Diamond

A targeted fall night electrofishing survey was conducted for young of year "YOY" (fingerling sized) Walleye on Diamond Lake during October 15, 2025. A targeted survey is generally used for sampling a specific kind of fish or time of year (i.e., spawning season, fall season, etc.) unlike a standard survey which samples a wider range of fish species during the summer months using standard methodology (i.e., standard time of year, set sampling stations, taking water clarity readings and oxygen/temperature profiles, etc.) and gears (i.e., lake survey gillnets, trapnets and possibly spring electrofishing for Largemouth Bass). Fall electrofishing surveys prior to 2020 were conducted at three stations for a total of 30 minutes. Six stations were sampled for a total of 120 minutes in 2020-2021 and 2023-2025 surveys. Five stations were sampled for a total of 100 minutes in 2022. The water temperature was 56 F. during the 2025 fall electrofishing survey. Submergent vegetation was moderate to light at all stations in 2025. Windy conditions were present along west stations (EW1, EW5 and EW6). Water clarity was moderate. We observed moderate numbers of adult Walleye, Bluegill, Largemouth Bass, Black Crappie, Brook Silversides and Yellow Perch in the 2025 fall electrofishing survey. We also saw abundant numbers of YOY Black Crappie, YOY Northern Pike, YOY Yellow Perch and YOY Sunfish in the near shore areas. Diamond is a moderately large (1,607 acres), productive, and moderately deep (27 feet maximum) lake with moderate submergent vegetation densities. It is in Kandiyohi County. Zebra Mussels were first documented in Diamond during 2018. Diamond is currently part of a statewide Zebra Mussel/Walleye study lake. Abundant numbers of small Black Crappie, Yellow Perch and shiner species were observed during previous fall electrofishing surveys. Abundant Northern Pike numbers were noted in the 2013 and 2018 summer surveys (9.00+ fish/gillnet), recent ice out trapnets and fall electrofishing surveys. Walleye egg collection resumed in 2014 on Diamond. Approximately, 60-70 quarts of Walleye eggs were collected for statewide and local quotas during 2014 and 2015. Approximately 191 quarts were collected during the early spring of 2016; 90 quarts in 2017; 25 quarts in 2018; 113 quarts in 2019; 78.75 quarts in 2022; 133.5 quarts in 2023; 72.3 quarts in 2024. Walleye egg take operations were not conducted in 2020, 2021 or 2025 on Diamond Lake. Prior to 2012, consistent and excellent Walleye natural reproduction had occurred in Diamond based on fall electrofishing surveys and oxytetracycline "OTC" markings. In recent years Walleye recruitment from natural reproduction or fry stocking has been variable maybe to a combination of factors such as poor early spring weather conditions, impacts of zebra mussels and an overabundance of predators in Diamond. Typical Walleye spawning occurs during mid-late April with hatching around mid-May. Generally, early ice out years are not conducive for good Walleye fry survival in rearing ponds or lakes if stocked in mid/late April. This is often due to extended cold/cloudy weather periods during April in addition to zebra mussel filtering which may deter phytoplankton production which in turn limits the emergence of early walleye food prey like zooplankton and aquatic insects. Spicer Strain (Diamond, Koronis, and Rice) Walleye fry (800,000 fish per year) were marked with oxytetracycline "OTC" and stocked into Diamond during the springs of 2014 and 2015 as part of a 10% return for egg take. Diamond was stocked with 1.3 million OTC marked fry in 2016. Both OTC marked (475,396 fish) and unmarked (606,540 fish) fry were stocked in 2017. Unmarked Spicer Strain Walleye fry were stocked on May 18, 2018 (930,788 fish) and May 14, 2019 (751,366 fish). No Walleye fry were stocked in 2020 or 2024. Spicer Strain Walleye fry (unmarked) were recently stocked in 2021 (761,438 fish), 2022 (636,132 fish), 2023 (1,010,477 fish) and 2025 (715,890 fish) in Diamond. Walleye fingerlings were recently stocked in 2024 (11,436 fish, 1,624 pounds) and 2021 (4,591 Spicer Strain fish, 935 lbs.) due to consecutive