool rains brought by thunderstorms.
“The thunderstorms brought as much as 3 inches of rain in a short time,” he said. “Cool rains lower the temperature of the top surface layer of the water. The cooler top layer of water then settles and mixes with the colder water at the bottom, and this action stirs up organic matter that decomposes and further reduces oxygen.”
An easy way for pond owners to check if their fish are oxygen-deprived is to observe ponds early in the morning, Higginbotham said. It’s at this time of day that the oxygen levels will be the lowest. Oxygen-starved fish will be at the surface of the water, where the oxygen levels are the highest.
Pond owners who have a motor-equipped boat can easily and cheaply counteract oxygen depletion, he said. They can simply back the boat and trailer into shallow water and leave the motor running until the fish recover. The submerged prop will stir up enough water to increase oxygen levels. If pond owners don’t have a trailer, Higginbotham recommends they lodge a boat with an outboard motor against a stump or above deep water against the bank.
Just cruising around the pond in the boat won’t help much, Higginbotham said. Cruising means the prop is pushing the boat, not the water, resulting in considerably less oxygen absorption. Pumps can also be used to increase oxygen, but the intake should be set within two or three feet below the pond surface.
AgriLife Extension district reporters compiled the following summaries:
Central: Soil moisture, rangeland and pastures were in fair condition throughout the region. Overall, crops and livestock were rated as being in good condition. The region received from 1 to 3 inches of rain. The corn and sorghum harvests neared completion. Some corn yields were better than expected, ranging from 50 bushels per acre to 198 bushels per acre. Pastures continued to decline due to temperatures as high as 100 degrees. Cattle remained in good condition. Producers were providing hay to cattle stressed by the hot weather.
Coastal Bend: Soil moisture was short, though spotty showers brought relief to some areas. Only a little grain sorghum was left in the field, while the corn harvest was completed. The rice harvest was underway but slowed by showers. Producers defoliated a lot of cotton, and the crop will be picked as soon as weather allows. There was also a fair amount of cotton that was behind in maturity with very few open bolls. Livestock were generally in good shape, but cows with large calves still suckling were starting to show signs of reduced body condition. Pasture conditions declined.
East: A cool front moved through the region, bringing as much as 4 inches of rain, which improved soil moisture in some areas. In other parts of the district, the cool front moved through without delivering rain. Where there was rain, armyworms were on the move and damaging hay meadows. Hay harvesting was over until grass growth resumes. Some producers were preparing to plant winter pastures. Hay supplies were good. Cows were still in good condition, and calves were gaining weight well. Where conditions remained dry, livestock were still in good condition, but producers were supplying some supplemental feed. Cattle numbers were up at market, with bulls higher than last week. Heavier steers and heifers finished lower, with some inferior quality calves selling at $8 per hundredweight lower. In Trinity County, horn flies were pestering cattle in force, and feral hogs were active but staying close to water sources.
Far West: The region had cooler temperatures as a cold front, a rare event for this time of year, pushed through on Aug. 19 and Aug. 20. Pasture and rangeland remained in fair condition throughout the region. Subsoil and topsoil moisture were adequate to short. Cotton was setting bolls and squaring. Corn and sorghum crops were in fair condition. Sunflower growers were harvesting. In Glasscock County, cotton and other crops were stressed by severe heat and lack of moisture. Most cotton was at cutout, and the sorghum harvest started. Culberson County received from 0.17 to 1 inch of rain. In El Paso County, pecans were at full water stage and growing well, while cotton was at full bloom and setting bolls. Alfalfa growers were ready to take a fifth cutting. The southern part of Presidio County received 1.5 inches of rain, strong winds and severe lightning as the cold front passed through. Fall cattle working was underway. Ward County had isolated showers with accumulations of up to 1 inch. Ranchers and hunters were optimistic about the dove season. Winkler and Loving counties remained under high alert for wildfire even though they received a few scattered showers. Conditions in Reagan County were very hot, dry and windy, which caused rangeland and pastures to dry out. Upton County producers expected cotton to be ready for harvest early.
North: Parts of the region got from 0.3 inch to 2 inches of rain, but most pastures and crops needed more moisture. Topsoil moisture was short to very short. A strong cool front moved through the area, dropping temperatures into the 70s and mid-80s. Grain sorghum looked decent. Soybeans were stressed by hot weather, and some producers bailed the crop for hay. Earlier hay production was good, but more rain was needed to produce another cutting. Livestock were in really good condition for this time of year. Horn fly counts continued to be extremely high, and mosquitoes were bad too. Grasshopper counts were low, and sugarcane aphids were not nearly as prevalent as they were last year. Wild hogs continued to cause damage.
