Data, the word, is plural. Everyday English slips into treating the word as a singular, data is, but data are. Understanding the biodiversity of the ocean requires data that are very very plural, the effort of thousands of scientists observing thousands of species. OBIS-SEAMAP plays an important role in centralizing the data we have for marine mammals, seabirds and sea turtles.

An observation of a single whale is valuable, and that single point also challenging to capture systematically. There’s the costs of time on a ship or plane, and the training to identify species at a distance in choppy seas. Or the engineering to develop a tracking tag, and the provisioning of tags that might never be recovered.

Analysis of a one animal, matched in season and space with others of its kind, begins to transform those data into knowledge about a species. Greater understanding develops as those movements are compared to other species – do they simply occupy the same habitat, or is there a mutual dependence? What were the water conditions on the days and locations these animals were present? Can we match remote sensing of the sea surface temperature to the animal’s position, or were clouds obscuring the satellite lens? Our grasp of biodiversity is built from many small measurements. in 2003, with a list of the thematic biodiversity databases it was bringing together, including OBIS-SEAMAP

In November of 1999, the first workshops took place to create an international ocean biodiversity information system (OBIS). Envisioned as a portal of all marine life data, it was aggregated from existing datasets and databases that had been making their way online as the web became a thing. By 2002, OBIS-SEAMAP ( was underway at Duke University, specializing in protected species. Starting with 49 datasets, it has expanded every few weeks ever since, currently encompassing 1526 datasets and millions of records of over 700 mammal, bird and turtle species. SEAMAP records are shared with website visitors and flow upwards to populate the encompassing “big” OBIS at, run by the United Nations International Oceanographic Data and Information program.

SEAMAP in 2004, with the earliest contributions of data concentrated in the North Atlantic
SEAMAP in 2021, with dataset coverage map greatly expanded

In February 2021 the OBIS-SEAMAP tools for exploring, visualizing and downloading data expanded too. This top-to-bottom rebuild of the application provides the biggest update to SEAMAP capabilities in a decade. Mapping search results now fills a browser window. You can take advantage of today’s high resolution screens to map out the dense points of a sea turtle telemetry track

Sea turtle tracking data from Dr. Catherine McClellen, combing density of animal observations with the telemetry lines from tags used to gather the dataset

This revision also fully incorporates a repository for models of cetacean habitat. Complementing empirical data served in the main mapping tool, SEAMAP is now a source of modeled behavior. Drawing on species density models commissioned by the US Navy, NOAA and BOEM, there are two applications, one covering Pacific and Gulf of Alaska study areas, another for the East Coast of the United States and Gulf of Mexico.

Tools displaying modeled density of North Atlantic right whales in June. The right side map overlays observation data of right whales in June queried from the primary SEAMAP database.

The revision also includes more contextual information, such as expanded species range maps, and quering data in commonly-used zones and boundaries.

While the Marine Geospatial Ecology Lab creates the mapping tools, the database and models exist because over 700 researchers share their scientific effort with the world, creating an ever-expanding understanding of habitat and biodiversity in an ocean that is changing fast.