low YOY Walleye catches in 2020-2021 and 2023-2024. Other Walleye fingerling or yearling stockings occurred in 2013 (33,889 fingerlings, 1,405 pounds), 2014 (3,454 yearlings, 359 pounds; 1,314 fingerlings, 146 pounds), 2015 (47,091 fingerlings, 1,917 pounds) and 2017 spring (20,784 yearlings, 1,261 pounds; 207 adults, 84 pounds). Walleye fingerlings/yearlings stocked into Diamond during 2015 and 2017 were from the local Spicer strain (Diamond, Koronis, and Rice) whereas previous fingerling or yearling stockings were from the Pike River Strain. Low YOY Walleye numbers (4.00 YOY/hour, 7.60 inches) were caught in the 2025 fall night electrofishing survey. Low Walleye yearling numbers were captured in 2025 (2.00 fish/hour, 12.07 inches). No YOY Walleye were captured in the 2024 fall night electrofishing survey. Low Walleye yearling numbers were captured in 2024 (2.50 fish/hour, 9.65 inches). Low YOY Walleye numbers (4.00 fish/hour, 7.15 inches) were caught in the 2023 fall night electrofishing survey. Abundant Walleye yearling numbers (20.50 fish/hour, 10.53 inches) were caught in 2023 fall night electrofishing survey. Abundant YOY Walleye numbers (70.80 YOY/hour, 6.37 inches) were caught in the 2022 fall electrofishing survey (fry stocked). Walleye hatch or fry stocking survival was good in many local lakes during 2022. Moderate numbers of Walleye yearling or two-year-old fish (8.40 fish/hour) were caught in 2022. YOY Walleye numbers were low in the 2021 fall electrofishing survey (4.50 YOY/hour, 6.26 inches). Moderate yearling and adult Walleye numbers (21.00 fish/hour) were caught in 2021. YOY Walleye numbers were also low in the 2020 fall electrofishing survey (0.50 YOY/hour, 7.09 inches). Low yearling Walleye numbers (1.50 fish/hour, 11.13 inches) were caught in 2020. YOY Walleye numbers were abundant in the 2019 fall electrofishing survey (110.00 YOY/hour, 7.03 inches). The YOY Walleye catch rates were low in 2018 (4.00 YOY/hour, 7.68 inches), 2017 (4.00 YOY/hour, 6.24 inches), 2016 (2.40 YOY/hour, 6.89 inches), 2015 (13.33 YOY/hour, 7.13 inches), 2014 (8.00 YOY/hour), 2013 (6.00 YOY/hour) and 2012 (6.00 YOY/hour) fall electrofishing surveys. The Diamond Lake historical average YOY Walleye catch rate is 79.77 YOY/hour. OTC marked Walleye accounted for 100% and 14% respectively of the 2014 and 2015 fall electrofishing YOY Walleye catches. OTC analysis was not done on the few YOY Walleye that were captured in 2016 and 2017 fall surveys. Walleye abundance was high in the most recent 2023 standard summer survey (30.33 fish/gillnet) compared to the historical average catch rate (18.73 fish/gillnet) for Diamond. The 2023 Walleye average weight and length were 1.53 pounds and 14.70 inches respectively from gillnets. The 2023 catch rate of quality size (15.00 inches and larger) Walleye was high (10.00 fish/gillnet). The 2023 catch rate of preferred size (20.00 inches and larger) Walleye was also high (5.00 fish/gillnet). Walleye growth rates were fair to good. The two prominent Walleye year classes present in the 2023 gillnet and trapnet catch were from 2022 (41%) and 2021 (29%). Current fish management activities on Diamond include monitoring the fish population on a periodic basis, protecting native aquatic vegetation through the permit process, participating in local watershed initiatives, preventing, and educating about the spread of invasive species, conducting Walleye egg take operations when needed, and stocking various fish species as warranted. Walleye fry will generally be stocked during egg take and odd years. Walleye fingerlings or yearlings will be stocked after two poor fall electrofishing surveys. Special regulations were enacted for Bluegill (5 fish bag limit) in 2021. A targeted trapnet survey of Bluegill occurred in May of 2022. A creel survey was conducted during the 2020-2021 winter and 2021 open water season. A fall night electrofishing survey is scheduled to assess Walleye natural reproduction and/or fry stocking annually. A targeted survey of the Diamond Lake fish population is currently scheduled for May (Bass Electrofishing, Bluegill Trapnets) and August (Gillnets) of 2026.

