Global ocean vital signs are stable, but bill of health isn't clean

The health record of world's oceans is here and according to it, their vital signs have remained relatively stable over the past five years.

A study by the researchers from the National Center for Ecological Analysis and Synthesis (NCEAS) at UC Santa Barbara and Conservation International synthesized five years' worth of vital signs on a host of indicators, ranging from water quality to food provision to tourism potential, and found that while overall ocean health appears to be stable, the oceans around many of the 220 countries analyzed are changing, and in many cases not for the better.

"With five years of assessments about where oceans are healthy and not as healthy, we finally have enough information to get a clear signal of what might be causing changes," said lead author Ben Halpern.

According to Halpern, countries that are seeing notable improvement in their oceans are taking concrete actions to make things better, like creating marine protected areas and improving their management of wild-caught fisheries. Indonesia, Mexico and Samoa are examples of such countries.

Among the countries that saw a decline in ocean health were those with consistent political instability, as well many Arctic and sub-Arctic countries, where coastlines are losing natural protection from storm damage and erosion, sea ice, which is rapidly melting.

A collaborative effort between Conservation International and NCEAS, the Ocean Health Index is like the Fitbit for oceans. It allows scientists to assess ocean health by measuring environmental, economic and social factors that reflect how people benefit from and affect oceans, and is designed to guide ocean policy and management.

"Imagine going to your doctor, and she tells you your resting pulse is 75 and your temperature is 99.1. Those single data points are barely useful," explained Halpern. "But now imagine you've done regular annual exams, and you've been keeping track of your diet and exercise regime. Your doctor shows you most of your stats are stable and last year, when you were exercising regularly and eating healthy, your blood pressure and cholesterol went down. That's profoundly more insightful information."

A regular, comprehensive diagnostic exam for the world's oceans provides decision makers with information and knowledge they can use to implement effective actions for improved sustainable ocean management, he added.

The results are published in the journal PLOS ONE.