Fishing Big Seven Lake

Big Seven Lake offers one of the best largemouth bass fisheries in southeastern Michigan, with 46% of bass over the 14-inch legal size and fish reaching 18 inches. The bass average 11.8 inches despite below-average growth (-1.8 index), benefiting from catch-and-release practices and the 14-inch size limit implemented in 1994. However, the fishery is hampered by a severely stunted bluegill population that scores only 'poor-acceptable' on the Schneider Index, with just 14% reaching the 6-inch harvest size and most dying by age 7. The 170-acre impoundment reaches 50 feet deep but 70% is 10 feet or less, creating extensive shallow habitat that allows young bluegill to escape predation and become overabundant. A thermocline develops between 15-25 feet in summer with oxygen dropping below 3 ppm underneath, limiting deep water fishing. Black crappie provide the best panfish opportunity with 87% over 7 inches and improved size structure in recent years. Walleye stocking since 1998 has been marginally successful - only 6 fish were caught averaging 22 inches, failing to significantly impact the bluegill population as intended. An interesting wrinkle is the accidental introduction of redear sunfish through contaminated walleye stockings, which have established a self-sustaining population but with declining average size from 8.3 inches in 2004 to 5.7 inches in 2012. The lake experienced a 54-inch drawdown in 2007 for dam repairs but fish populations recovered well. Water clarity is excellent with 7-10 feet of visibility, and the lake is well-buffered with alkalinity of 140-175 ppm. No-wake regulations keep fishing pressure manageable in this Seven Lakes State Park setting.