Assessment of the U.S. Outer Continental Shelf Environmental Studies Program: II. Ecology (1992)

The Minerals Management Service's mandate to assess potential impacts of OCS activities, as specified in the OCS Lands Act as amended in 1978 and in other authorities, although reasonable from the viewpoint of public policy, required the acquisition of information and the development of predictions that could not be accomplished with the available time, resources, and scientific expertise. Therefore, MMS has allocated its resources to studies that support specific lease sales at the expense of longer-term studies that would have provided a better scientific basis for prediction and assessment of impacts of OCS activities.

In general, with a few exceptions, the panel found that the information available on inventories and distribution of marine birds and mammals and the characterization of benthic environments were adequate to define the resources at risk because of OCS activities. The principal exception to that finding is the lack of information collected for OCS areas in the Gulf of Mexico, specifically on the at-sea distribution of birds and mammals; the distribution and abundance of sea turtles; and characterization of benthic communities, especially in deeper waters. In addition, data on seasonal and interannual variation of many ecological aspects of OCS areas are lacking.

There have been insufficient process-oriented programs for many regions of the OCS, studies that would yield information on ecological processes, population dynamics of resource species, and interactions between physical and chemical processes and biological communities. Such information is needed to support assessments of the sensitivity and vulnerability of biological communities to OCS-related activities, and it will also provide a basis for developing strategies for reducing impacts and mitigating them. Studies linking an understanding of physical and chemical processes, of their effects on biological communities, and of the fate and transport of OCS-related discharges are critical during all phases of OCS oil and gas activities. Those studies should assess not only the short-term effects of exploratory drilling on the OCS, but the long-term effects of chronic discharges during exploration, development, and production. The latter point was recommended in an earlier review of the OCS oil and gas program (NRC, 1978). The studies should also address potential cumulative effects on migratory species (e.g., gray and bowhead whales) that occur seasonally in different OCS regions.

There has been insufficient focus in the ESP on impacts of OCS activities on nearshore and onshore communities that, although unlikely to be affected during the early stages of exploration, could be seriously affected when shore-based facilities are constructed or spilled oil moves ashore. Concern for nearshore and onshore communities was highlighted in earlier

studies (NRC, 1978, 1989a), especially regarding areas where critical habitats of endangered or threatened species could be affected (e.g., the Gulf of Mexico).

Impact analyses to date have been narrowly focused on the potential impacts of spilled oil. More attention needs to be given to the other potential impacts of OCS development and production, including those associated with the combined discharge of drilling fluids, produced waters, spill dispersants, and other chronic discharges, in addition to ship and aircraft traffic, onshore development, pipeline construction, and removal of facilities as well as the overall cumulative effects of significant industrialization related to OCS oil and gas activities in an area and how impacts could be reduced.

Regional programs within the ESP vary from one region to another in the scientific quality of completed studies, the integration of data from different disciplines, and the acquisition of critical information. The variation was also recognized by the OCS Physical Oceanography Panel in its review of the ESP (NRC, 1990a). MMS should develop stronger scientific bases for its strategies for the acquisition of ecological information that can be incorporated into regional study plans. Strengthening the scientific bases of its strategies would result in less-fragmented studies that are better integrated across disciplines and regions and more closely fulfill the mandate for assessing the impacts of OCS oil and gas activities. Using the criteria highlighted in this report (Chapter 1) and a sound scientific strategy, priorities for regional study plans may be developed with an understanding of both the resources and habitats at risk and their vulnerability to various activities throughout the full range of OCS oil and gas activities (i.e., exploration through decommissioning).

Although some extensive data sets have been acquired (especially resource inventories), MMS has not yet established a data management system that will always allow it to determine where its effort has been expended or where biological resources are. The panel understands that MMS is again working on the development of a computerized data management system that is intended to permit retrieval of data on study effort, as well as on the distribution and abundance of organisms.

The panel offers six general recommendations for future ESP ecological studies.

• The ESP should support more ecological process-oriented studies and studies of ecological relationships designed to predict environmental impacts of OCS oil and gas activities.

