Page 12 - Vermilion Lake Association Spring 2021 Newsletter

Fisheries report....continued from previous page
Smallmouth Bass
Smallmouth bass are found throughout Lake Ver- milion and they provide an important fishery. Spring electrofishing targeting primarily smallmouth bass habitat has been conducted almost annually since 1989 as the primary assessment of the population. Based on survey results, smallmouth bass abundance has generally increased over the last three decades. Recent surveys indicate that the trend in increasing numbers continues in West Vermilion, but abun- dance has stabilized in East Vermilion. Abundance and size structure are very different between the
two basins, as West Vermilion tends to have higher numbers with much smaller fish on average when compared to East Vermilion. During the most recent management planning process, it was decided that bass assessment frequency could be reduced to once every three years and still adequately monitor the population. However, due in part to recent stake- holder concerns, sampling was conducted in 2020 for the second time in 3 years.
The lakewide catch rate of smallmouth bass during spring electrofishing in 2020 was 60.3 fish/hour. This was a slight decline from 2018, but near the average for catch rates in the five surveys since 2014. The East Vermilion catch rate of 44.0 fish/hour was similar to the 2018 survey and near the average of surveys since 2014.The West Vermilion catch rate of 93.0 fish/hour was down from the record high in 2018 (145.0 fish/ hour), but was average over the past five surveys. The average length of fish captured in West Vermilion was 7.4 inches and no fish over 13 inches were sam- pled. In contrast, the average length of fish sampled in East Vermilion was 10.8 inches and about one- fourth were over 13 inches. The fish ranged from 1
to 15 years old and each year class from age-1 (2019 year-class) to age-10 (2010 year-class) was represent- ed in the sample indicating consistent recruitment.
Overall, the smallmouth bass population in Lake Vermilion displays a stable to increasing trend in abundance based on electrofishing, gill net, seine, and creel data. Length and age distributions of fish indicate that recruitment to the fishery should con- tinue to bolster the population in the near future.
Abundance continues to remain higher in West Ver- milion, but fish are smaller on average due to slower growth compared to East Vermilion.
Largemouth Bass
Largemouth bass are a minor component of the Lake Vermilion fishery and are primarily found in West Vermilion. They do provide fishing opportunities and typically have low harvest rates. Spring electro- fishing is the standard assessment technique to assess largemouth bass populations in Minnesota. Howev- er, Lake Vermilion surveys have historically targeted smallmouth bass habitat because it is much more abundant in the lake. Largemouth bass were first captured during the standard electrofishing survey in West Vermilion in 2013 and have continued to
be rarely encountered. However, in 2020, the West Vermilion catch rate was 2.0 fish/hour for the second consecutive survey. Largemouth bass are not abun- dant and are limited to specific areas of preferred habitat in the lake. However, DNR electrofishing,
gill net, and creel data suggests a stable or increasing population primarily in West Vermilion.
Northern Pike
Northern pike are generally found in relatively low numbers in Lake Vermilion but are an important gamefish for some anglers. Ice-out trap-net surveys have been done periodically to obtain size structure information on the northern pike population and additional data is collected during annual fall gill- net assessments. Ice-out trap netting was not con- ducted in 2020, however 12 northern pike (0.6 fish/ net) ranging in length from 22.2 to 38.4 inches were captured in gill nets. The gill-net catch rate was at the 25th percentile of previous catches in Lake Ver- milion. Overall, a declining trend in northern pike abundance has been observed lakewide over the past three decades. At the same time, the size structure has shifted towards larger fish which can partially
be attributed to protected slot limit regulations that have been in place since 2003.
12 The Vermilion, Spring 2021