Dusky Sharks: South Africa

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Our first encounter with a dusky shark (Carcharhinus obscurus) occurred in South Africa in the waters just outside of Port St. Johns. We were there nine days to photograph the famous sardine run. As sharks take part in devouring the bait balls of fish created by the common dolphin we were hoping to photograph the dusky shark as well as spinner shark for the first time.

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Unfortunately, we did not photograph a dusky during the fish bait ball event as they were largely spinner sharks involved. However, we did have one encounter with a dusky near the chase boat. We got in the water and captured a few shots of this new species of shark for us. It is always exciting to see and photograph a new species of shark for the first time.

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Sardine Run South Africa

 

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The sardine run of South Africa occurs between June and July on most years. Millions of sardines (Sardinops sagax) attract thousands of predators including dolphins, tuna, sharks, whales, and birds. It also attracts people who wish to see and photograph this spectacular event.

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The long-beaked common dolphins (Delphinus capensis) are the driving force that creates the fish “bait ball”. Large pods of dolphins work cooperatively to herd the fish into these tight groups. Sardines along with mackerel (Scomber japonicus) group together when they are threatened. The dolphins force the fish up to the surface where they are easier to catch.

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After the dolphins have done the hard work many other predators begin to take advantage of such a large concentration of fish. The Cape gannets (Morus capensis) are large seabirds that begin to dive by the hundreds into the fish bait ball. They reach speeds of over 100 km/h (60 mph) as they hit the water. If not initially successful they will chase the fish underwater hoping for a meal.

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Not to miss out sharks begin to show up in large numbers. Spinner sharks (Carcharhinus brevipinna) were the most common on our encounters although there were also bronze whaler sharks (Carcharhinus brachyurous) called copper sharks in South Africa and dusky sharks (Carcharhinus obscurus).

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Each year can be very different. We had very poor visibility (10 feet or 3 metres) on our first 8 days and few bait balls. We did not see a single sardine in our 9 days on the water. Fortunately, we encountered a fairly large bait ball of mackerel on our final day in a pocket of water with relatively clear visibility that allowed us time to get in the ocean. This 20-30 minute event produced all of these pictures.

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Nurse Sharks: A Common Caribbean Shark

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When most people think of sharks, they think of species like the great white shark, tiger shark, and bull shark. These are known as requiem sharks and have that classic shark appearance. However, there a numerous species of shark that look very different from requiem sharks including the nurse shark (Ginglymostoma cirratum). These are very common sharks in the Caribbean and often encountered by new divers.

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The head is broad with tiny eyes and has two barbels (whisker-like appendages) that are used in the search of food. Their teeth are small and designed for crushing as part of their diet includes eating shrimp, crab, and lobster. They are nocturnal and during the day they are often seen laying under ledges but are also seen in the open on the sand.

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They are a fairly large shark and can reach over 3 meters or about 10 feet although most are much smaller. They can tip the scales between 90 to 115 kg (200-250 pounds). The gestation period for nurse sharks is about 6 months and generally, they have between 20-30 pups.

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Although many divers see them as harmless, their mouth can produce a tremendous suction and could easily suck in fingers or a hand which they generally will not let go of. Therefore, like all sharks, they must never be touched and need to be respected.

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Great Hammerheads (#1): Bahamas

Although we love to photograph all sharks, our favorite is the great hammerhead (Sphyrna mokarran). Generally, it is a cautious shark and will keep its distance from scuba divers. There are 9 species of hammerhead sharks worldwide but the great hammerhead is the largest. An average adult reaches lengths of about 3.6 to 4.3 meters (12-14 feet) but can reach 6 meters (20 feet) and exceed 550kg (1,200 pounds).

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Great hammerheads are newer sharks on the evolutionary scale and have developed some unusual characteristics. The unique feature of this shark is obviously the head. The “hammer” which is called a cephalofoil is full of electrical sensors. These pores called ampullae of Lorenzini aid in hunting as these sensors pick up electrical signals given off by all living creatures including humans.

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As you view these photographs notice how different the shark can look depending on the angle of the photograph. On a larger shark, the cephalofoil is about a meter (3 feet) in length and the eyes are at the ends which gives it a large range of vision.

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The diet of this shark is diverse. They will feed on a variety of fishes including tarpons, porcupine fish and even other sharks. As well, lobster, squid, and octopus form part of their diet.  However, their favorite food is rays. Stingrays bury themselves in the sand and the great hammerhead uses its cephalofoil with its electrical sensors to detect their location.

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Great Whites Of Guadalupe, Mexico

Our first liveaboard experience was to Guadalupe Island off Mexico in the Pacific Ocean. The sea conditions were rough with waves 7-9 feet and many people were very seasick. The good news is that we handled the conditions quite well and just felt a bit nauseated. It proved to us that we could handle very adverse sea conditions. The 400 km (250 mile) trip started from Ensenada, Mexico and took about 24 hours to cross on the 33 meter (110 foot) vessel called the Sea Escape. Guadalupe Island is a volcanic island and home to some very large great white sharks (Carcharodon carcharias).

great white9great white1great white6The great white shark, also called the white shark, can grow extremely large with some females capable of reaching 6+ meters (20 feet). As the females mature their girth increases considerably for every foot of growth. It was hard to imagine a 1900 kg (4,000 pounds) great white shark swimming a meter or two away from us and we had big expectations. Sadly, the largest shark we experienced was about 4 meters (12-13 feet). Certainly, not a monster female but a very large shark none the less.

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Our first experience with great white sharks was in South Africa but the water was not very clear (green water) so it was difficult to get good pictures. As our photographs show, Guadalupe is a great place to photograph these majestic creatures. We will certainly do Guadalupe island again with hopes of photographing a massive female.

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Galapagos Sharks In The Revillagigedo Archipelago

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.galap2galap3

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.

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Silky Sharks Of The Socorro Islands

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.silky2silky4

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.

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