In 2010, humans dumped more than 8 million tons of plastic into the ocean. To put that in perspective: that’s five grocery bags of trash for every foot of coastline around the globe. A study released earlier this year predicts that that number is supposed to increase tenfold in the coming years, just adding to the garbage patches floating, which now totals up to 245,000 tons.

But it’s not just pollution that’s ruining the sea. Biodiversity is threatened as coral reefs are dying and oceans acidify. According to the United Nations, by 2100, without major changes, more than half of marine species will be at risk of extinction. On top of that, sea levels are rising because of global warming — they have been rising 0.04 to 0.1 inches per year since 1900, according to the National Oceanic and Atmospheric and Atmospheric Administration, and that rate is becoming even faster.

Technology has already started to play big roles in the environmental movement, the conservation movement, and the food movement. We’ve always known tags and satellites and underwater robots have been used to study the ocean — but what about saving it?

Let’s take a look at four technologies that can help us clean and protect the sea and all the life in it.

1. The Ocean Cleanup

Cleaning the oceans in this lifetime seems impossible. Even with nets, collecting the immense amount of plastic floating in the water would take billions of dollars and thousands of years. One 20-year-old was fed up with the trash, so he started The Ocean Cleanup, which uses long floating barriers that work with ocean currents to passively collect the trash. Because most of the current flows underneath, and the plastic floats at the top, this technology prevents the bycatch of unwanted fish and other marine species. And, the platforms anchored to the seabed that are connected to the floating barriers are designed for large-scale deployments, cover millions of square miles without moving. The pilot deployment in coastal waters will start this year or in 2016, and the barrier will be 2000 meters long.

2. Sea robots

For years, scientists have been using robot-like machines to explore the depths of the ocean, where humans cannot go. Now, they can control robots above the water, and send robots with lights, sensors, and tools to bring back samples, take photos, and explore the seabed and the creatures that live that deep. Another, newer example is the Wave Glider SV3, an autonomous, solar-powered robot made by startup Liquid Robotics. The SV3 is the updated version of the original SV2, which uses the ocean’s endless supply of energy as propulsion to collect data during missions that can last up to a year. Both have Wi-Fi capabilities onboard, as well as large amounts of data storage. The SV3 can explore more than 90% of the world’s oceans, where even robots couldn’t go before.

3. Smarter nets

Every year, millions of dead fish are thrown back into the ocean. They were too young and small, or caught unsafely and end up dying because they’re so stress out from being caught. It’s an unsustainable and wasteful practice when much of the world’s population depends on fish to eat. But there are finally solutions being made. One type of technology came out of a partnership between scientists and fishing companies in New Zealand. Precision Seafood Harvesting uses high-tech trawl nets to identify and catch specific fish species instead of using traditional sprawling nets that catch everything in their path. It keeps more fish alive, healthy, and sustainable because they swim in a flexible PVC even when they are on deck, so they are less stressed and less likely to be injured. Safety Net Technologies created another trawl aimed at making sure other marine species don’t get caught in fishing nets. It can be retrofitted on existing fishing equipment, uses less fuel, and causes less damage to sea beds, and has special escape rings that allow fish to get out.

4. High-tech tagging

Research in animal tagging has exploded in the last couple of decades, and a recent report in the journal Science showed just how important that growth has been for marine life. Electronic tags are tiny and may weigh less than a penny now. They transmit data about movements, migration patterns, and interactions between wildlife to satellites and receiver stations for more than 10 years, and they can be attached to almost any type of creature, no matter how small. These high-tech tags are becoming especially important for bluefin tuna, which are relentlessly overfished thanks to sushi lovers around the globe.

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