Oceans of oxygen, gone

All animals have an effect on the environment, but some key species – called ecosystem engineers – can have a particularly large influence. Their impact can be positive, by creating and maintaining habitats and increasing biodiversity, but they can also be negative, by destroying habitats and reducing biodiversity. Interestingly, the magnitude of the effect that an ecosystem engineer has on the environment is often not a reflection of their size. Some are huge, such as elephants, which provide water for other animals during the dry season by digging up desiccated water holes until water flows. But others are tiny, such as plankton in the oceans, which influence the amount of light reaching the plants down below. In particular, the transportation of marinederived nutrients by animals is vital in shaping not only oceans but also freshwater and terrestrial ecosystems. Ivan González-Bergonzoni from the Universidad de la República, Uruguay, and his international team of researchers decided to observe this phenomenon from a seabird’s perspective.