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Methodology

Health Assessment Methods and Process

This assessment is consistent with and supports Network partner agency master plan goals and management objectives. Though these partners have different missions and mandates, they are all responsible for and entrusted with management and stewardship of the natural resources under their care. Each Network partner agency has specific language in their mission(s) and plans that support an ecological health assessment, which is provided in Appendix C. A synopsis of key points follows. 

California State Parks: The departmental operations manual specifies that resource health will be monitored to detect trends in baseline data and provide documentation of natural resource change to guide resource management. 

Contra Costa Water District: Management plans lay out actions designed to protect and enhance, and, where appropriate, restore native habitats for native species, including practicing environmental stewardship by protecting natural resources and minimizing environmental impacts. 

East Bay Municipal Utility District: Program goals and master plans commit to the maintenance and enhancement of biological resource values on district lands through active management, Habitat Conservation Plan compliance, and careful coordination with other resource management programs. 

East Bay Regional Park District: The master plan and management goals specify that the district will coordinate with other agencies and organizations in a concerted effort to inventory, evaluate, and manage natural resources and to maintain and enhance the biodiversity of the region. 

San Francisco Public Utilities Commission: Through its policies and management plans, the San Francisco Public Utilities Commission articulates its commitment to proactively managing the watersheds in a manner that maintains the integrity of the natural resources, restores habitats for native species, and enhances ecosystem function. It also commits to actively monitoring the health of the terrestrial and aquatic habitats both under its ownership and affected by its operations in order to continually improve ecosystem health and refers to the use of relevant indicators for meeting these commitments. 

Defining Ecological Health

The goal of the NatureCheck project is to measure wildlife health by establishing a baseline condition and identifying metrics that can be used to track trends over time. To do this, we had to define what “healthy” is for these species, and for East Bay protected areas more broadly. 

There is no single way to define ecological health; it is a term that encompasses a variety of elements and may be used for many different purposes. Ecological health can be hard to pin down, given that constant change can be brought about by factors that are largely beyond our control, such as climate change, wildfire, and disease. Therefore, Network partners determined that a healthy system could best be defined in terms such as resiliency, diversity, and functioning natural processes rather than a specific set of conditions. We also did not want to tie health to a point in the distant past—say, before European contact—because we are not, and will never be, living in those same conditions again. Therefore, we intentionally chose to establish this ecological baseline based on existing conditions inclusive of modern anthropogenic stressors rather than using historical conditions, which can no longer be feasibly achieved. 

For the purposes of this project, we define health for the East Bay as follows: 

Process and Methodology

In 2018, staff biologists from the five Network partner agencies began meeting to discuss the possibility of conducting an ecological health assessment. They formed workgroups focused on vegetation, fishes, amphibians and reptiles, birds, and mammals. These groups considered numerous potential indicator species and communities, including those that are iconic and charismatic, have special conservation status, or reflect the different habitat types or ecosystem processes found across the entire area of focus. (Appendix D in the 2022 NatureCheck report provides a table of all health indicators that were considered). 

Next, the workgroups began to gather existing data for this initial list. Species that did not have sufficient existing data (e.g., from across the study area, through time, or that could be pooled amongst partners) were removed from consideration unless they were keystone species and/or representative of a key part of the ecology that could not be captured in another way. For example, there are very little data on mammals, but staff felt it was important to include some analysis of them in this report. We conducted additional field work in 2019 to establish sentinel sites for California ground squirrels, start solstice exit surveys for roosting bats, and set up camera stations to support capturing wildlife usage in our land units. These studies provided an early data-collection framework for future analysis. 

By 2019, Network partners had settled on indicator species and communities that represented and reflected the health of East Bay ecosystems as we had defined it and for which we had existing information/data. Where we lacked sufficient data or were unable to complete quantitative metrics, we identified “data gaps” for future research or monitoring. 

Engaging Outside Expertise

With an initial list of ecological health indicators selected, workgroup leads prepared draft worksheets based on available data, reports, and project information (e.g., internal datasets, published papers, and white papers). These worksheets, which were the basis for preliminary drafts of the chapters in this report, included a rationale for choosing the species or community, a description of the resource and its significance, key ecological stressors, presumed current and desired conditions, proposed goals and metrics by which to measure condition and trend, existing information sources (e.g., research data, monitoring, restoration projects, etc.), and known information gaps. 

These worksheets were used to acquire additional information and perspectives during East Bay ecological health assessment expert workshops January 29–30, 2020, which brought together more than 70 resource managers, academic researchers, and other specialists representing 30 organizations. These experts recommended that some indicators be removed and others added, and provided valuable input, including identifying additional data sources and making suggestions for improved analyses. 

Data Management and Analysis

With the revised worksheets in hand, workgroup leads continued to pool and analyze data, revise indicators, and update the assessment. Though each indicator followed the same chapter template (outlined in a following section), individual leads took different approaches to geographic scope, data analysis, and other aspects of their methodology. Rather than summarizing those here, the approach each lead took is described on each indicator page. 

Data Gaps

Almost as important as bringing together what we know to create an ecological health baseline, this process also gave us a clear view of what we do not know. This includes a lack of data for entire communities or taxa that are ideal ecological health indicators as well as understudied aspects of specific species’ ecology. 

We are continuously evaluating ways to fill data gaps and to increase our confidence in the data we do have, such as providing greater coverage through more sampling across the area of focus. Some include data gaps important for resource management, such as pond hydroperiod data to help prioritize where restoration efforts should be focused. Identifying these data gaps is an important first step in focusing on how Network partners can continue to gather data to improve our confidence in subsequent analyses and to better detect trends. Another major missing component of ecological health is an assessment of invertebrates, the taxa that constitutes the majority of Earth’s biodiversity and provides the pollination necessary to maintain the global food chain. A recent review of scientific papers on the topic of insect population declines (Sanchez-Bayo and Wyckhuys 2019) reported a worldwide decrease of 2.5% per year. We intend to include an assessment of indicator invertebrate species in NatureCheck in the future. 

Looking Ahead

Assessing ecological health is an iterative and ongoing process that we intend to revisit on a regular basis (such as every five years) as we acquire more information and undertake resource-based projects, and as our understanding changes and grows over time.  

The NatureCheck project has allowed us to leverage multiple datasets to improve our understanding by: 

We plan to use what we have already learned to direct our land management, restoration, and stewardship efforts to where they are most needed and we can be most effective. Going forward, we expect more of these types of benefits to accrue. In addition to establishing actionable science, NatureCheck will help inform the public and increase understanding of these incredible resources. As NatureCheck trends are developed, we hope to be able to show how much ecological health has changed and what is most at risk. This information can help garner the support of the public and decision-makers for advancing projects that benefit ecosystem health.