Abstract

Red Sea is one of the most important repositoriesof the marine biodiversity in the world. Red Sea oil and gasreserves are estimated to be around 100 billion barrel of oilequivalent necistate the use of offshore structure to extract it.Most of offshore drilling rigs and production platforms arefound on group of large diameter piles which are driving intosea bed producing high amount of underwater noise.Underwater noise emitted during pile construction can maskbiologically relevant signals for marine mammals. This noisemight lead to behavioral reactions, harassment, and at veryhigh levels can injure or even kill the mammal.Range-dependent Acoustic Model, Rogers Model, was used toassess underwater noise propagation of offshore pile drivingtaking into account seabed bathymetry, temperature, andsalinity. It was found that an offshore pile driven with 235 kJrated energy diesel hammer can cause behavioral disturbanceto the marine mammal within a distance of 1000 m from the pilelocation; 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.