San Carlos Scuba Diving

I am always impressed at the remarkable level of camouflage that can be exhibited by marine organisms. These photos show a few of the masters. These were photographed during a recent dive at Isla San Pedro Nolasco, near San Carlos.

This first image is of a snail that proved incredibly elusive for me. I looked for this beautiful parasite on and off for over a year! It wasn’t until I brought along a flashlight that I was able to see it against the backdrop of its coral home/prey.

The snail is Epitonium billeeanum, a relative of whelks. It spends its entire life living among colonies of the sun coral, Tubastraea coccinea, where it passes its days slowly consuming the colonies and laying copious masses of eggs (the yellow clump over the snail). These in turn will hatch on a ready-made feast for these tiny snails.

Relying on exquisite camouflage and a nice array of venomous dorsal spines, the stone scorpionfish, Scorpaena mystes is reluctant to move when divers approach.

I’ve been stung three times by these fish – once during an underwater rescue when I placed my hand on a fish to get some leverage – thinking it was a rock. The other 2 envenomations occurred while handling these fish in my lab. Their toxin is very good at lowering blood pressure. In my case they were a little too good. The third sting required a long series of injections to keep my heart rate up.

Silhouetted against the water, scorpionfish are easy to see, but against the backdrop of the seafloor, it’s easy to see how they might be mistaken for a rock.

The winter water has begun to find its way into the San Carlos region. So with water temperatures dropping below 70 degrees, the question for warm water sissies like myself becomes “is it worth it”? Sure, California divers may scoff at such a question. 65-68 is downright balmy along the Pacific coast, but you need to realize, I wear a 5 mil just to teach scuba in the pool… a pool that is heated to 82 degrees all year long. While I may shudder at the thought of that first dip under, when the water creeps down the spine of my wetsuit, there is no doubt as to whether it is worth it. Despite my reluctance to even look at cold water, much less submerge; the winter diving in San Carlos is simply amazing. In this case, my inner marine biologist manages to beat up my inner water wimp. Of course wearing a dry suit has helped sway that battle a tad.

There are many reasons to go diving in the Sea of Cortez during the winter; increased species diversity, no packed boats, and pleasant air temperatures. But one of the big reasons to go has already shown up…Orcas! The Sea of Cortez is home to several resident pods of these beautiful creatures, and during the winter months they may be sighted cruising the shores of the central and northern Gulf. Divers in San Carlos have already been able too witness pods of these cetaceans at the surface, exhibiting their characteristic playful behaviors.

Orcas aren’t the only cetaceans whose abundance goes up in winter. These cooler months are prime season for viewing fin whales, grey whales, sperm whales, and even humpbacks and the largest mammals in the world arrive, blue whales. That is to say nothing of the superpods of dolphins that may aggregate in the wintertime.

The cool water brings with it the nutrients necessary to fuel the Sea of Cortez for another year. As the nutrients feed planktonic organisms, these in turn are devoured by larger species that follow this microscopic smorgasbord. Crustaceans are tasty staples for everything from migrating whales to diminutive Catalina goodies, a spectacularly colored fish seen only in cool water. Everywhere the reefs come alive with life as the winter bounty is consumed to make for a successful spring breeding season. Winter is truly the time to see the Sea of Cortez at its most vibrant.

During a recent excursion west of Isla San Pedro Nolasco, we encountered several pods of sperm whales, Physeter macrocephalus, resting at the surface between dives. Being a prime breeding ground for Humbolt “jumbo” squid, Dosidicus gigas,the Sea of Cortez is also a top site for finding their toothy predators, sperm whales. A recent study of predator-prey relationships between sperm whales and jumbo squid, researchers found the whales were making regular dives to depths of 600-1300 feet during the day, and 600 feet during the night. We were able to get photos of over 15 of these whales in 4 pods during a one-hour period

Finishing grad school and launching a business hasn’t left too much time for writing, but I’ll try to get caught up with my recent travels at least by sharing some pics! More to come as I resize…

Hurricane Henriette is due to reach mainland Mexico later today. Having weathered a few hurricanes and tropical storms in the Guaymas and San Carlos area, I do not envy what residents of the region may expect. The channeling effect of the Gulf basin can have far-reaching effects with storm surge being experienced as far north as Puerto Penasco and El Golfo de Santa Clara. This storm surge is already being reported in the San Carlos area with surge slapping into the doors in several condominium developments. Further south, reports are coming in that the surge has breached the seawalls and flooding is occurring.

Hurricane Henriette was expected to weaken significantly after it crossed into the Sea of Cortez, but it appears this was a short disturbance without lasting effect. Originally anticipated to be downgraded to tropical storm status, Henriette has retained enough strength to make landfall again as a hurricane.

Although only a category 1 hurricane, has already left 7 dead and thousands homeless after it made landfall along Los Cabos at the Southern tip of Baja, Mexico. The primarily desert regions of Baja are not as prepared to withstand hurricane forces as well as the tropical regions of the Caribbean. Caribbean hurricanes are a normal though potentially devastating part of each fall, and the flora and fauna recover quickly from such poundings. In Baja, the sandy soils saturate with water rapidly and begin to slide. Lacking dense vegetation, flash floods and mudslides can be catastrophic.

Hentiettes strength is expected to be felt for the next several days as it crosses over Sonora to the southwestern United States where flooding is expected in New Mexico and possibly Arizona. These desert regions will likely experience tremendous rainfall and flooding. Several years ago after a near-miss by a tropical storm, I remember putting my truck into 4-wheel-drive to drive through downtown Hermosillo! In several points, water was seeping around the doors and even smacking the windows.

Henriette, is expected to reach the mainland later today between Topolobampo and Bahia Kino. The specific track shows a likely landfall 25 -35 miles south of San Carlos.

Although the hurricane was disrupted as it crossed land from the Pacific to the Sea of Cortez, the Pacific system still produced winds of 75 miles (120 kilometers) per hour. The hurricane is now heading north at 12 mph and is about 70 miles from Los Mochis, Sinaloa, Mexico.

According to the National Hurricane Center, Henriette may bring storm-surge flooding to Mexico as high as 5 feet (1.5 meters) above normal levels, “dangerous battering waves,” and 12 inches (30 centimeters) of rain in mountainous areas, with the potential to cause “life-threatening flash floods and mudslides”. In response, Mexico has issued a hurricane warning from Topolobampo north to Bahia Kino and a tropical storm warning along the east coast of the Baja Peninsula from La Paz north to Loreto.