Have you asked yourself what the ocean means to you? California’s coast is central to the state’s identity, culture and economy. But what does it mean in people’s everyday lives? Who gets to enjoy the ocean’s benefits? And what barriers prevent some communities from benefiting from the ocean?

Whenever I arrive at a new spot, my instinct is to look around for signs. I’m curious to know the local rules, the species I might see, and any unique features of the area. I assumed this was common—that most people also stopped to read signs before heading out. But that assumption got flipped on its head when I started digging into how effective marine protected area (MPA) signage really is.

Over a decade ago, California led the nation to become the first network of marine protected areas (MPAs) in the United States. When the...