Conservation, Ecology, and Management of Catfish: The Second International Symposium

2011 ◽  
Keyword(s):  
International Symposium ◽  
Channel Catfish ◽  
Capture Efficiency ◽  
Ictalurus Furcatus ◽  
Blue Catfish ◽  
Conservation Ecology ◽  
Incidental Capture ◽  
Coastal Rivers ◽  
Second International

<em>Abstract</em>.—Use of trotlines to collect data on catfish populations can lead to incidental capture of endangered turtles. We evaluated the effectiveness of Zote© soap as a way to prevent capture of turtles on trotlines fished in coastal rivers of Mississippi and compared capture efficiency of cut bait and Zote© soap in research ponds. More than 11,000 hooks baited with Zote© soap were fished overnight in six coastal rivers of Mississippi, resulting in the capture of zero turtles, 193 blue catfish <em>Ictalurus furcatus</em>, and 462 channel catfish <em>I. punctatus</em>. Direct comparisons with other baits were not conducted in the coastal rivers because capture of a single endangered turtle would have resulted in revocation of our sampling permit. Therefore, comparisons of cut bait and Zote© soap were conducted in research ponds. The fi rst trial fished 440 hooks each of cut bait and Zote© soap. Cut bait and Zote© soap collected one and zero turtles, respectively, while each bait captured 48 channel catfi sh. The second trial fished 120 hooks each of cut bait and Zote© soap. Cut bait and Zote© soap collected two and zero turtles, respectively, and 15 and 8 channel catfish, respectively. A Mann–Whitney U-test indicated no signifi cant difference between bait type in number of catfish or turtles captured in either trial. While statistical differences in turtle catch between bait types were not found, preventing any capture of endangered turtles in the field is a high priority and our results indicated that use of Zote© soap provides the best method for eliminating turtle capture on trotlines in coastal rivers of Mississippi.

Conservation, Ecology, and Management of Catfish: The Second International Symposium

2011 ◽  
Keyword(s):  
International Symposium ◽  
Ictalurus Punctatus ◽  
Channel Catfish ◽  
High Abundance ◽  
Sampling Effort ◽  
Conservation Ecology ◽  
Standard Work ◽  
Second International

<em>Abstract</em>.—Baited, tandem hoop nets are increasingly being used to sample channel catfish <em>Ictalurus punctatus</em> populations in reservoirs. However, there have been no published studies to address the effect of soak duration on precision of catch. The effect of soak duration on precision of channel catfish catch in baited, tandem hoop nets was evaluated in three Texas reservoirs. Precision of channel catfish catch was inconsistent among reservoirs when one-night soak durations were used but improved with two-night and three-night soak durations. Although catch precision was similar for two- and three-night soak durations, sampling effort could be doubled using two-night rather than three-night soak durations during a standard work week if a manager did not prefer to leave gear unattended during a weekend. Thus, we recommend use of baited, tandem hoop-net series with two-night soak durations to sample high-abundance channel catfish populations in reservoirs.

Conservation, Ecology, and Management of Catfish: The Second International Symposium

2011 ◽  
Keyword(s):  
International Symposium ◽  
Freshwater Fishes ◽  
Valid Species ◽  
Conservation Ecology ◽  
Species Inventory ◽  
Distributed Order ◽  
Second International

<em>Abstract</em>.—Catfishes are a broadly distributed order of freshwater fishes with 3,407 currently valid species. In this paper, I review the different clades of catfishes, all catfish families, and provide information on some of the more interesting aspects of catfish biology that express the great diversity that is present in the order. I also discuss the results of the widely successful All Catfish Species Inventory Project.

Conservation, Ecology, and Management of Catfish: The Second International Symposium

2011 ◽  
Keyword(s):  
International Symposium ◽  
Pylodictis Olivaris ◽  
Blue Catfish ◽  
Conservation Ecology ◽  
Flathead Catfish ◽  
Tag Loss ◽  
Reward Value ◽  
Exploitation Rate ◽  
Time Correction ◽  
Regulation Changes

<em>Abstract</em>.—The Missouri Department of Conservation suspected that blue catfish <em>Ictalurus furcatus </em>and flathead catfish <em>Pylodictis olivaris </em>were being heavily exploited by anglers in 22,539-ha Harry S. Truman Reservoir in west-central Missouri. A reward tag study was initiated in 2004 to determine angler exploitation rates for both species. Three hundred blue catfish ≥ 482 mm total length (TL) and 194 flathead catfish ≥ 508 mm TL were equipped with transbody Carlin dangler reward tags in 2004 and 2005, respectively. All reward tags displayed a reward value of US$50. A 5-year post-tagging estimate of annual exploitation (<em>u</em>) was calculated with a 25% annual correction for angler nonreporting and a one-time correction for tag loss. The estimated annual exploitation rates for blue catfish ranged from 25.5% to 33.4% with a mean of 28.8%. The estimated cumulative exploitation rate (<EM>U</EM>) at 5-years post-tagging was 81.7% for all sizes of tagged blue catfish and 92.4% for tagged blue catfish ≥ 610 mm TL. The estimated annual exploitation rates for flathead catfish ranged from 0% to 3.9% with a mean of 1.8%. The estimated cumulative exploitation rate at 5-years post-tagging for flathead catfish was 8.8%. These exploitation rates indicate that blue catfish are being heavily exploited while flathead catfish are not. Of all the reward tagged blue catfish that were reported by anglers, 7% were reported as released while 22% of the reported flathead catfish were released. These results are being used to examine possible regulation changes to protect the blue catfish fishery at Truman Reservoir.

