Abstract
International and regional policies aimed at managing ocean ecosystem health need quantitative and comprehensive indices to synthesize information from a variety of sources, consistently measure progress, and communicate with key constituencies and the public. Here we present the second annual global assessment of the Ocean Health Index, reporting current scores and annual changes since 2012, recalculated using updated methods and data based on the best available science, for 221 coastal countries and territories. The Index measures performance of ten societal goals for healthy oceans on a quantitative scale of increasing health from 0 to 100, and combines these scores into a single Index score, for each country and globally. The global Index score improved one point (from 67 to 68), while many country-level Index and goal scores had larger changes. Per-country Index scores ranged from 41–95 and, on average, improved by 0.06 points (range -8 to +12). Globally, average scores increased for individual goals by as much as 6.5 points (coastal economies) and decreased by as much as 1.2 points (natural products). Annual updates of the Index, even when not all input data have been updated, provide valuable information to scientists, policy makers, and resource managers because patterns and trends can emerge from the data that have been updated. Changes of even a few points indicate potential successes (when scores increase) that merit recognition, or concerns (when scores decrease) that may require mitigative action, with changes of more than 10–20 points representing large shifts that deserve greater attention. Goal scores showed remarkably little covariance across regions, indicating low redundancy in the Index, such that each goal delivers information about a different facet of ocean health. Together these scores provide a snapshot of global ocean health and suggest where countries have made progress and where a need for further improvement exists.
Highlights
International, national and local-scale policies increasingly call for actions to improve ocean ecosystem health (e.g., [1,2,3,4])
Similar objectives have been set in the United States with the recent National Ocean Policy, which strives to achieve healthy oceans [6]
We define a healthy ocean through the lens of coupled socio-ecological systems as ‘one that sustainably delivers a range of benefits to people and in the future’ [7]
Summary
International, national and local-scale policies increasingly call for actions to improve ocean ecosystem health (e.g., [1,2,3,4]). Similar objectives have been set in the United States with the recent National Ocean Policy, which strives to achieve healthy oceans [6]. In all of these cases, quantitative measures – or indicators – of ecosystem health are the only way to gauge whether ecosystem health is improving, and whether management objectives are being achieved. The Ocean Health Index addresses these needs by describing and measuring the health of ocean systems through ten widely shared goals or values pertaining to how people interact with and benefit from marine ecosystems (Table 1; [7]). An important consequence of tracking different factors together is that one can develop an understanding of potential trade-offs or synergies between components, making informed choices on how to improve health
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
