Herbivory versus corallivory: Are parrotfish good or bad for Caribbean coral reefs?

With coral cover in decline on many Caribbean reefs, any process of coral mortality is of potential concern. While sparisomid parrotfishes are major grazers of Caribbean reefs and help control algal blooms, the fact that they also undertake corallivory has prompted some to question the rationale for their conservation. Here the weight of evidence for beneficial effects of parrotfishes, in terms of reducing algal cover and facilitating demographic processes in corals, and the deleterious effects of parrotfishes in terms of causing coral mortality and chronic stress, are reviewed. While elevated parrotfish density will likely increase the predation rate upon juvenile corals, the net effect appears to be positive in enhancing coral recruitment through removal of macroalgal competitors. Parrotfish corallivory can cause modest partial colony mortality in the most intensively grazed species of Montastraea but the generation and healing of bite scars appear to be in near equilibrium, even when coral cover is low. Whole colony mortality in adult corals can lead to complete exclusion of some delicate, lagoonal species of Porites from forereef environments but is only reported for one reef species (Porites astreoides), for one habitat (backreef), and with uncertain incidence (though likel

Updated checklist and analysis of completeness of the marine fish fauna of Isla del Coco, Pacific of Costa Rica

Isla del Coco, Costa Rica, is one of the five groups of oceanic islands of the Eastern Tropical Pacific (ETP), and is considered one of the most diverse. Since the mid-19th century, it has been the target of a number of scientific research expeditions that have produced specimen collections which are housed in natural history museums around the world. The fish assemblage of Isla del Coco is considered one of the most speciose and best documented group of marine organisms of the island. Despite this, recent work has resulted in a need to update the checklist for this important group. We performed a completeness analysis of the ichthyofauna of Isla del Coco based on scientific publications and reports of expeditions, specimens in foreign and national collections, and field surveys. We confirmed the presence of 514 species of marine fishes, representing an increase of approximately 23 % compared to what was previously reported. From a habitat perspective, 58 % of this assemblage is typically reef fishes, while the remaining 42 % are deep-water, and pelagic species. The average expected reef fish species richness is 318.2 ± 7.3, suggesting that the local inventory represents 93.7 % of the expected total richness. Our updated list and greater number of species has particular relevance to the conservation efforts at Isla del Coco, since current conservation efforts are protecting at least 50 % of ETP fish species and about 40 % of Costa Rica’s Pacific fish species.Fonds Français pour l’Environnement Mondial/[]/FFEM/FranciaConsejo Nacional de Rectores de las Universidades Públicas de Costa Rica/[]/CONARE/Costa RicaUniversidad de Costa/[]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Ciencias del Mar y Limnología (CIMAR)UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de BiologíaUCR::Vicerrectoría de Docencia::Ciencias Agroalimentarias::Facultad de Ciencias Agroalimentarias::Escuela de Zootecni