6 April 2018: Scientists have proposed a method to measure the health of the world’s oceans using biological, biogeochemical and physical “essential ocean variables” (EOVs). The data will support policies that prepare for, manage, adapt to and mitigate the effects of global ocean change and support the overall well-being of economies and societies.

In a ‘Global Change Biology’ paper titled, ‘Essential ocean variables for global sustained observations of biodiversity and ecosystem changes,’ scientists propose the coordination and integration of regular, long-term observations of EOVs. The authors recommend EOVs based on benthic invertebrate abundance and distribution, and microbe diversity and biomass. The scientists selected these EOVs from an analysis of potential EOVs on the extent and health of ecosystems, including on the cover and composition of hard coral, macroalgal canopy, mangrove and seagrass, and the status of ecosystem components, such as the abundance and distribution of birds, fish, mammals and marine turtles, and phytoplankton and zooplankton biomass and diversity.

The authors argue that EOVs can initiate understanding of and help address global ocean change. For instance, they cite an example of how coral reef monitoring in the 1970s and 1980s detected a decrease in coral cover and warming ocean temperatures. These findings then galvanized a global movement to establish international policies for coral reef conservation and management, including the Convention on Biological Diversity’s (CBD) Aichi Target 10 on minimizing reef loss and establishment of large-scale and long-term monitoring programs. Similarly, the authors argue that identifying and monitoring biological EOVs as part of a sustained Global Ocean Observing System (GOOS) can provide key information on global changes in marine ecosystems and resources in response to internationally agreed needs, including data needed to monitor progress towards the SDGs, Aichi Targets and the UN Framework Convention on Climate Change (UNFCCC).

EOVS can help scientists and policymakers communicate on the “combination of measurements that are of greatest importance to society.”

According to the Intergovernmental Oceanographic Commission (IOC) of the UN Educational, Scientific and Cultural Organization (UNESCO), EOVS can help scientists and policymakers communicate on the “combination of measurements that are of greatest importance to society” while still being feasible to measure.

The report’s lead author, Patricia Miloslavich, of the University of Tasmania in Australia and the Universidad Simón Bolívar in Venezuela, said “robust, sustained, and coordinated observations focused on specific measurements to assess changes in marine ecosystems” are critical to meet the data collection needs of the SDGs and other agreements and platforms on biodiversity, climate change, and ecosystem services. [IOC-UNESCO Press Release] [Publication: Essential Ocean Variables for Global Sustained Observations of Biodiversity and Ecosystem Changes]