The Abrolhos Nominally Herbivorous Coral Reef Fish Acanthurus chirurgus, Kyphosus sp., Scarus trispinosus, and Sparisoma axillare Have Similarities in Feeding But Species-Specific Microbiomes.

Coral reefs rely heavily on reef fish for their health, yet overfishing has resulted in their decline, leading to an increase in fast-growing algae and changes in reef ecosystems, a phenomenon described as the phase-shift. A clearer understanding of the intricate interplay between herbivorous, their food, and their gut microbiomes could enhance reef health. This study examines the gut microbiome and isotopic markers (δC and δN) of four key nominally herbivorous reef fish species (Acanthurus chirurgus, Kyphosus sp.

Hydrocarbon composition of oils spilt on the Brazilian coast in 2019 and 2022.

The chemical composition of spilt oils from events that took place on the north-eastern coast of Brazil in 2019 and 2022 was investigated to better understand their sources, and post-spill processes. Oils from both events originated from different sources, based on their fingerprints, hydrocarbons composition and specific biomarkers, such as the C23 tricyclic terpane and oleanane. Despite the differences, the source rocks share similarities in paleoenvironments and depositional conditions and both oils suffered little weathering, mainly due to evaporation and dissolution.

Seasonal and diel modulation of DOM in a mangrove-dominated estuary.

Rivers and estuaries are the main links between continents and oceans. The Paraíba do Sul River is among the most important rivers of the southeastern Brazilian region, carrying an average of 0.08 Tg of dissolved organic matter (DOM) to the ocean but has been facing significant changes in river discharge.

Metals and organic matter baselines in sediments in a cross-shelf gradient at Abrolhos Bank, SW Atlantic.

The present study performed geochemical fractioning of major and minor elements in a cross-shelf gradient of the Abrolhos Bank, where the largest and most diverse coral reefs in the South Atlantic are concentrated. The fractioning was performed using sequential extractions to determine the degree of availability and toxicity of the elements. The mobility pattern of the elements investigated were in the following order: Ca > Mn > Pb > Cr > Zn > Fe > V > Cu > Ba>Al > Ni > Ti.