Habitat reserves can promote ecological resilience to climate variability by supporting intact trophic webs and large-bodied individuals. Protection may also alter community responses to long-term climate change by offering habitat for range-shifting species. Here we analyse the species richness, diversity and functional traits of temperate reef fish communities over 20 years in a global warming hotspot and compare patterns in a marine reserve with nearby sites open to fishing. Species richness and diversity oscillated strongly on the decadal scale. Long-term warming signatures were also present as increasing functional trait richness and functional diversity, driven in part by a general increase in herbivores. Nevertheless, reserve sites were distinguished from fished sites by displaying: greater stability in some aspects of biodiversity; recovery of large-bodied temperate species; resistance to colonization by subtropical vagrants; and less pronounced increases in the community-averaged temperature affinity. We empirically demonstrate that protection from fishing has buffered fluctuations in biodiversity and provided resistance to the initial stages of tropicalization.
Bates A. E., Barrett N. S., Stuart-Smith R. D., Holbrook N. J., Thompson P. A., Edgar G. J.
Nature Climate Change