A targeted fall night electrofishing survey was conducted for young of year "YOY" (fingerling sized) Walleye on Diamond Lake during October 1, 2024. A targeted survey is generally used for sampling a specific kind of fish or time of year (i.e., spawning season, fall season, etc.) unlike a standard survey which samples a wider range of fish species during the summer months using standard methodology (i.e., standard time of year, set sampling stations, taking water clarity readings and oxygen/temperature profiles, etc.) and gears (i.e., lake survey gillnets, trapnets and possibly spring electrofishing for Largemouth Bass). Fall electrofishing surveys prior to 2020 were conducted at three stations for a total of 30 minutes. Six stations were sampled for a total of 120 minutes in 2020-2021 and 2023-2024 surveys. Five stations were sampled for a total of 100 minutes in 2022. The water temperature was 67 F. during the 2024 fall electrofishing survey. Submergent vegetation was moderate to abundant at different stations in 2024. Water clarity was fair. We observed moderate to abundant numbers of adult Walleye, Northern Pike, Bluegill, Largemouth Bass, Black Crappie, Brook Silversides, Shiner species and Yellow Perch in the 2024 fall electrofishing survey. We also saw abundant numbers of YOY Black Crappie, YOY Yellow Perch and YOY Sunfish in the near shore areas. Diamond is a moderately large (1,607 acres), productive, and moderately deep (27 feet maximum) lake with moderate submergent vegetation densities. It is in Kandiyohi County. Zebra Mussels were first documented in Diamond during 2018. Diamond is currently part of a statewide Zebra Mussel/Walleye study lake. Abundant numbers of small Black Crappie, Yellow Perch and shiner species were observed during previous 2014-2020 fall electrofishing surveys. Abundant Northern Pike numbers were noted in the 2013 and 2018 summer surveys (9.00+ fish/gillnet), recent ice out trapnets and the 2020 fall electrofishing survey. Walleye egg collection was resumed in 2014 on Diamond. Approximately, 60-70 quarts of Walleye eggs were collected for statewide and local quotas during 2014 and 2015. Approximately 191 quarts were collected during the early spring of 2016; 90 quarts in 2017; 25 quarts in 2018; 113 quarts in 2019; 78.75 quarts in 2022; 133.5 quarts in 2023; 72.3 quarts in 2024. Walleye egg take operations were not conducted in 2020 and 2021 on Diamond Lake. In recent years Walleye recruitment from natural reproduction or fry stocking has been variable due to poor early spring survival conditions and an overabundance of predators in Diamond. Typical walleye spawning occurs during mid-late April with hatching around mid-May. Generally, early ice out years are not conducive for good walleye fry survival in rearing ponds or lakes if stocked in mid/late April. This is often due to extended cold/cloudy weather periods during April that may deter phytoplankton production which in turn limits the emergence of early walleye food prey like zooplankton and aquatic insects. Spicer Strain (Diamond, Koronis, and Rice) Walleye fry (800,000 fish per year) were marked with oxytetracycline "OTC" and stocked into Diamond during the springs of 2014 and 2015 as part of a 10% return for egg take. Diamond was stocked with 1.3 million OTC marked fry in 2016. Both OTC marked (475,396 fish) and unmarked (606,540 fish) fry were stocked in 2017. Unmarked Spicer Strain Walleye fry were stocked on May 18, 2018 (930,788 fish) and May 14, 2019 (751,366 fish). No Walleye fry were stocked in 2020 or 2024. Spicer Strain Walleye fry (unmarked) were recently stocked in 2021 (761,438 fish), 2022 (636,132 fish) and 2023 (1,010,477 fish) in Diamond. Walleye fingerlings were recently stocked in 2024 (11,436 fish, 1,624 pounds) and 2021 (4,591 Spicer Strain fish, 935 lbs.) due to consecutive low YOY