2001: Oceana is established by The Pew Charitable Trusts, Oak Foundation, Marisla Foundation (formerly Homeland Foundation), and the Rockefeller Brothers Fund.

2002: Oceana merges with American Oceans Campaign, founded by actor/environmentalist Ted Danson.

2003: Official opening of Oceana’s South American Oceans office in Santiago de Chile. September 2003: Oceana strengthens European Office in Madrid, Spain.

2004: Oceana Europe opens its new branch in Brussels, Belgium. 

2005: After 5 months documenting fragile marine ecosystem in North and Central American waters, the Oceana Ranger completes the transatlantic expedition.

2006: The first European expedition of the Oceana Ranger crosses the Mediterranean

2007:  The Oceana Ranger crosses again the Mediterranean studying vulnerable marine habitats, marine protected areas and documenting the impact of destructive fishing.

2008: Oceana Europe launches two expeditions at the same time. The Oceana Ranger expedition studies the Atlantic and the Bay of Biscay while the Oceana-Marviva expedition crosses the Mediterranean and reaches Greece.

2009: Oceana opens its new office in Belize.

2009: The Oceana Ranger documents the Canary Islands.

2010: Oceana launches two expeditions: the first to look into the consequences of the Deepwater Horizon oil spill in the Gulf of Mexico, and the second to document Western Mediterranean habitats on board the Oceana Ranger.

2011: Oceana opens a new office for the Baltic based in Copenhagen.

2011: The first Baltic expedition takes place. The Oceana Ranger explores seamounts and underwater canyons in Portutal and Spain.

2012:  The Baltic Expedition takes a closer look at areas studied in the previous year. The Oceana Ranger explores deep sea areas in the Atlantic and Mediterranean.

2013: Oceana discovers a species new to science, a giant foraminifer called Spiculosiphon oceana.

2013: The first coastal expedition in the Baltic Sea takes place, while the Oceana Ranger studies the unknown Emile Baudot escarpment.