Tadpole's Outdoor Blog

October 4, 2011

Gar Research

Gar research intended to help trophy fishery

alligator_gar_cromped
OLD TIMER: Some alligator gar live to be 50 years old, according to biologists with Texas Parks and Wildlife Department. Photo by TPWD.

Despite being one of the largest freshwater fish species in North America, scientists knew little about alligator gar until relatively recently.

In the last two decades, knowledge about the species has grown tremendously in response to evidence that alligator gar populations are declining in many areas.

The primary reasons these gar have declined throughout much of their historic 14-state range are loss of floodplain habitats necessary for reproduction (from reservoir construction and river channelization) and overfishing, according to Texas Parks and Wildlife Department.

As a result, the American Fisheries Society has considered alligator gar “at risk of imperilment” since 2008.

TPWD in September 2009 adopted a one-fish per day bag limit for alligator gar. This made Texas the eighth state to adopt harvest regulations for this fish.

TPWD biologists say alligator gar longer than 6 feet are vulnerable because of their more desirable “trophy” size. Although alligator gar may reach 3 feet in length in three years, their growth rate slows with age, and the fish may take 20 to 30 years to reach a length of 6 feet.

Biologists have discovered that alligator gar can live more than 50 years and take about a decade to become sexually mature. It could take several decades to restore their numbers if depleted.

A number of research initiatives have been completed or are underway to better understand gar populations throughout Texas.

TPWD biologists have conducted studies to evaluate growth rates and life span, understand their reproduction, and track the seasonal movement of alligator gar. Biologists have also conducted studies to evaluate angler harvest rates of alligator gar and estimate population sizes.

Since 2009, 130 harvested alligator gar have been collected and aged from anglers at Trinity River bowfishing tournaments. Using information obtained from tournaments, biologists were also able to estimate harvest rates of alligator gar at the events.

While the Trinity River is a well-known stronghold for alligator gar in the state, many Texas reservoirs, such as Choke Canyon Reservoir and Lake Amistad, also support healthy populations.

TPWD began a tagging study of alligator gar in this year at Choke Canyon Reservoir. Tags returned by anglers will provide biologists with information on harvest, abundance, size structure, and survival.

In addition, recaptures of tagged fish during the spawning season will provide clues to number of spawning locations, how often fish spawn in the reservoir, and if fish return to the same locations to spawn each year.

Through the various research projects throughout the state, biologists plan to refine management objectives specific to certain rivers and reservoirs around the state to better maintain or enhance the alligator gar fisheries.

A population study of alligator gar in the Brazos River below Waco is currently in the planning stages.

TPWD officials say they plan to study and manage Texas alligator gar populations to sustain excellent fishing opportunities for this species for present and future generations to enjoy.

Information for this article came a news release issued by Texas Parks and Wildlife Department.

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