Living Resources Resource Document for the CESR Report

A challenge for most large-scale ecosystem restoration efforts is to quantify the
effects of multiple management actions on living resources. While there has been effort and analyses in the Chesapeake Bay to quantify the response of water quality and habitat to management actions related to the restoration of the Chesapeake Bay, analyses designed to quantify the responses of living resources are limited. This is partly due to the lack of requirement for such analyses. There is also the inherent challenge for such analyses to be able to detect responses and attribute them to specific management actions. There are many links between water quality and habitat. These challenges are not unique to the Chesapeake Bay, but rather are common to many ecosystems, especially when the response variable is mobile higher trophic level organisms, such as fish. In the situation of the well-studied and modeled Chesapeake Bay, the pieces exist to do analyses that relate water quality and habitat to fish and other organisms at biological scales relevant to management. The challenge is to put these pieces together so that a cohesive set of analyses can be done that allows for analyses to be tailored for specific situations, while also ensuring enough consistency to “roll-up” the results across analyses. There are many links between water quality and living resources imbedded in the water quality criteria and other goals of the 2014 Chesapeake Bay Watershed Agreement (CBWA). The water quality criteria used with the total maximum daily load (TMDL) were originally defined to support the Bay’s aquatic living resources and designated uses. There are also examples of qualitative, numerical, and implied (e.g., sustainable population) living resource targets for each major component in the CBWA. With the upcoming 2025 assessment, there is an opportunity for a programmatic-level determination on how to assess living resource responses. In support of a broader STAC (Science and Technical Advisory Committee) activity looking at the responsiveness of the watershed and estuarine environments to the TMDL and other management actions, we present an initial framework for how to perform statistical and ecological modeling analyses to examine the in-situ responses of living resources. The proposed framework, if implemented, will enable a coordinated effort that uses existing and new analyses to provide a broad view of how Chesapeake Bay’s living resources are responding to the broad set of restoration actions related to the goals of the CBWA. We propose a series of management questions and then outline four possible pathways for analyses that range from continuing the status-quo, to a comprehensive analysis that examines population and food-web level responses to restoration actions at system-wide scales. The ability to answer the management questions, and the degree of confidence in the answers, progresses going from the status-quo to a comprehensive pathway. The questions and challenges relating living resource responses to restoration are not unique to the Chesapeake Bay, but rather are common to many other large-scale restoration programs. The proposed framework would use the results of the water quality and habitat analyses to inform what types, timing, and magnitude of changes in water quality and habitat are expected from the TMDLs. Our proposed framework uses 12 ecological concepts and principles as the foundation, and then includes the steps involved in developing a strategic plan for statistical and modeling analyses. The framework is intended to aid in the decision-making about how to assess living resources’ responses and provides guidance in developing an analytic plan. If it is determined that analyses should proceed beyond the status-quo approach and the framework is implemented, resulting analyses will then attempt to translate these changes (observed and expected) to higher-order level responses of living resources (e.g., recruitment, population, sub-populations in subregions). Our proposed analyses would also provide information on realistic expectations for species responses to changes in water quality and habitat when species are long-lived, have complex life cycles, and are affected by multiple non-TMDL factors. The framework we describe has a series of linked modules: foundational concepts, available data and tools, logical workflow, illustrative examples, likely results and their interpretation, and suggestions for implementation. A strategic analysis based on the framework would provide a quantitative assessment of restoration progress based on in-situ responses and can also be used to provide feedback on the restoration goals, help design sensitive indicators, and inform adaptive management.