Report out of Catawba Island 7/13-7/15

I frequently fish out of Sterling State Park in Monroe, MI. Excellent walleye fishing but it slows way down in June when the water warms- it's only up to 26 ft. deep in MI water. Plus the algae bloom is thick and a real turn off. I retired in May!!! so I finally had the time to make my first trip to Catawba Island area 7/13-7/15. Stayed at East Harbor State Park and rented a slip at East Harbor Marina. All worked great. Tried different areas all 3 days. Limited each day in 36-42 FOW. Caught fish with Crawler Harnesses with 2-3oz bottom bouncers at 1.3-1.5 MPH. Day 1-N near Canadian Line, Day 2- E of Kelleys Island, Day 3- NE of S Bass Island. Really enjoyed the area with all the Islands and varying depths.

There were many boats anchored or drifting that appeared to be jigging on 7/15 E of S Bass Island. Can anyone tell me what they were targeting and how they were fishing for them. I'm guessing they were after perch as I caught one real nice one. Thanks

If they were anchored I would say they were fishing for perch.