Oak

Oak is a shallow, eutrophic, 339-acre lake located in northern Carver County near the city of Watertown. It is primarily managed for northern pike and secondarily largemouth bass and bluegill. The lake is occasionally stocked with walleye by a landowner who lives on the lake (with a permit from the DNR). Oak lake is subject to periodic winterkill so a permit to aerate has been submitted by the landowner as well. In August 2011, a population assessment was conducted to determine the size structure and abundance of game fish in the lake. Walleye abundance is high (7.3/gill net) in Oak Lake, although the population seems to be aging. In the 2005 assessment, catch averaged 26.7 walleye per gill net, and consisted of smaller younger age-3 and age-4 individuals averaging 15.4 inches and 2.0 lbs. The current population is larger and older averaging 21.2 inches and 3.7 lbs. The largest fish measured was 27.2 inches and 7.1 lbs. Eighty-two percent of the walleye were 15 inches or longer, 52% were 20 inches or longer, and 23% were 25 inches or longer. Walleye body condition was fair, with the larger fish being in better condition than the smaller. Walleye were present from the 4 most recent stockings. The majority (64%) of the population was comprised of age-10 individuals from the 2001 fry stocking. Walleye from the 2002 (9%), 2005 (7%), and 2006 (4%) year classes were also present. Age-2 (11%) and age-3 (4%) walleye were present as well. Walleye were not stocked in these years indicating illegal stocking may have occurred due to the low likelihood of fish migration or natural reproduction. Age-2, 3 and 6, walleye grew fast, however growth was slow for all other year classes. Walleye averaged 13.1 inches by age-2, 24 inches by age 6, and 21.6 inches by age-10. 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.

Oak Lake, located in Carver County near the city of Watertown is a shallow 339-acre eutrophic lake. This summer survey was conducted to evaluate the fish community following a winterkill event in 2001, supplementing the spring trap net assessment conducted in April 2005. A lakeshore owner stocked fish following the winterkill including 150,000 walleye fry in 2001 and 1000 walleye fingerlings in 2002. Oak Lake is subject to periodic winterkills and a permit to aerate has been submitted by a lakeshore owner.Walleye numbers were exceptionally high. The catch of 26.7 per gillnet is well above 75th percentile levels for lakes of this type. Walleye averaged 17.7 inches and 2.0 pounds. Relative weight averaged 80.6 indicating the walleye are fairly skinny. This survey's catch contrasted with the spring trapnetting survey in that it sampled a much higher proportion of 2001 year-class fish (84% of the walleye catch) compared to 2002 year-class (16%). The spring survey showed 80% of the walleye from the 2002 year-class. Growth rates appeared to be above average to age-II but slower thereafter.Bluegill were abundant in levels over twice the 75th percentile level. Eighty-three percent of the catch was Age-IV, 2001 year-class fish. The entire trapnet sample averaged 6.18 inches and 0.17 pounds. Bluegill averaged 6.13 inches and 0.17 pounds in the April assessment. Growth rates were about average for this lake type.The catch of 16.6 black crappie per gill net estimates abundance levels above 75th percentile levels. The crappie gill net sample averaged 6.9 inches and 0.19 pounds. The largest individual caught was 9.1 inches. Most (87%) of the crappie were age-III, 2002 year-class fish, while 12% were age-I. Some white crappies were sampled and they constitute a small component of the crappie population.Black bullhead were very abundant, and are the dominant species by biomass. They were sampled in above 75th percentile levels, 235 per gillnet, averaging 0.25 pounds.

The initial fisheries survey of Oak Lake found an impressive fish population present for several species. Northern were present good numbers with some quality size fish captured. Almost 1/4 of the northern pike sampled measured 31.0 inches or longer. Largemouth bass were also above average for abundance, but no individuals over 15.2" were captured. Walleye were present even though there is no record of any being stocked. It is possible they have migrated into the lake from the Crow River. Bluegill, black crappie, and pumpkinseed sunfish were also sampled in above average abundance. In the trap net sample, over 1/3 of all bluegill captured were 8.0 inches in length or larger, and approximately 1/5 of the pumpkinseeds collected were 7.0 inches or longer. Other species present in Oak Lake include black bullhead, white crappie, brown bullhead, carp and green sunfish.

Based on Minnesota DNR survey data, anglers target Walleye, Northern Pike, White Crappie, Black Crappie, and Largemouth Bass in Oak. See the full species list above for catch rates, size structure, and quality scores.

We don't have a confirmed public access point on record for Oak. Check the DNR LakeFinder page for current access details before you go.

Oak has a maximum depth of 11 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Oak is from 2011. Surveys this old should be treated with some caution — fish populations change over time.

Yes — Oak has confirmed Eurasian watermilfoil. Clean, drain, and dry your equipment to avoid spreading invasives to other waters.