The Marine Facilities staff turned out in force to transform this crab-fishing platform into a research vessel through the addition of four container vans that were well prepared for the task: the electronics (or underway watch) van, the MT's van, an office van, and the core-logging van (see photo on next page). The ship also had to be fitted with a winch for the Huntec DTS, a coring winch, an air compressor, a davit for the 12-kHz and 3.5-kHz towed transducers, and a small boatload of coring-related equipment for use in the sampling operation that followed the geophysical survey (see article "Sediment Sampling Off Southern California"). Using the vans and ancillary gear used in last year's operation paid dividends in that mobilization took less time by nearly a full working day.
The ship departed the CMG Marine Facility in Redwood City, California, on the morning of 4 June. It arrived about sunset the next day at the northern limit of the work area off Santa Monica, where we began work with the Huntec system. The time of day is an important aspect of describing operations during this year's survey. Because of restrictions related to concerns about marine mammals imposed by the Marine Mammal Protection Act (MMPA), the revised Coastal Zone Management Act (CZMA), and the California Coastal Commission (CCC), multichannel seismic-reflection profiling using the airgun sound source was limited to daylight hours only. At night, our surveys were restricted to use of the 12-kHz echo sounder and the high-resolution Huntec boomer system. (Note: geophysical operations offshore California are affected by four federal and state agencies; see section "Changing Climate for Offshore Surveys"). The underlying regulations are based on federal law and are expected to be enforced in all U.S. coastal waters eventually.
There were no major equipment failures during the entire 12-day survey, thanks in large measure to the efforts of Larry Kooker, Kevin O'Toole, Fred Payne, Hal Williams (all of our Marine Facility group), and Graham Standan of Geoforce, Inc. As a result, we were able to collect about 1,250 km of high-resolution multichannel seismic data. An additional 1,050 km of Huntec-only data were obtained during the night operations. On the last day of the cruise (17 June), Jon Childs and Pat Hart met us with a small dive boat to conduct acoustic source-level measurements of the Huntec and GI gun systems. We also tested the sparker sound source in the Huntec for evaluation by Brian Edwards for his proposed work next year on the shelf off Long Beach. Paralleling last year's operation, the Ocean Olympic was used for back-to-back cruises to save money by sharing mobilization/demobilization costs. Brian Edwards and Homa Lee took command in San Diego to continue their coring program off Santa Monica, in addition to obtaining piston cores for benefit of the earthquake hazards project (See article "Sediment Sampling in Southern California").
Changing Climate for Offshore Surveys (Or No Airgun Sound Source is Small Enough)
For this year's field operation, the National Marine Fisheries Service (NMFS), the agency empowered to enforce the MMPA, required that the USGS apply for an Incidental Harassment Authorization (IHA). The IHA request process nominally takes 120 days and the request was submitted to NMFS in mid-January 1999. One part of the IHA process requires NMFS to make the application available for public comment, which is done through notification in the Federal Register.
Following publication of the IHA request in the Federal Register, the California Coastal Commission (CCC) used authorization granted by provisions of the revised Coastal Zone Management Act to require the USGS to submit a Consistency Determination (CD). The CD documents that a federal activity (in this case the geophysical survey) will be conducted in a manner consistent with the State's coastal-zone management program. The process of application to the CCC included discussion and review at a monthly meeting of the CCC; for this cruise activity, the hearing was in May. The original request for a CD was denied, and the CCC requested that the USGS resubmit with additional conditions, this time requesting a Negative Determination (i.e., a finding that the proposed activity would have no effect on coastal-zone resources). The USGS complied and received verbal approval prior to the cruise. The most significant condition required by the CCC action was that airgun operations not be conducted during darkness.
After responding to questions raised as a result of the public comment period (including follow-up discussions between the USGS and NMFS), the USGS received the IHA on 3 June 1999. The IHA incorporated the conditions from the CCC and specified, among other restrictions, that
At the beginning of the field program, the marine-mammal observers provided a written protocol for the geophysical watchstanders with respect to meeting the conditions of the IHA. This marine-mammal protocol was stated:
The written protocol also stated the "cut-off distances": "100 m [for] dolphins, seals, and sea lions" and "250 m [for] large whales." The observers also requested that "if animals are seen off the stern, clearly within [the] shut down area and haven't been detected by [the] mammal team" . . . . then the watchstanders were to shut down the GI gun and immediately contact the mammal team.
All conditions stated in the protocol were followed throughout the cruise.
The program cost for meeting the requirements of the IHA are twofold. First, the number of pay periods of CMG personnel involved in the permitting process, which lasted from mid-December to early June, is equal to the number of pay periods for the 8-member CMG scientific staff during the 12 days of survey. Second, loss of multichannel seismic-reflection data collection during the night amounts to 38% of the total ship days contracted; for this year's 12-day survey, this amounts to more than $30K.
Another restriction on the survey resulted from the authority of the California State Lands Commission (SLC). The SLC has regulatory authority over waters within 3 miles of the coast. At present, the SLC bans all airgun seismic sound sources regardless of size and regardless of the intended use. For example, scientific research to define earthquake hazards cannot obtain an exemption to the ban. As a result, the survey with the GI gun could not extend within 3 miles of the coast. The SLC does not have restrictions on non-airgun sources such as the Huntec boomer system, but the geophysical survey lines were terminated at the 3-mile limit because Huntec boomer data by itself are insufficient for mapping fault systems in this area.
The important point of the above discussion is that these restrictions represent a problem not just for those who want to work offshore California. All of the coastal states will be developing, or have in place, management plans of their own under the revised CZMA, and the provisions of the MMPA apply everywhere with respect to U.S. oceanographic research. At present, not all areas of the oceans have come under strict enforcement, but it may only be a matter of time. "Establishing a precedent" was a key issue for the agencies acting on the approval process for our recent survey.
in this issue: Southern California Sediment Sampling