CEBIMário: Decadal changes in fish composition and traits diversity in a marine park in the Gulf of California

Local: Canal do CEBIMar no YouTube, link: https://youtu.be/Am4ZFyDah00

Palestrante: Damien Olivier (UABCS México)

Organizador: Juan Pablo Quimbayo (CEBIMar/USP)

Resumo: No-take marine reserves allow overexploited fish population to rebound. However, whether the resilience level of the community may recover is an open question. The community resilience to disturbances depends on the diversity of the species traits. We analyzed reef fish assemblages over 30 years in a no-take marine reserve to determine whether the fish composition and its ecological traits structure recovered after protection. We selected the National Park of Cabo Pulmo in the Gulf of California (Mexico), a marine protected area model for its good management. From 1987 to 2017, fish assemblages were monitored to quantify the species richness, density, and evenness. The ecological traits structure of the assemblages was computed thanks to the traits richness, dispersion, and redundancy. We observed three distinct phases, (i) a decline period from 1987 to 1998 during which the species richness and fish density severely decreased due to resources exploitation and coral reef damages; (ii) a fish density recovery period following the creation of the reserve from 1998 to 2011, and (iii) a mature period where fish assemblages appear to be stable. However, during the fish recovery period, the fish composition has changed. Some species became highly dominant while other pre-disturbance abundant species did not recuperate. Ergo, the fish assemblages’ evenness, traits dispersion, and traits redundancy decreased during the recovery period before stabilizing, probably decreasing the resilience ability of the community. Although Cabo Pulmo marine park is a success story since the fish density recovered, the prohibition of resource extraction alone did not restore the past resilience level of the fish assemblages, which may make them more vulnerable to future environmental disturbances.