The Galapagos shark (Carcharhinus galapagensis) is a species of requiem shark, family Carcharhinidae, found worldwide. This species favors clear reef environments around oceanic islands, where it is often the most abundant shark species. A large species that grows to 3.7 m (12 ft), the Galapagos reef shark has a typical fusiform “reef shark” shape and is very difficult to distinguish from the dusky shark (C. obscurus) and the grey reef shark (C. amblyrhynchos). An identifying character of this species is its tall first dorsal fin, which has a slightly rounded tip and originates over the rear tips of the pectoral fins.
Galapagos sharks are active predators often encountered in large groups. They feed mainly on bottom-dwelling bony fishes and cephalopods; larger individuals have a much more varied diet, consuming other sharks, marine iguanas, sea lions, and even garbage. As in other requiem sharks, reproduction is viviparous, with females bearing litters of 4–16 pups every 2–3 years. The juveniles tend to remain in shallow water to avoid predation by the adults. Galapagos sharks are bold and have behaved aggressively towards humans, and are thus regarded as dangerous. The International Union for Conservation of Nature (IUCN) has assessed this species as Near Threatened, as it has a slow reproductive rate and there is heavy fishing pressure across its range.
Posts tagged Middleton Reef
Jun 09
Galapagos Shark
Middleton Reef, Tasman Sea, Australia 29º25’24″S 159º03’35″E
Jun 09
Middleton Reef
Tasman Sea, Australia 29º26’52″S 159º05’01″E
Shipwrecks aground on Middleton Reef.
Middleton Reef is a coral reef in the Tasman Sea. It is separated by a deep oceanic pass some 45 km wide from nearby Elizabeth Reef, forming part of the Lord Howe Rise underwater plateau. Middleton Reef is around 220 km from Lord Howe Island and 555 km from the coast of New South Wales. In 1997 the Environment, Sport and Territories Legislation Amendment Bill 1996 included Middelton Reef in Australia’s Coral Sea Islands Territory.This island is included also in Elizabeth and Middleton Reefs
Middleton Reef is a platform reef and is among the southernmost platform reefs in the world. However, despite its relatively high latitude, a wide variety of flora and fauna exists both on the island and in the surrounding waters. This is due to its location where tropical and temperate ocean currents converge.
Middleton reef is about 8.9 km long by 6.3 km wide and is usually submerged. However, at low tide most of the reef flat is exposed. At high tide only one cay on the reef is visible, at one metre above sea level. The cay is called The Sound and is 100 m by 70 m.
The reefs form the Elizabeth and Middleton Reefs Marine National Park Reserve managed by the Government of Australia under the Natural Heritage Trust.
Surveys by the Australian Institute of Marine Science have highlighted healthy number of Black Cod Epinephelus daemelii which is now a threatened species in NSW waters. The survey in 2003 highlighted some 111 species of coral and at the same time identified 181 species of fish. The total number of recorded fish species on the reef is 311 across several surveys. High numbers of Galapagos sharks Carcharhinus galapagensis were observed at Elizabeth Reef.
