Final answer:
Fuels derived from organic matter in the ocean include biomass and hydrocarbons, specifically fossil fuels like coal, oil, and natural gas.
Step-by-step explanation:
Energy sources from the ocean that are derived from once-living organic matter include biomass and hydrocarbons. Fossil fuels such as coal, oil, and natural gas are created from organic matter consisting of prehistoric plants and animals, which were subjected to intense pressure and heat over millions of years, transforming them into energy-rich sources. While biomass is a renewable form of energy made from recently living organisms, fossil fuels are non-renewable as they take millions of years to form and are being depleted at a rate much faster than their formation.