THE BASS COLLEGE

Author: Todd Driscoll |

 Tournament fishing is popular at Sam Rayburn Reservoir.  TPWD’s most recent estimates indicate that 52% of Sam Rayburn anglers participate in at least one bass tournament per year, compared to only 6% of all Texas anglers.  We also estimate that there are over several hundred bass tournaments per year at Sam Rayburn, with tournament fishing (including practice fishing) comprising 36% of the total annual fishing effort, and 46% of the bass fishing effort.  Therefore, we know that tournament anglers handle a large number of bass every year at Sam Rayburn, and some of these fish may be relocated greater than 20 miles from their original capture point.  In addition, because a majority of the larger tournaments conduct weigh-ins at the lower, southeast end of the reservoir, concentration of largemouth bass at weigh-in sites is also likely.  These concerns can affect overall angler catch rates, both in a negative (relocation) and positive way (stockpiling following weigh-ins).  If stockpiling is severe, fish growth, body condition, and survival may be reduced.  

At least 12 peer-reviewed studies have examined largemouth bass movement and dispersal rates associated with tournament weigh-in sites.  Overall, combining most of the study results, largemouth bass traveled an average of 1 mile from the release site within 40 days.  By the end of the various studies (study lengths ranged from 3 months to 2.5 years), the average dispersal distance for each bass was 2.2 miles, but 51% of fish were still within 1 mile of the release site.  Only 14% of bass returned to their original capture site (homing behavior), and 22% were recaptured by anglers.

The most recent studies tend to indicate higher rates of dispersal and homing behavior.  At Lake Rideau, Canada 1996-1999, fish were displaced from 1 to 10 miles.  After 2 weeks, average dispersal distance of bass was only 440 yards.  However, 37% of fish eventually returned to their original capture site (all were displaced less than 5 miles).  A study at Chesapeake Bay, Maryland (2000) indicated that 64% of largemouth bass had moved at least 0.3 miles within a week.  The average final dispersal distance of bass was 6 miles from release sites and 95% were at least 0.3 miles away.  Even though fish were displaced 9 to 13 miles from capture areas, 30 to 40% of bass returned to initial capture areas.  At Lake Martin, Alabama (2005), bass moved an average of 5 miles from the release site after 10 weeks.  After 2 months, no fish were in close proximity to the release site, and all fish tracked over 3 months returned to within the same general area of capture.

However, the three recent studies above involved simulated tournament conditions.  That is, fish were collected with an electrofishing boat, implanted with an electric transmitter, and then displaced to mimic tournament displacement.  The researchers did this to minimize death of tagged bass by eliminating fish stress associated with livewell confinement and the weigh-in process, as implanting transmitters is a significant stressor by itself.  Nearly all of the older studies used bass from actual tournaments.  This indicates that the rate and distance largemouth bass disperse from a weigh-in site is related to fish condition.  Fish in good shape likely disperse quicker than stressed fish.

Due to the variable results from these studies, it is hard to make specific conclusions relative to Sam Rayburn or Toledo Bend reservoirs.  In general, it appears that if largemouth bass are released after tournaments in good shape, only short-term stockpiling occurs at release sites, as most fish disperse from release sites within 2-3 months and up to 40% of these fish may return to original capture sites.  Although fish displaced up to 13 miles have demonstrated homing abilities, few make it back to original areas if displaced over 6 miles.  In contrast, as tournament-related stress increases, bass will disperse less.  Specific rates of movement following release are likely affected by available habitat, food availability, location of release (main lake or cove), fish size, and water temperature.

Most importantly, a study we conducted at Sam Rayburn in 2003-2004 indicates that population-level impacts of tournament-related bass relocation and concentration are likely low.  No question, stockpiling at release sites does occur, as we estimated that 31,050 bass were transported to weigh-in sites during the one-year study.  But, we also estimated that tournament anglers transport only 5% of the total largemouth bass population of legal-length (31,050 of the 621,000 available bass) in one year.  Simply put, only 1 out of 20 bass are subjected to relocation and potential crowding at release sites per year.

Even though population-level effects are likely low, tournament organizers should still do everything possible to minimize potential overcrowding after release.  Properly aerated live-release boats or trailers should be used to scatter fish over broad areas, and weigh-ins should be spread out over the entire reservoir.  If you have questions about this article or area lakes, stop by the Inland Fisheries office at the Jasper State Fish Hatchery or contact us by phone (409-384-9572) or email ( todd.driscoll@tpwd.state.tx.usThis e-mail address is being protected from spambots. You need JavaScript enabled to view it ).  Good luck and good fishing!

Todd Driscoll is a district fisheries management biologist for Texas Parks and Wildlife Department where he has worked for 10 years.  He received a B.S. in Fisheries Biology from Kansas State University and a M.S. in Fisheries Management from Mississippi State University.  His primary responsibilities include fisheries management of Sam Rayburn and Toledo Bend reservoirs in Southeast Texas.  Todd is an avid bass angler and participates in approximately 25-30 local and regional bass tournaments per year.  He also represents Lowrance Electronics as a Technical Pro Staffer, working tournament support and service at BASS, FLW, and owner’s tournaments across the country.  

I always here about small tournament following large tournament where some anglers plan of attack is to recapture those released fish.  I have no idea of how successful that would be, considering stressed fish.