Phytoplankton — the microscopic, plant-like organisms that make up the base layer of the oceanic food chain — might be in serious trouble. A 2010 paper suggested that their numbers have declined 40% since the 1950s, largely thanks to climate change. But that paper is controversial because the methods for counting phytoplankton haven't been particularly strong. Now, scientists at Plymouth University in the UK want to improve the data collection methods and they need your help. Do you sail, fish, travel, or work on the ocean? If so, then you can participate in a global citizen science project, helping scientists gather data on phytoplankton populations from diverse locations around the planet.