Celebrate the Ocean

Join us as we celebrate and learn about our world ocean during National Ocean Month.

We're celebrating our ocean throughout the month of June. You can follow along on Twitter, Facebook, and Instagram. Look for #30daysofocean.

A sunset viewed from Kure Atoll, located near Midway Atoll in the Northwestern Hawaiian Islands. Image credit: Robert Schwemmer, NOAA National Marine Sanctuaries

One Global Ocean

While there is only one global ocean, the vast body of water that covers 71 percent of the Earth is geographically divided into distinct named regions. The boundaries between these regions have evolved over time for a variety of historical, cultural, geographical, and scientific reasons. Historically, there are four named oceans: the Atlantic, Pacific, Indian, and Arctic. However, most countries—including the United States—now recognize the Southern (Antarctic) as the fifth ocean. The Pacific, Atlantic, and Indian are known as the three major oceans.

Kelp forests within Monterey Bay National Marine Sanctuary

Ocean Life

Given the vast size of the ocean, it is impossible to know the exact number of species that live there. Researchers around the world continue to study marine life and habitats to help develop new strategies to preserve vital ocean ecosystems. Scientists estimate that 91 percent of ocean species have yet to be classified, and that 95 percent of the ocean remains unexplored. While these statistics may sound daunting, they have not stopped the global scientific community from striving to amass as much knowledge as possible about ocean life.

An illustration depicting a NOAA ship conducting a hydrographic survey using sonar.


Hydrography is the science that measures and describes the physical features of the navigable portion of the Earth's surface and adjoining coastal areas. Hydrographic surveyors study these bodies of water to see what the "floor" looks like. NOAA conducts hydrographic surveys to measure the depth and bottom configuration of water bodies. This information is vital to navigating the ocean and our nation's waterways.

coral reef

Coral Reefs

2018 is the International Year of the Reef. This yearlong designation aims to strengthen awareness globally about the value of, and threats to, coral reefs and associated ecosystems; promote partnerships between governments, the private sector, academia and civil society on the management of coral reefs; identify and implement effective management strategies for conservation, increased resiliency and sustainable use of these ecosystems and promoting best practices; and share information on best practices in relation to sustainable coral reef management.