Overview

• MDE confirmed close to 25,000 Atlantic menhaden dead from Canton through the Inner Harbor to Locust Point after inspectors surveyed the area Monday.
• The agency measured low dissolved oxygen and says a seasonal algal die-off, not a discrete pollution incident, likely triggered the mortality.
• Officials link the conditions to long-running nutrient loads from stormwater, wastewater overflows and agricultural runoff that fuel blooms and subsequent oxygen depletion.
• The incident follows two late‑August kills that claimed roughly 61,000 and 121,000 fish, highlighting a persistent pattern in the harbor.
• Residents reported a strong rotten‑egg odor and dark green water, while officials said wind, tides and routine trash skimming typically remove the carcasses from shorelines.