Baseline Conditions

The DEIS acknowledges that two baselines were used in assessing impacts:5

“For the purposes of this document … The baseline against which the no-action alternative is assessed is generally existing conditions … The action alternatives, on the other hand, are … assessed using the no-action conditions as the baseline condition. In other words, the analysis of the action alternatives may be documented by contrasting the expected future conditions under each action alternative to the expected future conditions under the no-action alternative.”

In other words, for alternative A, the DEIS assesses the expected impacts associated with the removal of DBOC’s operations. The expected impacts are compared to the existing conditions, i.e., the continued operation of the shellfish farm. By contrast, impacts associated with alternatives B, C, and D are compared to the less certain, expected future conditions under alternative A (considered the “no action” alternative).

The committee recognizes that, in NEPA practice, the “no action” alternative is usually considered the “baseline” under which current environmental conditions are compared. In these situations, environmental conditions would not change under a “no action” alternative. However, in the case of the DBOC, if the Secretary of the Interior took no action, the Special Use Permit (SUP) would expire and alternative A would be implemented, which would change current conditions. Given that the environmental impacts associated with existing conditions are known with greater certainty than those associated with alternative A (potential future conditions), assessing the impacts of action alternatives B, C, and D against “no action” alternative A increases the level of uncertainty in conclusions about the impacts of alternatives B, C, and D. Also, the use of two baselines introduces asymmetry into the analysis such that the impacts of “no action” alternative A cannot be compared to the impacts of the action alternatives (alternatives B, C, and D). This becomes a particular problem in the Summary of Environmental Consequences6 which presents the potential impacts of the four alternatives as if they were comparable, even though the impacts of the “no action” alternative A are assessed using a different baseline than that of the action alternatives (B, C, and D).

Scaling Impacts on Drakes Estero and Changes in Ecosystem Conditions

The DEIS7 defines a “local” impact as one that would occur within the general vicinity of the project area and a “regional” impact as one that would affect localities, cities, or towns surrounding the Seashore. The DEIS8 also defines a “direct” impact as one caused by an action that “occurs at the same time and place” and an “indirect” impact as one “caused by an action but is later in time or farther removed in distance, but still reasonably foreseeable.” For seven of the resource categories examined in this study (wetlands, eelgrass, wildlife and wildlife habitat, special status species, coastal flood zones, water quality, and soundscapes), the committee used the spatial scale as they interpreted the definitions of “direct”, i.e., the impact is direct when it causes a change in ecosystem state on the same scale as the impact source, and “indirect” if it is expressed on the scale of the Drakes Estero ecosystem.9 Thus, the potential spatial footprints of DBOC operations (onshore facilities, culture racks and bags, and motor boat corridors) would correspond to local scales of impact. In this context, the total area permitted for onshore operations would be less than 1% of the Drakes Estero watershed and the total area designated for cultivation (138 acres under alternatives B, C, and D) would be ~5.5% of the entire Estero (including Estero de Limantour) and about 10% of the intertidal and subtidal acreage in the potential wilderness area (Table 2.1). Actual utilized areas would likely be smaller. For example, the footprint of racks (7 acres) used in recent years are estimated to cover 13% of the subtidal culture beds. When considered in


5 DEIS, p. 234.

6 DEIS, Table ES-4.

7 DEIS, p. 235.

8 DEIS, p. 235.

9 These definitions of “direct” and “indirect” are not relevant to the socioeconomic category since direct impacts are assessed in terms of human uses on larger scales (market value of shellfish, employment, recreational use of the Seashore, etc.).

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