Abstract

Coral reefs in the Dominican Republic have declined rapidly due to global and local threats. Commercial extraction of parrotfish (Scarus spp and Sparisoma spp) has potentially led to a rapid reduction in herbivore populations in the DR. The environmental authorities established parrotfish bans in 2017 and 2021 for two years. However, the need for more baselines to understand the natural spatial and temporal variation of these assemblages hampers any attempt to evaluate the effectiveness of these bans. In this document, we present the results of a monitoring program to evaluate spatial and temporal variability of parrotfish assemblages across various spatial scales along the northern coast of the Dominican Republic. For this, we used a nested hierarchical design encompassing two spatial scales: (1) locality (hundreds of km) and (2) sites (hundreds of m) nested in the locality (three reef sites per locality) monitored at least three times a year (i.e., every four months). At each site, five 30x2 m belt transects deployed haphazardly into each reef were monitored to count fish herbivore fish using the AGGRA protocol. Temporal trends of herbivorous assemblages were variable at the scale of sites for 2021 (Permanova, df = 8, F = 2.3573, p level = 0.001, CV = 19.5171418260556) and 2022 (Permanova, df = 4, F = 2.7869, p level = 0.001, CV = 20.9719348349053). Our results highlight the importance of taking spatial variability as an essential factor in designing better and more efficient bans to protect herbivores in the Dominican Republic.