- Joined
- Mar 11, 2001
- Messages
- 70,011
- Reaction score
- 1,007
Lake Balmorhea becomes laboratory for bass study
Mike Leggett/Austin American-Statesman
June 19, 2003
Bass anglers long have argued over which kind of fish they'd rather have: big bass or dumb bass?
Texas Parks and Wildlife Department biologists thought that in a perfect world, maybe it was possible to have both.
A population of non-native sheepshead minnows threatening endangered pupfish in Lake Balmorhea, near Balmorhea in far West Texas, gave them the chance to begin finding out.
"It came out of our research when we found out we could make triploids (sterile, non-breeding bass)," said Bobby Farquhar, a regional biologist in San Angelo. "The theory was you could make sterile Florida bass to stock that would grow faster to make trophy bass and stock northern bass to be easier to catch."
Federal officials offered help in killing out all the fish in 500-acre Lake Balmorhea in 1998, Farquhar said, and TPWD biologists began stocking soon after for a study that could lead to the best of both worlds for Texas anglers.
"This was one of the few places where we could actually start totally over," he said.
Parks and Wildlife stocked approximately 70 percent native northern largemouths and 30 percent sterile triploid bass, Farquhar said, and has been conducting follow-up studies annually to track the percentages of those fish in the population, as well as the growth rates of the two kinds of bass.
The first year, the northern bass grew faster, he said, which was expected. By the second year of the study, the Florida bass had begun to catch up. In addition, the northern bass did seem to be easier to catch.
"We did an angling sample and an electro-fishing sample," Farquhar said. "The northern bass were reproducing the first year and we haven't had to stock them since."
Catch rates were quite high for anglers, too, though the fish were small. As expected, catch rates have declined as the fish have gotten older. More data will be needed, though, to determine whether the native bass are easier to catch and the Floridas really are going to grow more quickly to trophy size.
However, biologists still need to perfect the process for creating the sterile Florida bass that is reliable and financially feasible, he said. Fertilized eggs are subjected to pressure that creates a third chromosome (thus triploid, rather than the normal diploid) and renders the fish sterile. But not only is the process labor intensive, it can fail to produce sterile fish if the pressure treatment isn't perfect.
"We don't really know that the triploids will grow larger, or that the native northerns are easier to catch," Farquhar said, although there is evidence to that effect. "But if we can prove those in a reservoir situation, then there could be positive effects for bass anglers in the future."
"I think the most practical uses would probably be on smaller private lakes of 50 to 100 acres," Farquhar said, "but we could see them used in places like state parks and small city lakes."
The smaller lakes will offer the control needed to track and maintain populations at the levels needed to keep enough bass spawning and for enough trophy fish to keep anglers happy, he said.
Already there have been positive signs for Lake Balmorhea, though. There was an immediate increase in the number of anglers hoping to get in on the new lake effect created by killing off all the fish and re-stocking.
"Plus, we got rid of a lot of carp and other trash fish and the water cleared up," Farquhar said. "We have some vegetation going now, too."
mleggett@statesman.com
Mike Leggett/Austin American-Statesman
June 19, 2003
Bass anglers long have argued over which kind of fish they'd rather have: big bass or dumb bass?
Texas Parks and Wildlife Department biologists thought that in a perfect world, maybe it was possible to have both.
A population of non-native sheepshead minnows threatening endangered pupfish in Lake Balmorhea, near Balmorhea in far West Texas, gave them the chance to begin finding out.
"It came out of our research when we found out we could make triploids (sterile, non-breeding bass)," said Bobby Farquhar, a regional biologist in San Angelo. "The theory was you could make sterile Florida bass to stock that would grow faster to make trophy bass and stock northern bass to be easier to catch."
Federal officials offered help in killing out all the fish in 500-acre Lake Balmorhea in 1998, Farquhar said, and TPWD biologists began stocking soon after for a study that could lead to the best of both worlds for Texas anglers.
"This was one of the few places where we could actually start totally over," he said.
Parks and Wildlife stocked approximately 70 percent native northern largemouths and 30 percent sterile triploid bass, Farquhar said, and has been conducting follow-up studies annually to track the percentages of those fish in the population, as well as the growth rates of the two kinds of bass.
The first year, the northern bass grew faster, he said, which was expected. By the second year of the study, the Florida bass had begun to catch up. In addition, the northern bass did seem to be easier to catch.
"We did an angling sample and an electro-fishing sample," Farquhar said. "The northern bass were reproducing the first year and we haven't had to stock them since."
Catch rates were quite high for anglers, too, though the fish were small. As expected, catch rates have declined as the fish have gotten older. More data will be needed, though, to determine whether the native bass are easier to catch and the Floridas really are going to grow more quickly to trophy size.
However, biologists still need to perfect the process for creating the sterile Florida bass that is reliable and financially feasible, he said. Fertilized eggs are subjected to pressure that creates a third chromosome (thus triploid, rather than the normal diploid) and renders the fish sterile. But not only is the process labor intensive, it can fail to produce sterile fish if the pressure treatment isn't perfect.
"We don't really know that the triploids will grow larger, or that the native northerns are easier to catch," Farquhar said, although there is evidence to that effect. "But if we can prove those in a reservoir situation, then there could be positive effects for bass anglers in the future."
"I think the most practical uses would probably be on smaller private lakes of 50 to 100 acres," Farquhar said, "but we could see them used in places like state parks and small city lakes."
The smaller lakes will offer the control needed to track and maintain populations at the levels needed to keep enough bass spawning and for enough trophy fish to keep anglers happy, he said.
Already there have been positive signs for Lake Balmorhea, though. There was an immediate increase in the number of anglers hoping to get in on the new lake effect created by killing off all the fish and re-stocking.
"Plus, we got rid of a lot of carp and other trash fish and the water cleared up," Farquhar said. "We have some vegetation going now, too."
mleggett@statesman.com
