Ahyayha One Oyster at at Time Phosphorus Reduction Certificate Standards

Ahyayha One Oyster at a Time Phosphorus Reduction Standards

May, 2013


1. The Project as described in the Certificate is (was) implemented.

Public Policy Virginia dba The Center for Natural Capital, a 501 c-3 entity managing the Ahyayha Project, assures that the project described on the Ahyayha website has or will be completed.

2. Each certificate is unique.

Each certificate provided to a project Supporter is unique and cannot be duplicated to ensure against double counting.  Each certificate has a tracking number kept in a private registry.

3. Peer reviewed science was used to estimate sequestration.

Scientific literature was reviewed to find the most relevant information to estimate nitrogen sequestration likely to occur as a result of the project. Methodology used to calculate sequestration is described in Appendix I.

4. The project is inspected (verified).

Ahyayha staff will travel to the project to verify completion and ongoing continuation of project functionality within the stated project timeframe. This information will be posted to the Ahyayha project website.

5. Certificate Warranty

Except for the express standards set forth above, Public Policy Virginia dba The Center for Natural Capital makes no other warranties relating to the certificates express or implied as to any matter whatsoever, including without limitation the condition of the Certificates.

Appendix I

Metrics used to create certificates are based on the following papers -

  • Newell, Roger I.E.  2004.  Ecosystem influences on natural and cultivated populations of suspension-feeding bivalve molluscs: a review.  Journal of Shellfish Research, 23(1):51-61.

Based upon this information, it was estimated that a harvestable oyster removes .16 grams of phosphorus from the river. It is assumed that the oyster meat and shell are not returned to the river and therefore this is a permanent reduction. 500 oysters are harvested per cage and each cage lasts 10 harvest cycles. At a cost of $100 per cage, the nitrogen reduction cost per lb. is $56.82.


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