approximately 1,500 bbls. of muds and cuttings. During the initial drilling sediment loads in the near-bottom waters could markedly increase around the borehole from the discharge of muds and cuttings and severly impact filter feeding epifaunal and infaunal organisms. The extent of impact is generally difficult to determine and would depend largely on the hydrodynamics of the specific canyon system, which would dictate the flushing rate, sedimentation rate, and resuspension rate of the drilling particulates. The primary causes of negative impacts would be smothering, mechanical damage to filter apparati, and changes in substrate granulometry. Because the proposed deferral area is small in comparison to the Sale 111 area (2.5 percent) and the decrease in resource estimate is only 10 mmbbls., no change in the level of impact from the proposed action is expected for water quality, plankton, marine birds, endangered species, and recreation and tourism. Impacts on canyon area assemblages would be reduced by this deferral (Table II.B.6-1); however, impacts on benthos and fisheries for the entire planning area will remain the same. The following definitions are used in this DEIS to describe the levels of impacts estimated for each resource category as a result of oil and gas activities associated with proposed Sale No. 111. Table II.B.6-1, located at the end of this section, compares the impact levels for each alternative, according to the definitions given below. WATER QUALITY Water quality parameters change several orders of magnitude and/or toxic trace metals or hydrocarbons exceed U.S. EPA safe levels; and changes persist for months or longer. Water quality parameters change one or two orders of magnitude Some measures of water quality deviate from ambient measures, but Negligible Normal measures of water quality such as dissolved oxygen content, salinity, temperature, pH, transmittance, trace metal concentrations and hydrocarbon levels show no statistically significant changes from ambient conditions. BENTHOS AND PLANKTON Statistically significant changes (95 percent confidence interval) in the population levels which will persist past the next recruitment period. Statistically significant changes (95 percent confidence interval) in the population levels which do not persist past the next recruitment period. Local changes in population levels which are not statistically significant (95 percent confidence interval) from annual population dynamics. Local changes in population levels, or community structure, MARINE AND COASTAL BIRDS Major An interference with ecological relationships that will persist beyond one generation. This usually involves the mortality or biological alteration of a large segment of the population, community, or habitat. An interference with ecological relationships that is restricted to one generation. Some species may sustain substantial losses. Some habitat loss will occur. An interference with ecological relationships that is restricted to one or two consecutive seasons. Some species may sustain low losses. Habitat loss may occur. Negligible - An interference with ecological relationships that is relatively inconsequential to either the relationships or the species, community, or habitat. Any losses will not be discernible from natural variations. SENSITIVE COASTAL HABITATS Definitions for MARINE AND COASTAL BIRDS also apply for this resource category. FISH RESOURCES A regional population or species declines in abundance and/or distribution such that natural recruitment would not return it to its former level within several generations. A portion of a regional population changes in abundance and/or distribution for at least one generation, but the regional population is unlikely to be adversely affected. A specific group of individuals of a population in a localized area is affected for a short time (one generation), and the regional population is not affected. Negligible - A specific group of individuals of a population in a localized area experiences sub-lethal impacts which promote reduced biogenic activity or metabolic functions for a short time (less than one generation), and the affected organisms recover quickly to a preimpact condition, resulting in no apparent modification of the localized population. COMMERCIAL AND SPORT FISHING A 10 percent or greater economic loss to the industry. Some Less than 10 percent economic loss to the industry. Some financial loss to fishermen and secondary employment, but not measurable against the natural variation in fish and shellfish stocks. A small economic loss to the industry. A few fishermen affected but no effect on secondary employment. Fluctuations in fish and shellfish stocks are so small that economic losses to fishermen are not felt by the fishing community as a whole. Only a few local fishermen are affected for less than the season of harvest. ENDANGERED AND THREATENED SPECIES: COASTAL SPECIES, TURTLES, WHALES A large scale interference with ecological relationships. This could involve the mortality or alteration of a noticeable segment of the population, community, or habitat greatly increasing the risk of extinction. A local or temporary interference with ecological relationships. Some mortalities or habitat alteration may occur that would inhibit the return of a species or population to a non-endangered status. An interference with ecological relationships that is not particularly significant to either the relationships or the species, community, or its habitat. Activities should not inhibit the return of a species or population to a non-endangered status. An interference with ecological relationships that persists for less than 1 day. No mortalities or habitat alteration will occur. The population will not be affected. COASTAL RECREATION AND TOURISM Extensive closure of public water-oriented recreational facilities resulting in peak-season losses to local tourist industry. Losses not affected by gains in other local areas. Widespread negative visual effects from oil spills and/or drilling operations. Recreational lands permanently diverted to other uses. Coastal recreation areas experience reduced levels of usage. Dis Economic losses to local tourist industry are within normal annual fluctuations. Some psychological dissatisfaction with recreational visits to coastal areas but no significant decrease in usage levels. No obvious visual effects from offshore drilling operations. Land temporarily removed from recreational uses during off-season. Negligible - No identified economic losses to local tourist industry. reduction in usage levels and minimal psychological dissatisfaction with recreational visits. No visible impacts from offshore drilling operations. Coastal lands not previously used for recreational purposes are diverted to other uses. LAND USE AND COASTAL MANAGEMENT Major High incompatibility between OCS facilities and other uses such as recreation, housing, etc., with little or no mitigation measures (e.g., buffer zones) resulting in impacts of nuisance, noise, and traffic. Siting where no land-use plans are in place. Little or no land is available for expansion. Some incompatibility which may be caused by siting requests that result in changes to existing land-use plans and which still allow a lesser degree of the above impacts; or sitings occur in rural or natural areas adjacent to other developments (e.g. a support base near a farm site). Low incompatibility because impacts are obviated or mitigated by land-use plans, CZM programs, and Federal, State, and local regulations and permitting procedures which already exist. It is assumed that sitings must meet specifications before permits are granted. Conflict unlikely between siting of facilities and local land- An increase of greater than 10 percent in the employment level An increase of between 5 and 10 percent in the employment level of the affected area. An increase of between 0.5 and 5 percent in the employment level of the affected area. Negligible - An increase of less than 0.5 percent in the employment level of the affected area. An increase of greater than 10 percent of the baseline population of the affected area. An increase of between 5 and 10 percent of the baseline population of the affected area. An increase of between 0.5 and 5 percent of the baseline population of the affected area. Negligible An increase of less than 0.5 percent of the baseline population of the affected area. INFRASTRUCTURE Some new community facilities have to be constructed and a |