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Suggested Citation:"Summary." National Research Council. 2012. Scientific Review of the Draft Environmental Impact Statement: Drakes Bay Oyster Company Special Use Permit. Washington, DC: The National Academies Press. doi: 10.17226/13461.
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SUMMARY

In May 2012, the National Park Service (NPS) commissioned the National Research Council to conduct a scientific review of a Draft Environmental Impact Statement (DEIS) prepared to “evaluate the effects of issuing a Special Use Permit for the commercial shellfish operation” in Drakes Estero for a 10-year period.1 Drakes Bay Oyster Company (DBOC) currently operates the shellfish farm in Drakes Estero, part of Point Reyes National Seashore, under a reservation of use and occupancy that will expire on November 30, 2012 if a new Special Use Permit is not issued. Because the commercial shellfish operation is the single, nonconforming use in this congressionally-designated potential wilderness, closure and removal of the shellfish farm would prompt the conversion of Drakes Estero to full wilderness status. Congress granted the Secretary of the Interior the discretionary authority to issue a new 10-year Special Use Permit in 2009 (Public Law 111-88, Section 124); hence, the Secretary now has the option to proceed with or delay the conversion of Drakes Estero to wilderness. To inform this decision, the NPS drafted an Environmental Impact Statement (EIS) for the DBOC Special Use Permit. Under the National Environmental Policy Act (NEPA), an EIS is prepared to inform the public and agency decision-makers regarding the potential environmental impacts of a proposed federal action and reasonable alternatives. The Department of the Interior commissioned a peer review of the DEIS (Atkins Peer Review) that was released in March 2012.

This report reviews the scientific information presented in the DEIS that is used to determine the potential environmental impacts of a 10-year extension of DBOC operations. In particular, this report responds to the following tasks given to the committee: assess the scientific information, analysis, and conclusions presented in the DEIS for Drakes Bay Oyster Company Special Use Permit, and; evaluate whether the peer review of the DEIS conducted by Atkins, North America for the U.S. Department of the Interior is fundamentally sound and materially sufficient. The committee did not perform an independent evaluation of the environmental impacts of the proposed alternatives, but restricts its findings to the strength of the scientific conclusions reached in the DEIS and to the identification of concerns, if any, not covered in the Atkins peer review.2 The report focuses on eight of eleven resource categories considered in the DEIS: wetlands, eelgrass, wildlife and wildlife habitat, special-status species, coastal flood zones, soundscapes, water quality, and socioeconomic resources.

Ecological Setting

Drakes Estero is a coastal lagoon located approximately 25 miles northwest of San Francisco, California that extends northward into the Point Reyes peninsula from Drakes Bay. The ecosystem consists of five branching bays (Barries, Creamery, Schooner, Home and Estero de Limantour) with an area of ~2,500 acres and a narrow mouth allowing tidal exchange with coastal ocean waters. Major habitats include intertidal mudflats, sandbars, and subtidal eelgrass beds that support wildlife including native shellfish, finfish, shorebirds, and harbor seals. After trial plantings of the nonnative Pacific oyster (Crassostrea gigas) in 1932, farming of this species in Drakes Estero has continued as a commercial enterprise under various owners up through the DBOC which assumed ownership in 2005.

Alternatives Assessed in the DEIS

The DEIS assesses impacts of four alternatives on eleven resource categories, and classifies intensities of impact as beneficial or minor, moderate, or major adverse. The four alternatives (described in more detail in Chapter 1 of the DEIS) are briefly characterized below.

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1 Congress requested the NRC review in the December 2011 conference report.

2 Study statement of task is provided in Appendix A.

Suggested Citation:"Summary." National Research Council. 2012. Scientific Review of the Draft Environmental Impact Statement: Drakes Bay Oyster Company Special Use Permit. Washington, DC: The National Academies Press. doi: 10.17226/13461.
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No Action Alternative – Special Use Permit under which DBOC operates expires on November 30, 2012 and is not renewed:

Alternative A: mariculture activities cease and equipment is removed; Drakes Estero potential wilderness is converted to full wilderness.

