Composition of cetacean communities worldwide shapes their contribution to ocean nutrient cycling

• Published in: Nature Communications
• Main Authors: Lola Gilbert, Tiphaine Jeanniard-du-Dot, Matthieu Authier, Tiphaine Chouvelon, Jérôme Spitz
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Portfolio 2023
• Subjects: Science; Q; baleen whales
• Online Access: https://doi.org/10.1038/s41467-023-41532-y; https://doaj.org/article/48168271c3f34acb842147c601905227

Abstract Defecation by large whales is known to fertilise oceans with nutrients, stimulating phytoplankton and ecosystem productivity. However, our current understanding of these processes is limited to a few species, nutrients and ecosystems. Here, we investigate the role of cetacean communities in the worldwide biological cycling of two major nutrients and six trace nutrients. We show that cetaceans release more nutrients in mesotrophic to eutrophic temperate waters than in oligotrophic tropical waters, mirroring patterns of ecosystem productivity. The released nutrient cocktails also vary geographically, driven by the composition of cetacean communities. The roles of small cetaceans, deep diving cetaceans and baleen whales differ quantitatively and functionally, with contributions of small cetaceans and deep divers exceeding those of large whales in some areas. The functional diversity of cetacean communities expands beyond their role as top predators to include their role as active nutrient vectors, which might be equally important to local ecosystem dynamics.