Scientists find whales move nutrients across oceans through urine

A Nature Communications study reports that great whales move thousands of tons of nitrogen each year from polar feeding zones to tropical waters, mainly as urea-rich urine, a process researchers call the "great whale pee funnel".

A new study published in Nature Communications describes how migrating great whales transfer nutrients across ocean basins. Researchers report that whales feed in productive polar waters, metabolize stored fat during migration and release large volumes of nitrogen-rich urine in tropical and coastal areas. Scientists have named this large-scale transfer the "great whale pee funnel." The finding builds on earlier work about the "whale pump," which described surface nutrient release from whale feces. Key findings: - The research team estimates whales release over 4,000 tons of nitrogen annually, mostly as urea-rich urine. - Whales move more than 45,000 tons of biomass per year, a figure the study says is comparable to major natural upwelling systems. - In regions where whales pass through, available nitrogen levels can more than double. - Baleen whales are described as "capital breeders," feeding in high-latitude areas and fasting while migrating, which increases urine output. - Researchers note that before commercial whaling, cross-hemisphere nutrient flows from whales may have been up to three times greater. Summary: The study suggests whale migrations shift substantial amounts of nitrogen from polar feeding zones to tropical and coastal waters, where that nitrogen can support algae, plankton, and coral. Authors say the "great whale pee funnel" complements the previously described "whale pump" and points to a broader role for whales in ocean nutrient cycling. Researchers also note that rebuilding whale populations is linked to restoring larger nutrient flows that were reduced by commercial whaling. Undetermined at this time.