A new WWF report reveals an alarming decline in marine biodiversity over the last few decades. According to WWF's Living Blue Planet Report, populations of marine vertebrates have declined by 49% between 1970 and 2012, with some fish species declining by almost 75%.

In addition to fish, the report shows steep declines in coral reefs, mangroves and seagrasses that support marine food webs and provide valuable services to people. With over 25% of all marine species living in coral reefs and about 850 million people directly benefiting from their economic, social and cultural services, the loss of coral reefs would be a catastrophic extinction with dramatic consequences on communities.

According to the report, the biggest drivers of these declining trends are from human actions -- mainly overfishing, habitat destruction, and climate change. Although the report paints a dim picture of ocean health, it also provides solutions and opportunities to turn the tide. It highlights the need to protect critical marine habitats, manage fish stocks more sustainably, improve fishing practices, and redirect financial flows to support these needed initiatives.

"The good news is there are abundant opportunities to reverse these trends," said Brad Ack, senior vice president for oceans at WWF. "Stopping black market fishing, protecting coral reefs, mangroves and other critical ocean habitats, and striking a deal in Paris to slash carbon pollution are all good for the ocean, the economy, and people. Now is the time for the US and other world players to lead on these important opportunities."

One immediate opportunity for international action happens later this month when world leaders meet in New York to discuss the UN's Sustainable Development Goals. At the meeting, it's essential that political leaders support the goals with significant investment and meaningful implementation plans to address the habitat destruction, illegal fishing, overharvest, and marine pollution driving the degradation of our oceans.

"The ocean is a renewable resource that can provide for all future generations if the pressures are dealt with effectively," said Marco Lambertini, Director General of WWF International. "If we live within sustainable limits, the ocean will contribute to food security, livelihoods, economies and our natural systems."

Report is available for download at https://www.worldwildlife.org/publications/living-blue-planet-report-2015.