Largemouth and smallmouth bass population trends and status of the fishery

Largemouth bass and smallmouth bass populations across the zone were surveyed between 1992 and 2010, using the Nearshore Community Index Netting (NSCIN) survey methodology. There were a total of 27 NSCIN surveys conducted on 16 lakes in FMZ 18. In addition, BsM was conducted on 40 lakes in FMZ 18 from 2008 – 2010.

Bass abundance is impacted by harvest and quality of habitat and is estimated by the average number of bass per net (CUE). The mean bass catch rate from the NSCIN surveys is 5.6 largemouth bass/net and 2.9 smallmouth bass/net in FMZ 18.

The mean catch rate from the BsM surveys is 0.9 largemouth bass/net and 1.4 smallmouth bass/net. A greater number of age classes and high maximum age are indicative of successful recruitment and adult survival. The assessment data show that a number of both largemouth bass and smallmouth bass are reaching the common maximum ages of 15 years (Scott & Crossman, 1998) suggesting high survival. 5% of the largemouth bass and 8% of the smallmouth bass were 10 years or older.

The abundance and size distribution of largemouth bass and smallmouth bass are best explained by the ecology of each species and the habitat present in each lake. Some lakes provide diverse habitat and are able to support abundant populations of both species. Other lakes offer limited habitat for largemouth bass but are able to support healthy and abundant smallmouth bass populations. At the other end of the spectrum, some lakes provide a greater amount of shallow, vegetated largemouth bass habitat while smallmouth bass habitat is less abundant. Changes in the water clarity, climate change and shifts in the predator community have also increased the productive capacity of many of the lakes in FMZ 18 for visual predators such as bass.

Bass represent approximately 31% of the total catch and 22% (11% each bass species) of the total angler harvest in FMZ 18, which receives a total fishing effort of 63 rod hours per hectare (OMNR, 2009a). This proportion of effort has increased through time, based on both an increase in angling effort for bass and a decrease in walleye-targeted effort. The increase in effort has also led to an overall increase in the total number of bass harvested, but there is also evidence of increased catch and release of bass through time. The mean size of bass harvested (both species combined) has decreased. This could be due to changes in angler attitudes resulting in increased release rates of larger fish, or an emerging trend of targeting smaller bass for harvest.

In summary, bass populations in the majority of FMZ 18 lakes are considered to be very healthy, in relatively high abundance and are not showing signs of high mortality. Most populations have high proportions of fish at, near and beyond the age of maturity. The management focus for this species is to try and maintain populations in fisheries managed primarily for bass.

Bass management in FMZ 18

The increase in bass abundance in FMZ 18 has been recognized as a great opportunity in the fisheries management plan. The productivity of bass populations has substantially increased in recent years, with bass now accounting for a greater proportion of the piscivorous fish community. Both largemouth and smallmouth bass are considered integral components of healthy warmwater fish communities in FMZ 18 and support high quality recreational fisheries. MNRF and the Advisory Council identified a few challenges (as well as opportunities) to managing bass populations in FMZ 18.

Management challenges (in select fisheries):

  • decreased abundance of large adult fish
  • sustained high level of fishing effort for bass
  • continued public concern over the effects of tournament fishing on bass populations

Management opportunities:

  • over-population of bass in fisheries managed primarily for walleye or lake trout

The MNRF with the advice of the Advisory Council developed objectives and strategies to address the challenges (and opportunities) and help reach the following bass management goal.

Goal:

To maintain high quality, naturally reproducing bass fisheries

Objective 1:

Maintain bass abundance.

As described earlier in this section, bass population abundance in most FMZ lakes is high. MNRF and the Advisory Council agreed that the zone’s bass populations have increased in recent years. Angling effort for bass has also increased on FMZ 18 lakes. As a result, the total harvest of bass has increased, although harvest rates (relative to the proportion caught) have decreased. In addition, the average size of bass harvested has decreased, which may be attributed more to an increased emphasis on releasing larger fish than a decline in the quality of the fishery.

MNRF’s Provincial Fish Strategy and the FMZ 18 Advisory Council places priority on naturally reproducing, self-sustaining populations. A number of strategies are outlined in this document which will continue to provide or increase bass abundance and improve the quality of angling opportunities.

In other jurisdictions, bass are highly sought by anglers as both a quality sport fishing experience, and a desirable harvest opportunity. A number of Ontario resident anglers largely disregard the quality harvest opportunity offered by these species (anecdotal information, FMZ 18 Advisory Council).

The lakes within FMZ 18 currently support a moderate number of competitive fishing events targeting largemouth and smallmouth bass. There are numerous social issues and benefits associated with these events. A perception exists that these events threaten the sustainability and/or quality of the recreational bass fishery. All potential threats, including tournament angling, must be incorporated into fisheries monitoring programs.

