Describe how the mining of nodules may create problems between different countries.

Many thousands of square kilometres of the deep-sea floor are covered by metal-bearing nodules. They contain primarily manganese, but also nickel, cobalt and copper, which makes them economically promising. Although many countries and companies are already intensively investigating their distribution, it is not certain whether the manganese nodules will ever be mined. After all, at least for the intermediate future, there are enough metals available on land.