Abstract Oil pollution has significantly contributed to coral reef decline in the last five decades and a major oil spill reached Brazilian tropical coast in August 2019. Here, we report the first evidence of direct crude oil contact from that spill on reef coral species, and evaluate the effects of this disaster on coral vitality and benthic assemblage structure on the largest coastal marine protected area (MPA Costa dos Corais) in Brazil. We compared benthic cover in reefs with and without oil and monitored Siderastrea stellata colonies 90 days after oil contact. Oil stains between 0.5 and 150 cm were found in two of the 17 reef sites investigated. Multivariate analyses did not detect significant differences between oiled and non-oiled reefs and there was no evidence of S. stellata health deterioration. These results indicate minimal acute effects on coral vitality and intertidal reef benthic assemblage structure. Future studies should investigate oil effects on specific aspects of coral biology as growth, reproduction, bleaching susceptibility and metagenomics which can deteriorate over longer time frames, and we recommend long-term coral reef monitoring to support a robust assessment and mitigation of chronic oil impacts.

RESUMO A pressão pesqueira afeta o comportamento de peixes recifais, especialmente nas espécies alvo de pesca. Nesse contexto é importante entender se áreas fechadas a pesca ("no-take areas": NTAs), consideradas como melhor instrumento para recuperação dos estoques pesqueiros, garantem a integridade dos comportamentos dos peixes. Comparar distâncias iniciais de fuga ("fligth initiation distance": FIDs) de espécies entre recifes de uso múltiplos ("multiple-use areas": MUAs), onde a pesca é permitida (incluindo a pesca submarina), e as NTAs é uma abordagem útil para testar se as NTAs podem ser efetivas como refúgios para peixes recifais. Nesse trabalho FIDs de duas espécies alvo (Sparisoma axillare e Scarus trispinosus ) e uma não alvo (Halichoeres poeyi ) foram comparadas entre MUAs e NTAs. A possível influência do tamanho do grupo ("group size": GS) e o tamanho do corpo ("body size": BS) sobre FID também foram investigados. Foram amostradas quatro MUAs e quatro áreas NTAs no banco dos Abrolhos (Brasil). Nossos resultados mostraram que apenas FID das espécies alvo de pesca foi menor dentro de NTAs e que o BS teve um efeito positivo no FID de todas as espécies. Dentro da NTA, GS e BS foram maiores do que em recifes abertos à pesca apenas para S. trispinosus . Finalmente, sugerimos que NTAs em Abrolhos não são apenas importantes como recuperação dos estoques pesqueiros, mas estão possivelmente atuando como uma área repositória de peixes "ingênuos" (peixes que permitem aproximação humana) para os recifes onde a pesca é permitida.

ABSTRACT Fishing pressure affects the behavior of reef fish, especially of fishery-targeted species. In this context, it is critical to understand if fish behavior is preserved in no-take areas (NTAs), which are considered the best instrument for the recovery of fish stocks. Comparing the flight initiation distances (FIDs) of fish inhabiting multiple-use areas (MUAs), where fishing is allowed (including spearfishing), and NTAs is a useful approach to test whether NTAs can be effective as fish refuges. Here, we compared whether the FIDs of two target (Sparisoma axillare and Scarus trispinosus ) and one non-target (Halichoeres poeyi ) labrids are greater in the MUAs than in the NTAs. We also investigated whether group size (GS) and body size (BS) exert any effect on the FID. We sampled four MUAs and four NTAs in the Abrolhos Bank (Brazil). We found that only for the targeted species FID was shorter inside the NTAs and that the BS had a positive effect on the FID of all species. The GS and BS of the fish are greater in the NTAs than in the multiple-use areas only for S. trispinosus . Our study shows that fish, especially those species that are fishery targets, display an avoidance behavior against spearfishermen likely as a consequence of fishing pressure. We suggest that the NTAs in Abrolhos are not only important sites for the recovery of fish stocks but also possibly act as a repository area of naïve fish (fish that allow human approach), for reefs open for fishing.

Episodes of coral bleaching related to El Niño events have been increasing in frequency and severity. This phenomenon is cited as a major cause of degradation of coral reefs. This study evaluates the effects of coral bleaching on the Caramuanas reef community, which occurred during the southern hemisphere summer of 2009/2010. Within this period the sea surface temperature of 31°C and thermal anomalies up to almost 1°C were recorded. During and after this El Niño event, frequency and severity of bleaching, live coral cover, number of colonies, class size, disease occurrence, and mortality rate were monitored on corals larger than 20 cm in diameter. The samples were taken at twelve fixed transects, in three reef stations. Statistical analysis showed that the severity of bleaching was different between the two periods, during and after the 2010 ENSO event. The Caramuanas reef showed sublethal bleaching effects indicating that this reef is tolerant to bleaching when the temperature anomalies do not exceed 0.75°C within one week.

Los episodios de blanqueamientos de corales relacionados con los eventos de El Niño han ido aumentando en frecuencia e intensidad durante los últimos años. Estos fenómenos se citan como una de las principales causas de la degradación de los arrecifes de coral. Este estudio evaluó los efectos del blanqueamiento del arrecife de coral en la comunidad de Caramuanas, que se produjeron durante el verano austral de 2009/2010. En este período se registró temperaturas de la superficie del mar de hasta 31°C y anomalías térmicas del orden de 1°C. Durante y después de este episodio El Niño, se analizó la frecuencia y severidad del blanqueamiento, cobertura de coral vivo, número de colonias, clases de tamaño, aparición de enfermedades y tasa de mortalidad en los corales mayores de 20 cm de diámetro. Las muestras fueron tomadas en doce transectas fijas, divididas en tres estaciones de arrecife. El análisis estadístico mostró que la severidad del blanqueamiento fue diferente entre los dos períodos, durante y después del evento. El arrecife de Caramuanas mostró efectos subletales de blanqueamiento que probó que este arrecife es tolerante a los fenómenos de blanqueamiento cuando las anomalías de temperatura no exceden 0,75°C durante una semana.