BRA reservoirs get fish habitat help

BRA reservoirs get fish habitat help

Good news for those who like to fish: Fishing opportunities at Brazos River Authority System reservoirs is set to improve.

The Board of Directors at its quarterly meeting Monday authorized General Manager/CEO David Collinsworth to execute an agreement with the Texas Parks and Wildlife Department to perform fish habitat improvement on BRA System reservoirs.

The fish are getting some sustainable housing.

Photograph of US Army Corps of Engineers and volunteers loading structures on the tow barge, Proctor Reservoir, Texas, September 2019.
Photograph of US Army Corps of Engineers and volunteers loading structures on the tow barge, Proctor Reservoir, Texas, September 2019.

Success from past partnerships with TPWD to improve reservoir fish habitats prompted yet another agreement, said Tiffany Malzahn, BRA environmental and compliance manager. 

As a result of the 2011 drought, the lake levels and fish habitat in several reservoirs in the Brazos River basin were impacted for an extended period. On the plus side, that drought allowed the BRA to observe what fish habitat was available at varying water levels in all of the system reservoirs. A fish habitat in a full lake wouldn’t exist in a low lake because the habitat is now out of water for an extended period of time.

That information is aiding TPWD Inland Fisheries staff in determining where man-made habitat improvement will be the most beneficial to help the reservoirs’ fish withstand future severe drought conditions.

In 2016, BRA implemented the first interlocal agreement with TPWD to begin habitat improvement work on BRA System reservoirs. A different plan was made for each lake due to differences in fisheries, native habitat, and lake usage, Malzahn said. Each year BRA and TPWD Inland Fisheries staff will work together to select reservoirs for habitat improvement based on the level of impact observed during the 2011 drought, fishery need, and current reservoir conditions.

Each fish species has particular needs when it comes to shelter and food. Those needs then can change throughout the species’ life cycle. For instance, the area of the lake closest to the shore supports some stages of the life cycle, but not all. 

Two of the most important life functions for maintaining a reservoir fishery are spawning and recruitment. Most fish spawning activity takes place in the shallow areas. The shallower areas tend to have a wide variety of material, including sand, silt, clay, gravel, coarse woody debris and aquatic vegetation, which are all great for the fish to provide cover for young fish from predators.

Photo of Sydney Burgess on Possum Kingdom Lake holding a large fish and sitting next to a dog.
Photo courtesy of Sydney Burgess on Possum Kingdom Lake

Because of this, when a reservoir is facing a drought and water levels have dropped, eliminating that access for fish, there’s the chance for significant degradation of fisheries quality. By creating structures deeper in the reservoirs that mimic the habitat found in the shallower areas, each reservoir’s fishery is strengthened. These structures also mitigate the impacts of future fluctuating water levels and prolonged drought.

One lake level drop for a short duration isn’t problematic, Malzahn said. 

“It’s three years or more; there can be a fisheries collapse,’” she said. “We got lucky in the 2011 drought that the rain came before we hit that three-year mark, but it was pretty close in some areas.”

The BRA-TPWD study to develop the reservoir-specific information on habitat structures received the 2014 American Fisheries Society Outstanding Sport Fishery Development and Management Project Award.  The project was published in the Journal of the Southeastern Association of Fish and Wildlife Agencies.

To continue this partnership with TPWD, the Board on Monday, Oct. 26, 2020, approved allocating $15,000 in the fiscal year 2021 budget and $15,000 will also be included annually through fiscal year 2026.

For more information and GPS locations and maps of existing artificial fish habitat structures, go here.

The next board meeting will be Jan. 25, 2021. To see a full list of board actions, go here.

Photo of a sunset over the Brazos River north of Possum Kingdom Lake
Photo courtesy of Phil Causey