The two panels initially charged with identifying ocean metrics (physical/chemical and biological) worked together to develop a single table covering physical, chemical, and biological processes. This integration recognizes that the fluid dynamics of the ocean underlie its chemistry and biology and that the three cannot be considered in isolation.

The panels focused on climate metrics that are highly integrated with the impacts of climate change (Table 3-1). For example, the panels proposed a metric for the health of fisheries, which depends in part on the primary productivity of the ocean. In contrast, the GCOS equivalent focuses on ocean productivity as a fundamental indicator.

The panels gave higher priority to metrics that either integrate human impacts (e.g., fisheries) or could have significant impacts on the ecosystem services that provide value to society (e.g., the impacts of harmful algal blooms). Therefore, the ocean metrics are strongly weighted toward the human dimension of ocean processes, not simply the fundamental processes of climate change. The panels then further refined the metrics toward those for which there is significant potential for risk and vulnerability. For example, the panels considered the impacts of climate change (i.e., rising sea level) on the infrastructures of ports and harbors, which are crucial to global trade, but not on coastal recreation.

Many of the proposed indicators focus on emerging issues, as well as on new management and development strategies. In other words, they do not simply recapitulate ongoing indicators. For example, new approaches to management, such as of marine protected areas, should be studied now in order to assess their effectiveness as well as their impacts on ocean ecosystems.

Finally, the ocean panels recognized that many of their metrics are “process based” rather than “place based.” For example, because the location and intensity of fisheries shift over time, we cannot define a set of key places to monitor. Rather, we must ensure that there is ongoing feedback between the systems being observed and the systems observing them. Thus, the ocean indicators are often iterative in nature and should be refined as knowledge improves.

The panels relied on the six criteria to prioritize the metrics. It became clear that metrics could be distinguished based on the strength of their connection to climate processes and to environmental sustainability. As a result, the panels identified three priority levels: (1) high climate, high environmental sustainability; (2) low climate, high environmental sustainability; and (3) low climate, moderate environmental sustainability. The panels chose to not include metrics that have high climate, low environmental sustainability because the special emphasis of the report is on the environmental sustainability connection. As noted earlier, many other reports have addressed traditional climate change indicators.

Two examples will highlight this process. Sea level rise has a direct link to the climate system, and it is significant, dominant, measurable, historical, and well documented. Therefore, it was placed in the high climate, high environmental sustainability category. In comparison, fisheries health is significant, measurable (with varying quality), historical, and well documented, but climate change is not the only (or

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