Hay Lake is a small, mesotrophic lake near Grand Rapids, MN. The lake consists of a single, open basin and is connected to Island Lake via a shallow channel. Hay Lake outlets to the Prairie River via Hay Creek.
A population assessment was conducted in July of 2012 to determine the status of the fish community and collect data needed to assign a lake class. The assessment consisted of two gill nets and four trap nets set for a single night. Caution should be used when interpreting data, given the limited number of nets. The lake is difficult to sample due to sharp drop-offs and densely vegetated shoal areas. The lake was also sounded for bathymetric contours during the assessment.
The lake was relatively pristine, with only one dwelling clearly visible from the lake. The shoreline was in a natural state and emergent vegetation, primarily bulrush, ringed the entire lake. Water lilies were found in a few shoal areas, providing overhead cover for fish. Dense Chara spp. was found throughout the shoal area and submergent vegetation was found throughout the littoral area. The water was relatively clear with a Secchi disk reading of 10 feet.
Northern pike were the primary species captured in the gill nets. The catch was relatively high compared to lakes with similar habitats. When northern pike occur at high densities, average size is typically poor. Small pike dominated the Hay Lake sample, as only 30% exceeded 21 inches. Some larger pike were present, however, as pike ranged from 15.2 to 34.5 inches and averaged 20.3 inches. Recruitment appeared inconsistent, as 60% of the pike were from the 2010 year class. Growth was relatively fast despite the high catch, as individuals typically exceeded 21 inches by age 4 and 28 inches by age 6. Anglers can help maintain quality pike fishing by harvesting small pike and releasing pike exceeding 24 inches.
Hay Lake is difficult to sample with trap nets due to thick vegetation and sharp drop offs. Only four trap nets were set and few fish were captured. Bluegills were the most common fish in the trap net, but only 8 were sampled. Bluegills were generally of a quality size, ranging from 3.4 to 8.5 inches with a mean of 6.7 inches. The size structure was similar to bluegill from connected Island Lake and suggests good angling opportunities for quality-sized bluegill. Growth was moderate and similar to growth from lakes with similar habitats. Individuals typically exceeded 6 inches by age 5 and 8 inches by age 8. Anglers are encouraged to protect the quality of the bluegill fishery by voluntarily reducing harvest and releasing large bluegill.
Other species captured included bowfin, black crappie, and largemouth bass.
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.