Sensitivity of eastern oyster ( Crassostrea virginica) spermatozoa and oocytes to dispersed oil: Cellular responses and impacts on fertilization and embryogenesis
|Author(s)||Vignier J.1, 2, Volety A. K.1, 5, Rolton A.1, 2, Le Goic N.2, Chu F. -L. E.3, Robert Rene4, Soudant P.2|
|Affiliation(s)||1 : Florida Gulf Coast Univ, Coll Arts & Sci, Dept Marine & Ecol Sci, Ft Myers, FL 33965 ,USA.
2 : IUEM UBO, Lab Sci Environm Marin, UMR LEMAR 6539, Technopole Brest Iroise, F-29280 Plouzane, France.
3 : Virginia Inst Marine Sci, Coll William & Mary, Dept Aquat Hlth Sci, Gloucester Point, VA 23062, USA.
4 : IFREMER, Unite Littoral, Ctr Bretagne, CS 10070, F-29280 Plouzane, France.
5 : Univ North Carolina Wilmington, 601S Coll Rd, Wilmington, NC 28403, USA.
|Source||Environmental Pollution (0269-7491) (Elsevier Sci Ltd), 2017-06 , Vol. 225 , P. 270-282|
|WOS© Times Cited||16|
|Keyword(s)||Deepwater Horizon oil spill, Oyster, Spermatozoa, Oocyte, Flow-cytometry|
The 2010 Deepwater Horizon (DWH) oil spill released millions of barrels of oil and dispersant into the Gulf of Mexico. The timing of the spill coincided with the spawning season of Crassostrea virginica. Consequently, gametes released in the water were likely exposed to oil and dispersant. This study aimed to (i) evaluate the cellular effects of acute exposure of spermatozoa and oocytes to surface slick oil, dispersed mechanically (HEWAF) and chemically (CEWAF), using flow-cytometric (FCM) analyses, and (ii) determine whether the observed cellular effects relate to impairments of fertilization and embryogenesis of gametes exposed to the same concentrations of CEWAF and HEWAF. Following a 30-min exposure, the number of spermatozoa and their viability were reduced due to a physical action of oil droplets (HEWAF) and a toxic action of CEWAF respectively. Additionally, reactive oxygen species (ROS) production in exposed oocytes tended to increase with increasing oil concentrations suggesting that exposure to dispersed oil resulted in an oxidative stress. The decrease in fertilization success (1-h), larval survival (24-h) and increase in abnormalities (6-h and 24-h) may be partly related to altered cellular characteristics. FCM assays are a good predictor of sublethal effects especially on fertilization success. These data suggest that oil/dispersant are cytotoxic to gametes, which may affect negatively the reproduction success and early development of oysters.