Small-scale experimental contamination with diesel oil does not affect the recolonization of Sargassum (Fucales) fronds by vagile macrofauna

Abstract

ABSTRACT. Coastal regions are subject to various forms of environmental impacts, such as spills of crude oil and associated products, with a wide range of effects on benthic biodiversity. This study characterized the patterns of recolonization of the macrofauna associated with the brown alga Sargassum cymosum(C. Agardh), on fronds contaminated by diesel oil in a small-scale field experiment. We collected 40 fronds of S. cymosum from an algal bed in southeastern Brazil and defaunated each frond by immersion in fresh water. Half of the fronds were then immersed in seawater (control group) and the other half in a mixture of 50% diesel oil and 50% seawater (impacted group). The test fronds were returned to the algal bed, and natural recolonization took place over a period of 12 days. Samples of the vagile macrofauna were taken randomly at three-day intervals over the course of the recolonization period. No significant differences in the densities of most taxa were found between the impact treatment (IG) and control treatment (CG). At the end of the recolonization period (day 12), the faunal composition of the treated fronds was very similar to the natural conditions, indicating a high rate of community recovery and suggesting that benthic associations can be rather resilient to dieseloil impacts on a small scale.

Usage of Enzymes of Algae-macrophytes Antioxidant System for Monitoring Water Pollution By Oil Products

“…Different types of bacteria are developed, including those capable of oxidizing petroleum products [13]. Presumably, the penetration of petroleum products to the underlying layers is slowed down precisely due to the presence of this layer and the activity of bacteria that neutralize adsorbed petroleum products [14]. A single-layer plate is characterized for U. obscura, it has no protective layer and when it hits the surface of the thallus, the oil product quickly penetrates into the cells.…”