Invasions and extinctions reshape coastal marine food webs

• Published in: PloS one Vol. 2; no. 3; p. e295
• Main Authors: Byrnes, Jarrett E, Reynolds, Pamela L, Stachowicz, John J
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 14.03.2007; Public Library of Science (PLoS)
• Subjects: Animals; Biodiversity; Biomass; Carnivores; Coastal ecosystems; Coastal management; Coastal zone management; Community ecology; Conservation of Natural Resources; Detritivores; Ecology; Ecosystem; Ecosystem biology; Ecosystem management; Ecosystems; Endangered & extinct species; Environmental changes; Extinct species; Extinction (Biology); Extinction, Biological; Feeders; Filter feeders; Fishes; Food Chain; Food chains; Food webs; Grasses; Halophila; Herbivores; Human-environment interactions; Humans; Invasions; Invasive species; Laboratories; Limnology; Lutrinae; Marine ecology; Marine ecosystems; Marine systems; Plankton; Plankton - genetics; Population biology; Predators; Predatory Behavior; Seawater; Species Specificity; Strategic management; Studies; Taxonomy; Trophic levels; Wadden Sea; California
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0000295

The biodiversity of ecosystems worldwide is changing because of species loss due to human-caused extinctions and species gain through intentional and accidental introductions. Here we show that the combined effect of these two processes is altering the trophic structure of food webs in coastal marine systems. This is because most extinctions ( approximately 70%) occur at high trophic levels (top predators and other carnivores), while most invasions are by species from lower trophic levels (70% macroplanktivores, deposit feeders, and detritivores). These opposing changes thus alter the shape of marine food webs from a trophic pyramid capped by a diverse array of predators and consumers to a shorter, squatter configuration dominated by filter feeders and scavengers. The consequences of the simultaneous loss of diversity at top trophic levels and gain at lower trophic levels is largely unknown. However, current research suggests that a better understanding of how such simultaneous changes in diversity can impact ecosystem function will be required to manage coastal ecosystems and forecast future changes.