Blasting effects on incubating salmonid eggs

Blasting in or near water has the potential to affect fish negatively. The shaking of the substrate measured as peak particle velocity (PPV) has the potential to cause mortality of incubating eggs. Although a maximum allowable limit (13 mm/s) exists to protect eggs, no studies have related PPVs from blasting to egg mortality. To address this information gap, a field study and laboratory blast simulations were developed to measure egg mortality at different PPV exposures. Despite exposures over double the current guideline, no mortality was observed in lake trout (Salvelinus namaycush) eggs in the field. In the laboratory, increased mortality of rainbow trout (Oncorhynchus mykiss) eggs was found in exposures greater than 132 mm/s, during a very short period of egg development. Results indicate that the current PPV guideline provides ample protection for spawning beds and could be increased substantially, at least for Oncorhynchus species.