Numerical simulation of oil spills based on the GNOME and ADIOS

The Exxon Valdez oil spill emergency has shown that simulation of oil spills trajectory is the main action in planning response measures. Modeling the trajectory of the oil slick allows predicting in advance the direction of the motion of the stain, the time it will take to reach the shore and assess the possible environmental consequences for the contaminated coastal zone. In this paper, the Exxon Valdez oil spill trajectory was analyzed using two different models, the GNOME model and the HAZAT trajectory model. Conclusions are drawn about the reasons for the differences in the results provided by the two models. The accuracy of the simulation is strongly related to the input of geographic and meteorological data. In addition, ADIOS software was used to predict the weathering process of the modeled emergency event. It was found that the main factors influencing the change in the physical and chemical characteristics of oil dispersed in the water body are the wind speed and direction, water temperature and wave height.

It Seemed Like the Whole Bay Died

This chapter examines the impact of the Exxon Valdez oil spill on the Native peoples of Alaska. The disaster occurred in March 1989, when the supertanker Exxon Valdez ran aground on a reef in Prince William Sound. At least eleven million gallons of crude oil blackened more than a thousand miles of Alaskan coastline. The chapter considers what harm the disaster did to the Native individuals exposed to it and what damage it caused to the texture of their customary ways of life. In particular, it analyzes the ways that the oil spill affected the Alutiiq people's subsistence life as well as the Native way of being. It also discusses the Alutiiq's feeling of homelessness in the wake of the disaster.

Spatio-temporal models reveal subtle changes to demersal communities following the Exxon Valdez oil spill

Toxic pollutants such as crude oil have direct negative effects for a wide array of marine life. While mortality from acute exposure to oil is obvious, sub-lethal consequences of exposure to petroleum derivatives for growth and reproduction are less evident and sub-lethal effects in fish populations are obscured by natural environmental variation, fishing, and measurement error. We use fisheries independent surveys in the Gulf of Alaska to examine the consequences of the 1989 Exxon Valdez oil spill (EVOS) for demersal fish. We delineate areas across a range of exposure to EVOS and use spatio-temporal models to quantify the abundance of 53 species-groups over 31 years. We compare multiple community metrics for demersal fish in EVOS and Control areas. We find that areas more exposed to EVOS have more negative trends in total groundfish biomass than non-EVOS areas, and that this change is driven primarily by reductions in the abundance of the apex predator guild. We show no signature of increased variability or increased levels of synchrony within EVOS areas. Our analysis supports mild consequences of EVOS for groundfish communities, but suggests that long time-series and assessments of changes at the community level may reveal sub-lethal effects in marine communities.