When winds blow along a coast, surface water is pushed away and deeper water rises to replace it. That water is cold and full of nutrients, and it feeds plankton, which feed the rest of the food chain. Upwelling zones are easy to spot by cool surface temperatures.
California is one of the world’s five big upwelling regions, along the California Current. Near Carmel, submarine canyons help bring that water close to shore, which is part of why Point Lobos and Carmel Bay are so productive.
Upwelling also keeps the water cold, which helps make the marine layer that gives Carmel its cool, foggy summers.