Earlier this week, I took my daughter over to Catalina Island to dive at Casino Point, the popular underwater park established in 1962. It is also a no-take State Marine Conservation Area, one of California’s 124 marine protected areas. Fishing and nearly every other kind of “take” are prohibited. The visibility was great, maybe 60 feet, and the number and variety of fish we saw were impressive. The only downside is that we did not see a giant black sea bass.
But to me, the dive was a reminder of the steps California has taken to improve its marine ecosystems, and of how protection, as well as patience, can make a real difference. So I thought I’d take a quick look at how we got here and where we might be going, because the state is reviewing the network right now and considering changes that could expand some protected areas while shrinking or weakening others.
Twenty-some years ago, California tried something no one in the US had really done before: instead of scattering a few marine reserves along the coast and hoping for the best, it set out to build a connected network of underwater parks, designed by scientists and experienced water users with a personal stake in the ocean. The latter meant not only surfers, but also commercial and recreational fishermen, divers, and tribal communities. Oh, and there would be enforcement.
The idea came out of the Marine Life Protection Act, passed in 1999 at a low moment for the coast. Rockfish populations had severely declined. Abalone had been so overfished that it was literally impossible to find the delicious and popular gastropods. The state’s existing patchwork of protected areas was, in the law’s own assessment, created “piecemeal,” too small and scattered to be effective. The first two attempts at implementing the law failed. What finally worked was a slow, regional process that brought together interested parties who hashed out maps region by region. And it took nearly a decade. When the final piece snapped into place on the North Coast in December 2012, California had 124 marine protected areas covering about 16 percent of state waters (although only 9.4 percent was fully no-take), the largest scientifically designed MPA network in the world.
The bet was that protection, given time, would pay off. It has. In other words, we seemed to learn an obvious lesson: if you leave nature alone, it often recovers.
When the state completed its first decadal review of the network in 2023, the signal was clear: inside the MPAs, there are more fish, and they are bigger, particularly the species that fishing targets most, like kelp bass, lingcod, and rockfish.
We wrote about the astonishing recovery of rockfish a while back: by late 2025, many West Coast groundfish stocks previously classified as overfished had been declared rebuilt.
In recent years, I have also noticed more fish on my dives and heard similar observations from fishermen. That is anecdotal, of course, but it is consistent with growing evidence that California’s marine protected areas are helping fish populations recover.
On a recent boat trip to the Channel Islands, I spoke with Molly Morse, a biologist with the Benioff Ocean Science Laboratory at UC Santa Barbara. She explained why allowing fish to grow larger inside these reserves can benefit the surrounding ecosystem and even nearby fisheries.
“The marine protected areas are really a special place for allowing fish to grow,” she told me. “And when the fish get larger, they’re able to reproduce and produce a lot more offspring. So we get higher returns from bigger fish. So that means we have larger spillover.”
Oh, and by the way, the stakes go beyond fish. After the 2014–2016 marine heatwave, kelp forests inside Southern California’s fully protected reserves recovered faster and more strongly than those in unprotected waters, suggesting MPAs can also help broader ecosystems withstand a warming ocean.
Here’s why this all matters now: the network’s future is being decided as I write this. California officials are considering 15 proposals that could expand, shrink, or otherwise change protected areas along the coast, with the Fish and Game Commission expected to take them up in October 2026.
What’s important is that we now have many of these reserves for a relatively significant amount of time. It’s still nowhere near where we should be, but we’re finally beginning to see what long-term protection can accomplish. The Channel Islands marine reserves, established in 2003, are now 23 years old and have shown impressive gains in the number, biomass, and size of targeted fish within their boundaries.
A reserve doesn’t reveal what it’s doing in five years. It reveals it in twenty.
“It really takes time for these places to have an impact,” said Morse. “But we’ve already been seeing that effect. Scuba diving companies seek out these locations because their clients want to come see the large fish, the giant sea bass, that live here. Also things like recreational lobster fishing.”
What’s also key is the spillover effect that Morse mentions above: At the Channel Islands, spiny lobsters inside the MPAs have grown so large and abundant that they migrate into surrounding waters, where the lobster fishery has benefited.
The same spillover effect has also been documented along the Central Coast among fish living in and around other marine reserves.
I find the bigger picture here genuinely encouraging, and I don’t say that often about ocean news. We tend to talk about conservation as sacrifice and what we give up. California’s MPAs are a two-decade experiment showing that we get something back. They’ve become a model studied around the world, and the blueprint for the “30x30” targets now written into both state and international policy. None of it required new technology or a miracle. It required commitment and patience. AND the political will to leave some places alone for a while.
The ocean knows how to heal itself, assuming things don’t get so hot and miserable that the whole system comes tumbling down, an outcome that seems tragically more possible every day. But we’re not there yet, and I still have hope that, over time, we can make the right decisions. The key point is that we now have hard scientific evidence that these protections work.
And it’s happening right here in California.
Thank you for this refreshing news! Healing the ocean is so much more important to the survival of our planet than most people realize. I’m keeping my hopes up for more protection, not less.
Preserving the future and understanding the science of ecosystems.
Thank you for sharing