Protecting the Environment

Regulating seismic acquisition for marine mammal protection: Competing interests or mutual goal?

A status report on rapidly changing regulations that affect leaseholders and geophysical contractors

 Perry A. Fischer, Editor

 More than a dozen treaties, conventions and agreements, both national and international, as well as several nongovernmental organizations, shape marine mammal regulation with regard to oil and gas operations. Regulations are now being formed and implemented at a rapid pace. Leaseholders and operators need to stay informed, since they are the ones ultimately affected. This is an update on last year’s report with regard to ongoing and proposed marine mammal protection regulation for seismic operations in the Gulf of Mexico, the North Sea, offshore Canada and Australia. 

  BACKGROUND

 The seismic industry finds itself in a peculiar quandary: prove that what does not appear to be happening is in fact not happening. The absence of evidence of deleterious effects on marine life is insufficient. Industry must prove the lack of harm. Proving a negative is always a difficult, if not impossible, task. What usually happens is that a great deal of time and money is spent until both sides reach consensus (or are worn down or numb). Worldwide, there are even the beginnings of rumblings about the effects on prawns, lobsters, fish and other sea life, particularly commercial species.

 It’s not that the concerns aren’t valid. They are. Especially if one makes a living trapping lobsters, fishing, hunting seals, or simply wants to preserve the health and well being of marine mammals, common sense would indicate the need for some sort of inquiry, given the level of perceived acoustic energy released during seismic data acquisition. We all know that dynamite kills fish and, thus, the current ongoing regulation of explosives in marine environments seems appropriate. But explosives are not the focus here: acoustic airgun sources are.

 Moreover, there is no evidence – not even anecdotal – that seismic data acquisition harms marine mammal populations. Nevertheless, the burden of proving this negative falls in large part on the oil and gas industry. It has risen to the task, particularly through the geophysical contractors organization, the IAGC, by offering time, money, equipment, manpower and expertise to evaluate what risks, if any, seismic data acquisition poses to marine life.

 This is an ongoing process that must change with technology. For example, there is a new technology called seabed logging, which involves inducing electric current into the sea floor. It may be advantageous to increase the amount of electricity output, but what are the limits? Is there a negative environmental impact? None have been observed so far. The advent of permanent ocean bottom cable seismic systems, such as the new Valhall installation, might create new concerns, as well as allow for new mitigation measures. Repeat shooting of such installations is envisioned to be very frequent – every three months. The sound source used will likely be a towed airgun array by a field vessel, but newly developed seafloor sources, such as a polarized multi-component source from Bolt, offer enhanced sound source characteristics while reducing sound levels in the water column. The cycle of research, regulation and feedback will continue indefinitely, as long as humans move into the oceans in an increasingly pervasive way.

 The general trend seems to be as follows. Each nation engages in its own research; then, based on the results of that research and input from all interested parties, regulations are formed. The present regulatory areas being focused on concern seismic airgun sources: observing for marine mammals, slow start-up procedures, and reporting. Passive monitoring for marine mammals is in various initial stages of implementation.

  GULF OF MEXICO

 The MMS, in its recent Notice to Lessees and Operators (NTL), in cooperation with NOAA Fisheries, finalized procedures that have been in discussion and formulation for the past three years or so.

 Marine mammal observers. The NTL applies to all seismic operations throughout the Gulf of Mexico OCS in waters greater than 200 m deep. Visual monitoring means using trained observers to scan the ocean surface visually for the presence of marine mammals and sea turtles. Visual observers will be required on all seismic vessels conducting operations. They must have completed a protected species observer-training program. At least two observers will be required on watch aboard seismic vessels at all times during daylight hours when seismic operations are being conducted, unless conditions (fog, rain, darkness) make sea surface observations impossible.

 Seismic acquisition operators may use crew members, after training, as observers-and/or trained third-party observers. Other than brief alerts to bridge personnel of maritime hazards, no additional duties may be assigned to the observer during his/her observation watch. If conditions warrant more vigilant lookouts when navigating around maritime hazards, additional personnel must be used to ensure that watching for protected species remains the primary focus of the observers. No observer will be allowed more than four consecutive hours on watch as a visual observer, or more than 12 hours in a 24-hour period. At least a two-hour break time allowed before beginning another watch. Observers must be dedicated to the task and may not be assigned combined duties.

 Ramp-up procedures. The intent of ramp-up is to warn animals of pending seismic operations, to allow sufficient time for those animals to leave the immediate vicinity. Under normal conditions, animals sensitive to these activities are expected to move out of the area. For all seismic surveys, ramp-up procedures must be used to allow marine mammals and sea turtles to depart the exclusion zone before seismic surveying begins. The exclusion zone is an area at and below the sea surface within a 500-m radius from the center of an airgun array.