Action Alternatives – Special Use Permit for shellfish culture is reissued for an additional 10 years under the conditions specified in three alternatives:

Alternative B: Level of use consistent with conditions and operations present in fall 2010; Shellfish production limited to 600,000 lbs/yr.

Alternative C: Level of use consistent with conditions and operations at the time the current Special Use Permit was signed in April, 2008; Shellfish production limited to 500,000 lbs/yr.

Alternative D: Considers an expansion of operations and new or modified onshore facilities as requested by DBOC as part of the EIS process; Shellfish production limited to 850,000 lbs/yr;

Major Conclusions

For the eight resource categories, the committee evaluated conclusions in the DEIS concerning levels of impact of each alternative and the information and interpretations that led to them. The committee also commented on whether alternate, scientifically sound conclusions could be reached based on the available information (in the DEIS and the scientific literature) and the level of uncertainty associated with the conclusions. As noted in the previous NRC report on Drakes Estero (NRC, 2009), there is not an extensive scientific literature on Drakes Estero and research on the potential impacts of shellfish mariculture on the Drakes Estero ecosystem is even sparser. Therefore, the NPS had little primary data on which to base the DEIS and had to rely to a large extent on inference from research conducted in other areas. Although this was the only approach that could be used under the circumstances, it not only made it difficult to differentiate impacts of alternatives B, C, and D, it resulted in a moderate to high level of uncertainty associated with conclusions concerning levels of impact for most of the resource categories reviewed by the committee (Table S.1).

Impacts of the Alternatives

Alternative A can be readily distinguished from alternatives B, C, and D because mariculture activities would cease and all DBOC infrastructure would be removed. However, alternatives B, C, and D are differentiated primarily in terms of production limits for offshore activities (600,000 lbs, 500,000 lbs and 850,000 lbs for B, C, and D, respectively), which do not provide a clear basis for comparison. An overview of the DEIS impact findings shows that the expected impact intensities are the same for each action alternative regardless of resource category (Table S.1). Production limits dictate the maximum level of harvest, but do not directly scale with level of activities or spatial extent of mariculture operations. Additionally, harvest may vary as a function of environmental conditions, shellfish diseases, harmful algal blooms, predation, and market conditions, and therefore does not represent a reliable indicator of potential impact.

Adverse impacts are defined in the DEIS as minor, moderate or major in order to describe impacts based on their intensity or magnitude. It is noteworthy that only one category of beneficial impact is used, eliminating the possibility of distinguishing between effects that may range from minor to major beneficial in parallel with the definitions used for adverse impacts. Also, the definitions do not include a negligible impact, a useful category that is provided as an example in the NPS NEPA guidance, “Summary of Regulations and Policies — Impact Indicators and Criteria,” Director’s Order 12.3 For most of the eight resource categories that the committee was asked to review, the committee concluded that the DEIS does not define impact intensity levels that can be clearly related to the magnitude of the effect (spatial or temporal; direct or indirect). This makes it difficult to determine both the comparative impact of

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3 Available at: http://www.nature.nps.gov/protectingrestoring/do12site/tabs/tab22.htm.

Suggested Citation:"Summary." National Research Council. 2012. Scientific Review of the Draft Environmental Impact Statement: Drakes Bay Oyster Company Special Use Permit. Washington, DC: The National Academies Press. doi: 10.17226/13461.
×

the different alternatives and the relative levels of impact across resource categories. For example, both the moderate and major intensity definitions for wildlife and wildlife habitat include the mention of impacts on “individuals.” Such a definition implies that the mortality of an individual organism associated with flipping of oyster bags could be interpreted as a moderate impact on the resource, which would be incompatible with the level of ecological impact.

Level of Uncertainty and Alternate Conclusions

An estimate of uncertainty, which reflects the strength of the available scientific information, gives decision makers a better understanding of the range of potential impacts for a given action alternative. Therefore, the committee assessed the data and analysis for each resource category in terms of the level of uncertainty associated with the impact assessment given in the DEIS.4 Of the eight resource categories, the committee judged that the projected impact levels for seven had moderate to high levels of uncertainty and, for many of these an equally reasonable alternate conclusion of a lower impact intensity could be reached based on the available data and information (see Table S-1). To provide an accurate analysis for the decision maker, it is important for the EIS to include estimates of level of uncertainty as part of the assessment of environmental consequences.

