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Entries in fisheries management (62)

Thursday
Jan082015

DNA Research Reveals Trophy Bass Parentage at Guntersville

Contrary to popular belief, Guntersville trophy bass are not pure Florida strain, according to DNA research conducted during the 2014 Bassmaster Classic at that northern Alabama fishery.

From a scientific standpoint, however, that really isn’t surprising. Between 1981 and 1994, an estimated 500,000 Florida bass were released into Guntersville, but few have been added since.

“The population, instead, consists largely of hybrid crosses,” said Dr. Eric Peatman, an associate professor in Auburn University’s School of Fisheries, Aquaculture, and Aquatic Sciences.

Eight-pound-plus fish are 52 percent Florida and 48 percent northern. That’s in keeping with the assessment of Gene Gilliland, B.A.S.S. National Conservation Director, who said that bass with 50 percent or more Florida genes have enhanced trophy potential. “Below that, and it’s no greater than for native fish,” he added.

Peatman and his team also found that the “lakewide average genetic composition” is about 70 percent northern and 30 percent Florida.

“Four to five-pound fish do not vary significantly from the lakewide average in their genetic make-up,” he explained. “However, seven-pound-plus fish show an increase in Florida percentage to 42 percent of their genome.”

These findings suggest that stocking Guntersville with Florida bass has been effective in shifting the genetic baseline of the population and that trophy-size fish are bunched around a rough 50:50 genetic split, said Peatman, adding that more samples are needed to reach definitive conclusions.

“One of the missing components in this analysis is age,” the scientist said, adding that multiple ages likely are represented among those samples of larger bass. “Ultimately, we want to know what is the genetic composition of the largest size fish within each year class, or what mix of Florida and northern alleles produces the fastest growing fish.”

The Alabama Department of Conservation and Natural Resources (ADCNR) will with this aspect during its spring sampling.

“A final component in the mix is obviously habitat,” Peatman said. “The best performing genotype in one reservoir is not necessarily the best genotype in a different reservoir with different environmental parameters. “So we have plans to include different reservoirs and habitats in the analysis in the coming year as well.”

All of this work is part of a statewide project funded by ADCNR to better understand the impacts of the state’s Florida bass stocking program on the quality of its bass fisheries.

“The Classic and other tournaments throughout the year in Alabama represent an excellent opportunity to take non-lethal DNA samples from larger bass brought in by anglers,” Peatman said.

“At the end of the day, the goal is to use these genetic tools to help ALDCNR make proactive stocking and management decisions to ensure the highest quality bass fisheries for our anglers for years to come.”

(This article appeared originally in B.A.S.S. Times.)

Wednesday
Jan072015

Would Florida-Strain Bass Improve Your Fishery? Maybe . . . Not

In southeastern Oklahoma one winter, hatchery ponds for the state’s Florida bass stocking program were covered by ice for three weeks. One hundred miles to the south, at Lake Fork, just three days were below freezing.

Anglers at Fork during that time probably found the bite tough, but the world-class fishery suffered no long-term damage. In those ponds, meanwhile, 60 percent of the Florida bass brood stock died.

Yes, Florida bass grow faster and larger than their northern counterparts. And stocking them outside their native range has resulted in the creation of some spectacular trophy fisheries in states such as Texas, California, Georgia, and Alabama.

But desired outcome from the expensive effort is not a guarantee.

“In Oklahoma, we finally decided that stocking Florida bass was a waste of time in some places, no matter what fishermen want,” said Gene Gilliland, B.A.S.S. National Conservation Director and former assistant chief of fisheries for that state.

Still, anglers continue the drum beat to stock Florida bass in waters that biologists say are inappropriate, as Ron Brooks knows all too well.  And in their arguments for stocking, they cite “evidence” that really isn’t evidence at all, explained the Kentucky fisheries chief.

“We receive requests to stock the Florida strain fairly regularly, and they always site Tennessee’s stockings in Kentucky Lake and the larger bass there as a result,” he said, echoing the experiences of fisheries managers in several states.

But biologists haven’t verified that those large bass are the result of Florida strain stockings. “The truth of the matter is that Kentucky Lake is a very fertile lake with very abundant forage species,” Brooks added.

Recently, some wanted Kentucky to stock Florida bass in Cave Run Lake, an infertile fishery east of Lexington, with limited forage and almost no habitat in the lower end. And, oh yeah, muskies, fish that like cold water, do quite well there.

Still, Brooks said, explanations for why Cave Run is inappropriate fell on deaf ears.

In a nutshell, here’s what introduced Florida bass need to thrive: mild climate, abundant forage, and plentiful habitat, preferably vegetation. Originating in subtropic Florida, they’re most at home in shallow water with a long growing season and plenty to eat.