Walleye catches in 2020-2021 and 2023-2024. Other Walleye fingerling or yearling stockings occurred in 2013 (33,889 fingerlings, 1,405 pounds), 2014 (3,454 yearlings, 359 pounds; 1,314 fingerlings, 146 pounds), 2015 (47,091 fingerlings, 1,917 pounds) and 2017 spring (20,784 yearlings, 1,261 pounds; 207 adults, 84 pounds). Walleye fingerlings/yearlings stocked into Diamond during 2015 and 2017 were from the local Spicer strain (Diamond, Koronis, and Rice) whereas previous fingerling or yearling stockings were from the Pike River Strain. No YOY Walleye were captured in the 2024 fall night electrofishing survey. Low Walleye yearling numbers were captured in 2024 (2.50 fish/hour, 9.65 inches). Low YOY Walleye numbers (4.00 fish/hour, 7.15 inches) were caught in the 2023 fall night electrofishing survey. Abundant Walleye yearling numbers (20.50 fish/hour, 10.53 inches) were caught in 2023 fall night electrofishing survey. Abundant YOY Walleye numbers (70.80 YOY/hour, 6.37 inches) were caught in the 2022 fall electrofishing survey (fry stocked). Walleye hatch or fry stocking survival was good in many local lakes during 2022. Moderate Walleye yearling or age 2 fish numbers (8.40 fish/hour) were caught in 2022. YOY Walleye numbers were low in the 2021 fall electrofishing survey (4.50 YOY/hour, 6.26 inches). Moderate yearling and adult Walleye numbers (21.00 fish/hour) were caught in 2021. YOY Walleye numbers were also low in the 2020 fall electrofishing survey (0.50 YOY/hour, 7.09 inches). Low yearling Walleye numbers (1.50 fish/hour, 11.13 inches) were caught in 2020. YOY Walleye numbers were abundant in the 2019 fall electrofishing survey (110.00 YOY/hour, 7.03 inches). The YOY Walleye catch rates were low in 2018 (4.00 YOY/hour, 7.68 inches), 2017 (4.00 YOY/hour, 6.24 inches), 2016 (2.40 YOY/hour, 6.89 inches), 2015 (13.33 YOY/hour, 7.13 inches), 2014 (8.00 YOY/hour), 2013 (6.00 YOY/hour) and 2012 (6.00 YOY/hour) fall electrofishing surveys. The 2011 YOY Walleye catch rate was high (104.52 YOY/hour, 6.94 inches). The Diamond Lake historical average YOY Walleye catch rate is 87.78 YOY/hour. OTC marked Walleye accounted for 100% and 14% respectively of the 2014 and 2015 fall electrofishing YOY Walleye catches. OTC analysis was not done on the few YOY Walleye that were captured in 2016 and 2017 fall surveys. Walleye abundance was high in the most recent 2023 standard summer survey (30.33 fish/gillnet) compared to the historical average catch rate (18.73 fish/gillnet) for Diamond. The 2023 Walleye average weight and length were 1.53 pounds and 14.70 inches respectively from gillnets. The 2023 catch rate of quality size (15.00 inches and plus) Walleye was high (10.00 fish/gillnet). The 2023 catch rate of preferred size (20.00 inches and plus) Walleye was also high (5.00 fish/gillnet). Walleye growth rates were fair to good. The two prominent Walleye year classes present in the 2023 gillnet and trapnet catch were from 2022 (41%) and 2021 (29%). Current fish management activities on Diamond include monitoring the fish population on a periodic basis, protecting native aquatic vegetation through the permit process, participating in local watershed initiatives, preventing, and educating about the spread of invasive species, conducting Walleye egg take operations when needed, and stocking various fish species as warranted. Walleye fry will generally be stocked during years of egg take. Special regulations were enacted for Bluegill (5 fish bag limit) in 2021. A targeted trapnet survey of Bluegill occurred in May of 2022. A creel survey was conducted during the 2020-21 winter and 2021 open water season. A fall night electrofishing survey is scheduled to assess Walleye natural reproduction and/or fry stocking in 2025. A standard summer survey of the Diamond Lake fish population is currently scheduled for 2026.