Baselines

The DEIS employs two different baselines in assessing the impacts of the no action and action alternatives. In a typical EIS, the “no action” alternative is considered the current baseline environmental condition against which the impacts of the action alternatives are compared. However, for the DBOC Special Use Permit EIS, the no action alternative (alternative A) refers to a change from the current condition (the Special Use Permit would expire and DBOC would cease operation) and shifts to a new, future condition that is unknown. Impacts associated with action alternatives B, C, and D (10 year extension of the permit for the mariculture operation) are then compared to this projected future “baseline” (alternative A), while impacts of alternative A are compared to the better known existing conditions (i.e., with DBOC facilities and operations as described for alternative B) as the baseline. This introduces an extra level of uncertainty to the evaluation of the action alternatives and creates asymmetry in the assessments conducted for the action alternatives relative to the no action alternative. By invoking two baselines, the DEIS essentially contains two separate impact assessments, one for the no action alternative and another for the action alternatives, such that there is not a common basis for comparing the potential impacts of the no action alternative (A) with the potential impacts of the action alternatives (B, C, and D).

Suggestions for DEIS Revisions5

The committee provides the following high priority suggestions for revising the final EIS: (1) use definitions of impact intensities that demonstrably scale with their magnitude (e.g., minor, moderate,

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4 Low uncertainty is assigned when the committee finds that substantial scientific evidence exists to support the conclusions reached, i.e., the evidence demonstrates a strong cause-effect relationship between Drakes Bay Oyster Company (DBOC) actions associated with an alternative and a measurable effect.

Moderate uncertainty is assigned when the committee concludes that, while there is insufficient data and information for Drakes Estero, observations from other comparable ecosystems and current scientific understanding allow logical deductions concerning a possible cause-effect relationship between DBOC actions and a measureable effect.

High uncertainty is assigned when the committee concludes that there is insufficient data and information for Drakes Estero; observations from other comparable ecosystems are not available; and scientific understanding is insufficient or controversial such that conclusions regarding a possible cause-effect between DBOC actions and a measurable effect can be made only by inference.

5 These suggestions are based on the committee’s review of the scientific foundation of the DEIS and should not be interpreted as a conclusion that the DEIS does not meet NEPA requirements.

Suggested Citation:"Summary." National Research Council. 2012. Scientific Review of the Draft Environmental Impact Statement: Drakes Bay Oyster Company Special Use Permit. Washington, DC: The National Academies Press. doi: 10.17226/13461.
×

major), and fully reflect the range of both adverse and beneficial impacts including a category for negligible impacts; (2) provide a discussion of the levels of uncertainty for the impact intensities (e.g., Table S.1); (3) specify all assumptions used in assessing impact and in scaling the intensity of impact; (4) describe potential alternate conclusions as appropriate (e.g., Table S.1); (5) segregate impact assessments for alternative A from alternatives B, C, and D and indicate that the assessments are not comparable due to use of different baselines; (6) use all relevant and available information, especially for soundscapes and water quality (from research in Drakes Estero and in other comparable systems) and; (7) include additional mitigation options as possible permit conditions for the action alternatives to reduce impacts, e.g., an option to discontinue the culture of Manila clams would address some concerns about the establishment of that non-indigenous species in Drakes Estero; impacts of many DBOC practices (i.e., boat use, culture techniques, marine debris, soundscape disturbance) could potentially be reduced by the implementation of appropriate mitigation measures.

TABLE S.1 (opposite page). Summary of impact intensities from the DEIS and the committee’s assessment of the analyses and conclusions reached in the DEIS for each resource category. Level of uncertainty for each resource category, as estimated by the committee, is indicated by a white dot (low uncertainty), gray dot (moderate uncertainty) or black dot (high uncertainty); the level of uncertainty applies to conclusions reached in the DEIS and by the committee. For additional details see Chapter 3.

