Abstract
Red Sea is one of the most important repositories of the marine biodiversity in the world. Red Sea oil and gas reserves are estimated to be around 100 billion barrel of oil equivalent necistate the use of offshore structure to extract it. Most of offshore drilling rigs and production platforms are found on group of large diameter piles which are driving into sea bed producing high amount of underwater noise. Underwater noise emitted during pile construction can mask biologically relevant signals for marine mammals. This noise might lead to behavioral reactions, harassment, and at very high levels can injure or even kill the mammal. Range-dependent Acoustic Model, Rogers Model, was used to assess underwater noise propagation of offshore pile driving taking into account seabed bathymetry, temperature, and salinity. It was found that an offshore pile driven with 235 kJ rated energy diesel hammer can cause behavioral disturbance to the marine mammal within a distance of 1000 m from the pile location; temporary threshold shift within a distance of 30 m; permanent threshold shift within a distance of 50 m; and injury, or even death, within a distance of 20 m.