Fishing Discover regulations, impacts, and habitat

An Update on The Bass Spawning Sanctuary Project

Dave Philipp, Fisheries Conservation Foundation

Over the past 30+ years, our black bass research group (scientists from Carleton University, University of Illinois, and Fisheries Conservation Foundation) have studied local smallmouth and largemouth bass populations in the area.  These long-term studies have made the following relevant findings:

• For bass fry to survive and recruit into a population, nesting male bass must continue to guard their offspring against predation until their fry are developed enough to be independent of their male pguardian parent – a total of 4-6 weeks. 
• During that parental care period, if the male parent is removed from the nest via angling, his offspring can be consumed by predators very quickly.
• Despite the current regulations that prohibit bass fishing until the 3rd Saturday in June, the level of angling on nesting bass during their reproductive period has increased dramatically in lakes across the region. This has resulted in: 
  • A decrease in the abundance of spawning males and females

• A decrease in nest success rate 
• A decrease in the number of successful independent offspring 
• A decrease in the production of juveniles each year 

Bottom Line:  Populations of largemouth and smallmouth bass across the region are suffering from  recruitment overfishing, a phenomenon that occurs in many heavily exploited fish popualtions. This phenomenon occurs in bass when high levels of angling bass off their nests prevents the replacement of young fish (recruits) into the population, leading to long-term declines in the fishery.

In theory, the current closed season for bass fishing is designed to protect nesting bass from angling, but the regulation provides a well-used loophole for cheating because fishing is allowed for other species. As a result, the current regulation fails to protect even a single bass from illegal angling while it is nesting.

Clearly, we need to develop a different set of regulations. 

We have proposed a new regulation strategy to protect nesting bass, the use of Bass Spawning Sanctuaries (BaSSs).  These BaSSs are designated areas of a lake that are closed to ALL fishing until the parental care period has been completed (early July for many lakes).  This regulation is easily enforced because anyone fishing within the sanctuary during this period is clearly breaking the law.

Our Research Group was granted permission by the OMNR to conduct a Proof of Concept experiment wherein BaSSs are being tested in two lakes in the region, Opinicon and Charleston.  

To examine the effectiveness of these sanctuaries, we first monitored nesting success, reproductive success, annual juvenile production and angling pressure in 2022 and 2023, to collect baseline data before the BaSSs were instituted.  Then in 2024 and again this year, we are comparing the reproductive productivity of the bass within the BaSSs to bass outside the BaSSs.  After the first year we have already seen a huge jump in offspring recruitment rates.  The productivity inside the BaSSs is 5X greater for largemouth bass and 10X greater for smallmouth bass compared to outside the BaSSs.  Our recommendation for next steps to understand if the innovative BaSS regulation can be applied universally. is to expand the initial proof of concept study to include a number of lakes in the region that vary in size and depth, fishing pressure, and bass composition.

In addition to assessing how well the BaSSs are performing in protecting bass reproduction, the following studies are also being conducted to increase our understanding of bass populations:

• Using acoustic telemetry to track post-spawn movement of male bass 
• Measuring the demographic changes in bass populations since the 1990s
• Determining the how angling has changed bass catchability over the past 30 years 
• Assessing angler perceptions of the trends in fishing quality and their acceptance levels for the use of the innovative BaSS regulation.