A major achievement of the ESP was the characterization of benthic habitats and the distribution of bird and marine mammal populations. Although identification of resources at risk and characterization of habitats will still be required in new frontier areas of the OCS, the need for only broad-scale survey work has passed. Future research should focus on process-oriented programs designed to evaluate mechanisms that control the distribution of populations and communities such as trophic links between benthic habitats and pelagic communities. The research should focus on the appropriate temporal and spatial scales. For example, the processes by which and the rates at which populations recover from disturbance must be understood in all habitats affected by OCS-related activities. In addition, there is a critical lack of understanding of the proper temporal and spatial scales for evaluating OCS-related impacts, especially on benthic areas. Existing data (data from MMS, data on fisheries, and any other available data) should be analyzed and used to discern proper scales for future research. It is

critical to use information gained from studying OCS impacts and attempts to mitigate them in planning future activities. In other words, OCS activities should be treated as scientific experiments whenever possible.

MMS, through the National Oceanic and Atmospheric Administration's Outer Continental Shelf Environmental Assessment Program (NOAA/OCSEAP), supported the development of analytical chemical techniques for determining concentrations of hydrocarbons and biochemical techniques for examining sublethal effects of hydrocarbon contaminants, metabolites, and reaction products. Advances in methodology have progressed in the scientific community at large with funding from various sources. These techniques have improved understanding of the fate and effects of hydrocarbon contaminants in the marine environment. MMS should incorporate them into future study plans to improve understanding of the biogeochemistry of hydrocarbons that might affect benthic ecosystems.

The vulnerability of different shelf habitats to discharges from OCS oil and gas activities and the mechanisms that control recovery are not well understood. MMS should continue to direct its efforts toward a greater understanding of the mechanisms involved in habitat restoration and recovery.

For birds, MMS should promote studies of processes responsible for foraging aggregations, both near and away from breeding colonies, and integrate them with work in other specific disciplines (physical and biological oceanography, fisheries, etc.). MMS should cooperate with other organizations to take advantage of and help support current long-term studies of reproductive ecology that are developing data on population and community processes. MMS should conduct additional surveys of migratory routes to identify areas of concentration and their timing. For marine mammals, MMS should ensure that the emphasis of studies on high-profile species is not at the expense of others, less visible, that may be more sensitive or vulnerable.

OCS off and gas activities constitute only a portion of all human activities in the coastal and continental shelf areas (e.g., commercial fishing, shipping, sewage discharge, etc.) that can have adverse impacts on ecosystems and living resources. Thus, an understanding of the interactions of OCS activities and other disturbances is needed for an assessment of absolute and relative environmental impacts of OCS oil and gas activities.

In addition, OCS oil and gas development could have serious immediate and chronic long-term effects on intertidal and nearshore habitats. Because of their popular appeal and exposure to waterborne oil and debris, the narrow intertidal habitats are among the most valuable, yet vulnerable, marine habitats in the world. Although these fragile habitats and ecosystems are inshore of the legal OCS limits, they are vulnerable to the effects of OCS oil exploration and development and must be better represented in MMS's studies.

• More emphasis is needed on long-term and postlease studies that are directed toward a better understanding of the environmental impacts of OCS development and production.

Until recently, ESP studies have focused on preleasing activities, primarily in frontier regions of the OCS, and not on the effects of exploration, development, and production. Almost all the natural patterns represent time scales that must be evaluated in terms of decades, rather than years; and it is absolutely critical that long-term (multiyear) postlease studies be established. Postlease research involving exploration, development, and production must include long-term programs that can discriminate between natural changes and OCS-related changes and can discern interactions of OCS activities with other human activities in specific regions. Long-term studies, including time-series analysis (such as those conducted in the California

Cooperative Fisheries Investigation), should define the spatial and temporal extent of the impacts of OCS activities. For birds, MMS should establish a subset of potentially vulnerable colonies and should run a statistically based program to monitor numbers and reproductive biology of selected species during leasing, exploration, and production. Detailed long-term monitoring studies should also be done for selected species of marine mammals. The development of monitoring programs to verify predicted effects can be used to ensure that effects do not reach unacceptable levels. MMS should hold a workshop and collaborate with other agencies (e.g., FWS, NMFS, state agencies) to identify useful indicator species and to outline the types of long-term monitoring studies that could be done to verify the predicted effects, and detect the possible unforeseen effects of OCS activities in different regions.

