Sylvan

Three fish sampling events were undertaken on Sylvan Lake in 2024 including ice-out trap netting, spring trap netting targeting Bluegill and Black Crappie, and daytime electrofishing. Electrofishing took place in the upstream reaches of the reservoir in flowing water environments. None of these sampling strategies have been utilized in the past. Traditional methods such as summer gill netting and late spring electrofishing have failed to adequately assess some aspects of the fish community in recent years, thus these new efforts were attempted. Primary management species are Northern Pike and Bluegill with Walleye, Black Crappie, and Largemouth Bass as secondary species. The three new sampling techniques employed in 2024 produced useful sample sizes of several species. A total of 58 Northern Pike were captured in the combined samples with 48 coming from the ice-out trap nets. Of the combined trap net catch of 50 fish, 18% were within the zonal protected slot of 22-26 inches and the largest measured 32.6 inches. There were two pike that topped 30 inches but mean size was small at just 18.1 inches as nearly 2/3 were under 12 inches long. Eight pike were caught electrofishing and they varied from 14.3 to 27.4 inches. The combined trap net sample of Bluegills totaled 454 fish of which 294 were captured in the panfish trap nets and 160 being caught in the ice-out trap nets. Though the ice-out nets sampled fewer fish the size structure showed better quality than the panfish nets. Bluegills over 7 inches constituted 60% of the ice-out catch and 19% surpassed 8 inches. Average length was 7 inches and the largest fish was 9 inches. Average size in the panfish trap nets was 6.4 inches with 32% exceeding 7 inches and 3% over 8 inches. The longest Bluegill in the panfish nets was 8.6 inches. The management objective for Bluegill is having at least 30% of the trap net sample exceed 7 inches long. Otoliths extracted from Bluegills in 2020 revealed relatively slow growth rates for most age groups. Age 5 fish averaged 6 inches long, however most 7-9 year old fish failed to exceed 7.5 inches. Ice-out trap nets produced a sample of 86 Black Crappie while the targeted panfish trap nets caught just 4 fish. Crappie over 9 inches comprised 49% of the combined catch, average length was 8.8 inches and maximum length was 11.3 inches. The management objective for size structure calls for at least 25% of crappie to exceed 9 inches. Otoliths were collected during both trap net efforts. Crappies displayed growth rates somewhat below area means with Age 5 fish averaging near 9 inches and Age 6 fish averaging just above 10 inches. Attaining an adequate sample of Walleyes for management purposes continues to be difficult. Just a single 17.8 inch Walleye was found in the combined trap net sample. The electrofishing catch was comprised of 16 fish ranging from 14.2 to 23.6 inches in length. Mean length was 18.8 inches. A majority of the electrofishing effort took place upstream of the reservoir in riverine habitats. Historical gill net catches of Walleye have been minimal. Walleye fry stocking has been regularly practiced in the reservoir6 and will continue. No Largemouth Bass were observed while electrofishing presumably due to sampling mainly riverine habitats with current. Past daytime electrofishing efforts were conducted in early to mid-June in current free areas. Catch rates from those three surveys ranged from 22 to 60 per hour. Ice-out trap nets caught 20 Largemouth Bass and the panfish nets tallied just 3 fish. Larger bass dominated the trap net catch which revealed a mean length of 16.1 inches with fish over 16 inches comprising 61% of the sample. The largest bass measured 19.9 inches in length. Electrofishing produced a sample of 18 Smallmouth Bass ranging from 11.9 to 20.24 inches long. Average length of Smallmouths was large at 16.2 inches, 8 fish exceeded 16 inches and 2 were longer than 20 inches. No Smallmouth were found in the trap nets. Smallmouth Bass were likely prevalent in the 2024 electrofishing catch due to most of the sampling effort being conducted in riverine habitats upstream of the reservoir. Electrofishing performed in the reservoir in 2020 captured 7 Smallmouths of which 6 were juveniles under 8 inches long. Smallmouth Bass were originally documented in the reservoir in 2014 when 5 juveniles were observed during spring electrofishing. Non-target species prevalent in the trap nets included Bowfin (21 fish), Rock Bass (56 fish), and Pumpkinseed (55 fish). Relatively few Pumpkinseeds reached 7 inches long and average length was just 5.8 inches. Yellow Perch were captured in low numbers, but 2 individuals exceeded 10 inches.

