When it comes to the movement of nutrients in the ocean, we think of run-off from rivers, upwelling along coasts, and convective currents. We don’t typically think about animal migrations, but a new study of baleen whales (including species like humpbacks and right whales) suggests that these massive mammals provide a small but critical spreading service.
These whales feed in cold, nutrient-rich waters, like those in the Arctic, then travel thousands of kilometers to warm but nutrient-poor tropical waters to birth and raise calves. During that time, mothers do not hunt or eat; they live off their fat stores, which they also use to make milk for their offspring. Although they’re not eating during this time, they do still urinate, and it’s this activity that, according to researchers, adds some 3,000 tons of critical nitrogen to these areas. Since nitrogen is often a limited resource in these tropical waters, the whales’ urine may act like a fertilizer shipment for other species in their breeding grounds. (Image credit: C. Le Duc; research credit: J. Roman et al.; via Eos)