A standard survey was conducted on Diamond Lake during 2023. Prior Diamond Lake standard surveys were conducted in mid-July. Gillnets were set in mid-August as part of a statewide Zebra Mussel-Walleye study. Standard trapnets were set in mid-July. A near shore FIBI survey was also conducted in mid-July. A fall night electrofishing survey was conducted for young of year "YOY" (fingerling sized) Walleye on Diamond Lake during late September. A targeted survey is generally used for sampling a specific kind of fish or time of year (i.e. spawning season, fall season, etc.) unlike a standard survey which samples a wider range of fish species during the summer months using standard methodology (i.e. standard time of year, set sampling stations, taking water clarity readings and oxygen/temperature profiles, etc.) and gears (i.e. lake survey gillnets, trapnets and possibly spring electrofishing for Largemouth Bass). Diamond is a moderately large (1,565 acres), productive, and moderately deep (27 feet maximum) lake located in Kandiyohi County. Diamond Lake is highly developed with 352 homes/cabins, one resort, and one County Park/campground (2008 resurvey). The Diamond Lake County Park (55 camping sites) and main public access is located along the northwest side of the lake. A small public access is located on the east shore. Two Northern Pike Spawning Areas "NPSA" (NW corner and SW corner of the lake) had been operated adjacent to Diamond Lake in the past but are no longer used for rearing Northern Pike. Kandiyohi County Road #4 was rerouted around to the west side of the Diamond Lake County Park in 2018. The NPSA water control structure and fish barrier were removed due to the new culvert placement and road upgrades. There are numerous small inlets and one large inlet that drain primarily agricultural row crops via tile systems and wetlands into Diamond. A new perforated multi-culvert barrier was installed in 2012 at the largest inlet in order to prevent adult Common Carp from Diamond entering into three shallow upstream lakes (Hubbard, Wheeler, and Schultz) to spawn and degrade water quality. The outlet connects to the Middle Fork Crow River via a ditch system. The immediate watershed is primarily agriculture with residential homes, hardwoods, and wetlands comprising the remainder. The southeast bay "Dogfish" bay is the least developed portion of the lake. Submergent vegetation species (i.e., coontail, clasping-leaf pondweed, water celery, sago pondweed and northern milfoil) are varied and densities moderate in Diamond. Filamentous algae and water moss were also commonly occurring in Diamond. Curly-leaf pondweed has been a nuisance especially along the north portions of the lake in the past but has been less bothersome in recent years. Free floating vegetation species seen included star duckweed and lesser duckweed. Emergent vegetation present includes mostly hardstem bulrush (north point, east shoreline area) and cattail species (Dogfish Bay). Shoalwater substrates of the main basin are mostly sand, rubble, boulder, and gravel. Silt and muck compose most substrates in Dogfish Bay. Water levels were below average in recent years. Mid-summer dissolved oxygen levels (>7.0 ppm) were good down to 21 feet deep during 2023. Total phosphorus levels were moderate (0.033 ppm) in June of 2008. Water clarity was poor on July 27, 2023 (3.0 feet). Intense blue-green algae blooms were noted in Diamond during the 2023 summer. Diamond has been used as a Walleye egg take site for Spicer "Crow River" strain fish since 2014. Other local Spicer strain Walleye egg take lakes include Koronis, Rice and Elizabeth. Walleye natural reproduction was usually frequent and significant in Diamond prior to 