Suggested Citation:"Summary." National Research Council. 2012. Scientific Review of the Draft Environmental Impact Statement: Drakes Bay Oyster Company Special Use Permit. Washington, DC: The National Academies Press. doi: 10.17226/13461.
×
image

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1 Since Drakes Estero does not contain the habitat required for leatherback turtles, this resource category is not included here.

2 Surplus refers to the net value of the commodity or service. For a producer, this value would be equivalent to profit (sales minus expenses). For a consumer, this represents the difference between the value of the item (e.g. what the consumer would be willing to pay) and the cost of the item.

Suggested Citation:"Summary." National Research Council. 2012. Scientific Review of the Draft Environmental Impact Statement: Drakes Bay Oyster Company Special Use Permit. Washington, DC: The National Academies Press. doi: 10.17226/13461.
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Suggested Citation:"Summary." National Research Council. 2012. Scientific Review of the Draft Environmental Impact Statement: Drakes Bay Oyster Company Special Use Permit. Washington, DC: The National Academies Press. doi: 10.17226/13461.
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Suggested Citation:"Summary." National Research Council. 2012. Scientific Review of the Draft Environmental Impact Statement: Drakes Bay Oyster Company Special Use Permit. Washington, DC: The National Academies Press. doi: 10.17226/13461.
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Suggested Citation:"Summary." National Research Council. 2012. Scientific Review of the Draft Environmental Impact Statement: Drakes Bay Oyster Company Special Use Permit. Washington, DC: The National Academies Press. doi: 10.17226/13461.
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Suggested Citation:"Summary." National Research Council. 2012. Scientific Review of the Draft Environmental Impact Statement: Drakes Bay Oyster Company Special Use Permit. Washington, DC: The National Academies Press. doi: 10.17226/13461.
×
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Suggested Citation:"Summary." National Research Council. 2012. Scientific Review of the Draft Environmental Impact Statement: Drakes Bay Oyster Company Special Use Permit. Washington, DC: The National Academies Press. doi: 10.17226/13461.
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Suggested Citation:"Summary." National Research Council. 2012. Scientific Review of the Draft Environmental Impact Statement: Drakes Bay Oyster Company Special Use Permit. Washington, DC: The National Academies Press. doi: 10.17226/13461.
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In May 2012, the National Park Service (NPS) asked the National Research Council to conduct a scientific review of a Draft Environmental Impact Statement (DEIS) to evaluate the effects of issuing a Special Use Permit for the commercial shellfish operation in Drakes Estero for a ten year time span. Drakes Bay Oyster Company (DBOC) currently operates the shellfish farm in Drakes Estero, part of Point Reyes National Seashore, under a reservation of use and occupancy that will expire on November 30, 2012 if a new Special Use Permit is not issued. Congress granted the Secretary of the Interior the discretionary authority to issue a new ten year Special Use Permit in 2009; hence, the Secretary now has the option to proceed with or delay the conversion of Drakes Estero to wilderness. To inform this decision, the NPS drafted an Environmental Impact Statement (EIS) for the DBOC Special Use Permit. Under the National Environmental policy Act (NEPA), as EIS is prepared to inform the public and agency decision-makers regarding the potential environmental impacts of a proposed federal action and reasonable alternatives. The Department of the Interior commissioned a peer review of the DEIS that was released in March 2012.

Scientific Review of the Draft Environmental Impact Statement: Drakes Bay Oyster Company Special Use Permit reviews the scientific information presented in the DEIS that is used to determine the potential environmental impacts of a ten year extension of DBOC operations. In particular, this report responds to the following tasks given to the committee: assess the scientific information, analysis, and conclusions presented in the DEIS for Drakes Bay Oyster Company Special Use Permit, and evaluate whether the peer review of the DEIS is fundamentally sound and materially sufficient. Scientific Review of the Draft Environmental Impact Statement: Drakes Bay Oyster Company Special Use Permit focuses on eight of twelve resource categories considered in the DEIS: wetlands, eelgrass, wildlife and wildlife habitat, special-status species, coastal flood zones, soundscapes, water quality, and socioeconomic resources.
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