Sunday, November 21 marks World Fisheries Day, an annual occasion observed in many fishing communities around the world. It’s a great opportunity—even for those of us who do not fish for a living—to pause and reflect on the importance of maintaining healthy fisheries.

As a scientist, my research on tropical marine fishes has taken me around the world, including locations where I have seen firsthand the impacts that humans are having on marine resources.

In 2001, for example, I was part of a Smithsonian expedition to El Salvador studying the coastal fish fauna. We had a chance to work one day aboard a commercial shrimp trawler to sample the fishes that are collected along with shrimp in the trawl nets. Every four hours, two nets were brought on board, their contents dumped onto the deck, and the shrimp picked out. I’m not exaggerating when I say that less than 10 percent of the catch was shrimp. After the shrimp were sorted out, the rest of it—called bycatch—was shoveled overboard several hours later, almost all of it dead.

In Japan, I visited the Tsukiji Fish Market in Tokyo. Imagine a seafood market that extends block after city block after city block and comprises nearly 1,000 individual licensed seafood dealers. It handles some 2,000 metric tons of seafood per day, and it’s open for business nearly every day. After seeing its sheer magnitude, it’s easy to walk away wondering how there can be anything left in the sea.

I’ve been to the Galápagos Islands off the coast of Ecuador many times. Although the Archipelago and surrounding waters are supposed to be protected as a marine reserve, I’ve witnessed many examples of illegal fishing activities by large, industrial-size, foreign fishing vessels. Even shark finning—a particularly gruesome practice in which sharks are captured, the fins sliced off, and the finless shark returned to the water to die—has been a problem within the reserve. Most of the fins are sold for shark fin soup, a lucrative delicacy in some Asian countries.

You might be thinking that these are isolated incidents or problems typical in other parts of the world. But the truth is that no country is exempt: the decline in fishery resources is a global issue. In fact, a recent United Nations study estimated that three quarters of the world’s fish stocks are overfished. Factors such as the loss of essential habitats, pollution, and climate change combine to make the situation worse. Does this mean there’s nothing you can do? No. While planning, implementing, and enforcing fisheries management plans are the purview of international, national, and local regulatory bodies, everybody who purchases seafood can make a difference. Educate yourself on the issues surrounding the seafood you consume. Download a sustainable seafood Seafood Watch pocket guide. Know what you are buying, where it is from, and how it was caught (or was it farmed?). Can’t tell from seafood labels or menus? Question seafood retailers and restaurant staff. Let them know you want information. Be heard.

Now here’s the fun part. There are good, environmentally sound seafood choices regardless of where you live. Find out what they are. Try things you’ve never tasted before. Diversify. Cook new recipes with good seafood choices. Be adventurous. Make sustainable seafood the theme of dinner parties—and toast your contribution to a healthy ocean.

Editor’s Note: Dr. Carole Baldwin is a Curator of Fishes at Smithsonian’s National Museum of Natural History and co-author of One Fish, Two Fish, Crawfish, Bluefish: The Smithsonian Sustainable Seafood Cookbook. Take a photo tour of world fisheries, including some of the issues that Dr. Baldwin addresses, in our photo slideshow World Fisheries from Sea to Table.