Please contact the local fisheries management biologist for current information.
Executive Summary: If you’re looking for a spot where the fish are biting in high numbers, Diamond Lake is currently teeming with activity. Recent surveys by the Iowa DNR show that Black Bullheads are exceptionally plentiful, making it a reliable destination for a busy day on the water. For those seeking predators, the lake is home to an abundant population of young Northern Pike; while they are currently on the smaller side, they are in great physical condition and promise exciting action. Although species like Yellow Perch and Bluegill were found in lower numbers, the perch that were captured were impressively large—some reaching over 13 inches and weighing nearly a pound and a half. Overall, Diamond Lake offers a high-energy fishing experience with a healthy mix of abundant smaller fish and the potential for a few trophy-sized surprises. Detailed Summary: Diamond Lake is a 143-acre lake located in Dickinson County. Maximum depth measures 7 feet. An exploratory fyke-netting survey was performed on March 26 and 27, 2025 as part of the Iowa DNR general survey protocol. Black Bullheads were very abundant (380/net night) in the survey. Northern Pike were abundant (21/net night) and small, averaging 16.7 inches and ranging from 10.6 to 21.2 inches. Northern Pike weight averaged 1.1 pounds and ranged from 0.3 to 2.3 pounds. Mean relative weight of Northern Pike was 96, indicating that the average fish was in good condition (i.e., had a healthy weight for its length). Fish species observed in low abundance included Bluegill (N = 2, length range = 1.8–7.0 inches), Green Sunfish (N = 1, length = 4.1 inches), Johnny Darter (N = 1, length = 2.05 inches), Pumpkinseed (N = 6, length range = 2.7–6.0 inches), Tadpole Madtom (N = 1, length = 4.5 inches), Yellow Bullhead (N = 9, length range = 5.8–13.3 inches), and Yellow Perch (N = 6, length range = 3.8–13.5 inches). Yellow Perch weight averaged 0.57 pounds and ranged from 0.03 to an impressive 1.4 pounds. Mean relative weight of Yellow Perch was 108, indicating that the average fish was in good condition. If you have any questions or would like to learn more about Iowa’s fisheries, please contact fisheries biologist Andrew Carlson at andrew.carlson@dnr.iowa.gov or (712) 330-3706. - Last updated on 04/28/2026.
In nearly all cases, Iowa fish are safe to eat. Cleaning and/or preparing the meal causes most of the problems regarding taste or color of fish. Like all living creatures, fish are susceptible to diseases, parasites, and other naturally occurring conditions in the water. If you suspect your fish is affected by any of these conditions, do not eat it. Consider eating smaller and younger fish which usually have lower levels of contaminants than larger ones. Most contaminants accumulate in larger, older fish. For additional information, check out our resources for eating and cooking Iowa caught fish.
To learn more about fish tissue monitoring, visit our Fish Tissue Monitoring page .
The summaries listed below are a partial listing provided for your benefit. Familiarize yourself with the complete Fishing Regulations here: Iowa DNR Fishing Regulations and Laws.