Vast mountain ranges invisible from land dot the ocean floor yet remain largely unstudied. And for many of them, it may be too late.
Now, under the weight of extensive commercial fishing, many of these seamount ecosystems may collapse before they've ever been explored, scientists say. Very little is known about what researchers estimate to be about 100,000 uncharted undersea mountains.
One percent of such peaks that have been investigated so far were found to harbor extraordinary biological wealth.
But fishermen are damaging “seamounts” by dropping anchors and using heavy nets, scientists will claim as they announced the results of the global, decade-long Census of Marine Life at the Royal Institution in London.
Migrating predators such as great white sharks, turtles and tuna use the seamounts as refueling stops. Clouds of fish seek protection among the gardens of corals, anemones and sponges that thrive on their peaks, fed by nutrient-rich waters deflected up from the deep by their slopes. The mountains also act as biological stepping-stones, linking species across entire ocean basins.
Seamounts that are more than one mile (1.6 kilometers) high -- some 13,000 of them -- can be detected from space by their gravitational signature, which causes a bulge on the surface of the ocean. Smaller ones need to be detected by sonars on ships.
But where science lacked the funds to investigate them, fishermen have not, Dr. Timothy Shank, a biologist with Woods Hole Oceanographic Institution in Massachusetts, said, “There’s only one seamount chain I can think of that hasn’t been trawled -- Line Islands in the Pacific. So far it has been protected because it’s so remote.”
About three million tones of seafood are caught from seamounts every year, with a landed value of £2.6 billion ($4.1 billion,) according to a report in the journal Oceanography. Shank warned, “These are very fragile and slow-growing communities.”
The census began 10 years ago to create a solid base of knowledge about life in the sea and chart not only its diversity, abundance and distribution but also peer into its past and future. The £420 million project has involved more than 2,700 scientists from 80 nations. They logged more than 9,000 days at sea on 540 expeditions, and in the course of the decade have published more than 2,600 papers.
NewsCore contributed to this report