2012 compared to other Spicer Area lakes. Zebra Mussels were documented in Diamond during 2018. Water clarity may increase in the future due to Zebra Mussel presence during the early summer months, but intense blue-green algae blooms will likely occur during mid/late summer months. Diamond is a popular lake for a variety of fish species which include Walleye, Northern Pike, Black Crappie, Bluegill, Yellow Perch and Largemouth Bass. A targeted survey was conducted on Diamond in mid-May of 2022 as part of the ongoing statewide Quality Sunfish Initiative. Twelve standard lake survey trapnets were set at historical stations to target Bluegill and Black Crappie. Special regulations for several area lakes (Nest, Long (Hawick, Minnesota), Diamond, George and Florida) currently entail reduced bag limits (i.e., 5 or 10 fish) for Sunfish or Crappie. The Diamond Lake special regulation for Sunfish is a daily bag limit of 5 fish. Black Crappie numbers were abundant in 2023 gillnets (23.33 fish/gillnet). The 2023 Black Crappie numbers were low in trapnets (2.83 fish/trapnet) The Black Crappie historical catch rates are 8.63 fish/gillnet and 6.66 fish/trapnet. The Black Crappie average weights and lengths were moderate for gillnets (0.47 pounds, 9.08 inches) and trapnets (0.64 pounds, 10.30 inches) in 2023. The historical average weights were 0.28 and 0.36 pounds for gillnets and trapnets respectively. The 2023 catch rate of quality size (8.00 inches plus) Black Crappie was high (15.33 fish/gillnet). The 2023 catch rate of preferred size (10.00 inches plus) Black Crappie was also high (11.00 fish/gillnet). Black Crappie growth rates were moderate to excellent in Diamond. The 2019 year class comprised 51% of the 2023 Black Crappie gillnet and trapnet catch. Bluegill numbers were low in 2023 (1.42 fish/trapnet). The Bluegill historical average catch rate is 11.58 fish/trapnet. The 2023 Bluegill average size was large (0.31 pounds and 6.81 inches) from trapnets. Low numbers of large Bluegill (3.67 fish/gillnet, 7.03 inches and 0.32 pounds) were captured in the 2023 gillnets. The Bluegill historical average weight is 0.22 pounds and 0.36 pounds respectively from trapnets and gillnets. The 2023 catch rate of quality size (6.00 inches plus) Bluegill was low (0.75 fish/trapnet). A spring boat electrofishing survey for Largemouth Bass was not conducted due to time constraints in 2023. Largemouth Bass were not captured in gillnets or low trapnets, but abundant small/YOY fish were captured by seining and back-pack electrofishing during 2023. Northern Pike numbers were moderate in 2023 (6.00 fish/gillnet). The Northern Pike historical average catch rate is 5.15 fish/gillnet. The 2023 Northern Pike average size was moderate (2.80 pounds and 23.34 inches) from gillnets. The Northern Pike historical average weight is 2.75 pounds from gillnets. The 2023 catch rate of preferred size (28.00 inches plus) Northern Pike was low (0.33 fish/gillnet). Northern Pike possession limit regulations for Diamond in the North-central Zone are as follows: anglers can keep 10 Northern Pike, but not more than two pike longer than 26.0 inches; and all from 22.0 to 26.0 inches must be released. Northern Pike taken by spearing follow the same rules except one pike may be between 22.0 and 26.0 inches or two larger than 26.0 inches. Yellow Perch numbers were low in 2023 (13.00 fish/gillnet). The Yellow Perch historical average catch rate is 46.88 fish/gillnet. The 2023 Yellow Perch average size was small (0.12 pounds and 6.37 inches) from gillnets. The Yellow Perch historical average weight is 0.14 pounds from gillnets. Walleye numbers were abundant in 2023 (30.33 fish/gillnet). The Walleye historical average catch rate is 