Acute Effects of Underwater Construction Blasting on Fishes in Long Point Bay, Lake Erie

Abstract

We detonated 201 blasts 22.7–272.4 kg per charge with a high explosive (Hydromex) in 4–8 m of water at Nanticoke, Lake Erie. Shortly after each blast turbidity and CO2 concentrations increased markedly, returning to ambient levels within 3 h of the blast. Postblast pressure and charge weight were directly related (r = 0.70, P < 0.05). Fatality radii ranged from 20 to 50 m for 22.7 kg per charge to 45–110 m for 272.4 kg per charge. Common blast-induced injuries were swimbladder ruptures and hemorrhaging in the coelomic and pericardial cavities. Laterally compressed species were more susceptible to blast pressure gradients than were the fusiform fishes. Temporally, surface mortalities were high only in the spring and late summer. Spatially, 47% of the total blast mortality was not visible from the water surface. Key words: blasting impact, hydraulic pressure gradients, fish mortality, species specific susceptibility