Impacts that are unrelated to OCS activities but could contribute to a cumulative impact on whales include the annual subsistence level fisheries for humpback whales in Greenland (International Whaling Commission (IWC) quota of 8 in 1985) and Bequia, British West Indies (2 or 3 per year). Entrapment injury and mortality (17 killed in 1980) from inshore fishing gear along the Newfoundland coast is also a problem (Humpback Whales of the Western North Atlantic Workshop - New England Aquarium, Boston, MA, November 17-21, 1980). The IWC has set a fin whale quota of 8 for aborigines in West Greenland. This fin whale stock inhabits waters outside U.S. jurisdiction for the most part but may interact with fin whales in U.S. waters. No other species of endangered whales in the Western North Atlantic Ocean have huntable quotas set by the IWC, although illegal hunting of some species may take place. The high number of estimated spills (27) over 1,000 barrels each from petroleum imports may disrupt cetacean behavior, reduce the food supply in a localized area, and may contribute to the death of some individuals. Canadian offshore oil drilling in the waters around Nova Scotia and Newfoundland also could impact each endangered whale. The effects of Canadian drilling may be similar to those identified for drilling in U.S. waters. The cumulative effect of OCS activities and activities unrelated to OCS operations could result in a low number of additional whale mortalities which could inhibit the return of these animals to a non-endangered status or may even increase the risk of extinction.

Conclusion: The cumulative impacts of proposed and existing OCS exploration, production, and development in the Atlantic could have a moderate impact on most endangered or threatened whales. Impacts on the right whale could range from moderate to major. Non-OCS impacts will have a moderate to major effect on all endangered and threatened species.

Impacts on the Mid-Atlantic fish and shellfish resources in and near the proposed Sale area are primarily of two types, chronic and acute. Chronic impacts occur from habitual discharges of materials and/or toxicants. These discharges include drill muds and cuttings, formation waters, and small amounts of oil. Introductions of this nature are inherent in production of offshore oil and gas and are regulated with respect to volume, nature and manner of release (see Section IV.E.1 for more complete discussion). Acute impacts are caused by spills or blow-outs which are short-term, but release large volumes of hydrocarbons. In addition, impacts associated with pipeline placement and transportation of oil are discussed.

a. Chronic Impacts

Sale 111 exploration and development activities are projected to generate between 464,800 - 548,800 barrels of muds from exploration and delineation wells and 702,000 - 858,000 barrels of muds from production and injection wells. The amount of drill cuttings is projected to be approximately 348,960 barrels from exploration, delineation, production, and injection wells. For a discussion of the number of wells estimated and timing of releases, refer to Section IV.E.1 (Table IV.E.1-1).

Drilling Muds and Cuttings: Impacts of discharged drilling muds and cuttings vary according to the concentrations and types of additives used. Some of the most widely used constituents include barite, clays, lignosulfonates, lignite, and caustic soda (see Section IV.D.). Of principle concern are sublethal effects, particularly from chronic exposure to lignosulfonates and bioaccumulation of metals. In addition, it appears that particulate sulfur, metal flakes, and sand may contribute to hydrocarbon transport from operational facilities (Gallaway, 1981) thus increasing the size of the affected area. The National Research Council (1983) has summarized a vast amount of research concerning the fate and effects of drilling discharges in the marine environment. In order to understand the responses of marine organisms to drilling fluids, many bioassays have been performed to determine the concentration at which 50 percent of the test organisms die (LC50). Table IV.E.2-1 lists these concentrations for a wide variety of fish and shellfish as well as other marine biota. NRC (1983) compiled information on bioassay tests from over 70 drilling fluids and more than 60 species of marine organisms, and concluded that most water-based drilling fluids are relatively non-toxic. Toxicities associated with drilling muds and cuttings are actually thought to be largely attributable to the petroleum hydrocarbon content (Conklin et al., 1983).

Sublethal effects are more difficult to evaluate than acute toxicities. Tests to evaluate changes in growth and development in embryonic and larval stages and changes in adult behavior are less definitive than aquarium bioassays. In most cases, sublethal effects are observed at concentrations of 10 to 1,000 ppm, which is about 1-2 orders of magnitude below LC50 bioassay values (NRC, 1983).

Dispersion capabilities of most receiving waters tend to reduce concentrations of drill muds and cuttings to background conditions within a relatively short distance. Ayers et al. (1980) found that suspended solids and metal tracer concentrations in a field simulated 275 Bb1/hr test were at background levels

approximately 500 m from the discharge source, and reached the same levels in approximately 1,000 m from a 1,000 Bb1/hr test. "At most depths typical of the continental shelf, the majority of discharged fluids and cuttings are initially deposited on the seabed with 1,000 m of the point of discharge (NRC, 1983)."

