Revealing unexpected productivity around the Hawaiian Islands

Satellite image of Hawaii. Credit: NOAA

The typically nutrient-poor waters around the Hawaiian Islands are often referred to as a “marine desert,” but a new study has identified surprising bursts of productivity off the northern coasts of the islands during winter. Using satellite data and regional ocean models, researchers found that these high-chlorophyll events, which signal increased marine life, are caused by small circular water currents called eddies on the opposite side of the island chain. These eddies stir up nutrients from deeper waters, which are transported around the islands to fuel phytoplankton blooms. This discovery reveals a new, far-reaching mechanism for nutrient distribution in otherwise nutrient-poor regions and sheds light on how ocean dynamics, like eddies, can significantly impact ecosystems. This work, published in JGR Oceans, provides key insights for managing and protecting ocean ecosystems.