 Ramp-up procedures require visual monitoring of the exclusion zone for the absence of sperm whales for at least 30 min. before initiating airgun discharges. Ramp-up procedures may not be started at night or when visual monitoring conditions are not possible. Any shutdown due to a sperm whale sighting within the exclusion zone must be followed by a 30-min. all-clear period and then a standard, full ramp-up. Any shutdown for other reasons, including, but not limited to, mechanical or electronic failure, for a period greater than 20 min., must also be followed by full ramp-up procedures. Short periods of cessation of airgun firing, for various reasons, and periods of airgun silence not exceeding 20 min. will not require ramp-up for resuming seismic operations.

 Ramp-up procedures are initiated by firing a single airgun. The smallest airgun, in terms of energy output and volume, is the preferred initial airgun. Ramp-up continues by gradually activating additional airguns over a period of 20 – 40 min., until the desired operating level of the airgun array is obtained. Immediate shutdown of all airguns is required any time a sperm whale is detected entering or within the exclusion zone. Ramp-up of airguns can resume only when the exclusion zone has been visually inspected and absent sperm whales for at least 30 min. Operators may reduce the source level of the airgun array to maintain a minimum energy level of 160 dB re 1 mPa-m (rms) for routine activities, such as making a turn between line transects, or for maintenance needs. This procedure may be conducted during periods of impaired visibility (e.g., darkness, fog, high sea states) and does not require a 30-minute visual clearance of the exclusion zone before the airgun array is again ramped up to full output.

 Borehole seismic surveys. Borehole seismic surveys typically use much smaller airgun arrays and have an average survey time of 12 – 24 hr. They necessarily require the capability of moving the receiver in the borehole between shots. During daylight hours, when visual observations of the exclusion zone are performed as required above, borehole seismic operations are not required to ramp-up for shutdowns of 30 min. or less, provided that no marine mammals or sea turtles are observed in the exclusion zone during the shutdown. If marine mammals or sea turtles are sighted in the exclusion zone, ramp-up is required and may begin only after visual surveys confirm that the exclusion zone has been clear for 30 minutes. When conditions prohibit visual observation of the exclusion zone, ramp-up will not be required for shutdowns of 20 min. or less.

 Passive listening. Passive monitoring devices to determine the presence of marine mammals by detecting their sounds and vocalizations is in the experimental stage at this time. There is evidence suggesting that it can be effective, particularly for detecting sperm whales. MMS strongly encourages operators to participate in an experimental program by including passive acoustic monitoring as part of the protected species observer program. An incentive is that when used, night or poor visibility ramp-up, which is generally prohibited, is allowed. Further, for borehole seismic surveys, if using these passive acoustics during nighttime and periods of poor visibility, ramp-up is not required for shutdowns of 30 min. or less (instead of 20 min.). If used, monitoring for sperm whales with a passive acoustic array must be done by an observer proficient in its use.

 Reporting. A considerable number of forms and reports must be completed, both pre- and post-survey, as well as for whale sightings. These are available, together with instructions, from the MMS website.

 Research. Past studies have shown that at least several hundred sperm whales live in northern Gulf waters and are most often sighted near 1,000-m water depths. The Sperm Whale Seismic Study (SWSS) is a three-year research program begun in 2002 and sponsored by the US MMS. It involves researchers from Texas A&M University, Oregon State University, Woods Hole Oceanographic Institution, University of Durham, and Ecologic, in coordination with the International Association of Geophysical Contractors (IAGC). 

 The program is studying sperm whales and their response to seismic exploration, largely through tagging and tracking. Initial results include successful satellite-tracking tagging; collecting physical oceanographic data; survey sperm whales by visual and acoustic means (Figs. 1 and 2); perform biopsies for DNA samples; photograph sperm whale flukes (for ID). 

Fig. 1. For the SWSS, IAGC-provided seismic vessel, Rylan T., with Fairfield Industries’ vessel, Speculator, mounted on the back deck. Fairfield arranged for boat modifications and support personnel under contract to IAGC. Seamap Inc. contributed a prototype passive acoustic system, including hydrophone array, computers/ software, and technical team.

Fig. 2. Marine mammals are best spotted at sea using 25x150 “big-eyes” binoculars. On flat, calm seas, a whale or dolphin can be sighted from as far away as 4 – 5 mi.

  OFFSHORE UK

 The UK was the first country to establish regulations of seismic activity. The Department of Trade and Industry (DTI) regulates the oil and gas industry in cooperation with its statutory nature conservation adviser, the Joint Nature Conservation Committee (JNCC). DTI has commissioned a major Strategic Environmental Assessment research project, part of which will look at all noise sources from offshore oil and gas activities and rank them according to their level of environmental concern. Until the study results are available, the DTI regulations and JNCC guidelines that are described below will continue in force.

