An ecosystem-based approach and management framework for the integrated evaluation of bivalve aquaculture impacts

An ecosystem-based approach to bivalve aquaculture management is a strategy for the integration of aquaculture within the wider ecosystem, including human aspects, in such a way that it promotes sustainable development, equity, and resilience of ecosystems. Given the linkage between social and ecological systems, marine regulators require an ecosystem-based decision framework that structures and integrates the relationships between these systems and facilitates communication of aquaculture-environment interactions and policy-related develop- ments and decisions. The Drivers-Pressures-State Change-Impact-Response (DPSIR) manage- ment framework incorporates the connectivity between human and ecological issues and would permit available performance indicators to be identified and organized in a manner that facilitates different regulatory needs. Suitable performance indicators and modeling approaches, which are used to assess DPSIR framework components, are reviewed with a focus on the key environmental issues associated with bivalve farming. Indicator selection criteria are provided to facilitate con- straining the number of indicators within the management framework. It is recommended that an ecosystem-based approach for bivalve aquaculture be based on a tiered indicator monitoring sys- tem that is structured on the principle that increased environmental risk requires increased mon- itoring effort. More than 1 threshold for each indicator would permit implementation of predeter- mined impact prevention and mitigation measures prior to reaching an unacceptable ecological state. We provide an example of a tiered monitoring program that would communicate knowledge to decision-makers on ecosystem State Change and Impact components of the DPSIR framework.