More than five decades ago, the National Oceanic and Atmospheric Administration (NOAA) started measuring fish populations. 

Today, scientists and fishermen alike are striving to get better at determining how many fish there are in the sea. Among the many reasons for wanting a clearer picture of the ocean's population is a broad desire to protect marine ecosystems in the decades and centuries to come.

Gastropod, bioGraphic, and The Atlantic have joined forces to explore some of the new techniques -- including AI, drones, and autonomous submarines -- being deployed to improve ocean censuses. 

(Photo by Jeff Rotman)