Biological oceanographer Hugh Ducklow studies the marine food web, and how it interacts with the physical properties of the oceans. Much of his work is through the U.S. Long Term Ecological Research Program (LTER), in which researchers have for decades investigated trends across 28 land and marine regions in the United States, along with a few sites elsewhere. In addition to the open ocean, studies encompass deserts, coasts, rivers, forests and grasslands. From 2012 to 2018, while based at Columbia University's Lamont-Doherty Earth Observatory, Ducklow led the Palmer Station LTER site, the base for yearly cruises through 800 kilometers of icy waters off the Antarctic Peninsula.