Scientific and cleanup response to the IDOHO-QIT oil spill, Nigeria.

On 12 January, 1998, a 24 inch pipeline from the IDOHO platform to the Mobi l Qua Iboe terminal ruptured. This resulted in the release of approximately 40 000 bbl of Qua Iboe light crude oil into the marine environment. In res ponse to the spill, cleanup and containment equipment were immediately depl oyed. Dispersant application played an important role in the cleanup respon se because the bulk of the oil remained offshore and was transported westwa rd by prevailing currents, thus providing an extended opportunity for treat ment at sea. As a result of dispersant application, natural dispersal and e vaporation, over 90% of the oil was dispersed and evaporated offshore. Heav y shoreline oiling was limited and localized, with oiling of sensitive estu arine mangrove habitats limited to a few locations. Remnants of the spill t hat tracked 5-10 km offshore from the spill source were observed at Lagos h arbor, about 900 km west of the spill site. Most of the exposed sand beache s in the spill zone self-cleaned within 2-3 weeks and cleanup of the limite d number of heavily impacted shoreline areas recovered approximately 1000 b bl of oily waste. A national and international team of scientists was conve ned within 24 hours and initiated scientific studies to measure the short-t erm impact of the spill on environmental resources important to local human activities. Elements of the short-term scientific program were (1) an offs hore component, including fisheries, benthos, chemistry, microbiology; (2) a riverine/estuary component, including; extensive water analyses to detect any spill input to waters used by local settlements and chemical analysis of local fish market samples. The results of the short-term scientific stud y indicated that any initial environmental effects were limited and localiz ed. Based on the initial scientific program, a larger follow-up scientific program was initiated on September 15, 1998. This involved a multi-discipli nary program with the following components: offshore fisheries and benthic studies; a shoreline fate and effects program; a study of impacts to estuar ine mangrove habitats; and a study of any socioeconomic and human health ef fects. The study plan was based on comparisons of data from spill zone and non-spill zone locations. The key elements of the study design of this comp rehensive longer term study are described.