title: Patterns and emerging trends in global ocean health.
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.
authors.affiliation: National Center for Ecological Analysis and Synthesis, Santa Barbara, California, United States of America; Bren School of Environmental Science and Management, University of California Santa Barbara, Santa Barbara, California, United States of America; Imperial College London, Silwood Park Campus, Ascot, United Kingdom.
authors.forename: Benjamin S
authors.initials: BS
authors.lastname: Halpern
authors.affiliation: National Center for Ecological Analysis and Synthesis, Santa Barbara, California, United States of America.
authors.forename: Catherine
authors.initials: C
authors.lastname: Longo
authors.affiliation: National Center for Ecological Analysis and Synthesis, Santa Barbara, California, United States of America.
authors.forename: Julia S Stewart
authors.initials: JS
authors.lastname: Lowndes
authors.affiliation: National Center for Ecological Analysis and Synthesis, Santa Barbara, California, United States of America; Nicholas School of the Environment, Duke University, Durham, North Carolina, United States of America.
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Best
authors.affiliation: National Center for Ecological Analysis and Synthesis, Santa Barbara, California, United States of America.
authors.forename: Melanie
authors.initials: M
authors.lastname: Frazier
authors.affiliation: Betty and Gordon Moore Center for Science and Oceans, Conservation International, Arlington, Virginia, United States of America.
authors.forename: Steven K
authors.initials: SK
authors.lastname: Katona
authors.affiliation: Sea Around Us Project, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Kristin M
authors.initials: KM
authors.lastname: Kleisner
authors.affiliation: Union of Concerned Scientists, Cambridge, Massachusetts, United States of America.
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Rosenberg
authors.affiliation: National Center for Ecological Analysis and Synthesis, Santa Barbara, California, United States of America.
authors.forename: Courtney
authors.initials: C
authors.lastname: Scarborough
authors.affiliation: Betty and Gordon Moore Center for Science and Oceans, Conservation International, Arlington, Virginia, United States of America.
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Selig
mesh_terms: D003247:Conservation of Natural Resources; D055669:Ecological and Environmental Phenomena; D017753:Ecosystem; D005398:Fisheries; D038622:Internationality; D009792:Oceans and Seas