Medium-term responses of rocky bottoms to sewage discharges from a deepwater outfall in the NE Atlantic

• Published in: Marine pollution bulletin Vol. 54; no. 7; pp. 941 - 954
• Main Authors: Echavarri-Erasun, Beatriz, Juanes, José A., García-Castrillo, Gerardo, Revilla, José A.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.07.2007; Elsevier
• Subjects: Animal, plant and microbial ecology; Animals; Applied ecology; Applied sciences; Atlantic Ocean; Benthos; Biological and medical sciences; Coastal waters; Ecosystem; Ecosystem disturbance; Ecotoxicology, biological effects of pollution; Environmental impact; Environmental Monitoring; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Geography; Geologic Sediments - analysis; Geologic Sediments - chemistry; Heavy metals; Invertebrates; Marine; Marine and brackish environment; Metals, Heavy - toxicity; Monitoring; Outfalls; Pollution; Pollution effects; Risk Assessment; Sediment chemistry; Sewage - analysis; Sewage - chemistry; Soil Pollutants - toxicity; Wastewater; Wastewaters; Water Pollutants, Chemical - toxicity; Water treatment and pollution; Atlantic Ocean; A, Atlantic; Pollution effects; Outfalls; Benthos; Coastal waters; Ecosystem disturbance; Sediment chemistry; Wastewater; Environmental impact; Heavy metals; Monitoring; Coastal zone; Waste water; Aquatic environment; Ecosystem; Coastal water; Seawater; Hard substrate; Deep water; Perturbation; Outfall; Sediments; Heavy metal; Surveillance; Environment impact; Water pollution
• ISSN: 0025-326X; 1879-3363
• DOI: 10.1016/j.marpolbul.2007.02.014

An investigation on the effects of deepwater outfall discharges on the status of rocky reef communities was carried out. The sanitation system was found to be an environmentally suitable option for the protection of those habitats situated in high energy coastal environments. Sediments occurring between the predominating rocky substrates showed low values of the fine fraction (<63 μm) and organic matter content. In addition, high average concentrations of Cd, Hg and Zn were found in these sediments, though these values were similar to those registered in non-affected sites, far away from the outfall. On the other hand, those assemblages typical of hard substrates that settled near the outfall showed an increase in total richness and abundance of macroinvertebrates. Moreover, the average number of species of each taxonomic group, a good indicator of the maintenance of the previous trophic structure, only varied considerably over time at the rip-rap protection. In a global context, those changes were not directly related to the discharge disturbances, but to the natural variability or the successional processes occurring within those communities. Only communities dwelling in the rip-rap protection area were affected by the proximity of the discharges.