Ian Vianna da Rocha1,3, Estéfane Cardinot Reis1, Priscila Reis da Silva2, Guarani de Hollanda Cavalcanti2, Ricardo Coutinho3 and Marcia Vieira Reynier1*
1Laboratory of Environmental Analysis (LABTOX), Rio de Janeiro, RJ, Brazil.
2Research and Development Centre (CENPES) of Brazilian Oil, Gas and Energy Company PETROBRAS, Rio de Janeiro, RJ, Brazil.
3Department of Marine Biotechnology and Graduate Marine Biotechnology Program, Almirante Paulo Moreira Marine Research Institute (IEAPM), Arraial do Cabo, Rio de Janeiro, Brazil.
Received 13 April, 2020; Accepted 2 June, 2021
Drilling activities usually discharge large quantities of fluids and drill cuttings, which are composed of fine particles, such as barite, that can physically affect Lophelia pertusa. An experiment to assess the effects of barite smothering on L. pertusa was conducted with a water recirculation system. The corals were collected in Santos Basin, Brazil. The experiment was conducted in 23 L cone-shaped aquaria, adapted with an individual water recirculation system. Each exposure to suspended barite particles (50 and 100 mg·L-1) plus a control group was maintained in triplicate. Three nubbins were accommodated in the aquaria and acclimated for 7 days. The experimental design simulated two cycles of discharge, followed by a recovery cycle of 7 days each, totaling 35 days. Nine polyps per treatment were monitored twice per day regarding their behavior levels. Time-lapse photographs were also taken during the recovery periods. Total polyp survival in the control was 100%, while those in the 50 and 100 mg·L-1 groups were 94.2 and 93.6%, respectively, with no significant difference between treatments. Polyp activity was different between treatments, with both exposed aquaria displaying higher activity than control. This was probably related to the natural cleaning behavior of L. pertusa.
Key words: Barite smothering, sedimentation, impacts of oil and gas industry, Santos Basin, Southeastern Brazil, South Atlantic.
INTRODUCTION
Brazilian offshore oil production is responsible for over 95% of the total oil production in the country, which, according to the Brazilian National Petroleum Agency (ANP), totaled 944,117 million barrels in 2018. The major offshore oil and gas (O&G) fields in the country are located in the southeastern Brazilian continental margin. This area, which comprises the Santos, Campos, and Espírito Santo basins, is responsible for 95% of the […]