Our previous posts on the Revillagigedo Archipelago, also called the Socorro islands, have included the giant mantas(Manta birostris), whitetip reef sharks(Triaenodon obesus), and silky sharks (Carcharhinus falciformis). Although Galapagos sharks (Carcharhinus galapagensis) are fairly common especially at Roca Partida, we did not have any encounters with them there. However, on one dive we did come across a few juveniles at Socorro island and this gave us an opportunity to photograph this species.
Older sharks of all species have very scarred bodies which are simply a result of surviving in a dangerous ocean environment. However, these juvenile Galapagos sharks, which were about a meter (2-3 feet) in length, had skin with very few blemishes. Adult Galapagos sharks can reach 3 meters (9-10 feet) in length.
The silky shark (Carcharhinus falciformis) gets its name from the smooth texture and silky look of its skin especially when it is young. These sharks can grow to 2.5 meters (8 feet) in length and are very abundant in the Revillagigedo Archipelago. Generally referred to as the Socorro Islands, these volcanic islands lie approximately 390 kilometers (240 miles) off the coast of Cabo San Lucas in Mexico.
Although we encountered scalloped hammerheads, tigers, Galapagos, whitetip reef, and silvertip sharks the most numerous were the silky sharks. At dusk, as the sun was setting, a few of us slipped into the water behind the boat in an attempt to photograph these sharks with the sun’s rays penetrating behind them to give a visually stunning look. Thank you to Andy Murch of Big Fish Expeditions for showing us this technique as we are relatively new to underwater photography.
The focus of our trip was to photograph the giant mantas (Manta birostris) at San Benedicto Island in the Revillagigedo Archipelago. These are the largest mantas in the world and can be more than 20 feet (6 meters) across and weigh up to 3,500 pounds (1600 kilograms). The dive site called “the Boiler” is a cleaning station for these mantas where fish remove parasites from their bodies. Consequently, this site provides the best opportunities to see and photograph these gentle giants.
The Revillagigedo Archipelago lies approximately 390 kilometers (240 miles) off the coast of Cabo San Lucas in Mexico. These Pacific islands are more commonly referred to as the Socorro Islands. Aboard the Southern Sport, we dove 3 of the 4 islands (Roca Partida, San Benedicto, and Socorro).
A color variant from the more common black and white manta is an all black or nearly all black manta. It is not a different species of Manta birostris. However, it is exciting when one showed up as it looks so different.
San Benedicto is the island for the giant mantas. They are used to divers and show no fear of people. They swim It seems a bit surreal, even a few weeks after our encounter with them, to have had huge mantas swim within a few meters of us.
The Revillagigedo Archipelago lies approximately 390 kilometers (240 miles) off the coast of Cabo San Lucas in Mexico. These Pacific islands are more commonly referred to as the Socorro islands. Aboard the Southern Sport, we dove 3 of the 4 islands (Roca Partida, San Benedicto, and Socorro). The whitetip reef shark (Triaenodon obesus) is common here.
The whitetip reef shark rarely exceeds 1.6 meters (5 feet). It is nocturnal and rests during the day under ledges and caves. At Roca Partida, we observed many groups of whitetip reef sharks congregating in groups of 3 to 15 on the ledges. By approaching them slowly we were able to capture this behavior.
These sharks hunt at night and eat mainly crustaceans like crabs, lobsters, and shrimp as well as bony fishes. They tend to hunt in groups. During the day, it was interesting to observe many large lobsters out in the open just a few feet away from the whitetip reef sharks. Apparently, the lobsters know that they are safe from these sharks during the day.
The blue whales in the Sea of Cortez (see the previous post) was a neat experience but the grey whale encounters on the Pacific side of the Baja Penisula were breathtaking. Often female grey whales with calves will come up alongside the boat and occasionally let you touch and rub them. This is the experience we had. Grey whales can reach 15 metres (50 feet), weigh about 35 tonnes (75,000 pounds) and live approximately 60 years.
Each winter the whales migrate from Canada and Alaska south to The Baja Peninsula traveling up to 11,000 kilometres. There are a number of bays and lagoons along the Pacific (western side) where the pregnant mothers deliver their babies. At birth, the calves are about 4 meters (13 feet) long and weigh approximately 800 kg (1,764 pounds)! The babies are often playful and occasionally bring their heads out of the water making interesting photographs.
We were hoping to get some good underwater shots with our underwater cameras to get a different perspective of them as most people see then only from the surface. The water, however, is very green filled with phytoplankton and visibility was maybe 10 feet. Therefore, it proved difficult to get any good photographs but we have included a few to give a different perspective.
If someone is wanting a wonderful whale experience for themselves or for their family then we would highly recommend the grey whales at the fishing town of Adolfo Lopez Mateos, Magdelena Bay, Baja California Sur, Mexico. We were there towards the end of February.
Blue whales (Balaenoptera musculus) are the largest whales in the world reaching lengths approaching 30 metres (100 feet) and weighs up to 180 tonnes (400,000 pounds). They start arriving in the Loreto Bay National Marine Park, Mexico in February each year. There seems to be a sweet spot called the blue triangle where they are regularly seen. Danzante Island, Del Carmen Island and Monserrate Island make up this blue triangle in the Sea of Cortez. Some whales like humpbacks with their spectacular breaches, or grey whales that come next to your boat are more photogenic. However, blue whales just break the surface of the water to exhale, take in more air and descend.
On our way to our dive site, we saw some large waterspouts caused by the exhaling blue whales off in the distance so a detour was in order. Marine park rules dictate that you keep your boat a specific distance away from the whales. The way it works is that you see the blue whale in the distance, you move the boat towards them but by then they have descended again. The boat captain guesses where he thinks they will come back up (usually 6-9 minutes later) hoping they will surface closer to the boat. We played this game about 8 times and each time they came up a long distance from the boat. Great experience but now it was time to go to our dive site so off we went. Unexpectedly, the whale surfaced about 30-40 metres (100-130 feet) away from the boat which was close enough to get these photographs!
The purpose of our dive was to photograph Horn sharks and we got lucky on our second dive around Danzante Island in the Loreto Bay National Marine Park, Sea of Cortez, Mexico. Thank you to Juan Carlos Reyes Valerio our dive master for finding these rather reclusive sharks. Although we found 3 different horn sharks, 2 were deep in crevices and they were impossible to photograph. However, it only takes one and this shark was out in the open apparently waiting to be photographed. Horn sharks are not strong swimmers and this shark is trying to tuck as close to the rocks as possible.
This area has more than sharks and we saw 3 different species of ray, two that stayed still long enough for us to photograph. The ocellated electric ray or bullseye electric ray (Diplobatis ommata) can generate a moderate electric charge for self-defence. The bullseye or ocellus on the back is very distinctive and is where it derives its name. It is a small ray reaching about 10 inches (25cm) in length.
The second ray we were able to photograph was the spotted round ray also known as the Cortez round ray (Urobatis maculatus). They have short tails compared to many other rays and reach a length of about 17 inches (45cm). This ray didn’t stick around for very long before it headed to deeper water.
A surprise for us to come across was the banded guitarfish (Zapteryx exasperata). We were not aware that there were a guitarfish species in the Sea of Cortez. This fish can reach up to 4 feet (1.25m) and has both dorsal fins of nearly identical size. Unfortunately, it had its head facing away from us partly going into a crevice.