Conservation, Ecology, and Management of Catfish: The Second International Symposium

2011 ◽  
Keyword(s):  
International Symposium ◽  
Ictalurus Punctatus ◽  
Channel Catfish ◽  
Fish Density ◽  
State Agencies ◽  
Retention Efficiency ◽  
Conservation Ecology ◽  
Factors Influencing ◽  
The Mean ◽  
High Fish

<em>Abstract</em>.—In recent years, several state agencies have adopted the use of baited, tandem-set hoop nets to assess lentic channel catfish <em>Ictalurus punctatus</em> populations. Some level of escapement from the net is expected because an opening exists in each throat of the net, although factors influencing rates of escapement from hoop nets have not been quantified. We conducted experiments to quantify rates of escapement and to determine the influence of throat configuration and fish density within the net on escapement rates. An initial experiment to determine the rate of escapement from each net compartment utilized individually tagged channel catfish placed within the entrance (between the two throats) and cod (within the second throat) compartments of a single hoop net for overnight sets. From this experiment, the mean rate (SE) of channel catfish escaping was 4.2% (±1.5) from the cod (cod throat was additionally restricted from the traditionally manufactured product), and 74% (±4.2) from the entrance compartments. In a subsequent experiment, channel catfish were placed only in the cod compartment with different throat configurations (restricted or unrestricted) and at two densities (low [6 fish per net] and high [60 fish per net]) for overnight sets to determine the influence of fish density and throat configuration on escapement rates. Escapement rates between throat configurations were doubled at low fish density (13.3 ± 5.4% restricted versus 26.7 ± 5.6% unrestricted) and tripled at high fish density (14.3 ± 4.9% restricted versus 51.9 ± 5.0% unrestricted). These results suggest that retention efficiency is high from cod compartments with restricted throat entrances. However, managers and researchers need to be aware that modification to the cod throats (restrictions) is needed for hoop nets ordered from manufacturers. Managers need to be consistent in their use and reporting of cod end throat configurations when using this gear.

Conservation, Ecology, and Management of Catfish: The Second International Symposium

2011 ◽  
Keyword(s):  
International Symposium ◽  
Size Structure ◽  
River System ◽  
Population Characteristics ◽  
Blue Catfish ◽  
Growth And Survival ◽  
Conservation Ecology ◽  
Flathead Catfish ◽  
Management Actions ◽  
Catch Rates

<em>Abstract</em>.—Catfish are popular recreational fish in Alabama, and management interest has been rising. We hypothesized that tailwater habitat more closely resembling lotic conditions would provide more suitable conditions for catfishes compared to impounded habitats. We examined and compared population characteristics, including abundance, age and size structure, growth, and survival of blue catfish <em>Ictalurus furcatus</em>, channel catfish <em>I. punctatus</em>, and flathead catfish <em>Pylodictis olivaris</em> between tailwater and reservoir habitats in a section of the Coosa River in 2001–2002. Coosa River system tailwater habitats appear to generally provide higher quality environments for abundance and growth of catfishes than reservoir habitat, although results were often not consistent among species. We found no differences for many comparisons of stock descriptors between tailwater and reservoir habitat. We found that blue catfish were larger (48 mm total length larger) and flathead catfish electrofishing catch rates were higher (13 fish/h greater) in tailwater areas. Catfish populations in the Coosa River were characterized by slow growth and high longevity, findings in accord with other recent otolith-based age analyses from populations in the Southeast. All species had moderate to high annual survival (57–88%), likely indicating light exploitation levels. Catfish populations in this section of the Coosa River appear robust, and the tendency for these dam tailwaters to have higher quality catfish populations may warrant management actions to enhance/sustain these fisheries.

Conservation, Ecology, and Management of Catfish: The Second International Symposium

2011 ◽  
Keyword(s):  
North Carolina ◽  
International Symposium ◽  
Maximum Size ◽  
Large Fish ◽  
Blue Catfish ◽  
Conservation Ecology ◽  
Size Limit ◽  
Catch And Release ◽  
The North ◽  
Gill Net

<em>Abstract</em>.—Blue catfish <em>Ictalurus furcatus </em>were introduced into North Carolina reservoirs in the mid-1960s and have recently become a popular target for anglers pursuing large catfish. In 2008, the North Carolina Wildlife Resources Commission enacted a maximum size limit for blue catfish at Badin Lake and Lake Norman where only one fish greater than 813 mm could be harvested daily. Surveys indicated that few fish larger than 813 mm were present in either system and that the time to reach the size limit was 12 years in Badin Lake and 20 years in Lake Norman, on average. Although few large fish were present in either system, tournament anglers at Lake Norman kept larger fish in a higher proportion than found in gill-net surveys or harvested during a recent creel survey. Modeling results suggested that the regulation would have little or no impact on increasing the number of large catfish in either population. However, the regulation will protect some rare fish that grow to the maximum size limit and potentially allow recapture opportunities if catch-and-release mortality is low.

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