Abstract
Population models are based upon the ideology that removing large, old
individuals provides space for young, fast-growing counterparts that can
maximize (fisheries) yields while maintaining population and ecosystem
stability. Yet, we revealed that compensatory density dependence only
existed for 49% of target coral-reef fishes exposed to growing fishing
pressure across Pacific islands. Remaining species slowly disappeared
from landings and reefs with limited population replenishment. To
understand these remarkable differences, we constructed phylogenies for
dominant fish families and discovered that large patristic distances
between sister species, or greater isolation, predicted size-and-age
truncation. Isolated species appeared to have greater niche dominance or
breadth, supported by their faster growth rates and group foraging
behavior. In contrast, closely related species may have more restricted,
realized niches that led to their disappearance and replacement.
Phylogenetic attributes offered novel guidance to proactively manage
multispecies fisheries and improve our understanding of ecological
niches and ecosystem stability.