Black Tip Reef sharks
The blacktip reef shark (Carcharhinus melanopterus) is a species of requiem shark, in the family Carcharhinidae, easily identified by the prominent black tips on its fins (especially on the first dorsal fin and its caudal fin). Among the most abundant sharks inhabiting the tropical coral reefs of the Indian and Pacific Oceans, this species prefers shallow, inshore waters. Its exposed first dorsal fin is a common sight in the region. The blacktip reef shark is usually found over reef ledges and sandy flats, though it has also been known to enter brackish and freshwater environments. It typically attains a length of 1.6 m (5.2 ft).
Stingrays are common in coastal tropical and subtropical marine waters throughout the world. Some species, such as Dasyatis thetidis, are found in warmer temperate oceans, and others, such as Plesiobatis daviesi, are found in the deep ocean. The river stingrays, and a number of whiptail stingrays (such as the Niger stingray), are restricted to fresh water. Most myliobatoids are demersal (inhabiting the next-to-lowest zone in the water column), but some, such as the pelagic stingray and the eagle rays, are pelagic.
There are about 220 known stingray species organized into ten families and 29 genera. Stingray species are progressively becoming threatened or vulnerable to extinction, particularly as the consequence of unregulated fishing. As of 2013, 45 species have been listed as vulnerable or endangered by the IUCN. The status of some other species is poorly known, leading to their being listed as data deficient
Green Sea Turtle
This sea turtle's dorsoventrally flattened body is covered by a large, teardrop-shaped carapace; it has a pair of large, paddle-like flippers. It is usually lightly colored, although in the eastern Pacific populations parts of the carapace can be almost black. Unlike other members of its family, such as the hawksbill sea turtle, C. mydas is mostly herbivorous. The adults usually inhabit shallow lagoons, feeding mostly on various species of seagrasses. The turtles bite off the tips of the blades of seagrass, which keeps the grass healthy.
Like other sea turtles, green sea turtles migrate long distances between feeding grounds and hatching beaches. Many islands worldwide are known as Turtle Island due to green sea turtles nesting on their beaches. Females crawl out on beaches, dig nests and lay eggs during the night. Later, hatchlings emerge and scramble into the water. Those that reach maturity may live to 80 years in the wild.
The coastal environments of Moorea offer an unparalleled opportunity for studies of coral reef ecosystems. An offshore barrier reef forms a system of shallow (mean depth ~ 5-7 m), narrow (~ 0.8-1.5 km wide) lagoons around the 60 km perimeter of Moorea. All major coral reef types (e.g., fringing reef, lagoon patch reefs, back reef, barrier reef and fore reef) are present and accessible by small boat. Prior to 2008, the reefs were in excellent condition and had been subjected to relatively few natural disturbances during the last several decades. An outbreak of the Crown-of-Thorns seastar (Acanthaster planci) that began in 2007 and a near miss.
The rich research opportunities afforded by the reefs of Moorea are greatly facilitated by the infrastructure and the ease with which field research can be conducted. The field portion of the Moorea Coral Reef LTER is staged from the Richard B. Gump South Pacific Research Station on Cooks Bay on the north shore of Moorea, which has been operated by the University of California since the early 1980's. Station facilities include several laboratory buildings, a flow-through sea water system, a dock, launch ramp, a fleet of small boats and vehicles, a SCUBA compressor and dive lockers. Station housing includes a dormitory and several bungalows.
The playful spinner dolphin makes itself known with a splash. Skilled acrobats, the small dolphins regularly leap out of the water and perform complicated aerial maneuvers. They can spin multiple times in one leap, which can be nearly 10 feet high.The leaping and spinning likely serve several purposes, including the removal of irksome remoras, fish that latch on to eat parasites. Biologists also think the dolphins use their moves to communicate, each one signaling something different: “Let’s go” or “Danger!” or “I find you attractive.”
Like other dolphins, spinners also vocalize with whistles, echolocation clicks, and other sounds.
The lemon shark (Negaprion brevirostris) is a species of shark from the family Carcharhinidae. Lemon sharks can grow to 3.4 metres (11 ft) in length. They are often found in shallow subtropical waters and are known to inhabit and return to specific nursery sites for breeding. Often feeding at night, these sharks use electroreceptors to find their main source of prey: fish. Lemon sharks enjoy the many benefits of group living such as enhanced communication, courtship, predatory behavior, and protection. This species of shark gives birth to live young, and the females are polyandrous and have a biennial reproductive cycle. Lemon sharks are not thought to be a large threat to humans. The lemon shark's life span is unknown, but the average shark is 25 to 30 years oldLemon sharks feed at night and are mainly piscivorous; however, they have been known to feed on crustaceans and benthic organisms. Intraspecific predation, or cannibalism, of juvenile lemon sharks by larger conspecifics has also been documented. Rather than feeding randomly, lemon sharks display a high degree of preference for certain species and size of prey when environmental conditions are favorable. They also tend to prefer a prey when it is more abundant and available. Lemon sharks feed selectively on species that are slower and more easily captured by using a stalking technique. For example, parrotfish and mojarras are common prey in the Bahamas because they use camouflage rather than an escape response and are vulnerable due to their stationary foraging behavior. Lemon sharks feed on prey that are intermediate in size compared to other available prey. This tendency can be explained by the tradeoff between the probability of capture and the profitability when it comes to prey size. The general trend in the foraging behavior of lemon sharks conforms to the optimal foraging theory, which suggests a positive relationship between prey selectivity and availability.