Question

What are the ill effects of human induced deposition in the marine beds?​

Answer 1

Answer:

Mining on the ocean floor could do irreversible damage to deep sea ecosystems, says a new study of seabed mining proposals around the world. The deep sea (depths below 200m) covers about half of the Earth’s surface and is home to a vast range of species.

Little is known about these marine environments, and researchers from the University of Exeter and Greenpeace say mining could have “long-lasting and unforeseen consequences”– not just at mining sites but also across much larger areas.

The study, published in Frontiers in Marine Science, is the first to give a global overview of all current plans to mine the seabed, in both national and international waters, and looks at the potential environmental impactsincluding physical destruction of seabed habitats, creation of large underwater plumes of sediment and the effects of chemical, noise and light pollutionarising from mining operations.

“Our knowledge of these ecosystems is still limited, but we know they’re very sensitive,” said Dr David Santillo, a marine biologist and senior Greenpeace scientist based at the University of Exeter. “Recovery from man-made disturbance could take decades, centuries or even millennia, if these ecosystems recover at all.”

“As we learn more about deep sea ecosystems and the role of oceans in mitigating climate change, it seems wise to take precautions to avoid damage that could have long-lasting and unforeseen consequences.”

Despite the term “mining”, much seabed mining would involve extraction of minerals over very wide areas of the sea floor rather than digging down to any great depth, potentially leaving a vast “footprint” on the deep-sea habitats in which these mineral deposits occur.

Rising demand for minerals and metals, including for use in new technology, has sparked renewed interest in seabed mining.

Some operations are already taking place, generally at relatively shallow depths near national coastlines.

The first commercial enterprise in deeper waters, expected to target mineral-rich sulphides at depths of 1.5-2km off Papua New Guinea, is scheduled to begin early in 2019.