title: Long- and short-term effects of smothering and burial by drill cuttings on calcareous algae in a static-renewal test.
abstract: Discharge of drill cuttings into the ocean during drilling of offshore oil wells can impact benthic communities through an increase in the concentrations of suspended particles in the water column and sedimentation of particles on the seafloor around the drilling installation. The present study assessed effects of water-based drill cuttings, barite, bentonite, and natural sediments on shallow- and deep-water calcareous algae in short-term (30 d) and long-term (90 d) experiments, using 2 species from Peregrino's oil field at Campos Basin, Brazil: Mesophyllum engelhartii and Lithothamnion sp. The results were compared with the shallow-water species Lithothamnion crispatum. Smothering and burial exposures were simulated. Oxygen production and fluorescence readings were recorded. Although less productive, M. engelhartii was as sensitive to stress as Lithothamnion sp. Mesophyllum engelhartii was sensitive to smothering by drill cuttings, barite, and bentonite after 60 d of exposure and was similarly affected by natural sediments after 90 d. These results indicate that smothering by sediments caused physical effects that might be attributable to partial light attenuation and partial restriction on gas exchange but did not kill the calcareous algae in the long term. However, 1-mo burial by either natural sediments or drill cuttings was sufficient after 60 d for both species to reduce oxygen production, and the algae were completely dead under both sources of sediments.
authors.affiliation: LABTOX-Environmental Analysis Laboratory, University City, Rio de Janeiro, Brazil.
authors.forename: Márcia V
authors.initials: MV
authors.lastname: Reynier
authors.affiliation: Marine Biodiversity Institute, Rio de Janeiro, Brazil.|Department of Oceanography, Almirante Paulo Moreira Marine Research Institute, Arraial do Cabo, Rio de Janeiro, Brazil.
authors.forename: Frederico T S
authors.initials: FT
authors.lastname: Tâmega
authors.affiliation: LABTOX-Environmental Analysis Laboratory, University City, Rio de Janeiro, Brazil.
authors.forename: Sarah D A
authors.initials: SD
authors.lastname: Daflon
authors.affiliation: Department of Oceanography, Almirante Paulo Moreira Marine Research Institute, Arraial do Cabo, Rio de Janeiro, Brazil.|Botanical Garden of Rio de Janeiro Research Institute of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Maurício A B
authors.initials: MA
authors.lastname: Santos
authors.affiliation: Department of Oceanography, Almirante Paulo Moreira Marine Research Institute, Arraial do Cabo, Rio de Janeiro, Brazil.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Coutinho
authors.affiliation: Marine Biodiversity Institute, Rio de Janeiro, Brazil.|Department of Oceanography, Almirante Paulo Moreira Marine Research Institute, Arraial do Cabo, Rio de Janeiro, Brazil.|Botanical Garden of Rio de Janeiro Research Institute of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Marcia A O
authors.initials: MA
authors.lastname: Figueiredo
mesh_terms: D004781:Environmental Exposure; D019015:Geologic Sediments / Q000737:chemistry*; D061329:Oil and Gas Fields / Q000737:chemistry*; D000461:Rhodophyta / Q000187:drug effects / Q000254:growth & development*; D013997:Time Factors; D018675:Toxicity Tests; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D014874:Water Pollutants, Chemical
keywords: Calcareous algae; Drill cuttings; Sedimentation