Continental shelf.
Persian Gulf: 66% world's oil reserves.
Arguably the most important source of energy worldwide. Countries that possess oil have a great degree of political power.
Gas
Annotations:
Continental shelf.
Persian Gulf: 33% world's gas reserves.
One of the world's most valuable sources of energy.
Metals
Gold
Annotations:
Ocean floor.
Manganese
Annotations:
Ocean floor.
Nodules on abyssal plain.
Silver
Copper
Tin
Titanium
Cobalt
Minerals
Diamonds
Annotations:
Continental shelf off Africa and Indonesia.
Sulphur
Annotations:
Ocean ridges & rift valleys.
Sand
Annotations:
Continental shelf.
Gravel
Annotations:
Continental shelf.
Biotic resources
Fish
Annotations:
Overfishing of popular fish species has become an issue.
Unsustainable fishing is brought about through the use of trawlers and the accumulation of bycatch.
Line and pole fishing has been encouraged by NGOs to avoid catching the wrong fish.
Dolphins, sharks, and even whales have been known to get caught in trawler nets.
Red snapper
Cod
Shellfish
Shrimp
Underwater cables
Internet
Annotations:
Much of the world's connection to the internet is still maintained by cables between continents. Disruptions in these cables could have catastrophic effects to the world's economic systems, which nowadays are almost entirely run by computers communicating with each other.