Reservoir Blues

This content is archived

Published on: Nov. 14, 2012

It was a warm summer morning and the three catfish anglers pulled their boat up to the trotline with great anticipation. They had caught several nice fish the night before, and numerous smaller fish, but this line would be different.

The boys grabbed the line while their grandpa drove the boat. “Grandpa, we have a good one!” one of them shouted. As they eased closer to the big blue catfish they could tell it was a giant. The fish fought hard as the three tried to get it in the net. At the last minute, the large blue made a hard run and broke the dropper line, leaving only a tale of the one that got away.

This might sound like a common fish story, but for Truman Reservoir and Lake of the Ozarks, it’s not as common as it used to be. In the early years following the building of Truman Dam, Truman Reservoir and the area directly below the dam on Lake of the Ozarks became known as world-class blue catfish waters. The reservoirs combined span more than 100,000 acres and were once destinations for anglers wanting to catch a fish of a lifetime. Early on this was possible, but now blue catfish weighing 50 pounds or more are rare.

Blue catfish are Missouri’s largest catfish. The current alternative method state record was caught by Azel Goans in 1964 and weighed 117 pounds, a record that stands nearly 50 years later. The giant blue was caught from the Osage River near Osceola, an area that is now flooded by Truman Reservoir. In 2010, the former pole-and line world record, and current state record blue catfish, was caught from the Missouri River near St. Louis. That fish weighed 130 pounds. Blues are pursued because they can reach large sizes and are great to eat. However, it takes time for these fish to grow. Blues can live 20 to 30 years and, on average, take five years to reach about 1 pound and 15 years to reach about 12 pounds in Truman Reservoir and Lake of the Ozarks.

A Common Concern

Truman Reservoir impounded the Osage River upstream from Warsaw in 1979. The dam became a barrier to blue catfish migrating upstream from Lake of the Ozarks and a concentration point for large blue catfish making their annual spring spawning runs. Truman was a new reservoir full of food and had plenty of water for blue catfish to roam and grow to large sizes.

Retired Department Hatchery Manager Gary Heidrich remembers those days. “I worked in the Truman basin before the dam went in,” he says. “Once the dam was built and the reservoir flooded, 50-pound blue catfish were very common. It was easy to go out and catch those fish, and many larger fish upwards of 80 pounds were caught each year.”

Fishing pressure increased once the reservoirs gained fame for producing heavy stringers of blue catfish. Department biologists and conservation agents noticed the increasing fishing pressure beginning in the late 1980s and early 1990s. As the number of anglers rose, the number of large blues fell.

Local angler Alvin Franklin has chased catfish on the Lake of the Ozarks for more than 50 years. “I can remember the days when we used to catch a lot of big ones,” he says. “I haven’t seen as many big ones as we used to. I think if they can come up with a slot limit or a length limit, that’s got to help things. And if we don’t have that, the younger generation won’t know what a big catfish is. That would be a shame.”

Biologists decided to take a closer look at catfish angler opinions and catfish populations. In Lake of the Ozarks below Truman Dam, biologists had concerns with declining numbers of larger, mature fish and determined that harvest was too high. Subsequent research led to the implementation of a no-fishing zone directly below the dam, and protective regulations for catfish were implemented beginning in 1998.

In 2002, the Department conducted a statewide survey of catfish anglers and asked several questions of anglers who fished Truman Reservoir. Truman catfish anglers were asked whether fishing for catfish had improved, declined, or stayed the same for the 10-year period spanning 1992 through 2002. More anglers (35 percent) believed that the quality of catfish angling had declined, while only 11 percent believed that fishing for catfish had improved.

Between 2003 and 2005, the Department also conducted a Truman Volunteer Catfish Angler Creel. Catfish anglers (308) were asked to rate their fishing trips. The largest percentage (41 percent) ranked their trips as poor, while the smallest percentage (15 percent) ranked their trips as excellent. Combined, the categories of fair and poor accounted for 64 percent of the responses from anglers in this latter survey, suggesting that future management efforts should be directed at improving these fisheries.

In 2003, the Department drafted the Statewide Catfish Management Plan and discussed its elements with anglers at six public meetings. Public response was gathered and the following key strategy was identified: Implement new regulations, based on sampling and creel data, to protect large catfish in Truman Reservoir and Lake of the Ozarks.

Between 2004 and 2008, Department biologists tagged 300 blue catfish on Truman Reservoir using $50 reward tags. At the end of the five-year period, the combined harvest rate on blue catfish 24 inches and larger, or about 5 pounds, was 92 percent. A 92-percent angler harvest rate for medium-size blue catfish does not allow blue catfish to remain in the population long enough to reach their growth potential. This “growth-overfishing” is recognized as a major contributing factor to the decline in blue catfish sizes.

The Department conducted further sampling of blue catfish during 2010 and 2011. During that time, 1,099 fish were sampled on Truman Reservoir, with an average weight of 4 pounds. A total of 869 fish were sampled on Lake of the Ozarks, with an average weight of 3 pounds. Meanwhile, blue catfish caught by anglers were showing the same trend.

Truman volunteer catfish anglers also shared information from their 2003–2005 fishing trips. The 3,760 blues caught using a full range of legal methods (measured by anglers) averaged only 3 pounds.

Finally, conservation agents began measuring angler catches on both reservoirs in 2010.

