Researchers purposely released oil into a North Sea shipping zone to gain insight into what happens directly after a spill.

Little is known about the immediate aftermath of oil spills because researchers don't usually arrive on the scene for several days after the event, Ecole Polytechnique Fédérale de Lausanne reported. The study, published recently in the journal Environmental Science & Technology, could help shape emergency responses right after an oil spill.

Toxic hydrocarbons from oil spills can be a threat to aquatic species; evaporated compounds can also pose a risk to rescue workers or anyone who breaths them in. Once spilled, oil is exposed to water and sunlight after spending millions of years underground.

"In its new environment, the oil immediately begins to change its composition, and much of that change happens on the first day," said Samuel Arey, a researcher at EPFL and Eawag in Switzerland and corresponding author of the study. Oil is a "complex mixture of many hydrocarbon compounds." Some of these volatile compounds can evaporate within hours, polluting the atmosphere. Others, including toxic naphthalene, simultaneously dissolve into the seawater, and can harm important aquatic life.

Since the Exxon Valdez catastrophe in 1990, which released over 40,000 cubic meters of oil into the ocean. researchers have been working to evaluate the extant of marine animals exposed to the harmful substance.

In order to collect data on the immediate impact of an oil spill researchers created their own four cubic meter spill in a shipping zone already tainted with pollutants. The experiment was carried out on a summer day with two-meter-high waves, within one day the slick had almost completely dissipated, but on a cooler day it would most likely have persisted longer.

The team tested the data against a computer model; the findings could help researchers asses the immediate impact of future spills on both humans and the environment.