A Review of Natural Resource Agency Recommendations for Mitigating the Impacts of Underwater Blasting

Abstract

A questionnaire was sent to fish and wildlife agency directors in each state to determine current agency policies on the use of explosives for legitimate purposes within waters under their jurisdiction. Questions targeted three areas of concern for fish and wildlife agencies: (1) what type of permit, if any, was required; (2) what information did the agency provide to the applicant; and (3) what mitigative techniques were required of the applicant by an agency or recommended to protect aquatic life from explosive pressures. Thirty-three state natural resource agencies require permits. Only two states, Oregon and Pennsylvania, have permit application forms specific to underwater explosive use and natural resource protection. Only five states provide an information package to the blaster. Seventeen mitigation measures were identified. They fall into three general categories: (1) review of the explosive design and provide mitigation recommendations based on that design; (2) evaluation of the potential impact and mitigative recommendations based on biological considerations; and, (3) evaluation of potential impact and require physical measures (e.g., bubble curtains, physical barriers, etc.) to minimize impacts. Each mitigation recommendation is reviewed based on existing literature and/or the physics of explosions. General mitigation recommendations are provided.

Keywords:

• underwater explosions
• mitigation
• compensation
• delays
• decking
• stemming
• repelling charges
• bubble curtain
• physical barriers.