How much Sargassum was in contact with oil from the 2010 Deepwater Horizon spill? Using Landsat and AVIRIS satellite imagery and 2010-2011 NRDA observations, the authors estimated Sargassum coverage in oiled areas ranged from 1296 ± 453 km2 (for areas with > 5% thick oil) to 736 ± 257 km2 (for areas with > 10% thick oil).
The most significant result from this study is the finding that all satellite instruments and high-altitude airborne instruments will miss significant amounts of Sargassum in all seasons. Therefore, even though they could provide general distributions of large Sargassum patches, satellite data alone are insufficient to provide accurate estimates of the total Sargassum coverage. Scaling factors using the much higher-resolution observations from low-altitude airborne measurements are required to provide a more accurate estimate of Sargassum coverage. At present, the Landsat-based Sargassum coverage estimates scaled using low-altitude airborne measurements represent our best knowledge of Sargassum coverage before, during, and after the DWH oil spill in 2010.
Full Citation: Hu, C.; Hardy, R.; Ruder, E.; Geggel, A.; Feng, L.; Powers, S.; Hernandez, F.; Graettinger, G.; Bodnar, J.; McDonald, T. (2016) Sargassum coverage in the northeastern Gulf of Mexico during 2010 from Landsat and airborne observations: Implications for the Deepwater Horizon oil spill impact assessment, Marine Pollution Bulletin, Volume 107, Issue 1, 15 June 2016, Pages 15-21, http://dx.doi.org/10.1016/j.marpolbul.2016.04.045.