COS 6-6
Fish community reassembly after a coral mass mortality: Higher trophic groups are subject to increased rates of extinction
Our understanding of community dynamics
has been influenced by theories emphasizing 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. Here, we tracked reef fish community
reassembly after a catastrophic coral mortality in a relatively
unfished archipelago. We extend the stochastic model underlying
MacArthur and Wilson's Island Biogeography Theory to take into account for trophic identity.
Results/Conclusions
We calculated colonization and extinction rates calculated from decadal presence-absence data based
on i. species neutrality, ii. trophic identity and iii. site-specificity.
Our 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.