Shutterstock/Siraphatson Chanthanan

Scuba divers know that the ocean we love is in serious trouble, and it can be hard to feel like nothing we do can make a difference. As a conservation scientist, I spend my time studying the ocean’s biggest threats and the most effective solutions to those threats, finding evidence-based solutions that we know will work.

The Ocean's Number One Threat

When people ask me, “What’s the biggest threat to the ocean?” my answer is clear. The number one threat to marine biodiversity is not oil spills, not plastic pollution and not climate change—those are all big problems, but another problem impacts more species and more habitats. The number one threat to marine biodiversity, by far, is unsustainable fishing practices.

“A lot of wild-caught seafood comes from the ocean. These are wild populations, and we need to take care in how we catch these animals,” says Jennifer Dianto Kemmerly, the vice president of global ocean conservation at the Monterey Bay Aquarium.

“Some fishing methods catch too much, some take fish indiscriminately out of the ocean and could be mistakenly taking other species, and some of the fishing gear can damage the seafloor.”

Does Sustainable Seafood Exist?

And when people ask me what’s the number one thing someone can do to help save the ocean, my answer is just as clear: Don’t support unsustainable fishing practices. Notice that I didn’t say we all have to give up seafood and be vegan—sustainable seafood exists! And that’s where this month’s highlighted organization, Monterey Bay Aquarium’s Seafood Watch, comes in.

“We assess the environmental impacts of how fisheries and aquaculture are being managed and make recommendations, getting the information out there so people can make their own choices,” Kemmerly says.

Related Reading: The Sea Hero's New Seawall

How Seafood Watch Works

Here’s how it works. Seafood Watch operates a sustainable seafood standard by which all fisheries and seafood products can be judged. Then, its team of experts assesses commonly available seafood options against this standard, resulting in an easy-to-use, color-coded guide.

“Green we think is a best choice for environmental sustainability, yellow is a good alternative if you can’t find something green in your area, and red we recommend for consumers to avoid because there are really concerning environmental issues,” Kemmerly says.

These regularly updated guides are available nationally, regionally, and for specific seafood products such as salmon, crabs and sushi. Currently, the guides can be accessed and downloaded via the Seafood Watch website.

The team is also working on relaunching the Seafood Watch app, a previous version of which had over 2 million downloads, Kemmerly says. The new app is slated for release later in 2026, so stay tuned.

Related Reading: How Can I Help Protect the Ocean?

Seafood Watch also advises restaurants that serve seafood on how to make their supply chain more sustainable, and just a few weeks ago, it introduced a public-facing guide to finding restaurants near you that serve sustainable seafood options.

You can help save the ocean by not only not ordering unsustainable seafood options, but by preferentially ordering sustainable options—and telling your waiters and seafood counter staff that this is important to you. This sends a signal to markets that people care about where their food comes from and that people want foods with lower environmental impacts. If enough people do this, it will make a big difference—indeed, it already has started to help.

“If any community can see change to the ocean environment over time, it’s scuba divers,” Kemmerly says. “If there’s any audience who has the level of awareness and passion to do something, it’s divers. Get involved. Let your favorite restaurant know that this is an important issue to you, that you’re a diver and you want to see marine resources cared for, and that starts with what you buy.”

Learn more by visiting SeafoodWatch.org or by following the organization on Instagram.