Fish community reassembly after a coral mass mortality: higher trophic groups are subject to increased rates of extinction

• Published in: Ecology letters Vol. 18; no. 5; pp. 451 - 461
• Main Authors: Alonso, David, Pinyol-Gallemí, Aleix, Alcoverro, Teresa, Arthur, Rohan
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01.05.2015
• Subjects: Animals; Anthozoa; Archipelagoes; Biodiversity; Biogeography; community structure; Coral reef fish communities; Coral Reefs; corals; dispersal community assembly; Endangered & extinct species; Extinction; Extinction, Biological; fish communities; Fishes - classification; MacArthur and Wilson island biogeography; model validation; Models, Biological; Mortality; niche community assembly; Population Dynamics; post-disturbance community reassembly; Predators; Species extinction; stochastic extinction-colonisation models; Stochastic models; stochastic processes; trophic island biogeography; MacArthur and Wilson island biogeography; dispersal community assembly; stochastic extinction-colonisation models; post-disturbance community reassembly; trophic island biogeography; Coral reef fish communities; niche community assembly
• ISSN: 1461-023X; 1461-0248; 1461-0248
• DOI: 10.1111/ele.12426

Since Gleason and Clements, our understanding of community dynamics has been influenced by theories emphasising either dispersal or niche assembly as central to community structuring. Determining the relative importance of these processes in structuring real‐world communities remains a challenge. We tracked reef fish community reassembly after a catastrophic coral mortality in a relatively unfished archipelago. We revisited the stochastic model underlying MacArthur and Wilson's Island Biogeography Theory, with a simple extension to account for trophic identity. Colonisation and extinction rates calculated from decadal presence‐absence data based on (1) species neutrality, (2) trophic identity and (3) site‐specificity were used to model post‐disturbance reassembly, and compared with empirical observations. Results indicate that species neutrality holds within trophic guilds, and trophic identity significantly increases overall model performance. Strikingly, extinction rates increased clearly with trophic position, indicating that fish communities may be inherently susceptible to trophic downgrading even without targeted fishing of top predators.