Largemouth catchability hereditary

Urbana, Ill. – That 7-pound “bucketmouth” you landed on only
your second cast of the day?

Turns out, it may not be your refined angling skills that put
him in the boat.

And it may not be dumb luck, either.

According to researchers at the University of Illinois, a
largemouth bass’ propensity to being caught may have more to do
with the fish’s genes – that is, if Ma and Pa Bucketmouth were easy
to catch, then so too will Junior.

Results of the 20-year study indicate that vulnerability to
being hooked by anglers is a heritable trait in largemouth bass.
Details of the findings were recently published by the journal
Transactions of the American Fisheries Society.

David Philipp, ecology and conservation researcher at U of I,
indicated that a lot of fish were caught in order to complete the
study.

“We kept track over four years of all of the angling that went
on, and we have a total record – there were thousands of captures,”
he said. “Many fish were caught more than once. One fish was caught
three times in the first two days, and another was caught 16 times
in one year.”

The U of I research team included Philipp, Steven Cooke, Julie
Claussen, Jeffrey Koppelman, Cory Suski and Dale Burkett. Studies
began in 1975 with the resident population of bass in Ridge Lake,
an experimental study lake in Fox Ridge State Park in Charleston.
Because it was a controlled study, anglers had to reserve times and
every fish that was caught was put into a live well on the boat.
The fish were measured and tagged to keep track of how many times
each fish had been caught.

More than 1,700 fish were collected when the pond was drained
four years later.

“Interestingly, about 200 of those fish had never been caught,
even though they had been in the lake the entire four years,”
Philipp said.

Philipp explained that largemouth males and females that had
never been caught were designated “Low Vulnerability” parents. To
produce a line of LV offspring, these parents were allowed to spawn
with each other in university research ponds.

Males and females that had been caught four or more times in the
study were designated “High Vulnerability” parents that were
spawned in different ponds to produce a line of HV offspring.

Fish in each group were then marked and raised in common ponds
until they were sizeable enough to become targets for anglers.

With each generation of bass, the difference in “catchability”
grew.

Most of the selection is occurring on the LV fish – that is, for
the most part, the process is making that line of fish less
vulnerable to angling, the study reveals.

“We actually saw only a small increase in angling vulnerability
in the HV line,” Philipp said.

Fisheries biologists have long known that females lay eggs and
then leave the nest. Male bass become the primary parent, guarding
the nest against brood predators for about three to four days
before the eggs hatch. Even after the baby bass start to swim, the
father bass stays with the young bass for roughly three weeks while
they feed and grow.

Philipp explained that the experiment sped up what’s actually
happens in the natural world.

“In the wild, the more vulnerable fish are being preferentially
harvested, and as a result the bass population is being
directionally selected to become less vulnerable,” he said. “We
selected over three generations, but in the wild the selection is
occurring in every generation.”

An offshoot of the research has led Philipp to question whether
or not the growing practice of catch-and-release is helping
conserve largemouth populations.

“If bass are angled and held off of their nests for more than a
few minutes, when they are returned to the lake, it’s too late;
other fish have found the nest and are quickly eating the babies,”
he said.

Philipp said he is recommending that to preserve bass
populations across North America, management agencies need to
protect males during spawning seasons.

“There should be no harvesting bass during the reproductive
period,” he concluded. “That makes sense for all wildlife
populations. You don’t remove the adults during reproduction.”

Philipp recommended that if fishing tournaments were held during
the spawning season, then regulations should require that there be
immediate catch-and-release, eliminating the use of tournament
weigh-ins.

Philipp, who has also taken part in a study on the Largemouth
Bass Virus in Illinois, is urging fisheries management to go even
further – proposing that a portion of each lake be set aside as a
bass spawning sanctuary, where all fishing would be prohibited
until after bass reproduction is complete.

Meanwhile, scientific research that suggests some largemouth
bass may be easier to catch if it is in their genes is eliciting
varied responses from Illinois’ bass fishing community.

“I guess that explains why I always come in last place with an
empty livewell. I’m messing with the wrong bass family,” Tom Akin,
an amateur bass angler from Carbondale, said. “I need to go after
the family down the street.”

Leo Hollus, of Rockford, simply rolled his eyes and offered,
“Fishing is still about dumb luck.”

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