A significant number of scientific studies have been allocated to quantifying and identifying the causes of tournament related mortality, particularly for bass. Bass tournament research led directly to improved tournament procedures that have resulted in the decline in overall mortality to the point where properly organized events can have initial mortality rates for bass that are below 5% (Gilliland et al., 2002). As the popularity of competitive fishing increased, resource managers shifted the focus to less obvious impacts such as delayed mortality or the displacement of fish from natural home ranges. A large-scale study of competitive fishing events in FMZ 17 concluded that these events did not represent a threat to the sustainability of the largemouth bass populations (Ridgway, 2006). Furthermore, research has identified air exposure, particularly during the tournament weigh-in, as a critical stressor on tournament caught bass (Suski et al., 2004). This research has contributed to improvements in tournament weigh-in procedures that may further increase survival of tournament caught bass. The economic benefits of competitive fishing events for local communities can be considerable and the long-term success of such events is entirely dependent on the proper and responsible management of existing resources. Trophy bass fisheries can generate a great amount of economic revenue (Chen et al., 2003; Corbett, 1999).

Strategies to address the objective include:

  • utilize catch limits and seasons to maintain angler harvest at sustainable levels
  • monitor bass populations to assess the effectiveness of current regulations
  • identify bass research priorities to MNRF and academia to better inform bass management
  • encourage harvest of other non-traditional sport fish species (e.g. black crappie, panfish) in fisheries primarily managed for bass
  • encourage responsible practices (BMP’s) with competitive sport fishing event organizers locally and across the zone; and communicate the facts associated with competitive fishing events to the angling and general public (economic revenues, results of biological monitoring)
  • through outreach, education and monitoring enable regulatory compliance for competitive fishing events

Objective 2:

Increase bass fishing opportunities.

Climate change modeling predicts a dramatic increase in the recruitment of warmwater fish species, including bass. In addition, changes to the physical characteristics of the lakes (e.g. increased vegetation growth) may have contributed to a shift in the piscivore community. These changes to the fish communities in FMZ 18 suggest that the lakes can absorb increased angling effort and harvest directed at bass populations without compromising the sustainability of the fishery. This trend must continue to be monitored to ensure that the quality of the bass fishery is maintained.

One component of MNRF’s mandate is to provide fishing opportunities within the sustainable use of the fisheries resource. The abundance of both bass species can support a significant level of harvest. Currently, existing bass angling opportunities are being under-utilized on a number of waterbodies, within FMZ 18.

Strategies to address the objective include:

  • implement the existing extended bass season (3rd Saturday in June to December 15)

The goal, objectives and strategies have been summarized in Table 3.

Table 3: bass management summary

Adapted from tabular format

Bass management goal

To maintain high quality, naturally reproducing bass fisheries.

Objective 1:

Maintain bass abundance.

Strategies
  • Utilize catch limits and seasons to maintain angler harvest at sustainable levels.
  • Monitor bass populations to assess the effectiveness of current regulations.
  • Identify bass research priorities to MNRF and academia to better inform bass management.
  • Encourage harvest of other non-traditional sport fish species (e.g. black crappie, panfish) in fisheries primarily managed for bass.
  • Encourage responsible practices (BMP’s) with competitive sport fishing event organizers locally and across the zone; and communicate the facts associated with competitive fishing events to the angling and general public (economic revenues, results of biological monitoring).
  • Through outreach, education and monitoring, enable regulatory compliance for competitive fishing events.
Progress reviewed by
  • BsM Cycle 3
  • NSCIN Cycle 1
IndicatorBenchmarkTarget
Median (area weighted – BsM) CUEW (all lakes combined)
  • BsM
  • NSCIN
Current kg/netCurrent kg/net
BsM Proportion of lakes where biomass ratio (B/Bmax) is > 0.5Current % of lakesCurrent % of lakes
Proportion of lakes where mortality rate ratio (Z/M) is < 2:
  • BsM
  • NSCIN
Current % of lakesCurrent % of lakes
Objective 2: 

Increase bass fishing opportunities.

Strategies
  • Implement existing extended bass season (3rd Saturday in June to December 15).
Progress reviewed by

N/A

IndicatorBenchmarkTarget
N/AN/AN/A

Bass monitoring and assessment

The provincial BsM program is the primary lake survey method used to collect fisheries data in Ontario. The program collects information on a large number of lakes to determine status and trends of fisheries at the FMZ scale. The BsM program collects information about fish species, abundance, population structure, growth, maturity and fishing effort. For largemouth bass, that may not be captured in sufficient numbers to adequately monitor population status using BsM, additional enhanced monitoring may be required. Enhanced monitoring may entail modified BsM projects that target largemouth bass habitat, or using other MNRF standardized netting protocols (FWIN, NSCIN), and specifically targeting warm water lakes. Additional enhanced monitoring will help inform local land-use planning and resource management decision making, consistent with the goals, objectives and outcomes of the FMZ18 plan.

Strategies:

  • develop a more effective monitoring program for bass
  • implement a monitoring program to effectively assess bass population status across FMZ18
  • develop public/partner opportunities to measure fishing pressure and harvest rates via public reporting (e.g. volunteer angler diary program)

Current bass regulations:

The FMZ 18 bass fishery is currently regulated with an open season from the 3rd Saturday in June to December 15th, a catch and possession limit of six (6) fish for a Sport Licence and two (2) for a conservation licence. Prior to 2013, a shorter season (4th Saturday in June to November 30th) was in place. The additional opportunities were provided based on the preliminary discussions of the Advisory Council regarding the management of bass. No size limits are in place and the catch and possession limit is an aggregate limit for largemouth and smallmouth bass. Historically established to protect prime bass spawning areas, eight (8) of the nine (9) year-round fish sanctuaries located within the zone, are bass-specific.