Dock

Dock Lake is located southeast of Marcell, MN in the Big Fork River Watershed. Dock Lake has 31 surface acres and a maximum depth of 40 feet. The water is soft, which limits fish production and growth rates. The lake is moderately clear, but bog stained. Water clarity allowed visibility down to 12 feet in July 2020. There is a small, earthen boat landing suitable for a small boat or canoe, but parking is limited to one rig. The previous Fisheries Lake Management Plan was written in 2011. The lake has no inlets or outlets. The lake is one of several lakes in this area where Northern Pike are not present. Bluegill and Largemouth Bass were considered the primary management species because they were naturally occurring and well suited to the lake. Walleye and Black Crappie were secondary species because they are popular with anglers, but are less suited to the lake's habitat. Walleye reproduction is poor, but Walleye were stocked prior to 2009 in a failed effort to improve sunfish size quality. No stocking has occurred since 2009. The lake was surveyed in 2020 to determine the status of the fishery. The survey included 4 gill nets and 6 trap nets. Bluegill were the most common fish captured. The trap net catch rate was typical for lakes with similar habitats, but below average for Dock Lake. Past surveys suggested relatively high abundance and moderate size quality. Size structure was similar to past surveys, as Bluegill lengths ranged from 3.4 to 9 inches and averaged 5.9 inches. Growth was similar to previous surveys and was typical for lakes with similar habitats. Bluegill growth averaged less than one inch per year, limiting overall size potential. Given the relative abundance and moderated size quality, Bluegill anglers should find good opportunities to catch Bluegill, although size quality may limit the popularity of the fishery. Given the lake's small size, Bluegill quality could be negatively impacted by harvest, so anglers are encouraged to release fish exceeding 8 inches. Largemouth bass have been sampled in trap and gill nets in all past assessments, but in very low numbers. In 2020, too few bass were captured to characterize the population. Boat electrofishing provides a better means to characterize bass populations but was not conducted in 2020. Past electrofishing surveys resulted in moderate numbers of bass, but poor size quality. Lakes with similar habitats rarely produce favorable conditions for Walleye. Dock Lake historically produced higher than expected catch rates, however. Walleye were likely introduced when fry were stocked prior to 1942. Early surveys suggested that natural reproduction was adequate to maintain a population. More recent surveys suggest that natural reproduction declined after the late 1970s. In 2020, Walleye were captured at a rate of 1.3 per gill net. Walleye were generally large, ranging from 19.7-22 inches. Most fish were from the stocked 2009 year-class. No younger fish were sampled, suggesting poor natural reproduction in recent years. Black Crappie catches have typically been low and growth rates have been described as slow. In 2020, too few crappie were captured to characterize the population. White Sucker were the only other species sampled. Aquatic Invasive Species were not found in Dock Lake. Anglers and boaters are reminded to help stop the spread of invasive species by removing all aquatic plants from boats, trailers, and equipment. All drain plugs must be removed and live and bait wells must be drained before leaving the access. Anglers and boaters are encouraged to power wash and thoroughly dry all equipment prior to use in another water body.