18.73 fish/gillnet for Diamond. The 2023 Walleye average size was moderate (1.53 pounds and 14.70 inches) from gillnets. The Walleye historical average weight is 1.78 pounds from gillnets. The 2023 catch rate of quality size (15.00 inches plus) Walleye was high (10.00 fish/gillnet). The 2018 catch rate of preferred size (20.00 inches plus) Walleye was moderate (5.00 fish/gillnet). Walleye growth rates were fair. The two prominent Walleye year classes present in the 2023 gillnet catch were from 2022 (41%) and 2021 (29%). Older Walleye (ages 7-17) were also captured in the 2023 survey. Low YOY Walleye numbers (4.00 fish/hour, 7.15 inches) were caught in the 2023 fall night electrofishing survey. Abundant Walleye yearling numbers (20.50 fish/hour, 10.53 inches) were caught in 2023 fall night electrofishing survey. Abundant YOY Walleye numbers (70.80 YOY/hour, 6.37 inches) were caught in the 2022 fall night electrofishing survey (fry stocked). Walleye hatch or fry stocking survival was good in many local lakes during 2022. Moderate Walleye yearling or age 2 fish numbers (8.40 fish/hour) were caught in 2022. YOY Walleye numbers were low in the 2021 fall electrofishing survey (4.50 YOY/hour, 6.26 inches). Moderate yearling and adult Walleye numbers (21.00 fish/hour) were caught in 2021. YOY Walleye numbers were also low in the 2020 fall electrofishing survey (0.50 YOY/hour, 7.09 inches). Low yearling Walleye numbers (1.50 fish/hour, 11.13 inches) were caught in 2020. YOY Walleye numbers were abundant in the 2019 fall electrofishing survey (110.00 YOY/hour, 7.03 inches). The YOY Walleye catch rate was low (4.00 YOY/hour) in the 2018 fall electrofishing survey. Low YOY catch rates (< 15 YOY/hour) were documented from 2012-2018. The 2018 Walleye YOY average size (7.68 inches) was large. The 2015 YOY catch rate was 13.33 YOY/hour with 14% coming from an Oxytetracycline "OTC" marked fry stocking and the remaining from natural reproduction. The 2014 YOY catch rate (8.00 YOY/hour) was a 100% from an OTC marked fry stocking. The Diamond Lake historical average YOY Walleye catch rate is 94.38 YOY/hour. The 2011 YOY Walleye catch rate was 104.52 YOY/hour (6.94 inches). Abundant numbers of yearling Walleye were sampled in a 2014 (54.00 fish/hour, 8.66 inches) and 2017 (24.00 fish/hour, 9.24 inches) fall electrofishing surveys. OTC returns from fry stockings were low in the 2018 gillnet catches (0%, 2017; 7.7%, 2016; 22.2%, 2015; 0%, 2014). Recent Walleye stockings included 2013 (33,889 fingerlings, 1,405 pounds Pike River strain), 2014 (825,505 Spicer strain fry; 1,314 Pike River strain fingerlings, 146 pounds; 3,454 Pike River strain yearlings, 359 pounds), 2015 (804,992 Spicer strain fry; 47,091 Spicer strain fingerlings, 1,917 pounds), 2016 (1,290,613 Spicer strain fry), 2017 (1,081,936 Spicer strain fry; 20,784 Spicer strain yearlings, 1,392 pounds stocked in 2017 spring; 207 adults, 84 pounds) and 2018 (930,788 Spicer strain fry) and 2019 (751,366 fish). No Walleye fry were stocked in 2020. Spicer Strain Walleye fry were stocked in 2021 (761,438 fish), 2022 (636,132 fish) and 2023 (1,010,477 fish) in Diamond. Walleye fingerlings (4,591 Spicer Strain fish, 935 lbs.) were stocked in Diamond during late October of 2021 due to consecutive low YOY Walleye catches in 2020 and 2021. Black Bullhead numbers were low in 2023 (1.33 fish/gillnet). The Black Bullhead historical average catch rates are 29.66 fish/gillnet and 14.01 fish/trapnet. Black Bullhead were absent in the 2023 trapnets. Black Bullhead abundance was the highest (221.00 fish/gillnet) during the 2003 survey. The 2023 Black Bullhead average weight was large (1.16 pounds) from gillnets. The Black Bullhead historical average weight