Overview

• Researchers conducted four expeditions in the North Pacific Transition Zone to collect water samples, phytoplankton and ocean dynamic measurements.
• Isotopic analysis by the University of Hawaii team distinguished industrial iron from natural sources and quantified its share in surface waters.
• Additional iron from pollution fuels a stronger spring phytoplankton bloom and accelerates nutrient depletion leading to earlier summer scarcity.
• The fertilization effect has driven the boundary between nutrient-poor and nutrient-rich waters northward, a trend amplified by ocean warming.
• Scientists warn that these shifts in primary production could cascade through marine food webs and alter fish and other sea life biomass.