How Can We Catch Tuna and Protect Sharks?

Credit: Joi Ito, Creative Commons

Mike Sweeney, Managing Director of Global Fisheries, The Nature Conservancy
Steven Victor, Director of Micronesia Program, The Nature Conservancy

Shark fin soup has become a symbol of mistreatment of marine life. Sharks caught for their fins are tossed back into the sea. Unable to swim, they starve to death, are eaten or drown. People pay a lot of attention to fishing practices like this, and it has become illegal in many countries. But legal tuna fishing in the Pacific Ocean is destructive to sharks as well. This is an industry essential for the livelihoods of people across the region. Tuna fishing doesn’t need to be shut down, but it can be more sustainable. The question becomes: How can we catch tuna and protect sharks?

In the island nation of Palau, part of the region that controls the largest and most productive remaining tuna fisheries in the world, the government took shark fin bans to another level and created the world’s first shark sanctuary years ago. More recently, Palau created a groundbreaking national marine sanctuary that will turn 80 percent of its roughly 230,000 square mile exclusive economic zone into a no-take protected area. Palau’s 20,000 people rely on this zone, which is about the size of France. A recent New York Times Magazine article trumpeted the importance of Palau’s efforts to combat illegal fishing. This is a big step, but it’s not enough. Poachers aren’t the only problem – legal fishing practices are harmful too. Fishermen need to find a better way to fish for their own livelihoods and for the ocean’s health.

Hooking sharks, turtles and rays

Each year, Western and Central Pacific tuna fisheries produce tuna valued at more than $7 billion, yet current fishing practices, particularly in the longline sector, are hugely inefficient. One third of everything longline tuna fishermen in Palau catch is sharks, turtles and rays. Imagine the scale of the problem – there are 5 million hooks set on 100,000 miles of fishing line every day in our oceans. That’s enough fishing line to circle the earth four times. Yet, a huge portion of what they bring in is unintentional bycatch. What other industry would accept a 30 percent error rate?  And these aren’t just errors like defective machining, these errors decimate our oceans.  This is an industry ripe for innovation. With more effective methods, fishermen could catch tuna more sustainably and with a lot less waste. Solving this problem is vital for ocean health and would be a boon to Palau’s tourism industry, which is grounded in majestic marine life. A dead shark is worth about $100, while a live shark in Palau could be worth up to $1.9 million in tourism because sharks buoy Palau’s snorkeling and diving, considered to be the best in the world.  Removing so many sharks poses risks to the ecosystem as a whole. These species are the top of the marine food chain, and losing too many of them can throw the environment out of whack.

The reason for change is clear, but the science on how to do it is missing. The Nature Conservancy recently purchased a year’s worth of fishing rights in Palau to test new fishing methods, such as dropping lines deeper, fishing in the daytime instead of at night, using different sized hooks and different bait less likely to hook bycatch, including turtles and sharks. Scientists will tag accidentally caught blue and silky sharks, which make up the majority of bycatch, to better understand if they survive after release. This science will combine with efforts by the people of Palau to build high-performing tuna fisheries characterized by fleet accountability, sustainable levels of tuna harvest and low bycatch of at-risk species like sharks and turtles. It’s not realistic to shut down the planet’s fisheries. Protected areas coupled with strong, science-based fisheries management yields the best outcomes for people and for nature.

Solutions for seafood

Seafood is the only protein source on earth where a healthy ecosystem generates more food and more profit. Already 3 billion people on earth rely on seafood for some of their food, and for 1 billion it is their primary source of protein. While it’s easy to blame poachers for problems at sea and focus on protecting the ocean from fishing, solutions will only work if they are economically viable and environmentally sustainable. Fishing is a crucial source of income for communities all around the world and a critical food source. There must be a better way, and we’re going to find it.

Changing Planet


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Protect. Transform. Inspire. The Nature Conservancy is uniquely positioned to be a leader in taking on the most complex challenges facing the planet. Our place-based projects in over 40 countries serve as living laboratories where new ideas to protect nature are tested, perfected and adapted for other places. We engage businesses, governments and communities in delivering these on-the-ground results – demonstrating how conservation innovations can transform how our food, water and energy are produced. And by empowering more leaders and communities all over the world with solutions that work, we will inspire action at the scale of the challenge.