Marine resources are economically significant due to their vast diversity and the essential services they provide, supporting numerous industries and livelihoods globally. These resources encompass living organisms, non-living materials, and the ocean's capacity to provide energy and facilitate trade.

One of the most direct economic contributions comes from fisheries and aquaculture. The global fishing industry provides food security and employment for millions. For example, the tuna industry alone is a multi-billion dollar enterprise, supporting economies in many Pacific island nations. Aquaculture, or fish farming, has grown significantly to meet increasing demand, with countries like China being major producers of farmed fish and shellfish, contributing substantially to their GDP.

Energy resources from the ocean are also crucial. Offshore oil and natural gas extraction, particularly in regions like the North Sea, Gulf of Mexico, and Persian Gulf, represents a massive economic sector. Beyond fossil fuels, renewable marine energy sources like offshore wind farms (e.g., in the North Sea), tidal power (e.g., La Rance Tidal Power Plant in France), and wave energy are emerging, promising sustainable economic growth.

Mineral resources found on the seafloor, such as polymetallic nodules (rich in manganese, nickel, copper, and cobalt) and seafloor massive sulfides, hold immense future economic potential, although their extraction is currently limited and controversial. Sand and gravel, extracted from coastal areas, are vital for construction.

Furthermore, marine biotechnology is a rapidly expanding field. Marine organisms are sources of novel compounds with pharmaceutical applications (e.g., anti-cancer drugs from sponges), industrial enzymes, and cosmetics, creating new high-value industries.

Lastly, the ocean facilitates global trade and tourism. Shipping lanes are the backbone of international commerce, with major ports acting as economic hubs. Coastal and marine tourism, including activities like diving, cruising, and beach holidays, generates billions of dollars annually, supporting local economies in popular destinations like the Caribbean, Mediterranean, and Southeast Asia.