Daytime electrofishing was performed on Sylvan Reservoir June 9, 2020. Trap netting was planned for mid-June but could not be conducted due to activity restrictions and staff shortages resulting from the Covid-19 pandemic. Largemouth Bass and Bluegill were targeted during this assessment and otoliths were extracted from these species for aging purposes. Two electrofishing stations specifically targeted bass while a third station targeted Bluegill. Few Black Crappie were observed and none were collected. The bass catch was relatively low as few fish were shallow presumably due to post-spawn behavior. A total of 33 Largemouth Bass were collected including some individuals netted in the third station which targeted Bluegill. Bass were taken while targeting Bluegill to provide a larger sample size for length frequency and aging analysis. The catch rate of Largemouth Bass was 22/hour. Largemouth Bass ranged from 3.2 to 17.2 inches in length and average length was 9.68 inches. Fish exceeding 12 inches accounted for 36% of the catch. Fish exceeding 12 inches accounted for 36% of the catch. Spring electrofishing catch rates for bass were higher in 2008 and 2014 at 60 per hour and 49 per hour, respectively. The percentages of bass over 12 inches were 31% in 2008 and 29% in 2014. Aging showed normal growth rates and consistent reproduction with 11 year classes present up to age 19. Age 2 and 3 fish made up over ½ of the aged sample. Seven (7) Smallmouth Bass were also captured and six of these fish were juveniles (<8 inches). The largest Smallmouth Bass was 16.5 inches. Smallmouth Bass were first documented in the reservoir in 2014 when five juveniles were captured during spring electrofishing. Large concentrations of spawning Bluegill were observed making electrofishing highly effective. A sample of 253 Bluegill was collected in less than ½ hour of effort producing a catch rate of 588/hour. Bluegill ranged from 3 to 7.5 inches in length and average size was 5.91 inches. Almost ½ (48%) of the fish were between 6 and 7 inches and only 8% exceeded 7 inches. Ages 2-7 and 9 were present in the aged sample with Age 5 fish comprising 59% of the catch. Age and growth characteristics indicate the lake has limited capability of producing large numbers of quality Bluegill (8 inches). Fish reached 6 inches in length by Age 5 but most 7-9 year old fish failed to exceed 7.5 inches. While fishing for sunfish it is best to limit your harvest of the large individuals, especially the males. The large males exhibit the best growth rates and also inhibit smaller and slower growing males from spawning. Studies have shown that it is important for sunfish to use their resources for growth instead of reproduction at younger ages and smaller sizes. Male Bluegill can usually be discerned from females by their brighter coloration and darker orange bellies.

Sylvan Reservoir is a riverine lake formed at the confluence of the Crow Wing River and Gull Rivers by the Sylvan Dam. Most of the land around the main basin is owned by Minnesota Power and Light Company or is part of the Camp Ripley Military Reservation. Any private development is on the Gull River. Anglers have long used the bridge over the Gull River for fishing. The area around the bridge was improved for shore fishermen with the addition of large granite blocks. Shore anglers also utilize the boat access dock for fishing. The species most sought after from the bridge and dock is Bluegill. Boat anglers fish not only the reservoir for Northern Pike, Walleye, Black Crappie, and Largemouth Bass, but travel up both rivers as well. Large sediment deposition areas with lush vegetation are located in the middle of the reservoir and on the south side of where the Crow Wing River enters. Curly leaf pondweed is common in both the main reservoir as well as the Gull River. Stream flow from the Crow Wing River has carved a deeper channel in the reservoir, which follows the south shoreline for much of the main basin. Boat anglers are advised to consult maps or watch their depth finders while traveling toward the Crow Wing River. Water clarity is impacted by rain events and flows from the two major tributaries. Bluegill numbers are considered to be within the normal range when compared to similar type lakes. Fish between 6.5 and 7.5 inches in length were common in the survey. Few Black Crappie were netted during the survey but a wide range of sizes was observed. The two gear types used in this survey, trap nets and spring electrofishing, typically do not represent Northern Pike and Walleye populations well unless performed during spring or fall. The Northern Pike observed in the survey were all less than 26 inches in length but larger pike have been recorded in previous surveys. Sylvan historically has had a low Walleye population despite regular stocking prior to 1994. The population was then sustained by natural reproduction until 2006 when stocking was performed. Fry stocking still occurs, but with two major rivers feeding the reservoir, it is not known if the Walleye are staying in the reservoir. Walleye have been observed and fished below both the Placid Lake Dam and Gull River Dam. Some nicer Largemouth Bass were documented during daytime electrofishing on the reservoir. Although the average size of the bass caught was about 10 inches, there were some fish up to 19 inches measured. Five smaller Smallmouth Bass, under seven inches in length, were also sampled during the electrofishing effort. Sylvan Reservoir supports a diverse roughfish community that is indicative of a riverine system. White Sucker, Shorthead Redhorse, and Silver Redhorse were all sampled in the survey along with Bowfin or Dogfish, Brown Bullhead, Yellow Bullhead, and Common Carp. Some other fish species found in the reservoir include Pumpkinseed Sunfish, hybrid sunfish, and Rock Bass.

Based on Minnesota DNR survey data, anglers target Smallmouth Bass, Largemouth Bass, Northern Pike, Rock Bass, and Bluegill in Sylvan. See the full species list above for catch rates, size structure, and quality scores.

Minnesota DNR records list public access for Sylvan. Check the DNR LakeFinder page for the launch type and directions before you go.

Sylvan has a maximum depth of 31 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Sylvan is from 2024.

Yes — Sylvan has confirmed faucet snail and zebra mussel. Clean, drain, and dry your equipment to avoid spreading invasives to other waters.