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NMFS issues proposed IHA for Apache Covers offshore Cook Inlet seismic program south of area surveyed this year; agency says surveys will not impact beluga whales Alan Bailey Petroleum News
The National Marine Fisheries Service has issued a proposed incidental harassment authorization, or IHA, for the offshore seismic surveying that Apache Alaska Corp. plans to do in Cook Inlet in 2013. Apache is conducting a multiyear 3-D seismic program offshore and onshore the inlet, as part of a search for new oil resources in the Cook Inlet basin.
This year the company completed seismic surveys in the northern part of upper Cook Inlet, up the west side of the inlet and over a fairway across the inlet to the northern coast of the Kenai Peninsula. According to the proposed IHA, Apache now plans to conduct surveys to the south, off the coast of the Kenai Peninsula, from Anchor Point in the southwestern peninsula to Point Possession to the north of Kenai, and on the west side of the inlet from the McArthur River to the Beluga River.
Apache anticipates starting work in intertidal areas in March, possibly earlier, with offshore surveys taking place between April and September, the proposed IHA says.
The Fisheries Service requires comments on the proposed IHA by Jan. 9, after which the agency will have 45 days in which to issue or deny the authorization. An IHA allows the minor, unintended disturbance of marine mammals during an industrial operation, under the terms of the Marine Mammals Protection Act.
Protected species Of particular sensitivity when it comes to offshore Cook Inlet seismic work is the possibility of disturbance to the Cook Inlet beluga whale, a marine mammal sub-species that has been listed as endangered under the Endangered Species Act. The Steller sea lion, another protected species, can also be found in the waters of the inlet. And in February the Fisheries Service issued a biological opinion for all of the Cook Inlet intertidal and offshore areas within which Apache anticipated conducting surveys. That biological opinion concluded that the surveys are unlikely to put the beluga whales or the sea lions in jeopardy, or to adversely impact the beluga whales’ critical habitat.
In April the Fisheries Service issued an IHA which covered Apache’s work this year across the northern part of the inlet, but did not include the areas to the south that Apache wants to survey in 2013. An appeal against the issue of that first IHA has yet to be resolved in the federal District Court in Alaska.
Uses air guns Apache conducts its offshore surveys by firing air guns towed in the water behind a survey vessel, and using special recording devices called hydrophones to record sounds echoed from subsurface rock units. Each hydrophone sits on the seafloor, housed in a small, disk-shaped, self-contained node. The echoed sounds are recorded and precisely timed by a recording device inside each node — after retrieval of the nodes from the sea, data can be downloaded into a computer for merging into a complete seismic dataset for the survey area.
Onshore, along the coast, small explosive charges detonated underground in boreholes provide a sound source, instead of air guns, for nearshore data acquisition.
Another sound system, using what are known as “pingers,” enables precise determinations of the locations of the seafloor recording nodes.
No threat to animals The new IHA that the Fisheries Service now proposes for Apache’s next phase of surveying says none of the sounds from the seismic operations — the air-gun shots, the on-land detonations and the use of pingers — constitutes a threat to any of the marine mammals in the inlet, given the mitigation measures that Apache will need to have in place for its survey operations. Those mitigation measures include the establishment of a safety and disturbance zone around an air-gun operation, with a requirement to change course, or to power down the air guns if an animal appears likely to enter the zone. Depending on the proximity of the animal, a complete air-gun shutdown might be required.
A team of experienced protected species observers, or PSOs, on vessels engaged in a survey would monitor for wildlife in proximity to the survey operations.
At night, after PSO activity has finished for the day, a single “mitigation air gun” will operate continuously, to alert animals of the presence of the seismic operation during periods when the regular air guns are shut down for some reason. If the mitigation air gun itself has to be shut down for more than 10 minutes, perhaps after a vessel crew member has spotted an animal within the safety zone for this gun, the seismic operation will be suspended until the following day.
Apache has already conducted tests that have demonstrated that underwater sounds from onshore detonations are not loud enough to harass animals in the water, the proposed IHA says.
Beluga whale monitoring An on-land observation station will enable some PSOs to monitor for marine mammals from onshore, while helicopter surveys will monitor for beluga whale aggregations around river mouths, prior to the start of survey operations near these locations.
Apache has told Petroleum News that, for the offshore surveys conducted in 2012, the company conducted aerial reconnaissance flights beyond what were required under the terms of the IHA. John Hendrix, Apache’s general manager in Alaska, said that the seismic survey in the northern part of the Cook Inlet did not disturb any beluga whales.
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