U.S. flag An official website of the United States government.

dot gov icon Official websites use .gov

A .gov website belongs to an official government organization in the United States.

https icon Secure websites use HTTPS

A small lock or https:// means you’ve safely connected to a .gov website. Share sensitive information only on official, secure websites.

Ocean Sampling Day

Crowd-sourcing global data on the ocean's smallest creatures

A Bucket of Ocean Data

Once a year, thousands of scientists and volunteers across the globe participate in Ocean Sampling Day, an international collaboration to collect water samples from the Earth's oceans and rivers. Here, Tiani Naholowaa collects water at a sampling site in Hawaii on June 21, 2014.

June 21, 2015, is the summer solstice and the longest day of the year. It's also the day that thousands of scientists and volunteers across the globe will participate in Ocean Sampling Day, an international collaboration to collect water samples from the Earth's oceans and rivers.

The purpose of Ocean Sampling Day is to collect baseline information on the diversity of marine microorganisms (also called microbes) so that changes in ocean ecosystems can be detected by comparing samples from the same locations over time. Marine microbes make up 98 percent of the biomass of the world ocean and are responsible for most of the biological activity there. Some are so tiny that up to a million of them live in just one milliliter of seawater. That's about one-fifth of a teaspoon! They also inhabit every part of the ocean, from the surface to the sea floor and even sub-seafloor rocks.

"Ocean Sampling Day provides a mechanism for detecting changes in microbial populations that may reveal clues to ocean health, and, ultimately, to the health of the planet," says Suzanne Skelley, director of the Cooperative Oxford Laboratory on Maryland's Eastern Shore.

Because microbes evolve rapidly in response to environmental changes, they are "canaries in the coal mine" of marine ecosystems. Detecting these changes, be they small or large, depends on scientists learning as much as they can about some of the world's tiniest organisms.

Scientists at the Cooperative Oxford Laboratory (COL) annually participate in Ocean Sampling Day. The lab combines the unique scientific, response, and management capabilities of NOAA, the Maryland Department of Natural Resources, and the U.S. Coast Guard. COL scientists define cause-and-effect relationships between ecosystem stressors and the health of coastal resources, and create products, models, and tools to inform public policies and coastal management decisions at the local, state, and national levels.