The seas are dying, say activists, scientists and watchers-of-the-apocalypse.

Some point to rising levels of toxins in the ocean and an array of environmental imbalances that have put whole species of aquatic life at risk of extinction. Others quote that scary part of Revelation that predicts one-third of the fish in the ocean will die, along with, by the way, one-third of its ships.

In the midst of all this aquatic doom-and-gloom, a small company headquartered in Sausalito is offering a much more optimistic view of the future of our oceans, along with a strong call to change our relationship with the sea, and the tasty creatures that live in it.

“I’m not sure it’s accurate to say the seas are dying, but they are definitely very seriously challenged,” says Sean Wittenberg, co-founder and president of Safe Catch, a fast-rising, ecologically minded and slightly quirky company producing canned and cooked tuna that is as nutritious for consumers as it is respectful of the oceans in which those fish are caught. “Certain parts of the ocean are more challenged than others, because of the impact of industrial pollution, and because of reckless human behavior.”

Wittenberg and his Safe Catch co-founder, Bryan Boches, are fully aware of the ironies and challenges of launching an environmentally friendly canned-tuna company. Still, both founders see the sustainable harvesting of fish as an important effort that—assuming industry practices and consumer attitudes change—brings a number of powerful plusses to counter its many minuses.

It comes down to the fact that healthy fish is healthy protein.

“The healthiest things on earth to put in your body still come from the ocean,” Wittenberg says. “There are plenty of healthy fish in the sea. You just have to be willing to pass on those that aren’t.”

And the healthier the oceans become, the safer the food we pull from it. Currently, Safe Catch produces a whole line of high-end, ecologically minded, health-conscious tuna products, packed in attractive cans and pouches bearing the lofty admonition “Eat Pure. Live Pure,” and the remarkably specific promise, “Made for Elite Athletes, Kids and Pregnancy.”

Each can carries a lot of printed information—short statements, positive affirmations and little icons identifying that the tuna was caught using dolphin-safe methods, with lines and poles; that it was hand-cut, sushi-grade fish when it was placed in the can; that it was cooked in its own juices; and, before any of that, that it was tested to the highest level of any canned tuna brand on the market.

“We’ve performed a million mercury tests to date,” Wittenberg says. “And that’s just the beginning.”

There was a time when tuna was among Americans’ favorite foods. But when reports of mercury levels in the canned variety began to become common, and doctors warned of mercury’s dangers—especially to pregnant women—American consumption of tuna plummeted.

According to Wittenberg, Safe Catch is the only brand of tuna that tests the mercury level of every fish before buying, cooking and canning it. Most companies test one or two fish out of a larger batch. This is not effective: two fish of the same size, caught at the same time, could have wildly varying levels of mercury.

As Wittenberg explains, the FDA has set a mercury limit in fish of 1.0 parts per million—meaning that mercury is safe as long as it’s consumed at that level or lower, according to the government. But that’s not good enough for Wittenberg and Boches.

Safe Catch set its own, stricter mercury limits, which the company says are between three and 10 times stricter than the government’s, depending on the fish and the product. Safe Catch’s wild albacore tuna, for example, is held to a safety standard of .3 ppm (three times stricter), while its Safe Catch Elite Wild Tuna must meet a standard of .1 ppm (10 times stricter that the FDA).

Using those standards, the company rejects an average of one out of every three tuna it tests—leaving one to ask, what happens to those other fish?

“They end up in the marketplace, probably purchased by some other company,” Wittenberg says. “If they’ve made it as far as testing, we know they’re basically good fish. They’re just not good enough for us.”

Before Safe Catch was called Safe Catch, it was a technology company devoted to developing new forms of testing fish for mercury levels. The process they developed, Wittenberg says, is a proprietary product, details of which he cannot legally reveal in too much detail.

Wittenberg and company set out to perfect the process more than a decade ago, then began presenting the new technology to seafood companies, offering to test and certify their catches. Safe Catch was then a testing company, but after a number of big tuna companies passed, the team decided to take the knowledge and the testing device and swim in a different direction.

The company’s goals are manifold: to produce healthier tuna and do it in a way that might restore populations of fish that are being unsustainably harvested by other companies; and, to a degree, put tuna back into the American consciousness as a healthful and relatively inexpensive staple.

“This actually all started,” Wittenberg says, “because my mom had mercury poisoning when I was a kid, and she became very sick. Before then, we ate a lot of tuna. Everyone ate a lot of tuna.”

He recalls his mother sending him to school every morning with a paper bag lunch. “There was always an apple or some other piece of fruit, a juice box, something sweet once in a while, and a sandwich,” he says. “And two days a week, that sandwich was tuna fish. Then my mom got sick. Then she read an article in Prevention magazine, talking about how pregnant women and children were at risk of mercury poisoning, and that so much of our tuna had become contaminated, we simply can’t trust any of it anymore. I remember my mom saying, ‘Well, Sean, you just lost 40 percent of your lunches.’ She never made tuna sandwiches again.”

During their time developing the company’s testing tools, Wittenberg and Boches worked with fisherman in Honolulu, Chile, the Philippines and throughout the continental United States and Canada.

“We established some very good relationships, gained some knowledge of the seafood supply chain,” Wittenberg says. “So in 2013, when we decided to transform ourselves from a testing company into a product company, we had a pretty good idea who we wanted to work with, and how the industry functioned.”

They created a plan that set out how their fish would be acquired and tested, placed into cold storage and shipped to Thailand, where the cooking and canning is done on manufacturing lines reserved solely for Safe Catch products.

“It was a pretty steep learning curve,” he says. “But we threw ourselves out there and learned how to do it. . . . It was tough, but we’re pleased with where we’ve arrived.”

Now the cans are on the shelves at thousands of locations, from health-food stores to grocery chains. They’ve used social media to get the word out, of course, and recruited major “influencers” around the world—elite athletes, scientists, actors, authors, moms and kids—to lend their own name and brand to tell people about Safe Catch.

And then there are the upside-down cans. “When you are doing as much as we are, and you are as poor as we are, you have to communicate about your product in any and every way you can,” Wittenberg says. “The best way to do that is on the grocery store shelves. We just have a lot to say, a lot of information we want to get out there, so we say it on our labels. And by turning the can upside-down, we can put a label on the top, and use it to say more stuff. That’s the reason for the upside-down can.”

And perhaps, metaphorically—it’s also a symbol of Safe Catch’s push to turn the industry upside-down as well?

“That’d be nice, but it’s going to take more than one company in California,” Wittenberg says. “We’ve enjoyed some success, definitely. And the industry is watching. So who knows? The product is catching on, so to speak, with health and wellness customers. We might be able to bring confidence back to the shelves, and put more tuna back in kids’ lunch bags.”