Corexit, oil and marine microgels

Area of Science:

• Marine Chemistry
• Biogeochemistry
• Environmental Science

Background:

• Corexit, a dispersant used in the Deepwater Horizon oil spill, has been studied for toxicity and oil removal.
• Its impact on surface ocean carbon dynamics, specifically dissolved organic matter (DOM) to particulate organic matter (POM) transformations, remains unclear.

Purpose of the Study:

• To investigate the effect of Corexit, alone and with oil, on the formation and stability of DOM microgels.
• To understand the implications for the ocean's DOM-POM continuum and carbon cycling.

Main Methods:

• Laboratory experiments examining DOM microgel formation in the presence of Corexit.
• Assessing the stability of pre-existing microgels under Corexit exposure.
• Investigating the combined effects of Corexit and oil (CEWAF) on microgel dynamics.

Main Results:

• Corexit alone significantly inhibited DOM microgel formation and reduced the stability of existing microgels.
• Corexit in combination with oil (CEWAF) effectively facilitated DOM microgel formation.
• These findings reveal a complex interaction affecting the DOM-POM continuum.

Conclusions:

• Corexit's application during oil spills can disrupt natural processes governing the DOM-POM continuum.
• The dual effect of Corexit (inhibitory alone, facilitative with oil) necessitates careful consideration for its environmental impact.
• Future oil spill management strategies should account for Corexit's influence on ocean carbon dynamics.