Simply for survival, climate is the most critical of the three. Temperature drop of just a few degrees can stress Florida bass, and rapid and/or severe drop can kill them. Unfortunately, a clear geographic boundary for determining where Florida bass can live and where they can’t does not exist.

 “It’s not a north/south thing,” Gililland said. “It’s a diagonal, with cold moving from the northwest to the southeast.”

To thrive, meanwhile, Florida bass require plenty of food both throughout the year and during all stages of their life cycle. In their native range, that means mostly golden shiners, shad, and sunfish. But they will grow large and fat on other species, including trout in California and tilapia in Mexico’s Lake El Salto.

Shallow-water, vegetated habitat is the least critical of the three components, especially if the climate is mild and food plentiful.

Okay, some of you say, “I understand that. But what’s the big deal if you stock Florida bass in a lake and they don’t do well. No harm, no foul. Right?”

Wrong.

Introducing Florida bass is not the same as a supplemental stocking to enhance a depleted fishery. There’s only one reason to stock them: To grow trophy fish. If a water body isn’t conducive for that, then Florida genes mixed into the native strain actually can harm the fishery, making them less hearty, at least in the short term. Eventually, Florida genes will disappear from the population.

But the money wasted to maintain brood stock, spawn them, and stock the offspring still will have been wasted.

Additionally, as Florida bass breed with native bass, the potential for growing to trophy size is lost over time. “You can’t just stock and leave them,” Gilliland said. “As long as you have 50 percent or greater Florida genes, there’s still the potential. Below that, it’s no greater than with just native fish.”

Still, many anglers who want big bass in their home waters continue to lobby for something that is not in the best interests of their fisheries.

“Believe me, if past research projects indicated that Florida strain bass would produce lunker bass in Kentucky, we would have stocked them years ago,” said Brooks, voicing the frustration of many fisheries managers. “We strive to produce the best fisheries possible within the limits of our resources.”

(This article appeared originally in B.A.S.S. Times.)

Monday
Dec292014

Michigan to Start Online Scheduling for Bass Tournaments

Photo by Ron Kinnunen

Beginning Jan. 1, if you want to schedule a bass tournament at a state-managed access site in Michigan, you can do so online. The Michigan Tournament Fishing Information System web application is intended to reduce scheduling conflicts. But it also could improve management of the state’s bass fisheries if organizers will use it to report catch data.

Here’s more from Michigan DNR:

"This system is designed to help both tournament organizers and recreational anglers and boaters avoid ramp conflicts. In addition, tournament organizers can electronically report their catch data and help Fisheries Division effectively manage our valuable fisheries resources.

"By policy, Fisheries Division will not assist nor become involved in promoting fishing tournaments. However, Fisheries Division recognizes that bass tournament catch and effort data can provide important information about bass populations across the state of Michigan."

Wednesday
Nov192014

Angler Who Took Daughter Fishing Fights Back and Wins

How would you feel about being fined for taking your child fishing with you?

That’s what happened to Jack Pick early last spring, as he was ice fishing with his 3-year-old daughter on Saskatchewan’s Turtle Lake. A conservation officer charged him with having more than two lines in the water because he had four, two for himself and two for his daughter.

The officer alleged that the child wasn’t “able to set, maintain, watch, and retrieve fish on her own lines.”

Pick challenged the charge and, representing himself at trial, submitted one item in his defense, the 2014 Saskatchewan Anglers’ Guide. It features a father helping his young daughter fish.

In reviewing the rules, the judge decided that no minimum age limit exists to be an angler and found Pick not guilty.

“Just because an individual is three years of age, and does not have the ability to do everything required when fishing, it does not mean that he or she cannot legally fish,” he said.

Congratulations to the judge for showing common sense, a trait too often absent today in government officials, and to Pick for fighting back and winning, especially in such a simple but indisputable fashion.

To learn more, go here, and be sure to read the comments. My favorite:
“An infant is physically incapable of fishing, a 3 yr old is not (I have taken a 3 yr old fishing, so I know). Yeah they need some help, but so does my wife who won't bait her own hook.

Monday
Nov172014

Freshwater Fish Harvest Data Inadequaate

Those who plan dams and other river projects don't know how important rivers are for fish harvest , according to scientists. AP Photo by Janet Jensen

Wow. Researchers say that worldwide accounting of freshwater fish harvested for consumption is “inaccurate and grossly underestimated” and that the amount “could equal the current amount of marine fish caught.”

As a consequence of this, planning for dams and other river projects doesn’t adequately account for the effect they might have on fish populations.

That’s bad news not only for commercial harvest of freshwater fish, but recreational angling as well.

“It’s not a question of whether we should stop using water for other purposes, but we need to consider what harms are being created, and if they can be mitigated,” said one of the Michigan state scientists. “People are losing jobs and important sources of food because fish habitats are being degraded, greatly reducing fish production in these waters.”

Read more here.