One important component of postlease analysis is the understanding of the long-term effects of oil spills on both the OCS and nearshore habitats. Therefore, MMS should take advantage of accidental and experimental oil spills for research, to examine the persistence of hydrocarbons in the marine environment, to identify the processes related to the degradation of hydrocarbons, and to define the mechanisms that control the recovery of specific biological communities (as it did in a recent study of the Nestucca oil spill off the Washington coast (Strand et al., 1990)). It is extremely important that the sites of large oil spills receive periodic restudy. MMS should hold a workshop, together with other agencies, to develop contingency plans for responding scientifically to different kinds of oil spills in different areas and to use them as a means for verifying otherwise unverifiable hypotheses concerning the effects of oil and marine living resources and the ecosystems of which they are a part. The data collected from many studies of the Exxon Valdez oil spill were not available for review and incorporation into this report. When most of the data have been made public and peer-reviewed, we are likely to gain valuable insights about the fate and effects of spilled oil in subarctic environments.

• Models are important for understanding ecosystem processes and environmental impacts of OCS activities. However, the development of models requires observational data for verification, and use of models does not replace the need for further work in the assessment of environmental impacts of OCS activities.

Modeling is an important tool that can provide insights into a variety of ecosystem processes and should be used not as a substitute for field programs, but in conjunction with field programs to identify specific information gaps. To improve predictive capability for ecosystem modeling, MMS should:

• Use models to identify critical data gaps and processes that must be understood to predict accurately the possible environmental impacts of OCS activities.

• Provide data on rates and processes for models.

• Take advantage of theory and techniques that are being developed for constructing ecosystem models.

• Take advantage of modeling expertise that exists outside of current MMS contractors.

In all cases, models should be tested against and calibrated with field observations before their outputs are used to assess and manage OCS environmental impact.

• MMS needs a data management system that is accessible in a timely manner and allows the integration of information from different disciplines.

MMS has produced a large quantity of data—some interpreted, some not. Improvement is needed in MMS's data management, including synthesis, storage, and retrieval. MMS should continue to develop integrated data bases on biological resources potentially at risk. The data bases should be reproducible as maps. Formats should permit ready retrieval on a geographic basis. GIS systems could be developed and used to help organize and integrate multidisciplinary geographic data in each OCS region. MMS should continue to develop information exchanges with other agencies. In addition, MMS should continue to encourage the publication of study results in the peer-reviewed scientific literature. Final reports can be difficult to find, and they often are not critically reviewed or integrated for an understanding of broad-scale impacts of OCS-related activities when not published in peer-reviewed scientific literature.

• MMS should sharpen its focus on the specific scientific hypotheses underlying its strategies for the acquisition of information so that the information can be incorporated into regional study plans, and should strive to integrate regional study plans across disciplines and regions.

MMS needs to develop study plans that include more hypothesis-testing and greater recognition of the spatial and temporal scales on which effects of specific OCS activities can occur. The recommendations of Carney (1987) for the design of benthic monitoring programs can be applied to other aspects of the OCS program, specifically in the selection of processes that can be studied, statistical design of sampling programs, and identification of appropriate temporal and spatial scales for sampling specific characteristics.

• MMS should help in the curatorship of the large collections obtained during its studies.

MMS requires (appropriately) that samples be competently identified and that voucher specimens be maintained. It is critical for determining whether change has occurred that all specimens be available for inspection. Indeed, frozen tissue samples from selected animals also offer extremely important reference information for assessment of future impacts of OCS activities. In order to provide taxonomic continuity for future MMS-supported research, MMS should support the systematists that made the benthic programs possible, and especially should support the extremely important long-term curatorship of archived samples. The marine mammal tissue bank being developed by NMFS (to which MMS contributes) could usefully be expanded to include birds and fish.