A major report by the World Wildlife Foundation has found that the world’s oceans are in peril, with some marine populations declining by almost half in the last 40 years. The scale of the loss is unprecedented and further decline could prove catastrophic for the human population. But what can be done?

What’s Causing The Decline?

The world’s ocean life provides important ecosystem services such as the provision of food, medicines, and livelihood. For thousands of years, mankind has turned to the seas for life-giving sustenance. Yet, in recent centuries, technology has allowed us to take more than ever before–and that’s not exactly a good thing.

Enormous commercial fleets, sophisticated computer equipment, and even government subsidies have led to too many boats on the water and too much marine life being caught. On top of that, poor fishery management, bycatch of juvenile fish, and pirate fishers (boats that don’t follow the rules) only exacerbate the problem.

In the U.S., for example, roughly 17% of major fish stocks are not being fished sustainably–despite having strong fishery laws. Worldwide, more than a pound of marine animals are being caught for every four pounds of fish. Many are killed in the nets or are later tossed overboard to die. And shrimping is even worse: four or more pounds of unwanted animals are caught for every one pound of shrimp.

And while exploitation of natural resources is the major threat to marine life, climate change is changing the oceans faster than ever before. Even with their vast ability to absorb heat and carbon dioxide, the oceans were 0.17 Celsius warmer in 2017 than in 2000–and while that number may seem negligible, it’s actually taken a huge toll. From coral bleaching, to fish migration, to acidification, the ocean is reaching the limits of what it can actually handle.

Which Species Are In Danger?

All of the world’s ocean life is at risk, but marine creatures of the Pacific Ocean are in greater peril than the rest. This is because there are fewer regulations in Asia, and they are fishing more waters. Of particular concern is the Chinese practice of “shark-finning”, or removing just the fins from the shark and throwing the body back in the water.

In addition, global populations of the Scombridae family of food fish (tunas, mackerels, and bonitos) have fallen by an astounding 74%, while other creatures such as the Hawksbill Turtle and Hawaiin Monk Seal are critically endangered.

It’s not just the fish and animals that are in trouble. Their habitats are, too. Some, such as mangroves and seagrasses, have seen a significant decline. It is also estimated that 75% of the remaining coral reefs in the world are currently in danger–and while they are technically an animal, they also serve as a home for many other creatures.