Fish Kill update: Possum Kingdom Lake and Lake Granbury

Fish Kill update: Possum Kingdom Lake and Lake Granbury

June 3, 2020: The BRA environmental lab has completed evaluation of water samples obtained from Lake Granbury. After reviewing well-collected samples and consulting with Texas Park and Wildlife Department, we’ve determined the cause of the recent fish kill at Lake Granbury is a moderate toxicity golden algae bloom.


Golden algae is not a hazard or public health concern.  It does not harm people or animals.


Here’s more information: 



Golden algae is a naturally occurring microscopic alga that typically occurs in surface waters state-wide. Blooms of this algae can produce toxins that are lethal to fish, mussels and clams.  In Texas, these toxic events have most often occurred in waters with high salt or mineral levels. There is no evidence the toxins produced by golden algae are harmful to humans, livestock or wildlife. It characteristically appears as brownish or tea-colored water. 


Possum Kingdom Lake’s fish kill was spotted in two to three areas, mostly on the north side of the lake. Lake Granbury’s fish kill was spotted mostly in areas south of the Hwy. 377 Bridge.  The dead fish will continue to float downstream toward the dams. We do not believe the fish kill is active, so the fish you’re seeing now are a result of the algae bloom several days ago, and not the result of a new fish kill.


This is a very unusual time of the year to have a golden algae bloom as they are most prevalent during cold weather. It’s possible the inflows into the reservoir from a recent storm in the Lubbock area could have brought water with high amounts of salinity, which triggered the golden algae to bloom.


Warmer temperatures expected later in the week should decrease the chances for future golden algae blooms.


Most of the time, dead fish are not removed from waterways. As part of the natural life cycle, the fish will usually be consumed by other wildlife. You should not consume fish from either reservoir that are dead or dying. If you are fishing for food consumption, eat only fish that appear healthy at the time they are caught.


Though golden algae fish kill events are caused by a toxin that is lethal to fish, golden algal blooms will have no effect on people. Avoid the area where sick or dying fish are in the water.


If you need to report a fish kill, it’s helpful to provide as much information as possible to authorities. Details such as the location, date, and time you noticed the fish kill are important. If possible, note if there is an obvious change in the water's color, clarity or if there is any odor.


If you’re familiar with fish, try to estimate the number, size and species you see, or if they are all simply very small or large. You might also give TPWD observations on recent weather conditions and behavior of the fish. Are they all dead or are some still alive? You might also note changes, if any, to plants or other animals in the area you may see that are affected.


If the fish kill is on a BRA reservoir, you can reach us at 1-888-922-6272 or information@brazos.org.


If you see a fish kill on the Brazos River, or anywhere in the state, call the Texas Parks and Wildlife Department’s Kills and Spills Team 24-hour communication center at (512) 389-4848.