An international study led by the Institute of Environmental Science and Technology at the Universitat Autònoma de Barcelona (ICTA-UAB), Spain, has investigated how marine ecosystems responded to past episodes of ocean deoxygenation. To do so, researchers studied fossil remains of lanternfish—one of the most abundant and important fish families of the deep ocean—preserved in seabed sediments of the Eastern Mediterranean, dating back more than 10,000 years. Their findings have been published in the journal Communications Earth & Environment.