Laboratório de Ciências Marinhas, Universidade do Sul de Santa Catarina--UNISUL, Av Colombo Sales 84, Laguna, 88790-000, SC, Brazil.
Environ Monit Assess. 2010 Aug;167(1-4):49-63. doi: 10.1007/s10661-010-1515-3. Epub 2010 Jun 4.
The present study investigates the effects of drill cutting discharges on the structure of meiofauna communities in an area of the shelf break at Campos Basin, Southeast Brazil. Drilling activities were operated, in a first phase, with water-based fluid and, in a second phase, with synthetic fluid paraffin-based (NAF-III). A total of 135 samples taken at a pre-drilling situation (MS1) and two post-drilling moments (MS2 and MS3-3 and 22 months post-drilling, respectively) were analyzed. Effects on meiofauna were dependent on two main factors: 1-the impact received during drilling operation, if water-based or synthetic/water-based drilling fluid and 2-the background state, if it already presented signs of previous drilling activities or not. Based on univariate and multivariate analysis, there were evidences that the most affected area after drilling was those under the influence of synthetic-based fluid and that already had signs of previous drillings activities. The region impacted only by water-based fluid was less affected and the only one that completely recovered after 22 months. Nematodes and copepods had different responses to the impact. While copepods flourish in the impacted area and recovered 22 months after drilling, nematodes were adversely affected shortly after drilling and the community structure only recovered where hydrocarbons had been depleted.
本研究调查了钻屑排放对巴西东南沿海大陆架边缘地区中海洋动物群落结构的影响。在第一阶段，采用水基流体进行了钻探作业，在第二阶段，采用合成流体石蜡基（NAF-III）。在钻井前（MS1）和两次钻井后（MS2 和 MS3-3，分别在钻井后 22 个月）共采集了 135 个样本。中海洋动物的影响取决于两个主要因素：1- 钻井作业过程中受到的影响，如果是水基或合成/水基钻井液；2- 背景状态，如果已经存在先前钻井活动的迹象。基于单变量和多变量分析，有证据表明，钻井后受影响最大的区域是受合成基流体影响且已经有先前钻井活动迹象的区域。仅受水基流体影响的区域受影响较小，并且是唯一一个在 22 个月后完全恢复的区域。线虫和桡足类对影响的反应不同。桡足类在受影响的区域大量繁殖，并在钻井后 22 个月恢复，而线虫在钻井后不久受到不利影响，只有在烃类耗尽的地方，群落结构才会恢复。
