Simultaneous exposure to chronic hypoxia and dissolved polycyclic aromatic hydrocarbons results in reduced egg production and larval survival in the sheepshead minnow (Cyprinodon variegatus).

Estuarine fish in the northern Gulf of Mexico are exposed annually to hypoxic conditions. In addition to hypoxia, fish located throughout the northern Gulf of Mexico were potentially exposed to oil released during the Deepwater Horizon incident. Therefore, the interaction between oil exposure and hypoxia is worth investigating. To examine this interaction, the authors exposed adult and larval sheepshead minnow (Cyprinodon variegatus) to crude or dispersed oil under both normoxic and hypoxic conditions. The authors examined total egg production, egg hatching success, and larval survival post hatch. The authors' results indicate that co-exposure to crude or dispersed oil and hypoxia resulted in a significant decrease in egg production, as well as a significant decrease in both egg hatch success and larval survival post hatch. The significant impact on reproductive success following crude or dispersed oil and hypoxia exposure indicates the importance of including environmental parameters such as hypoxia when evaluating the impact of an oil spill.