Oak Lake Fishing guide

The northern pike population is moderately low for its lake type (2.3/gill net). Pike have not been collected in high abundance since 1995 (when 10.3 per gill net were observed). Winterkill has occurred since then and may explain the shift in population abundance. In 2011, northern pike averaged 23.1 inches in length and 2.8 lbs, with the largest reaching 27.3 inches and 4.4 lbs. Eighty-nine percent were 14 inches or longer and 78% were 21 inches or longer. Northern pike displayed good body condition. Ages ranged from 1 through 6, with 44% age 5. Growth was average compared with statewide averages.

Ten largemouth bass were collected during the assessment; however, passive sampling gears, such as trap nets and gill nets, are not effective methods for collecting largemouth bass. The data presented for this species is not indicative of relative abundance or size structure. Electrofishing is the typical method for largemouth bass assessments but was not conducted during this survey. Despite this, in the nets we observed a large size structure. Mean size was 14.8 inches and 2.5 lbs with the largest reaching 20.9 inches and 7.3 lbs. Eighty percent were 12 inches or longer, 50% were 15 inches or longer, and 10% were 20 inches or longer. A largemouth bass fishery is present in Oak Lake; however the population can't be fully determined from these net-based survey results.

Black crappie abundance was high in gill nets (68.3/net) and moderate in trap nets (7.9/net). Catch in both gears was the highest it has been in recent assessments despite recent hard winters. Average length and weight of all black crappie sampled was 6.6 inches and 0.22 lbs, with the largest measuring 10.2 inches and 0.52 lbs. Sixty-one percent were 5 inches or longer, 28% were 8 inches or longer, and <1% was 10 inches or longer. Individual black crappie were in good condition with the smaller fish in better condition that the larger. Ages ranged from 2 through 6, with age-2 (49%) the most represented. The 2007 and 2008 year classes were equally as strong representing 20 and 19% of the population, respectively. Growth was average for ages 2 through 4, but slow for ages 5 and 6. Black crappie reached 6.9 inches by age 3 and 9.8 inches by age 6.

The 2011 assessment represents a historical high in white crappie numbers sampled here; however, their abundance is considered moderately low (2.0/gill net, 2.3/trap net) for its lake type. Size structure of white crappie was good. Average length and weight from both trap nets and gill nets was 8.7 inches and 0.40 lbs, with the largest measuring 12.5 inches and 0.95 lbs. Eighty-two percent were 5 inches or longer, 54% were 8 inches or longer, 54% were 10 inches or longer, and 4% were 12 inches or longer. Body condition of white crappie was good, the smaller fish tended to be in better condition than the larger. Ages ranged from 1 through 6, with all age classes well represented. Growth of white crappie was fast compared to other similar West Metro Area lakes. Fish averaged 8.2 inches by age 3 and 11.7 inches by age 5.

Despite bluegill abundance being high (27.0/trap net), the catch was the lowest observed from all previous assessments. However, since the 2005 assessment, mean weight has increased from 0.17 lb to 0.25 lb. In 2011, mean length was 6.8 inches, with the largest measuring 8.1 inches and 0.41 lbs. Size structure was skewed toward larger individuals. Eighty-eight percent were 6 inches or longer and 0.4% were 8 inches or longer. Individual bluegill condition was good, with the smaller fish in better condition than the larger. Ages ranged from 1 through 8, with most year classes well-represented. Growth was average for ages 1 through 4, then became slow for all older year classes. Bluegill averaged 5 inches by age 3, 6.3 inches by age 5, and 7.3 inches by age 7.

There was an abundance of rough fish sampled in Oak Lake. Black bullhead (104.3/gill net) and common carp (6.3/gill net) were common. Other fish species sampled in low abundance were brown bullhead, hybrid sunfish, yellow bullhead, and yellow perch.

An assessment of fish in the shallow, nearshore habitats was also conducted using backpack electrofishing and seining. Five species were sampled which included bluegill, black crappie, largemouth bass, northern pike, and yellow perch. The purpose of the nearshore sampling is to calculate an Index of Biotic Integrity score. An Index of Biotic Integrity (IBI) is estimated based on all fish sampled in this assessment. The absence of sensitive species such as minnows and darters contribute to a low IBI score. Oak Lake scored 25.8 out of a maximum of 160, indicating possible water quality and habitat impairment.