The discovery and naming of the first HNLC region, the North Pacific, was formalized in a seminal paper published in 1988. The study concluded that surface waters of the eastern North Pacific are generally dominated by picoplankton despite the relative abundance of macronutrients. In other words, larger phytoplankton, such as diatoms which thrive in nutrient-rich waters, were not found. Instead, the surface waters were replete with smaller pico- and nanoplankton. Based on laboratory nutrient experiments, iron was hypothesized to be a key limiting micronutrient.