Long- and short-term effects of smothering and burial by drill cuttings on calcareous algae in a static-renewal test.
Environ Toxicol Chem
; 34(7): 1572-7, 2015 Jul.
Article
em En
| MEDLINE
| ID: mdl-25689779
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.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Sedimentos Geológicos
/
Rodófitas
/
Campos de Petróleo e Gás
Idioma:
En
Revista:
Environ Toxicol Chem
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Estados Unidos