Both the deep and coastal waters around San Carlos are home to an abundance of sea life that includes more than 1000 species of fish and shelled invertebrates. The Sea of Cortez ecosystem changes between winter and summer months. Dramatic shifts in currents, air and water temperatures result in altered nutrient levels and marine life.
Cooler waters bring an explosion of small fauna (Dall's goby and nudibranchs) from the deep, as bigger fish (tuna and billfish) head south to warmer waters. Pacific seahorse, mysid and possum shrimp are common among reefs during the winter months, as well as visually-appealing species such as butterfly fish, parrot fish and damselfish (small serranids, labrids, scarids, chaetodonts, haemulids, pomacentrids and more). Sargassum (red seaweed) grows up to six feet in shallow coves.
Various species of sargassum die off as spring elicits warmer water temperatures, and red and purple coralline algae are revealed--encrusted among piles of rubble along the shore. These coves are home to green moray eels, Pacific octopus, Christmas tree worms and anemones, while various species of sea hares, starfish and cucumbers may be seen on sandy stretches.
The Sea of Cortez is home to the flying mobula and vaquita marina--recognized as the most endangered porpoise in the world. The waterway also sees many migratory sea creatures pass through over the course of a year including the California gray whale, leatherback sea turtle and manta ray. Many of these endangered species can be seen while snorkeling in the Sea of Cortez, depending upon the season.
San Carlos lies at a longitude of 111 degrees west and a latitude of 28 degrees north. The area experiences dramatic climatic changes due to eastern desert influences and the constantly-shifting waters of the Gulf to the west. Average rainfall totals just a few inches annually. These unpredictable geographical factors may affect what you can expect to see while snorkeling in San Carlos, Mexico.