Given the preceding knowledge of the fates and affects of drill muds and cuttings, NRC (1983) concluded that even sublethal effects on pelagic biota moving past the point of discharge are confined to a very small area around the point of discharge.

Oil Discharges

Inherent to production of offshore oil are inadvertent crude oil discharges. Such releases could occur during normal operations or from tanker loading. Some general statements can be made about the toxicity of oil to marine organisms: (1) lethal toxicity ranges from 0.1 ppm - 100 ppm soluble aromatics for adult organisms, (2) larvae are usually 10-100 times more sensitive than adults, (3) sublethal effects have clearly been demonstrated with aromatic compounds as low as 10-1000 ppb and (4) tainting of shellfish has been demonstrated with "oil" concentrations as low as 100 ppb (Johnston, 1979).

Monitoring of the effects of exploratory drilling on Georges Bank has been undertaken following Sale No. 42. The Minerals Management Service, via its biological monitoring program, has been sampling benthic organisms during and after exploratory drilling. Hydrocarbon analysis of tissue from ocean quahog (Arctica islandica) and fours pot flounder (Paralycthys oblongus) was performed on samples collected near the drill sites. The Science Applications, Inc. (1982) portion of the study concluded that "Although the number of samples analyzed is limited, there is no significant evidence to date of significant aliphatic or aromatic hydrocarbon contamination due to drilling activities in any of the tissues analyzed as part of the Georges Bank Monitoring Program." These preliminary data cannot be extrapolated to all marine biota, but they give an initial indication of the effects of exploratory drilling on selected species within the area of investigation.

Formation Waters: Formation waters are primarily generated during the production phase of the field. Given the projected 160 million barrels of formation waters projected (Table IV.E.1(c)), it is estimated that these discharges will contain 4,000 barrels of hydrocarbon materials. In addition to hydrocarbons, formation waters contain mineral salts, heavy metals, may be denser than receiving waters, and are often devoid of oxygen. The impact of formation waters is directly linked to the physical oceanography of the receiving waters. The mid-Atlantic planning area ranges in water depth from 10 and 3,250 m with the majority of the area being deeper than 100 m. Given the generally deepwater nature of the area, dispersion and dilution of formation waters is expected to be rapid and occur within short distances of the point source, resulting in minimal impact to mid-Atlantic fish resources.

In reviewing the effects of drilling discharges on marine biota the National Academy of Sciences (1983) concluded: "The panel's review of existing information on the fates and effects of drilling fluids and cuttings on the OCS shows that the effects of individual discharges are quite limited in extent and are confined mainly to the benthic environment." These results suggest that the environmental risks of exploratory drilling discharges to most OCS communities are small.

Acute impacts are caused by spills or blow-outs, discharging relatively large volumes of oil within a short time. These could occur at the rig site or along an established tanker transportation route. Hydrocarbon introductions into the marine environment have been shown by many researchers to have the potential to affect marine organisms (AIBS, 1978); Connell and Mills, 1980, 1981; Johnston, 1979; Malins and Hodgins, 1981; NAS, 1975). Some of the effects include direct mortality (most likely during early life stages), interference with olfactory perception, latent reproductive deficiency, alteration of normal behavior patterns, and bioaccumulation of some toxins.

Oil can be both lethal and sublethal. The wide range of impact intensities is dependent upon the species affected, time of year of the spill, chemical composition of the oil, amount spilled, previous exposure, and the physical oceanographic characteristics of the receiving water. Interacting physical, chemical and biological forces vary in importance depending on the post-spill time. For an overall review of the processes affecting the fate of oil in the sea, refer to Lee (1980), and Section IV.B.2 (Figure IV.B.2-1 and 2-2).

Oil toxicity values for important mid-Atlantic species as oyster, blue crab, hard and soft clam, sea scallop, fluke, lobster and scup are limited. Most toxicity studies seem to indicate that early life stages are the most susceptible to oil spill impacts because of the demonstrated mortalities at low concentrations. However, in a study by Neff and Anderson (1981), postlarval brown shrimp (Penaeus aztecus) were found to exhibit a 6.6 ppm 96 hour LC50 using No.2 fuel oil. At later life stages test values were 3.7 ppm and 2.9 ppm. This seems to contradict of the general theory that early life stages are more sensitive to oil than adults. This variance of test results suggests that toxicity studies are beneficial only as a source of background information. Neff and Anderson (1981) found that among ten species tested (96 hour LC50 --sargassum worm, errant benthic worm, sedentary benthic worm, oppossum shrimp, prawn, grass shrimp, brown shrimp (postlarvae), silverside minnow, Gulf killifish, sheepshead minnow) there was no relationship between phylogenetic position or habitat and relative sensitivity to oil. Despite this variability in susceptibility to oil, it would appear that most fish demonstrate acute toxicities in the range of 1 to 10 ppm (MMS, 1983; Connell and Miller, 1981). It is reasonable to expect mid-Atlantic fish resources to exhibit similar responses.

