Long Island

Temperature and dissolved oxygen (DO) measurements were collected from the deepest basin in Long Island Lake on August 5th, 2025, to evaluate the quantity and quality of cold, oxygenated water (i.e., oxythermal habitat) available to Lake Trout, the most sensitive coldwater species present in this lake. During the summer, Lake Trout require a layer of oxythermal habitat that contains water temperatures below 8.8 degrees C (47.8 degrees F) and dissolved oxygen concentrations above 3.0 mg/L. Based on the profile from the deepest basin, the water temperature decreased below 8.8 degrees C (47.8 degrees F) at 39.4 feet and the dissolved oxygen concentration stayed greater than 3.0 mg/L at 45.9 feet at the time of sampling. The thickness of this layer of water in the water column was 6.6 feet, indicating that oxythermal habitat was present for Lake Trout. Further, the temperature at which dissolved oxygen decreased to 3.0 mg/L (i.e., TDO3, a single variable to characterize oxythermal habitat) was never reached because dissolved oxygen remained above 3.0 mg/L throughout the sampled depths. In this case, the minimum temperature, 8.4 degrees C (47.1 degrees F), was substituted as TDO3. TDO3 values cooler than 8.8 degrees C (47.8 degrees F) indicate that oxythermal conditions were suitable for Lake Trout at the time of the survey. Data collected by the Minnesota Department of Natural Resources during the late summer period of maximum oxythermal stress (July 26th to Aug 24th) in 2024 and 1983 indicated no suitable oxythermal habitat 2024, and a 35.9-foot thick layer in 1983. When inadequate oxythermal habitat is available, Lake Trout are squeezed into unfavorable, warmer water conditions and experience higher levels of stress.

Temperature and dissolved oxygen (DO) measurements were collected from the deepest basin in Long Island Lake on August 5th, 2025, to evaluate the quantity and quality of cold, oxygenated water (i.e., oxythermal habitat) available to Lake Trout, the most sensitive coldwater species present in this lake. During the summer, Lake Trout require a layer of oxythermal habitat that contains water temperatures below 8.8 degrees C (47.8 degrees F) and dissolved oxygen concentrations above 3.0 mg/L. Based on the profile from the deepest basin, the water temperature decreased below 8.8 degrees C (47.8 degrees F) at 39.4 feet and the dissolved oxygen concentration stayed greater than 3.0 mg/L at 45.9 feet at the time of sampling. The thickness of this layer of water in the water column was 6.6 feet, indicating that oxythermal habitat was present for Lake Trout. Further, the temperature at which dissolved oxygen decreased to 3.0 mg/L (i.e., TDO3, a single variable to characterize oxythermal habitat) was never reached because dissolved oxygen remained above 3.0 mg/L throughout the sampled depths. In this case, the minimum temperature, 8.4 degrees C (47.1 degrees F), was substituted as TDO3. TDO3 values cooler than 8.8 degrees C (47.8 degrees F) indicate that oxythermal conditions were suitable for Lake Trout at the time of the survey. Data collected by the Minnesota Department of Natural Resources during the late summer period of maximum oxythermal stress (July 26th to Aug 24th) in 2024 and 1983 indicated no suitable oxythermal habitat 2024, and a 35.9-foot thick layer in 1983. When inadequate oxythermal habitat is available, Lake Trout are squeezed into unfavorable, warmer water conditions and experience higher levels of stress.

Temperature and dissolved oxygen (DO) measurements were collected from the deepest basin in Long Island Lake on August 5th, 2025, to evaluate the quantity and quality of cold, oxygenated water (i.e., oxythermal habitat) available to Lake Trout, the most sensitive coldwater species present in this lake. During the summer, Lake Trout require a layer of oxythermal habitat that contains water temperatures below 8.8 degrees C (47.8 degrees F) and dissolved oxygen concentrations above 3.0 mg/L. Based on the profile from the deepest basin, the water temperature decreased below 8.8 degrees C (47.8 degrees F) at 39.4 feet and the dissolved oxygen concentration stayed greater than 3.0 mg/L at 45.9 feet at the time of sampling. The thickness of this layer of water in the water column was 6.6 feet, indicating that oxythermal habitat was present for Lake Trout. Further, the temperature at which dissolved oxygen decreased to 3.0 mg/L (i.e., TDO3, a single variable to characterize oxythermal habitat) was never reached because dissolved oxygen remained above 3.0 mg/L throughout the sampled depths. In this case, the minimum temperature, 8.4 degrees C (47.1 degrees F), was substituted as TDO3. TDO3 values cooler than 8.8 degrees C (47.8 degrees F) indicate that oxythermal conditions were suitable for Lake Trout at the time of the survey. Data collected by the Minnesota Department of Natural Resources during the late summer period of maximum oxythermal stress (July 26th to Aug 24th) in 2024 and 1983 indicated no suitable oxythermal habitat 2024, and a 35.9-foot thick layer in 1983. When inadequate oxythermal habitat is available, Lake Trout are squeezed into unfavorable, warmer water conditions and experience higher levels of stress.

Based on Minnesota DNR survey data, anglers target Northern Pike, Lake Trout, and Yellow Perch in Long Island. 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 Long Island. Check the DNR LakeFinder page for current access details before you go.

Long Island has a maximum depth of 85 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Long Island is from 2019.

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