Application of a noise model for environmental impact assessment of deep sea mining

The Chatham Rise is a submarine feature extending
eastward from the South Island of New Zealand. The rise has water depths of 80 - 500m and hosts economically significant amounts of rock phosphate nodules on/within the seabed. Chatham Rock Phosphate (CRP) are planning to mine the phosphate using conventional dredging methodology adapted for deep water. CRP commissioned HR Wallingford to undertake underwater sound modelling for the mining operation. The sound modelling was undertaken to inform the environmental impact assessment of potential effects on commercial fish in the area. The model used was the HAMMER tool developed by HR Wallingford, which is a parabolic equation model similar in principle to RAM.