Populations of Marine Life Have Declined by Half Since 1970

Many of the world’s marine species, including populations of fish crucial to human food security, are in potentially catastrophic decline, according to an updated study of marine mammals, birds, reptiles and fish by the World Wildlife Fund.

The findings of the “Living Blue Planet” report, published Wednesday, reveal a decline of 49 per cent in the size of marine populations between 1970 and 2012. Not only are the consequences disastrous for ecosystems, they spell trouble for all nations, especially those in the developing world whose people are heavily dependent on the ocean’s resources.

From the World Wildlife Fund website:

Many species essential to commercial and subsistence fishing – and therefore global food supply – are significantly depleted due to overfishing. Global population sizes of the Scombridae family of food fish that includes tunas, mackerels and bonitos have fallen by 74 per cent. Declining stocks of bluefin and yellowfin are of particular concern. Some species found in UK waters, including the vulnerable porbeagle shark and the critically endangered leatherback turtle, have also undergone precipitous declines.

While over-exploitation is identified as the major threat to ocean biodiversity, the study finds that climate change is causing the ocean to change more rapidly than at any other point in millions of years. Rising temperatures and increasing acidity levels caused by carbon dioxide are further weakening a system that is already severely degraded through overfishing, habitat degradation and pollution.

Dr Louise Heaps, Chief Advisor on Marine Policy at WWF-UK said:

“As well as being a source of extraordinary natural beauty and wonder, healthy seas are the bedrock of a functioning global economy. By over-exploiting fisheries, degrading coastal habitats and not addressing global warming, we are sowing the seeds of ecological and economic catastrophe.

“But there are clear steps that all governments can take to restore our oceans. Creating networks of well-managed Marine Protected Areas is a proven way to enable wildlife and habitats to recover. Pushing for a strong global deal on climate change would help the seas sustain life far into the future. Taking serious steps to implement this year’s Sustainable Development Goals in the UK and abroad could help build a global economy that values natural capital, respects natural habitats and rewards responsible business.

“Every one of us can take meaningful action, starting today, by ensuring that all the seafood we eat is responsibly sourced and Marine Stewardship Council accredited. And as ocean stakeholders, we can call for governments and the private sector to invest in the recovery of our ocean so that we can benefit in the long-term from what it has to offer.”

The analysis tracked 5,829 populations of 1,234 species, from sea birds to sharks to leatherback turtles, making the data sets almost twice as large as past studies.

The report also shows steep worldwide declines in the cover of coral reefs, mangroves and seagrasses that support fish species and provide valuable services to people. It is very possible that we could lose coral reefs from most areas by 2050 as a result of climate change. With over 25 per cent 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 these reefs would be catastrophic.

Read the rest of the report here.

–Posted by Roisin Davis