Photo of the Week: April 12, 2010

Hi Gang!

This week’s POTW is an image of a blacktip reef shark, Carcharhinus melanopterus. A beautiful shark, this species occurs in Indo-Pacific regions from the Red Sea and east Africa all the way to the Hawaiian Islands and the Tuamotus. The blacktip reef shark is also found in the eastern Mediterranean.

Although their common names are similar the blacktip reef shark is a different species than the blacktip shark, Carcharhinus limbatus. A cosmopolitan species, the blacktip shark occurs worldwide in coastal areas in tropical and subtropical waters. This species is commonly seen at some of the shark feeds in the Bahamas.

Let’s return to the blacktip reef shark. The blacktip reef shark is usually found in shallow waters on and around coral reefs, and it is occasionally found in more brackish areas. Adults are usually encountered on reef faces and reef flats, while the juveniles are found in relatively shallow water, and are common in some lagoons and mangrove areas.

Blacktip reef sharks attain maximum proportions of just less than 6 feet in length and 165 pounds. While they are not the largest of reef sharks, blacktip reef sharks are capable of impressive bursts of speed. They are pursuit predators that feed mostly on a variety of bony reef fishes, but they are also known to feed on small sharks, stingrays, crustaceans, mollusks and arthropods. In some areas blacktip reef sharks are also know to prey upon sea snakes. Blacktip reef sharks have been documented to hunt and feed cooperatively as a group of sharks work together to push schools of small fish up against a shoreline. Once they have the school corralled the sharks cut through the school and feed en masse.

Blacktip reef sharks are preyed upon by some larger sharks and some species of larger groupers.

As a rule, when they are not baited blacktip reef sharks tend to be wary animals that prove difficult to approach. This week’s POTW was taken during a dive in Yap and bait was being used to attract a gathering of gray reef and blacktip reef sharks. Yap’s shark dive does not receive as much publicity as a lot of shark dives, but I think it provides a wonderful opportunity for photographers and videographers. The bait is placed on the bottom near the top of a wall at a depth of approximately 50 feet. The dive is timed for the tide meaning that a current will wash the scent from the bait along the face of the wall, and within minutes- if that long- the sharks start to show up. After that it is a matter of picking your location and being patient.

I hope you enjoy this week’s POTW.

See you next week!

Marty