June 8, 2011 --
In celebration of World Ocean's Day today, Discovery News highlights some of our favorite advancements in marine science and technology. What are some of yours? Tell us in the comments section below. This image shows the species of clusterwink snail, Hinea brasiliana, producing light using a phenomenon known as bioluminescence. Biologists discovered that the snail scatters light in all directions, rather than focusing it into a single beam. The light creates the illusion that the snail is bigger than it really is, giving it a glowing presence for warding off predators. The Scripps marine biologists who studied the snail are now investigating how its luminescent properties could be applied to the fields of optics or bioengineering.
Up to 420 whale sharks (Rhincodon typus) gathered off the coast of the Yucatán Peninsula in Mexico, forming the world's largest known assembly of this species. The 2009 discovery, published in the scientific journal PLoS ONE in April 2011, counters the widely held belief that whale sharks, which can weigh more than 79,000 pounds, are solitary animals. The sharks congregated in two areas, with one group feeding on the fish eggs of spawning little tunny (Euthynnus alletteratus), a member of the mackerel family; the other group feeding on copepods (small crustaceans) and shrimp.
Every year, thousands of loggerhead sea turtles hatch on the beaches of Florida and flap desperately toward the sanctuary of the surf. Thirty-one years later, the surviving females return for the first time, to lay eggs and begin the cycle anew. The intervening three decades are fraught with peril, from natural predators to oil spills to entanglement in fishing gear. And yet, the biggest factor determining how many turtles survive to sexual maturity is none of those. It is, simply, the conditions in the ocean in that very first year, when the hatchlings make it into the water and begin their battle for survival. Correlating nesting counts with climate shows that over time, the strong year-to-year swings that frequently occur in nesting counts can be tied to inter-annual temperature variations three decades previously.
The race is on for the next human return to the deepest point in the ocean: the subduction zone of the Pacific's Mariana Trench. At 36,201 feet (11,033 meters), the only manned exploration of the site was by Captain Don Walsh, USN (Ret.) and the late oceanographer Jacques Piccard in 1960 using the aviation-fuel-filled Trieste bathyscaphe. Now three ocean adventure seekers are competing for the return title: Triton Submarines CEO Bruce Jones, Hollywood Director James Cameron, and British mogul Richard Branson. Cameron's commissioned submersible will be made from composite materials and powered with an electric motor. Branson's one-person submersible is made from carbon fiber, titanium, and has a quartz viewing dome. His sub, equipped with wings, is expected to "fly" to the deepest parts of every ocean basin. The Triton Submarine, pictured here, like most other submersibles uses an acrylic dome and is currently certified for 3,300 feet deep. Jones is now engineering the Triton 36,000 with a glass dome for repeated journeys to the ocean's deepest point.
In November last year, biologists unveiled a gossamer, ghostly creature discovered in the deepest reaches of the ocean between Indonesia and the Philippines. The squidworm, up to 9.4 centimeters (3.7 inches) in length, is far more elegant than its name would suggest. Swimming upright, it navigates by moving two body-length rows of thin, paddle-shaped protrusions that cascade like dominoes. From the squidworm to the fish in Bali, exploration of the ocean continues to reveal new species even after the decade-long Census of Marine Life has completed its survey.
A major flow of seawater known as the Agulhas Current -- the Indian Ocean's equivalent of the Gulf Stream -- carries warm water from the Tropics toward the southern pole along the southeast coast of Africa. When the saltier, denser Agulhas Current water reaches the tip of South Africa, most of it curls back eastward in the big Indian Ocean subtropical gyre, but some of it "leaks" across the tip of South Africa. In the past these escaped eddies likely brought the first great white sharks into the Mediterranean. If these leaks get bigger, however, what else are they capable of doing?
