Data from: Size, age, and habitat determine effectiveness of Palau's Marine Protected Areas

Palau has a rich heritage of conservation that has evolved from the
traditional moratoria on fishing, or "bul", to more western
Marine Protected Areas (MPAs), while still retaining elements of customary
management and tenure. In 2003, the Palau Protected Areas Network (PAN)
was created to conserve Palau's unique biodiversity and culture, and
is the country's mechanism for achieving the goals of the Micronesia
Challenge (MC), an initiative to conserve ?30% of near-shore marine
resources within the region by 2020. The PAN comprises a network of
numerous MPAs within Palau that vary in age, size, level of management,
and habitat, which provide an excellent opportunity to test hypotheses
concerning MPA design and function using multiple discreet sampling units.
Our sampling design provided a robust space for time comparison to
evaluate the relative influence of potential drivers of MPA efficacy. Our
results showed that no-take MPAs had, on average, nearly twice the biomass
of resource fishes (i.e. those important commercially, culturally, or for
subsistence) compared to nearby unprotected areas. Biomass of non-resource
fishes showed no differences between no-take areas and areas open to
fishing. The most striking difference between no-take MPAs and unprotected
areas was the more than 5-fold greater biomass of piscivorous fishes in
the MPAs compared to fished areas. The most important determinates of
no-take MPA success in conserving resource fish biomass were MPA size and
years of protection. Habitat and distance from shore had little effect on
resource fish biomass. The extensive network of MPAs in Palau likely
provides important conservation and tourism benefits to the Republic, and
may also provide fisheries benefits by protecting spawning aggregation
sites, and potentially through adult spillover.