Once again, the average size of fish that anglers have been catching on Truman Reservoir is 4 pounds, and the average size on Lake of the Ozarks is 3 pounds.

Citizens and Science Seek a Solution

In 2006, the Department implemented changes to the statewide regulations for blue and channel catfish. Once combined in a daily limit of 10, blue and channel catfish were separated. The new regulations allow 10 channel catfish and five blue catfish daily statewide. Fisheries Division Chief Chris Vitello explains, “We made this change with future management in mind. We know that channel and blue catfish are very different and by separating the two, we would be able to better manage each in the future as we learned more about populations of these important sport fish.”

In 2009, the Department formed a working group to review available data and consider ways to reverse the decline of the blue catfish fisheries in Truman Reservoir and Lake of the Ozarks. The group determined that regulation changes would be necessary to recover the quality of the blue catfish populations in both reservoirs and developed four, primary objectives:

  • Provide harvest protection for intermediate and larger blue catfish that studies found are being harvested at excessive rates, allowing more fish to reach larger sizes.
  • Increase the harvest of small blue catfish, allowing anglers every opportunity to take fish home for the table, and reduce the number of small blue catfish to reduce competition for food. With less competition for food, blue catfish growth should improve.
  • Retain the catfish angler base on both reservoirs and their tributaries.
  • Maintain good relations with the angling and non-angling public while continuing to promote the local catfish fishing-based economy.

Numerous regulation options were considered. Protected slot-length limit regulations, where blue catfish within a prescribed size range must be released, were determined to be the best alternative. Protected slot-length limits allow intermediate-sized blue catfish, those being harvested at high rates, a chance to grow to larger sizes. At the same time, daily limits on fish shorter than the protected slot length limit should be increased and larger fish above the slot would require some level of additional protection.

With a science-based roadmap in place, the Department gathered more public input. Three stakeholder meetings were held in 2010 to discuss several regulation options. The majority of attendees supported a regulation change. Some stakeholders, while supportive of a regulation change, believed that the changes might be too restrictive. Others indicated support for existing regulations. Additional comments were gathered using an online, public link.

This information was used to revise the proposed regulation changes and, in August 2012, an updated regulation proposal was discussed with the public at a series of three open houses. With science and public input as the driving forces, the Department is considering the following changes to blue catfish regulations for Truman Reservoir, Lake of the Ozarks, and their tributaries:

Ten blue catfish daily limit: This reflects an increase in the current daily limit for blue catfish and should help to improve blue catfish growth in both reservoirs.

Protected slot-length limit of 26 to 34 inches, or about 7 pounds to 16 pounds: Blue catfish from 26 to 34 inches would have to be returned to the water, unharmed, immediately. This protected slot-length limit protects blue catfish that are being harvested at rates too high to sustain a quality fishery and is intended to increase the number of larger fish in the population of each reservoir.

Two blue catfish larger than 34 inches: These fish would count toward the daily limit of 10. This would still allow anglers to take home larger blue catfish.

Predictive modeling indicates that, given the proposed regulation changes and adequate time, Truman Reservoir and Lake of the Ozarks will support five times as many blue catfish 34 inches and larger than they do now.

If approved, the proposed regulations would be implemented on Truman Reservoir and Lake of the Ozarks and their tributaries and include the no-boating zone below Truman Dam. Regulations for channel and flathead catfish would remain unchanged except for the no-boating zone below Truman Dam where they would return to the statewide daily limit of 10 channel catfish and five flathead catfish.

All proposed regulation changes will be considered through the Department’s standard regulation review process and are subject to approval by the Conservation Commission.

Better Blues for the Future

Even with new regulations, it will take time to see improvements, perhaps as long as eight to 10 years to see the full effect of the proposed changes, because blue catfish are slower growing. Department biologists will track changes in the blue catfish populations in both reservoirs and report their findings to anglers. We will continue to listen to the public. If substantial improvement in the quality of blue catfish populations in these reservoirs is not achieved, we will revisit the regulations and make adjustments as needed. These big reservoirs were once home to large blue catfish. With sound science and public input, we could be on the verge of returning the big blue catfish of the past. A recent comment posted on the Department’s website says it best: “My boys love to go out fishing with daddy and come back to tell me all their fishing tales. The best stories are the ones where they spread their arms open wide and say, ‘We caught a fish this big, Mommy!’ I want to ensure that they will always have those fishing tales to tell.”

Missouri is a great place to fish. Efforts to improve blue catfish fishing on Truman Reservoir and Lake of the Ozarks will help to ensure that current and future generations can continue to stretch their arms open wide to the tune of reservoir blues.

Weigh In on Regulation Changes

MDC is considering the following protective regulations for blue catfish on Truman Reservoir and Lake of the Ozarks and their tributaries, including the no-boating zone below Truman Dam, in an effort to improve quality and reverse the decline of larger blue catfish in these waters. Both reservoirs contain large numbers of smaller blue catfish, but numbers of large blues have declined.

  • Increase the daily limit from five to 10 blue catfish.
  • Add a protected slot-length limit for medium-size blue catfish of 26–34 inches (7 to 16 pounds).
  • Allow the harvest of two blue catfish above the protected slot-length limit.

We are seeking public input. Please share your comments with us online at mdc.mo.gov/node/18097.

Content tagged with

Shortened URL
http://mdc.mo.gov/node/19753