The U.S. National Marine Fisheries Service has issued a Letter of Authorization to BP Exploration (Alaska) Inc., to take marine mammals, by harassment, incidental to operation of offshore oil and gas facilities in the U.S. Beaufort Sea, Alaska. This LOA is effective from January 13, 2014, through January 14, 2019. This LOA is issued under the Marine Mammal Protection Act. It still uses 180 and 190 dB re 1 mPa to establish marine mammal exclusion zones.
Click here to read the Federal Register notice of this LOA.
One has to wonder why NMFS is so recluctant to use the best available science in this field. The 180/190dB data originated from a table top excerise by the HESS study team – hardly a robust scientific effort. Studies published more recently (2010-2013) show that dB thresholds should be set at higher dB levels for both TTS and PTS (e.g. see the peer reviwed and published studies by Finneran).