Ocean ecosystem health has become an important topic in global and local policies.
The European Union has set the overall objective of achieving ‘good environmental status’ for marine waters.
In the United States, the recent National Ocean Policy strives to achieve healthy oceans.
However, it is not easy to monitor the complex ocean ecosystem, which contains interactions among all living and nonliving things in oceans.
To solve the problem, scientists develop the Ocean Health Index (OHI). The index measures the health of ocean systems via widely shared values.
In a research recently published in PLoS ONE, scientists presented the 2nd annual global assessment of the OHI (2012 – 2013).
OHI has 10 goals, including sustainable food production, available fishing opportunities, conservation of species and habitats, clean ocean waters, conservation of places and species for their culture value, employment and revenues from marine sector, conservation of protective habitats, conservation of carbon storing habitats, sustainable harvested non-food products, and so on.
The Index measures performance of these goals on a quantitative scale from 0 to 100 and combines these scores into a single Index score, for each country and globally.
Researchers calculated OHI for 221 coastal countries and territories.
The results showed that top 10 scores were all obtained by island territories and nations (5 in the south hemisphere), such as Howland Island, Greenland, Macquarie Island, Malta, Jarvis Island, and Prince Edward Islands.
Many countries on both coasts of central Africa and several in the Caribbean had the lowest scores.
South Georgia and South Sandwich Islands showed the greatest year-to-year increase due to its highly productive waters, whereas Cook Islands had the largest decrease because its natural products were reduced.
In addition, many lowest scoring countries are poorer and have a recent history of war or civil strife.
Globally, OHI changed a little, with only one goal changing more than one point (natural products). Improved methodologies for fisheries the tourism led to higher scores in these goals.
Researchers suggest that OHI provides valuable information to scientists, policy makers, and resource managers.
They also conclude that changes of even a few points indicate potential successes (when scores increase) that merit recognition, or concerns (when scores decrease) that require actions. Moreover, large changes deserve greater attention.
Future work will keep tracking the OHI global results to help achieve sustainable ocean ecosystem.
Citation: Halpern BS, Longo C, Lowndes JSS, Best BD, Frazier M, Katona SK, et al. (2015). Patterns and Emerging Trends in Global Ocean Health. PLoS ONE, 10: e0117863. doi:10.1371/journal.pone.0117863
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