March 12, 2026 — NOAA Fisheries scientists have found telltale changes in cool, highly productive water upwelling along the West Coast. These changes can provide “an early warning system” signaling greater risk of humpback whales getting entangled in fishing gear.
The wind-driven upwelling of cold, deep-ocean water fuels the West Coast’s rich coastal ecosystem. It attracts marine life to the cool corridor where the nutrient-rich water rises along the coast. The problem is that whales drawn to plentiful prey become entangled at high rates in gear from commercial fisheries attracted to the same productive waters.
Scientists found that entanglements increase especially when the cool water corridor shrinks in what they call “habitat compression.” This draws the whales into even closer proximity to fishing gear with lines to the surface.
California and other West Coast states have restricted lucrative fisheries for Dungeness crab in recent years to avoid entangling protected whales. NOAA Fisheries and others are also exploring new fishing technologies that could reduce entanglement risk.
Earlier research in 2023 found that changes in the cool waters could forecast marine conditions that increase risk of whale entanglements up to 6–12 months in advance. NOAA Fisheries and NOAA’s Physical Sciences Laboratory produced draft forecasts based on the findings. New research in PLOS Climate confirms the forecasts are accurate and could provide valuable intelligence on how to reduce entanglement risk so fisheries can continue their important contributions to the coastal economy.
Earlier research had suggested a connection between the ocean changes and entanglement risk; the new study confirmed the link and showed how to measure the changes. California fishermen welcomed the research insight, saying it could better help assess the risk of entanglements. They noted that fishing crews have local insight—such as details of currents—that can help interpret the research findings for certain areas of the coast.
“That is one piece of information, but a lot of other factors are also at play,” said Dick Ogg, who has fished for crab and other species off Northern California for almost 30 years. “We need to make decisions based on the whole picture.”