Manta Survey at Komodo National Park
Depth: 18 m
Duration: 50 min
- 26 ℃
- Slight - able to hold position with little effort.
- To many divers in the sandy area. And, there're a group of diver who did a course training there
The reef manta ray (Manta alfredi) is a species of ray in the family Mobulidae, the largest rays in the world. Among generally recognized species, it is the second-largest species of ray, only surpassed by the giant oceanic manta ray
Not to be confused with the blacktip shark, Carcharhinus limbatus. The blacktip reef shark (Carcharhinus melanopterus) is a species of requiem shark, family Carcharhinidae, easily identified by the prominent black tips on its fins (especially on the first dorsal fin and the caudal fin). Among the most abundant sharks inhabiting the tropical coral reefs of the Indian and Pacific Oceans, this species prefers shallow, inshore waters, and its exposed first dorsal fin is a common sight in the region. Most blacktip reef sharks are found over reef ledges and sandy flats, though they have also been known to enter brackish and freshwater environments. This species typically attains a length of 1.6 m (5.2 ft). Blacktip reef sharks have extremely small home ranges and exhibit strong site fidelity, remaining within same local area for up to several years at a time. They are active predators of small bony fishes, cephalopods, and crustaceans, and have also been known to feed on sea snakes and seabirds. Accounts of the blacktip reef shark's life history have been variable and sometimes contradictory, in part reflecting geographical differences within the species. Like other members of its family, this shark is viviparous with females giving birth to two to five young on a biennial, annual, or possibly biannual cycle. Reports of the gestation period range from 7–9, to 10–11, to possibly 16 months. Mating is preceded by the male following closely behind the female, likely attracted by her chemical signals. Newborn sharks are found further inshore and in shallower water than adults, frequently roaming in large groups over areas flooded by high tide. Timid and skittish, the blacktip reef shark is difficult to approach and seldom poses a danger to humans unless roused by food. However, people wading through shallow water are at risk of having their legs mistakenly bitten. This shark is used for its meat, fins, and liver oil, but is not considered to be a commercially significant species. The International Union for Conservation of Nature has assessed the blacktip reef shark as Near Threatened. Although the species as a whole remains widespread and relatively common, overfishing of this slow-reproducing shark has led to its decline at a number of locales.
Other impacts may sometimes be seen on coral reefs. These include evidence of bomb or cyanide fishing, sedimentation, pollution or trash
Poor diver etiquette, including poor buoyancy control, improperly secured gear, excessive photography flashes, and careless fin kicks, can result in diver induced damage to coral reefs.
Bleaching occurs when corals expel their symbiotic zooxanthellae - pigmented, algae-like protozoa that live within the coral's cells. High temperature, pollution or other stresses can cause the coral to expel its zooxanthellae, leading to a lighter or complete loss of color.
Boat anchors can cause significant physical damage to corals, especially at reef sites that receive a lot of boat traffic and where insufficient moorings are available. Heavy anchors can smash even the most sturdy corals, while anchor chains and lines can scrape coral and remove living tissue, or wrap around corals and cause damage as the lines move in the water.