The U.S. Minerals Management Service, long concerned about the potential effects of noise related seismic activity on whale behavior in deepwater Gulf of Mexico, has concluded the activity poses no serious threat to the creatures.
MMS said findings from its environmental assessment of marine life in the U.S. Gulf would be included in an information package used by MMS to petition the National Oceanic and Atmospheric Administration for new regulations.
The petition specifically would request that NOAA allow “incidental takes” or the unintentional catching of sea mammals resulting from seismic and other related activities in the U.S. Gulf, under enabling regulations of the Marine Mammal Protection Act.
Violation under current rules could force operators to shut down seismic survey activities and face civil penalties, depending on the extent of harm.
MMS said it analyzed “the best available information” on the effects of seismic surveys on marine resources and marine mammals, including the endangered sperm whale. The agency said it reviewed hundreds of documents from around the world.
“The conclusion of the environmental assessment was that geological and geophysical activities are not expected to result in significant adverse impacts to any of the potentially affected resources,” MMS said.
The environmental assessment included seismic surveys, deep-low side-scan surveys, electromagnetic surveys, geological and geochemical sampling, and remote sensing surveys “which are used extensively to support oil and gas exploration in the Gulf of Mexico,” the agency said.
Seismic surveys occur annually
Each year there are about 20 MMS-permitted 3-D seismic surveys in the U.S. Gulf.
In addition to noise generated from air guns and other tools used in seismic surveys, the assessment looked at vessel and aircraft noises and seafloor disturbances.
MMS considered several options in its study ranging from the status quo to tighter restrictions on seismic activity. The agency essentially is sticking with current regulations that give whales the right of way in the U.S. Gulf, a stipulation the MMS first used in the 2002 Western Gulf of Mexico oil and gas lease sale and later amended to include all blocks under lease in the U.S. Gulf.
The so-called MMS whale rule, based on conclusions reached by NOAA’s National Marine Fisheries Service, covers a specified noise “exclusion zone” encompassing a 1,600 foot radius around the seismic vessel. Upon sighting a whale within the zone, operators are required to halt activities and then to ramp up slowly once the whale departs. The rule applies in waters over 600 feet in depth.
“Visual monitoring will begin no less than 30 minutes prior to the beginning of ramp up and will continue until seismic operations cease or until sighting conditions do not allow observation of the sea surface,” MMS stipulated in its recent finding.
Moreover, visual monitoring must be conducted using trained “protected species observers,” which may include vessel crews provided they are properly trained.
Continuous day and night seismic survey operations are allowed. However, if a whale is spotted within or moving toward the exclusion zone, an immediate shutdown is required. Ramp up after a whale clears the zone is only permitted during daylight.
MMS also is encouraging but not requiring the use of acoustic monitoring equipment to locate vocalizing marine mammals, particularly sperm whales. The equipment would allow ramp up and start of a seismic survey during times of reduced visibility.
Industry not included in decision making
Restrictions first imposed in 2002 brought a predictable howl from industry and seismic companies in particular, largely because they were not included in the decision-making process and because they contended the decision was based on faulty science. Industry also was concerned that the National Marine Fisheries Service could extend noise restrictions to drilling and platform operations in the U.S. Gulf. Under the Endangered Species Act, MMS is required to adopt mandates in NMFS biological reports. It’s believed about 500 sperm whales reside in the U.S. Gulf. The giant creature, which can grow to over 60 feet in length and weigh 50 tons, is the world’s largest toothed animal. In the Gulf, the sperm whale generally can be found in water depths greater than 600 feet and can dive more than 3,000 feet in search of food.
Sperm whales have been spotted across the U.S. Gulf, but seem to congregate in waters off the Mississippi River Delta region, where nutrients flushed from the river system attract sea life on which the whales feed. Squid is one of their favorite meals. Scientists also believe Mississippi Canyon, among the most prolific deepwater exploration and production areas in the U.S. Gulf, would be a major calving area for the female sperm whale. But there is a lot scientists admittedly don’t know about sperm whale behavior, which includes an adequate explanation for the noticeable absence of adult males in the Gulf.
There also has been a running dispute over the level of noise frequency that might impair whale behavior. NMFS contends the sperm whale functions in a sensitive sound environment, relying on echo locators to hunt for prey and to communicate with other whales over long distances.
However, industry contends that after years of operating in the U.S. Gulf there is no hard evidence that noise from seismic and drilling activities harms whales. Moreover, costs increase due to operations delays when whales are sighted and work halted and because whale spotters have to be trained.
