Loss of a Harvested Fish Species Disrupts Carbon Flow in a Diverse Tropical River

• Published in: Science (American Association for the Advancement of Science) 2006-08, Vol.313 (5788), p.833-836
• Main Authors: Taylor, Brad W, Flecker, Alexander S, Hall, Robert O. Jr
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal Migration; Animal, plant and microbial ecology; Animals; Applied ecology; Aquatic ecosystems; Biofilms; Biological and medical sciences; Biomass; Body Size; Carbon; Carbon - metabolism; Conservation of Natural Resources; Conservation, protection and management of environment and wildlife; Ecosystem; Ecosystems; Environmental degradation: ecosystems survey and restoration; Evolution; Feeding Behavior; Fish; Fisheries; Fishes - anatomy & histology; Fishes - physiology; Food Chain; Fresh water ecosystems; Freshwater; Freshwater ecosystems; Freshwater fishes; Fundamental and applied biological sciences. Psychology; Lotic systems; Marine ecology; Marine ecosystems; Population Dynamics; Predators; Prochilodus mariae; Rivers; Seasons; South America; Species; Synecology; Tropical Climate
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1128223

Harvesting threatens many vertebrate species, yet few whole-system manipulations have been conducted to predict the consequences of vertebrate losses on ecosystem function. Here, we show that a harvested migratory detrital-feeding fish (Prochilodontidae: Prochilodus mariae) modulates carbon flow and ecosystem metabolism. Natural declines in and experimental removal of Prochilodus decreased downstream transport of organic carbon and increased primary production and respiration. Thus, besides its economic value, Prochilodus is a critical ecological component of South American rivers. Lack of functional redundancy for this species highlights the importance of individual species and, contrary to theory, suggests that losing one species from lower trophic levels can affect ecosystem functioning even in species-rich ecosystems.