Should the harvesting of krill in the antarctic region continue to be restricted, or should fisheries all over the world be allowed to harvest krill at any rate they choose?

Depends on your viewpoint but it's generally agreed by scientists and conservationists that krill harvesting restrictions are necessary despite this meaning less profit for companies selling them. This is because krill are an essential part of the food chain in this area, and unregulated fishing could mean there are not enough left to breed in order to sustain the population. This could make the ecosystem very unstable which would also have the knock on affect of there eventually being no krill left for these fisheries to harvest anyway.

The answer would be sand and gravel