Another interesting MDC study

[Al Agnew]

This is an old study that started back in 2001, but I'd never seen it until the Smallmouth Alliance published it in their most recent on-line newsletter. It's entitled "Current River Smallmouth Bass Tagging Project". In 2001 and 2002, they attended the tournaments of the Current River Smallmouth Bass Anglers Association, counted and measured all fish brought to the weigh-ins, assessed the condition of each bass, measured air and water temperatures, and tagged random fish. Except for one tournament, the tags were not reward tags, in that one they had a $5 reward. They publicized the tagging in local newspapers and radio, and furnished tag reporting cards to local businesses and permit vendors.

Their stated objectives were 1) evaluate size distrubution of tournament-caught smallmouth, 2) determine harvest and release rates of smallmouth, 3) determine extent of movement of tournament-caught smallmouth, and 4) evaluate smallmouth angler demographics.

The tournaments were always held on Saturdays, mostly from 7 AM to 5 PM. Weigh-ins were either at Deer Run Campground near Van Buren or the public access at Doniphan, but some anglers trailered their boats to other accesses. The weigh-ins were designed to maximize survival of released smallmouth, with large plastic weigh-in bags, tubs of water near the scales, and efficient and quick weigh-ins. All fish were released at the weigh-in sites. There were 20-25 boats participating in the tournaments, 2 anglers per boat, and up to 8 smallmouth could be weighed in per boat, with a 12 inch minimum size limit. Only smallmouth were accepted. The study included six tournaments in 2001 and eight in 2002. From 60 to 143 smallmouth were tagged after each tournament.

1662 smallmouth were brought in during the 14 tournaments. Average length was 13.6 inches. Winning bags ranged from 9.16 to 16.09 pounds, and big bass ranged from 1.7 pounds to 3.92 pounds. 79% of the bass were assessed to be in good condition when released, but this figure varied from 55 to 98%, depending upon the tournament. Water temperatures varied from 58 to 85 degrees.

1051 smallmouth were tagged in total. 19% of the tags were returned as of 2004. Anglers reported releasing 76% of the tagged bass caught. They noted that since all bass were of legal size, the release was probably voluntary, although they acknowledged the possibility that the fish had been caught after the angler had already kept their six legal fish and kept on fishing, but they discounted the possibility, believing that would have required too high a catch rate. Anglers near Doniphan released 88% of the tagged bass, while anglers near Van Buren released only 60%. Tagged bass were caught from 1 to 746 days after tagging, with an average of 122 days.

Of the bass released at Van Buren, 39% were re-caught less than 2 miles up or downstream, 12% within 5 miles upstream, and 24% within 2 miles downstream, for a total of 75%. Of those released at Doniphan, 28% were re-caught less than a mile away, 12% within 5 miles upstream, and 24% within 2 miles downstream, for a total of 67%.

Locals caught the majority of tagged bass, 32% being anglers from the Poplar Bluff zip code, 16% from Van Buren, and 12% from Doniphan. 4% were taken by out-of-state anglers.

Of the fish caught during the tournaments, about 39% were 12-12.9 inches, 25% 13-13.9", 15% 14-14.9", 10% 15-5.9", 5% 16-16.9", 3% 17-17.9", 2% 18-18.9", and 1% 19-19.9". The best winning bag was 16.09 pounds on June 2, 2001, but the next best was 12.9 pounds. The biggest big bass, 3.92 pounds, came on June 29th, 2002, and in 6 other tournaments the big bass was over 3 pounds. Worst tournament overall was June 15th, 2002, when only 71 bass were weighed in and the big bass was 1.7 pounds, but it was only the second lowest for winning bag at 10.7 pounds, the lowest being July 27th, 2002, with a 9.16 winning bag.

The condition of the fish were graded thus:

Good--coloration and slime coat normal, fish very active. 80% of the bass were rated good.

Fair--some discoloration around edges of tail fin, reduction of slime coat. 17% were rated fair.

Poor--major discoloration, slime coat mostly absent, fish very lethargic. 1% were rated poor.

Dead--2% were dead.

There was a fairly strong correlation between water temperature and number of fish rated less than good; the warmer the water the more the fish suffered.

Of fish released at Van Buren, 1% were re-caught up to 16 miles downstream, another 6% up to 8 miles downstream, 2% up to 4 miles downstream, 24% up to miles downstream, 39% less than a mile from the release point, 12% up to 5 miles upstream, 7% up to 7 miles upstream, 5% up to 10 miles upstream, 1% up to 12 miles upstream, and 2% up to 24 miles upstream. Of fish released at Doniphan, 4% were re-caught up to 6 miles downstream, 9% up to 4 miles downstream, 28% less than a mile from the release point, 30% up to 4 miles upstream, 12% up to 6 miles upstream, 12% up to 9 miles upstream, 4% up to 14 miles upstream, and 1% up to 18 miles upstream. These mileages were picked for the data points because they were the miles upstream or downstream of other accesses and campgrounds. Two fish released at Van Buren were re-caught between Round Spring and Jerktail Landing.

There were tags returned by anglers in Kentucky, Florida, Virginia, Michigan, and Illinois. 1-2 tags were returned by anglers in a couple of far northern Missouri counties, far southwest MO, the Kansas City area, St. Louis County, Jefferson County, and the Cape Girardeau area. But most of the returned tags came from anglers living within an hour's drive of the river.

The study made the following recommendations:

1. The club should continue current weigh-in procedures.

2. Tournaments in July and August should be for a half-day only or else have two weigh-ins.

3. They should continue releasing fish at the weigh-in site; while the study showed the fish didn't usually move far from the site, the high release rate of re-caught fish seems to indicate that the concentration of them around the weigh-in site was not a big problem.

4. Any further dissemination of smallmouth info should be targeted in the Poplar Bluff/Van Buren/Doniphan area.

[trythisonemv]

Very interesting

[rFisherk]

I once float camped from Owl's Bend to Van Buren. I found the final stretch, from about 10 miles above Van Buren to be the least productive: so much so, I vowed to avoid that section of the river. Could have been me. River is very different down there, with long stretches of dead water, interspaced by very deep pools. I found it relatively uninteresting, compared to further upstream, so didn't fish very diligently. But now I'm wondering if the proliferation of tournaments had something to do with it?

[Al Agnew]

Ron, I'm not sure it's the tournaments themselves that would cause that stretch to be unproductive. According to that study, releasing all the tournament-caught fish in that area would make it BETTER fishing. But, there are apparently a bunch of smallmouth anglers that live in Van Buren, according to that study, and it stands to reason that they would fish that section the most...it has a couple of good concrete boat ramps and it's quick and easy to get to. And most jetboat anglers don't run more than 10 miles or so from the ramp...10 miles gives them enough water for a full day of fishing if they choose. I suspect it's simply the fishing pressure overall, not just tournament fishing pressure. After all, the study also noted that many of the tournament participants trailer their boat to other accesses to fish, so they aren't all pounding that 10 mile stretch in the tournament. I kinda think the tournaments are a wash in that respect...they put more fish into that stretch around the weigh-in site, but they also bring more fishing pressure to that same stretch, as both some tournament participants and some other anglers are probably taking advantage of those concentrated released fish.