Do whales have a louder voice in Washington than seismic contractors?

A few months ago I wrote about the International Association of Geophysical Contractors (IAGC) and its attempts to put sound science before knee-jerk reaction when it comes to the effects of offshore seismic activity on the marine mammal population. At the time there was a fear that, unless the industry did something fast, lawmakers regulators would enact adopt legislation rules that would severely impact the contractors' ability to shoot seismic surveys in the US Gulf of Mexico.

That fear has now been realized. Recently the US Minerals Management Service (MMS) announced that, starting with Outer Continental Shelf (OCS) Lease Sale 184, scheduled for August, seismic contractors will be subject to "mandatory mitigation efforts" to ensure that marine mammals are not adversely affected by their activities. The stipulation is based on a National Oceanic and Atmospheric (NOAA) Fisheries Biological Opinion that, IAGC claims, incorrectly characterizes the industry's acoustic emissions.
Such mitigation efforts include "soft starts" of airguns, visual monitoring for sperm whales and immediate shutdown of operations if the animals are present. The stipulation also prohibits start-up of operations at night.

The IAGC has not been idly standing by. President Chip Gill and Phil Fontana of Veritas DGC met with representatives of MMS and NOAA Fisheries to argue their case and supplied IAGC members (and the press) with copies of letters sent to those agencies requesting immediate action. In a letter to Dr. William Hogarth, who heads up NOAA Fisheries, Gill wrote, "The stipulations would result in some significant changes in the operation of seismic activities in the OCS that we believe are unwarranted and unnecessary. As a matter of fact, we believe some of the requirements could actually result in greater impacts on marine mammals."

Note to the NOAA Fisheries: don't argue science with scientists. Seismic contractors know a thing or two about how sound travels in different media. IAGC provided a 16-page technical discussion of how airguns work. It also included a thorough discussion of the biological opinion and where its inaccuracies occur.

Chief among these:

1. The characterization of the frequency content of acoustic emissions from airguns is incorrect. While the NOAA document states that seismic signals had the same frequency as sperm whale communication, about 2.5 kHz, IAGC argues that the predominant energy generated by airgun arrays is concentrated below 300 Hz.

2. There is little overlap in the airgun frequencies and the hearing sensitivity of sperm whales. A sperm whale's most sensitive auditory range is between 2.5 kHz and 60 kHz, while predominant seismic frequencies are lower. "This divergence strongly suggests that the potential for negative physical impact on sperm whales from airgun signals has a very low probability," the report states.

3. Airgun emissions are not likely to interfere with sperm whale communications due to differences in frequencies and emission intervals. While NOAA argues that seismic frequencies are within the range used by the whales to communicate with each other, a sonogram provided by Dr. Peter Tyack of Woods Hole Oceanographic Institute shows that airgun signals would occur only at the very low frequency end of a whale's "click spectrum."

4. Evidence indicates that sperm whale displacement from airgun emissions is not a problem. A monitoring program conducted in 2001 as a joint project between MMS and NOAA Fisheries tracked a sperm whale for 9 months. The whale stayed within a relatively small area during that time, and an active 3-D seismic survey was being conducted near the center of its foraging area.

5. There's no scientific justification for the 180-dB threshold value. The MMS stipulation includes a requirement that NOAA-approved observers monitor waters for sperm whales within a calculated 180-dB impact zone. Seismic operations will be forced to stop if a whale is detected within this zone. Gill argues that, based on his previous four points, this stipulation is overly restrictive.

The conclusion urges NOAA Fisheries to re-evaluate its biological opinion. "In the absence of a re-evaluation, the application of the resulting stipulation in its present form has a high probability of seriously undermining the efficiency and economic viability of exploration and development seismic surveys in at least the Western Gulf of Mexico (and likely the entire Gulf of Mexico) without providing meaningful or necessary benefit to the animals of concern," Gill writes. Strict adherence to the rules could, in fact, significantly extend the duration of a survey, extending exposure to the animals that are intended to be the beneficiaries of this ruling.

Since Gill alerted IAGC members to the problem, two major bullets have been dodged. First is the revocation, for now, of a ruling that would have required a 5-mile radius "exclusion zone." The presence of whales within that 5-mile radius would have required immediate shutdown, and in the event that the zone couldn't be visually monitored, shutdown would be mandatory. (This, of course, begs the question of who can see a sperm whale 5 miles away, even under the clearest conditions.)

The second bullet dodged was an MMS decision to require all seismic contractors to apply to NOAA for "incidental harassment authorizations" (IHAs) These authorizations would allow a seismic vessel to come close enough to a whale to cause the animal to change its course of direction without incurring penalties. These permits are not easy to come by, and any company doing business in the Gulf of Mexico would have been required to apply for one. Any American company would have to apply for an IHA to operate in any body of water in the world outside of the 3-mile coastal territorial boundaries.

Gill attributes these successes to "the spotlight that was shone on this issue through engaging the top management of these agencies." But there's still work to be done. He has urged members of the seismic community to act quickly by educating themselves on the issue, informing others, following events and acting when called to do so.

For more information, visit www.iagc.org.

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