New Texas Alligator Gar Study

[Tim Smith]

There seems to be a consistent interest in gar here. There aren't many alligator gar left in Arkansas, but there are a few.

Texas, where the head of Parks and Wildlife was calling them "trash fish" just a few years ago, has a large population and seems to finally be taking steps to understand and manage the fishery for one of the largest freshwater fish in the world.

From the AFS message boards....

#Despite being one of the largest freshwater fish species in North America,

scientists knew little about alligator

<http://www.worldfishingnetwork.com/fishing-101/species/gar-8474.aspx> 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 alligator 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. As a result, the American Fisheries Society has considered

alligator gar "at risk of imperilment" since 2008.

Texas is fortunate to still have many of the best populations of large

alligator gar in the world. The Trinity River has become one of the most

popular locations to fish for the species. Susceptibility to habitat loss,

coupled with increased fishing pressure, prompted Texas Parks and Wildlife

Department (TPWD) to adopt a one-fish per day bag limit on September 1,

2009. This made Texas the eighth state to adopt harvest regulations for

alligator gar.

Alligator gar longer than six feet are considered to be more vulnerable to

angler harvest due to their more desirable "trophy" size. Although alligator

gar may reach three 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 six

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. Many states are already in the

process of stocking and attempting to reestablish alligator gar populations.

By setting a one-fish per day regulation, Texas inland fisheries biologists

hope to prevent the decline in alligator gar populations seen in other

areas.

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.

Efforts to increase age data for alligator gar from waters throughout the

state are underway by collecting otoliths from angler-caught alligator gar.

Otoliths are pairs of small bones in the inner ears of fish which contain

annual growth rings similar to the rings in a tree. Age data make it

possible to determine how fast fish grow, how long they are capable of

living, and compare historical river conditions to the year the fish were

hatched.

By comparing age data with historical water levels, biologists observed high

river flows during late spring can result in strong alligator gar

reproductive success. For example, high river flows in 2007 resulted in a

very strong year-class of alligator gar in the Trinity River. In the current

drought year, alligator gar may produce few to no offspring at all.

Knowledge about which environmental conditions produced the most fish will

allow biologists to better predict strong and weak year classes. Biologists

may also be able to work with river and reservoir controlling authorities to

help provide the conditions necessary for successful reproduction.

From October 2008 through July 2010, a study on the Trinity River used

acoustic tags to track the movements of alligator gar between Lake

Livingston and Trinity Bay. Biologists found alligator gar were concentrated

in deep pools in the main river channel for most of the year but moved to

tributaries and protected backwaters during flooding. Biologists also found

that although some fish moved more than 100 miles, most of the alligator gar

remained within 15 miles of their tagging locations. There was little

interaction between fish tagged in different parts of the river, suggesting

that alligator gar near Trinity Bay may be a separate population than

alligator gar near Lake Livingston Dam. Further research is needed to

determine if these populations should be managed separately.

A mark-recapture study in the river between Dallas and Lake Livingston

(about 200 river miles) was also conducted with the help of fishing guide

Kirk Kirkland. Captain Kirkland tagged alligator gar, and TPWD recorded the

number of tagged fish he and other anglers caught.

With these data, biologists estimated that this portion of the river

contained about 9,200 alligator gar 42 inches long or longer and about 1,400

fish 78 inches or longer. It was determined that about three to four percent

of these alligator gar were harvested annually with most (73 percent) of the

harvest occurring between April and July of each year. Biologists also

estimated that only about 5 percent, or 400 fish 42 inches or longer, could

be harvested each year from this portion of the river and still sustain this

trophy fishery.

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. Only about one alligator gar was harvested for

every four bowfishers at the Trinity River tournaments, and it took an

average of 50 angler-hours to harvest an alligator gar at a tournament.

Angers harvested an average of 21 fish each year 42 inches or longer during

the three studied tournaments, or about 5 percent of the sustainable annual

harvest of 400 fish. This level of harvest from tournaments alone is well

below estimated sustainable levels; however, biologists still need more

information to determine what total percentage of alligator gar are

harvested annually outside of bow fishing tournaments and using other

methods like rod and reel.

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 Choke Canyon Reservoir in 2011. 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.

Future research needs will involve further assessments of alligator gar

populations around Texas to better understand fishing pressure and harvest.

A population study of alligator gar in the Brazos River below Waco is

currently in the planning stages. TPWD's goal is to study and manage Texas

alligator gar populations to sustain excellent fishing opportunities for

this species for present and future generations to enjoy.

[gotmuddy]

Good read. For decades people would catch them and throw them up on the bank. I love to fish for them, when I was a kid we would take heavy saltwater gear and spend the evening on the river.

[Wayne SW/MO]

Hopefully they will take the bow out of the picture.

[Fredrick]

They should be game fish everywhere people rip on all gar every where . They look scary so people think they should kill them . People love caching pike or muskie why should gar be any different. I think they are great they are a natural species why can't people understand they important like any other fish. I think the alligator gar populations are way down but long nose gar are up in population. I saw a spawn in swan creek forsyth mo in 2009 that was amazing. It rivaled salmon spawns in Alaska. The creek was thick with them I mean it was so full of gar it was crazy I took two steps in and they all went back a few feet they are harmless . My wife landed one on an ultra light about 3 feet long on a blue gill what a blast!!

[Quillback]

I don't understand why Texas doesn't have catch and release rules for alligator gar, and no bowfishing. Should have the same regs in Arkansas also. As far as I know they aren't any good to eat, so might as well release them and establish a trophy fishery.

[brother dave]

Well I haven't eaten an alligator gar, short nose and long nose gar are quite tasty