Hobbies And Interests
Location
Spinner dolphins thrive in tropical and subtropical climates and can be found in the Pacific, Atlantic and Indian oceans. Dolphins near Hawaii and Central America spend the day swimming at depths of 3,000 feet, however at night they migrate towards the surface of the water. Staying close to the ocean floor allows them to detect the shadows of would-be predators such as sharks and killer whales against the sand. Costa Rican dolphins stay closer to coastal areas, preferring to swim up to 90 miles away from the shore.
Distribution
Dolphins travel in large groups of up to 1,000 and they emit sounds that are imperceptible to the human ear to alert each other in the case of danger. They are also known to travel with other species such as yellow-fin tuna, which has resulted in the slaughter of many dolphins by fishermen hunting tuna fish. This has resulted in an 80 percent decline in the population since 1960. Dolphins are active at night and rest during the day, however they are still conscious and can still see, meaning they are able to avoid danger. Their "sleep" merely consists of turning their sonars off.
Feeding
As they spend most of their time at the bottom of the ocean, they feed on small deep-ocean creatures such as squid, jellyfish, shell-less snails and lantern fish. Although they have teeth, they use them to hold their prey still rather than for chewing. They remain in large groups when diving to the ocean floor to feed.
Importance
To their detriment, spinner dolphins are important to the fisheries industry as fishermen will deliberately seek to capture the dolphins with nets, knowing that yellow-fin tuna fish will usually be found among them as they travel together. They are also used as shark bait and consumed by humans in Japan and certain South American countries.