Panhandle: Many parts of the region received rain, from 1 inch to as much as 3 inches. Sugarcane aphids continued to be found at economic thresholds for treatment. Cotton was generally doing well, but still needed more heat units to catch up in maturity. In Collingsworth County, high winds accompanied heavy rains, which broke tree limbs and caused some damage to crops around field edges. Some cotton fields were showing signs of bacterial blight increased due to the cool, wet conditions. Deaf Smith County producers were evaluating damages after another hailstorm. Crop adjusters had just finished accessing losses from the last hailstorm. Along with sugarcane aphid in grain sorghum, mites and southwestern corn borer were producers’ main concerns. Farmers were applying manure and chemical fertilizer to fields in preparation for wheat planting. Hansford County had unusually cool weather conditions with highs in the 70s and 80s. Corn was progressing well but needed more heat units. In Lipscomb County, sugarcane aphid numbers in grain sorghum were not high enough to warrant spraying. Randall County had 60 mph winds on Aug. 18, accompanied by some hail. Most of the damage was to structures; there was no significant damage to crops. In Wheeler County, sugarcane aphids were confirmed, and some producers started spraying to control the insect in grain sorghum.
Rolling Plains: As much as 1.5 inches of rain fell across parts of the region. Cotton was doing well, though some of the crop was still behind in maturity. Producers were fertilizing wheat. Some early planted grain sorghum was harvested with excellent yields. Sugarcane aphids were being found in haygrazer fields and were causing harvesting issues due to the sticky honeydew they secrete. Grasshoppers continued to be a problem in some areas. Rangeland continued to decline because of lack of rain, but most areas were still in acceptable condition for grazing. Livestock remained in generally good condition.
South: Some areas received light showers, but conditions were generally hot and dry throughout the region. In the northern part of the region, peanuts under irrigation were setting pods. Cotton was opening bolls. Some producers were providing supplemental feed to stocker cattle and cow-calf herds. Body condition scores on cattle slightly declined but remained fair. Soil moisture was short to very short in Atascosa, Frio and McMullen counties, and adequate in La Salle County. In the eastern part of the region, high temperatures slowed rangeland and pasture grass growth. The harvesting of corn and sorghum crops was mostly finished, except for some late planted crops that had yet to mature. Cotton was a week or two away from being ready to harvest. Rangeland and pastures continued to decline. Topsoil moisture was mostly short to very short in Duval, Kleberg, Kenedy and Jim Wells counties. Subsoil moisture was generally in the adequate range throughout the eastern counties. In the western part of the region, pecans were in good condition, watermelons and cantaloupes in small-acreage areas were doing well. Corn and sorghum harvesting was completed. Cotton was maturing rapidly, and some fields had already been defoliated. Producers were actively providing supplemental feed to livestock because of declining forage availability and quality. Soil moisture was short throughout the western counties. In the southern part of the region, Hidalgo County cotton was damaged by hail. Many fields had already been defoliated and were ready for harvest. In Starr County, producers were preparing fields for fall vegetable planting. Soil moisture remained generally adequate in the southern counties, and rangeland and pastures were in good to fair condition.
South Plains: Cotton looked good, but was generally behind in maturity. Dryland cotton needed rain. Pastures benefited from cooler temperatures. In Floyd County, grain crops looked great, and harvesting of early planted corn was expected to start in the next week or so. In Cochran County, cotton development ranged from five nodes above white flower to hard cutout, and was pest free. Sorghum maturity was all over the board. Sunflowers, peas and peanuts continued to mature. In Hockley County, cotton was progressing, but the crop needed warmer temperatures to reach its full yield potential. Corn was maturing, and some producers were gearing up for harvest. In Lubbock County, temperatures were more moderate, and irrigation had to be continued because only light, spotty showers were received. Early planted corn and grain sorghum looked good. Some early planted corn was harvested. Cotton ranged from six to seven nodes above white flower to hard cutout. Garza County cotton continued to progress well where moisture was available. Most of the crop was in either early or mid-bloom stage. Temperatures were mostly in the 90s, with a short cooling trend towards the weekend, and about 0.3 inch of rain. In Scurry County cotton needed rain.
Southwest: Hot and dry conditions were the general rule. Some areas received rain, but more was needed. This was typical August weather for the region. Rangelands were extremely dry, which increased the chance of wildfire. The corn harvest was in full swing with good yields reported. The grain sorghum harvest was nearly completed. Wildlife was in good shape, but livestock needed supplemental feed to maintain body condition.
West Central: Hot, dry, windy conditions continued through most of the week. A few areas received isolated showers late in the week. A weak cold front cooled things off for a few days, but temperatures soon returned to the triple-digits. Wildfires, most started from lightning strikes, popped up in many areas. The wildfire danger continued to be high throughout the region. Producers were preparing fields for fall planting. Cotton was in mostly good condition, but still showing signs of drought stress. The grain sorghum harvest wound down, with good yields reported. Cutting and baling hay continued in some areas, but forage and hay crops were heat and drought stressed. Grasshoppers continued to be an issue, and producers were spraying as needed. Rangeland and pastures were in fair condition but declining rapidly. Livestock remained in fair to good condition.