Oxidative stress response in the seaside sparrow (Ammospiza maritima) following the Deepwater Horizon oil spill
The Deepwater Horizon (DWH) oil spill introduced massive amounts of oil into our saltmarsh ecosystem of Louisiana. The main toxic component of DWH oil are polycyclic aromatic hydrocarbons (PAHs). PAH metabolites have the capability of reacting with molecular oxygen to create reactive oxygen species (ROS) via a redox cycling reaction. The relatively unstable ROS then react with and cause oxidative damage to organic molecules, which results in more stable reactive oxygen metabolites (ROMs). This oxidative damage therein creates oxidative stress in the organism, if the antioxidant defense system barrier is breached. Our goal is to quantify the oxidative stress response of birds exposed to the Deepwater Horizon oil. We will be measuring serum levels of reactive oxygen metabolites and antioxidant barrier strength using d-ROMS and OXY-Adsorbent tests, respectively. These measurements will tell us the magnitude of oxidative damage done on organic molecules within the organisms and whether the antioxidant barriers in exposed birds were significantly higher than in unexposed birds. Additionally, we will be measuring cardiac tissue levels of glutathione (GSH) which is a molecular, endogenous antioxidant that aids in combatting pro-oxidants and mitigates oxidative stress. With these results, we aim to assess whether contamination from the DWH oil caused a direct toxic effect in the seaside sparrow, with important implications for their fitness.