 Observers and ramp-up. The UK has ramp-up procedures, marine mammal observers and reporting requirements similar to those in the Gulf of Mexico. In certain areas, observers must be cetacean biologists or similar. There are more stringent mitigation requirements in certain areas and in certain seasons. The DTI is the farthest along of any country in implementing passive acoustic monitoring.

 Passive acoustic monitoring. The DTI intends to phase in the passive acoustic monitoring (PAM) systems in a phased way based on geographic sea. All seismic surveys and some high-resolution seismic site surveys in areas of particular sensitivity for marine mammals need to use passive acoustic monitoring in addition to visual observation by one or two marine mammal observers as a condition of permitting. As the technology matures over the next few years, DTI thinks that PAM should be used on all seismic surveys. 

 Most PAM uses a towed hydrophone system to detect marine mammal vocalizations. However, static buoys can be deployed to monitor a given area, and DTI would like to encourage the industry to experiment with such a system. DTI has requirements for PAM systems. Generally, they must be able to accurately identify marine mammals within a 500-m radius, and if not using software to identify marine mammals from other sounds, use trained PAM operators.

 Other mitigation measures. DTI is even considering the possibility of using active sonar to detect non-vocalizing marine mammals, although no such commercial systems exist, and the possibility of doing more harm than good exists by introducing more noise into the environment. DTI has commissioned a desktop study of the technique.

 Two other areas under research, but at the far end, are ambient noise imaging and mitigation at source. Ambient noise imaging attempts to classify anomalies in ambient noise in the marine environment and to identify them, perhaps as marine mammals. Mitigation at source involves reducing the frequencies produced that affect marine mammal frequencies, to reduce source pressure level to baffle unwanted noise or develop alternative source technologies.

  CANADA

 Canada also has ramp-up procedures, marine mammal observers and reporting requirements similar to those in the Gulf of Mexico. The government also encourages, but does not require, passive acoustic monitoring. Seismic exploration activities will not be allowed in the Sable Gully area, which is slated to become a Marine Protected Area.

 The Department of Fisheries and Oceans (DFO) conducted a $1-million research program before – and during – petroleum seismic exploration off Nova Scotia in spring 2003. A national team of federal scientists gathered background data on ocean noise levels and the distribution of Northern Bottlenose whales and other marine mammals before seismic exploration begins. 

 Once seismic exploration begins, additional instruments on the seabed and in the water column will monitor and record noise levels and the whale sounds. Researchers will monitor any changes in marine mammal distribution or behavior. The research will be coordinated with seismic activities. The field studies will provide scientists with more background information on the location and population of marine mammals in the Scotian Shelf area. Funding is being provided by DFO, Natural Resources Canada, the Atlantic Canada Opportunities Agency, the Nova Scotia Department of Energy, and from the industry-supported Environmental Science Research Fund.

  AUSTRALIA

 The environmental protection legislation governing offshore seismic operations is the EPBC Act 1999. This country established seismic mitigation guidelines in 2001 that are likely to undergo considerable regulatory upgrades in the near future. Public scrutiny is very high. For example, the state government of Victoria recently placed the Twelve Apostles Marine National Park off limits to seismic and, apparently, all E&P activity. The marine mammal regulation is species specific. 

 There are requirements for marine mammal observers and soft start-up is similar to the other areas, but with significant differences from the US, UK and Canada. In Australia, the radius of observation is 3,000 m instead of 500 m. Observations must begin 90 min. before airgun startup, rather than 30 min. Two hours must have passed after seeing a whale, and infrared night-vision binoculars should be used at night. Ten minutes per hour is the minimum observation requirement during operations.

  THE INDUSTRY CHALLENGE

 The seismic industry has to live with the reality of public perception and misconception, and has taken a proactive stance toward protecting marine life. Reality is the first casualty in this process. Each side often perceives that self-interest will cause the facts to be skewed, even deliberately falsified. The reality is that no one wants to harm any marine life, especially not marine mammals. The only two cases on record where marine mammals might have been harmed or killed by seismic – and the evidence is not conclusive – occurred from scientific seismic investigations, not oil and gas operations.

 For its part, the industry has scored some significant victories in educating biologists and policymakers to the acoustic reality of seismic sources. First, seismic airguns are in arrays and do not generate the equivalent energy of a single point source. Second, the sound is focused downward; horizontal propagation is greatly reduced, meaning that only mammals swimming directly below the airguns have much chance of being affected. Last, the frequencies generated are below the range of hearing for almost all mammals. But there are exceptions.

 Most troubling of all is that there remains – and perhaps always will – a loosely defined concern as to whether seismic sources could seriously negatively interfere with marine mammal behavior. The question is, in the absence of evidence of harm, how far will governments go in the name of precaution? For now, cooperation and fact finding, based on mutual concerns, seems to have won the day.