Background: Dock Lake is a 31 acre lake in Itasca County near Marcell, MN and is located within the Chippewa National Forest. The public access is located on the north end of the lake off County Road #49 and is administered by the U.S. Forest Service. The lake has soft, infertile water, which greatly limits fish production resulting in a limited fish community. The lake management plan (LMP) for Dock Lake was last revised in 2005. Bluegill and walleye were the primary management species. The long range goal of the plan was to determine if walleye fingerling stocking could maintain the walleye population above 1.5/gill net and significantly increase bluegill quality with 80% of the bluegill exceeding a quality size of 6 inches and 20% exceeding the angler preferred size of 8 inches. Dock Lake has a history of producing relatively slow growing bluegill with catches within the interquartile range for the lake class. Low predator abundance was believed to contribute to the slow growth of bluegill. Dock Lake also historically produced a modest population of walleye that typically exceeded the lake class third quartile value of 1.5/gill net. The walleye population appeared to be maintained by limited natural reproduction. An evaluation of the effect of walleye stocking on bluegill growth and subsequent size structure was conducted from 1990 to 2010. The objective of this study was to determine if walleye fingerling stocking could alter the bluegill size structure or growth rates. Results: The most recent population assessment was conducted on Dock Lake in August of 2010 and consisted of 4 gill net and 9 trap net sets. Index of Biological Integrity (IBI) sampling, which involved near shore sampling, was conducted in mid-July. Walleye were caught at a rate of 3.3/gill net, which was high compared to lakes with similar habitats and above average for Dock Lake. The long range catch rate goal of the lake management plan was exceeded. Walleye ranged from 7 to 26 inches with an average size of 12.3 inches. Walleye ranged in age from 1 to 7 and the 2009 year class comprised 63% of the catch. Most walleye (72%) were associated with stocked year-classes. Growth rates were near the statewide average until age-4, and relatively slow thereafter. Bluegill were captured at a rate of 14.3/trap net, an average rate compared to similar lakes. Size structure was poor as only 20% exceeded 6 inches and no fish exceeding 8 inches were captured. The LMP length goals were not met as the size structure did not improve. Growth remained relatively slow, although average compared to similar lakes, with individuals exceeding 6 inches at age-7. The popularity of the bluegill fishery is likely limited given the poor size structure. Black crappie were captured at a low rate compared to similar lakes. Crappie ranged in size from 6 to 11 inches. Growth was near the statewide average with individuals exceeding 8 inches by age-4. Crappie catches have typically been low in Dock Lake. Low population size likely limits the potential of the crappie population. Largemouth bass were captured at a average rate compared to similar lakes. Size ranged from 9.6 to 13 inches. Growth was near the statewide average with individuals achieving 12 inches by age-5. Other species captured included central mud minnows. This fish community is unique in that it historically lacked two species that are common in most other lakes in this area: northern pike and yellow perch. Northern pike were, however, introduced (source unknown) sometime after the 1999 assessment and were captured at a rate of 1.5/gill net in 2004. No pike were captured in the 2010 assessment. Walleye fingerlings were stocked at a relatively high rate every other year since 1991. Five assessments were conducted from 1991 to 2010. Walleye catches generally increased from 1.2/gill net in 1991 to 3.3/gill net in 2010 and the strongest year classes generally corresponded to stocked years. Conversely, bluegill catches peaked in 1994 at 31.8/trap net and declined to 14.3/trap net in 2010. The relationship between bluegill and walleye catches were not strongly correlated despite the general trends in catch rates. The weak correlation suggests that walleye abundance did not strongly influence bluegill catches. Bluegill growth rates remained poor during the evaluation period despite decreased abundance in recent years. Total length at ages 2-8 did not significantly increase, indicating no meaningful changes in growth had occurred. The protection of water quality and habitat is critical in maintaining or improving fish and wildlife populations. Unfortunately, human activities often negatively impact our lakes. Fertilized turf-grass lawns and failing septic systems along with the removal of shoreline and aquatic vegetation, mowing to the shore, and installing sand blanket beaches result in destabilized shorelines, uncontrolled erosion, and increased run-off, contributing excess nutrients and sediment to the lake and degrading water quality and habitat. By understanding the cumulative impacts of our actions and taking steps to avoid or minimize them, we can help insure our quality water resources can be enjoyed well into the future. Anglers can further help insure quality fishing by practicing selective harvest and catch and release.

Dock Lake has a fish population consisting of walleye, largemouth bass, bluegill, black crappie and for the first time, northern pike. Walleye have been stocked biennially in an attempt to determine if they are an effective predator on bluegill and can reduce bluegill abundance and improve size structure. Fourteen walleye were sampled on Dock Lake in the test-netting portion of this assessment. A total of 11 walleye (2.8/gill net) were sampled in the 4 gill nets and 3 walleye (0.3/gill net) were sampled in the 9 trap nets. Four walleye (5.1/hour) were sampled during the fall electrofishing portion of this assessment. The walleye population appears to be maintained by stocking. Some walleye captured were from non-stocked years, however, yearlings were stocked several times clouding the evaluation. The mean back-calculated length at age was within 15% of the statewide averages. Bluegill have historically fluctuated within the trap net interquartile range of 4.3-32.8. In this assessment, bluegill were sampled at 22.8/gill net and 19.3/trap net. The gill net sampled bluegill ranged in length from 3.7 to 8.3 inches and had a mean length of 5.1. The trap net sampled bluegill ranged from 3.5 to 9.3 inches and had a mean length of 6.8 inches. The mean back-calculated length at age was <85% of the lake class #21 averages at age 2 to 4 but within 15% for ages 1, 5 and 6. Growth rates generally increase as the fish ages. These results were very similar to what was observed in the last assessment. It suggests competition for limited food in the early years. Adequate food appears to be available for larger bluegill. Largemouth bass were sampled at 0.8/gill net while none were sampled in the trap nets. The electrofishing assessment in September sampled 20 largemouth at a rate of 25.5/hour. They ranged from 6.9 to 15.8 inches in that assessment and had a mean length of 10.4 inches. The mean back-calculated length at age was within 15% of the statewide averages. Black crappie were sampled at 3.0/gill net and 3.2/trapnet. They ranged in length from 4.3 to 10.4 inches in the gill net and 3.9 to 10.6 in the trap net. Growth was within 15% of the statewide median. Northern pike, never sampled before in Dock Lake, were sampled in this assessment. Three individuals ranging from 26.6 to 29.1 inches were sampled. It is suspected that these fish were introduced by anglers since no DNR stocking has taken place and the lake was one of several lakes in this area where northern pike were not native.

Based on Minnesota DNR survey data, anglers target Walleye, Northern Pike, Largemouth Bass, Bluegill, and Black Crappie in Dock. 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 Dock. Check the DNR LakeFinder page for current access details before you go.

Dock has a maximum depth of 40 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Dock is from 2020.

No invasive species are on record for Dock in Minnesota DNR data. Always clean, drain, and dry your equipment to help keep it that way.