Trout anglers want different things from the Little Red River, but scientists say that the river's trout fishery cannot be all things to all people.
Trout inhabit a 30-mile section of the Little Red River below Greers Ferry Lake that's known as the Greers Ferry Tailwater. The trout fishery was created in 1963 when the creation of Greers Ferry Dam and Greers Ferry Lake obliterated native warm water fisheries in the tailwater. Trout were stocked to mitigate the loss of native game fish, creating a very popular and world famous fishery that produced a 40-pound, 4-ounce brown trout in 1991 that held the all-tackle world record for nearly 20 years.
The Little Red River continues to live off that reputation even though it probably does not support a fish remotely in that league these days. At the same time, the Little Red is also very popular with casual anglers that enjoy catching stocker size rainbow trout to eat.
Steve Lochmann, a professor in the Aquaculture and Fisheries Center at the University of Arkansas-Pine Bluff, said that one cohort of anglers want more trout in the Little Red River. Another cohort wants bigger trout in the Little Red River. A third cohort wants more trout and bigger trout. Ultimately, that means two-thirds of the Little Red River's anglers are going to be disappointed with the way the Arkansas Game and Fish Commission manages the fishery.
"If you ask one hundred trout anglers who fish the Greers Ferry Tailwater, 'Do you want to catch more fish or bigger fish', an equal number will answer, 'Both,' " Lochmann said. "Another number that answers want more fish and bigger fish, and that's theoretically not possible."
The main limitation is the ability of a limited amount of habitat to sustain enough fish to satisfy all of the different angling factions. Biological carrying capacity describes the ability of a habitat's natural food supply to support the animals that dwell there.
An optimum growth rate for a brown trout is 2 inches per year, Lochmann said. Brown trout in the Little Red River grow an average of 1 inch per year. They grow slower than trout in other systems because there is simply too much competition for food.
Lochmann said there is not a simple solution. Stocking fewer rainbow trout alone won't achieve the desired result. Anglers must also remove a significant number of small brown trout.
"Hypothetically, if you have 10 times too many trout in that tailwater to get brown trout to grow 2 inches a year, and you took away half of them, guess what! You would still have five times too many trout in the tailwater to get the brown trout to grow 2 inches a year," Lochmann said. "It's a problem of not having enough food for too many mouths to feed."
The situation is identical to the role of biological carrying capacity in deer management, where it is settled science. Every deer manager knows that having too many deer for the amount of food and quality of food on the landscape will result in low body weights and sub-par antler growth.
"We are absolutely talking about the same thing for deer," Lochmann said.
Conversely, every deer hunting community divides down the same lines. Some hunters want more deer. Other hunters want bigger deer with bigger, more massive antlers. Others want both. The third option is only possible by substantially increasing the amount and quality of food on the landscape.
That is much harder to accomplish in an aquatic system for several reasons. For starters, a tailwater is a moving system, Lochmann said.
"It's not like you're fertilizing Uncle Joe's farm pond where the fertilizer can stay there and develop a big bloom of plankton that goes up the food chain so you get faster growth of brown trout. That's not happening because the water is moving."
Another factor is the behavioral characteristics of a wild brown trout. A young brown trout starts out eating invertebrates and insect larvae. When it reaches adulthood, a brown trout prefers to eat fish, including small rainbow trout.
Rainbow trout are another matter altogether. They live their first year in concrete pens eating processed pellets. Brown trout ignore the baits and methods that anglers use to catch rainbow trout because brown trout are not stocked in the Little Red River. They reproduce naturally. They are wild fish that never experience a domesticated phase.
This causes a misconception among anglers that brown trout are scarce in the Little Red River because they catch so few of them. There are plenty of brown trout in the Little Red River, Lochmann said, but they are harder to catch because they are wild.
"There's not always an agreement about what the nature of the trout fishery should be," Lochmann said. "Brown trout are not going to bite corn on a hook. These brown trout are wild. They were not raised in hatchery. They did not have food rained on their heads for the first eleven months of their life. For that reason, a lot of people think there aren't a lot of brown trout in the tailwater simply because its harder to fish for a brown trout than it is for a rainbow."
Nevertheless, helping brown trout to grow 2 inches a year requires decreasing the number of brown trout in the tailwater.
"One way to do that is to harvest them," Lochmann said. "Anglers don't want to harvest fish, but they want more bigger brown trout. That's a management conundrum. In most systems, the manager would tell the angler you have to harvest some small fish so that the food there is feeding fewer mouths so that everybody can grow faster. That's the science that says maybe you should have fewer brown trout so that you get more bigger brown trout."