Sublethal effects of oil on biota are difficult to quantify. However, some literature does exist concerning actual oil-induced effects. Tilseth et al. (1984) investigated the sublethal effects of the water soluable fraction of Ekofisk crude oil the early larval stages of cod (Gadus morhua). After exposing cod larvae to oil-polluted sea water, it was observed that at the highest test concentrations (0.245 ppm - 0.265 ppm) reduced growth was exhibited (largely because upper jaw deformation occurred), there was a reduction in feeding efficiency, and larval swimming speed was seriously reduced. In addition, tests were performed to investigate the recovery capabilities of the cod larvae after exposure. At exposure concentrations of 0.6 ppm or less, no lasting effects of the exposure to oil were observed. However, larvae exposed to oil concentrations of 4.1 ppm or higher did not recover their feeding ability within 24 hours after placement in clean seawater. The final implications of this study were that the observed sublethal effects on cod larvae would probably have caused heavy mortality in an open sea population at the onset of exogenous feeding.

The magnitude of impact from a spill is highly variable. Assessment of impact on biological resources is most often based upon long term effects to the population as a result of initial egg and larvae mortalities. Egg and larvae mortalities are critical because these early life stages are often pelagic and therefore, unable to avoid spills. In addition, toxicity thresholds are lower at these stages. Adults are not immune from the effects of an oil spill, but exhibit greater toxic resistance and responses other than direct mortality. Such responses to oil spills often include avoidance behavfor (Nelson-Smith, 1972) or sublethal effects, which are difficult to evaluate. However, benthic organisms, such as shellfish, cannot avoid oiled waters, and demersal biota, such as blue crabs, may not necessarily avoid oiled sediments (0lla et al., 1980). For any mid-Atlantic species, eggs and larvae generated would be subject to ecological conditions which are extremely variable from year to year. This results in widely fluctuating annual recruitment. Those species that rely heavily on one or a few successful year classes to supply the majority of the recruitment are particularly vulnerable to environmental perturbations, both natural and man induced, such as oil spills.

An evaluation of the interactive relationships between biological, physical and chemical parameters of a hypothetical spill was performed by the University of Rhode Island and Applied Science Associates, Inc. (1982). This investigation concluded that "For any species, seasons of low and high impact susceptibility can be defined, and it can be shown that the impact estimates are most sensitive to timing and location, in that those two factors, together with the transport mechanisms of wind and currents, determine whether or not any impact occurs at all. However, given a situation in which an impact is found to be probable, the magnitude of this impact is most dependent upon the characterization of the stock recruit relationship (Reed et al., 1980; Reed et al., 1982), and is much less sensitive to toxicity threhold level or the hydrocarbon entrainment (dispersant addition) rate." This study shows that in analysis of impacts on fish resources from oil spills, the determining factors are the biology and fitness of the species rather than the nature of the spill. However, this analysis must be done with the ever-present background fluctuations of a complex ecological system which can be thrown out of balance if one small faction of the trophic matrix is severely affected.

The URI and ASA (1982) study was applied only to cod and herring in the North Atlantic because the biological data base available for other species was not complete enough to warrant usage. Mid-Atlantic fish resources also have a data base of insufficient depth to warrant model analysis. This means the application of the compensatory behavior concept can be qualitative only in the mid-Atlantic, and not quantitative.

An evaluation of potential risks to mid-Atlantic fish resources must consider the likelihood of contact to the known resources if a spill were to occur from within the proposed sale area. In addition, spill trajectories must be evaluated with respect to distribution of eggs and larvae both spatially and temporally. Previous analyses of this type have been able to track a spill from within the proposed sale area and then give a conditional probability of contact for a delineated target (1.e. calico scallop beds; DEIS 90), or for coastal land segments. Coastal areas often contain an abundance of fish and shellfish and serve as nursery or grow-out areas. Probabilities of an oil spill occurring and contacting offshore areas have not been determined prior to this EIS. It is known that spawning occurs throughout the majority of the continental shelf and during the entire year in the mid-Atlantic (see Figure 41, Appendix H). By utilizing offshore spawning segments, analysis of potential