is 0.95 pounds for gillnets. Yellow Bullhead numbers were abundant in 2023 (13.67 fish/gillnet). The 2023 Yellow Bullhead average size was large (0.93 pounds). Common Carp numbers were moderate in 2023 (1.00 fish/gillnet) and slightly above the historical average catch rate of 0.72 fish/gillnet. Low numbers of Common Carp (0.25 fish/trapnet) were captured in the 2023 trapnets. The 2023 Common Carp average weights were 8.27 pounds and 11.94 pounds respectively from gillnets and trapnets. A nearshore fish survey was also conducted in the 2023 summer. Seine hauls were conducted at 16 Fish-based Index of Biologic Integrity "FIBI" stations. One seining station was sampled with a bag seine of 50 foot width and 1/8 inch bar mesh in depths of 3.5 feet or less. Fifteen seining stations were sampled with a bag sein of 15 foot width and 1/8 inch bar mesh at stations because of dense submergent vegetation. Near shore electrofishing was conducted at all 15 FIBI Stations with a back-pack unit in water depths generally less than 2 feet deep. The 16 FIBI Stations were spaced equally apart around the entire shoreline of the lake in a variety of near shore habitats. Each station was approximately 100 feet long. Two back-pack electrofishing runs were conducted with the initial run of 100 feet near the shore-water interface in depths of < 1 foot and the second run of 100 feet long about 10-20 feet from shore in depths up to 2 feet. Twenty fish species were captured in the near shore sampling gear. Low species numbers of intolerant habitat disturbance (Banded Killifish and Iowa Darter) were captured in Diamond Lake. Tolerant fish species captured included Black Bullhead, Common Carp, Fathead Minnow and Green Sunfish. The nearshore data were combined with trap net and gill net data from a standard survey to describe the fish community and provide a Fish-based IBI (FIBI) score. FIBI tool 2 was used for scoring and resulted in an FIBI score of 18 which is below the impairment threshold (45). The FIBI uses fish community data to measure a lake's health, and the types of fish species present can help identify any stressors that may be negatively affecting the lake environment. In Minnesota lakes, certain fish species cannot survive without clean water and a healthy habitat (e.g. Blackchin Shiner, Iowa Darter, and Rock Bass), while other species are tolerant of degraded conditions (e.g. Green Sunfish). The FIBI score, composed of several fish community diversity and composition metrics, indicates the overall health of a lake by comparing it to what is expected for a healthy lake. For additional information on the FIBI, search for "lake index of biological integrity" on the mndnr.gov website. Data from this survey will contribute biological information about the health of the fish community to the North Fork Crow River Watershed assessment process in coordination with MN Pollution Control Agency. Current fish management activities on Diamond include monitoring the fish population on a periodic basis, protecting native aquatic vegetation through the permit process, participating in local watershed initiatives, preventing and educating about the spread of invasive species, and stocking various fish species as warranted. A fall electrofishing survey is scheduled to assess Walleye natural reproduction or fry stocking annually. A survey of the Diamond Lake fish population is currently scheduled for 2025.

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

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

Diamond has a maximum depth of 27 feet and a mean depth of 16 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Diamond is from 2023.

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