The ocean is a wild, wonderful and mysterious place, and 80% of our ocean remains unmapped, unobserved and unexplored. Unfortunately, just because an area is unexplored does not mean humans haven’t had an impact. A new report from expert scientists about the diversity of life on our planet found that only 3% of the ocean is totally free from human pressures, and a staggering 40% of the ocean has been significantly impacted by humans. These human impacts on our ocean come at the cost of putting marine life at risk of extinction.

In the report, scientists estimate that one million plant and animal species are at risk of extinction around the world—many of which could go extinct within a few decades. And many of the species at risk live in our ocean. This includes about a third of the corals that form coral reefs, a third of sharks and rays and more than a third of marine mammals. According to the report, marine life is threatened primarily by unsustainable fishing and other types of exploitation, as well as changes in land and sea use, including coastal development. New threats, such as climate change and the growing problem of plastic pollution, are also having significant and negative effects on our ocean.

If you love our ocean and the diversity of life found underwater, these facts are heart-wrenching on their own. But the loss of biodiversity in our ocean also matters for people and our wellbeing. Species—and the ecosystems they’re a part of—are important for our livelihoods, economy and culture. Biodiversity can be thought of as a safety net for humanity, providing us with food, clean air and water, energy and materials. Coral reefs and mangroves protect communities from flooding and storms. Marine life supports tourism and jobs in much of the world. And our ocean has absorbed much of the carbon dioxide we’ve released by burning fossil fuels.

Even in such a gloomy report, there are signs of hope. The evidence suggests things would be worse if not for the conservation actions we’ve already taken. We’ve brought species back from the brink of extinction through investment in conservation. These positive examples are relatively few and far between, yet they show the power of taking appropriate action. In our ocean, unsustainable fishing was cited as a major threat to biodiversity, which means that good management of fisheries is one area where conservation efforts can make a real difference. Around the world, we’ve seen that getting sustainable management in place—and doing so in partnership with local communities—has the ability to recover fish populations that have been fished too heavily. This and other efforts show that one key to success is having local, national and global governments that make and enforce policies that better reflect the contributions nature makes to people.

Our second sign of hope is that scientists say that it is possible to save many of these million threatened species. It will take transformative change. For our marine species, it means stepping up to be a voice for our ocean, reducing ocean trash, curbing climate change and ocean acidification, pushing for sustainable fishing that takes the whole ecosystem into account, and reducing runoff and pollution into ocean waters. If we do nothing, the loss of biodiversity will only accelerate through 2050.

What you can do:

• Take interest and pride in your local biodiversity. Learn about the species that help to make your local area unique, and join efforts to monitor and protect these species.
• Take actions to reduce your carbon footprint. Carbon dioxide and other greenhouse gas emissions are causing climate change, which is making the biodiversity crisis worse.
• Reduce your consumption and waste—particularly single-use plastic, such as straws and grocery bags. Plastic pollution has increased tenfold in our ocean since 1980 and is especially harmful to sea turtles, seabirds and marine mammals.
• Join a beach cleanup, such as the International Coastal Cleanup.
• Eat sustainably caught seafood. Seafood Watch is a great place to start to find recommendations.

Want to learn more? Check out a summary of the report here.