Question

Ocean water contains vast quantities of minerals . But their extraction is not always economically beneficial. What was the main diffculty to extract minrals from the ocean

Answer 1

The main difficulty to extract minerals from the ocean is that it is very expensive and difficult. This is because the minerals are stored under the seabed which is the lowest layer of the ocean. It is located between the continental shelve (shallow end) and the abyss which means that humans can barely collect these minerals expect for if it is el Niño year where the prevailing wind (trade wind) changes direction and the current with cold water brings minerals by increasing pressure there to move the minerals upwards.

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Answer 2

1) it is very expensive.
2) as they are at sea level or at seabed it very hard to extract.