Enhanced bacterioplankton activity after the ‘Prestige’ oil spill off Galicia, NW Spain

Abstract

The response of coastal bacterioplankton communities to the 'Prestige' oil spill in November 2002 was investigated off A Coruña (NW Spain). Abundance and activity (leucine uptake) of bacterioplankton communities were analysed in relation to total soluble hydrocarbon concentrations (THC) measured monthly for 1 yr after the spill. Temperature, chlorophyll a, total and particulate organic carbon (TOC and POC, respectively), along with oxygen concentrations were also measured. The highest THC values (140 µg l -1 ) were found near the coast shortly after the spill, decreasing thereafter, although peak concentrations of 75 µg l -1 were detected in summer. Besides those peaks, THC was much lower and was not correlated with TOC or with bacterial abundance or activity. In contrast, bacterial variables were significantly correlated with water temperature, chlorophyll a and TOC concentrations. Compared to data obtained before the spill, bacterial abundance did not change but bacterial activity was significantly enhanced, especially during winter and summer. Potential hydrocarbon degradation by bacteria was indicated by elevated production rates and an increase in the apparent oxygen utilisation during winter. The estimated degradation rates could account for the observed decrease in THC after the initial spill. Changes in hydrocarbons after the winter, however, could not be related to bacterial production, as the latter was more related to changes in phytoplankton biomass and TOC.

Rapid microbial respiration of oil from the Deepwater Horizon spill in offshore surface waters of the Gulf of Mexico

“…The polar membrane lipid analyses were conducted from samples filtered at sea and would have included both freeliving microbes and microbes adsorbed to oil flocs. If biomass estimates from polar membrane lipids provide a more faithful indication of microbial abundance than flow cytometry, then our observations of consistent microbial standing stocks inside and outside of the slicks agree with studies of the 1979 IXTOC I oil spill in the Bay of Campeche (Atlas et al 1980) and the 2002 Prestige oil spill off the coast of Portugal (Bode et al 2006), where there were no differences in pre-and post-spill bacterial abundances. An alternative explanation is that since polar membrane lipids were similar inside and outside the slick, the abundance data are indicating that there was more biomass per cell inside the slick than outside the slick (i.e.…”

“…Indeed, a study that traced the carbon isotopic signatures of the planktonic food web in the Gulf of Mexico after the Deepwater Horizon spill concluded that there was trophic transfer of carbon from oil to bacteria to higher levels in the food web (Graham et al 2010). In addition, previous research on the response of the microbial community to the Prestige oil spill off the coast of Spain suggests that grazing control resulted in an increase in bacterial production and respiration within oil contaminated waters without a subsequent increase in bacterial biomass (Bode et al 2006). However, it must be noted that these two studies were conducted in nearshore environments that were unlikely to have been as nutrient depleted as waters we studied in proximity to the Deepwater Horizon site.…”

Dynamics of the hydrocarbon‐degrading Cycloclasticus bacteria during mesocosm‐simulated oil spills

“…After fuel addition bacterial abundances usually tend to increase according to both experimental and field observations (Ohwada et al ., 2003; Nayar et al ., 2005; Sargian et al ., 2005; Bode et al ., 2006). Our results also show an overall increase of PA after PAHs treatment as compared with the control.…”

Changes in bacterial activity and community composition caused by exposure to a simulated oil spill in microcosm and mesocosm experiments

“…The effects of oil spills on the natural bacterioplankton communities of coastal ecosystems have been studied using in situ measurements (e.g. Bode et al 2006), laboratory experiments (Maruyama et al 2003, Castle et al 2006, Cappello et al 2007a) and experimental systems such as mesocosms , Ohwada et al 2003, Cappello et al 2007b). This last type of approach avoids the effects caused by advection, diffusion and mixing under natural conditions, and it also offers the possibility of comparison with natural populations to which PAHs have not been added, thus allowing statistical testing of hypotheses.…”