A giant, low-oxygen “dead zone” where no sea life can exist occurs each summer in the Gulf of Mexico. However, the added effects of this year’s Deepwater Horizon oil disaster raise new questions about just how much environmental degradation the Gulf can handle, Bloomberg News reports.

“You start adding these things up, and there’s a question of what the cumulative effect is and how much additional stress the ecosystem can take,” said Kevin Craig, an assistant scholar/scientist at the Florida State University Coastal and Marine Laboratory who has studied oxygen depletion for a decade.

The dead zone, caused by chemical runoff into the Mississippi River that flows into the Gulf, is estimated to be the size of Massachusetts this year.

The damage to wildlife from the oil spill and the dead zone could be compounded by hurricanes, Craig warned. Tropical storms could flush animals out of their marsh habitats and damage oyster beds.

While the Gulf can recover from hurricanes and low oxygen, the effects of the oil spill remain a long-term concern.

“How it’s going to influence hypoxia or wildlife or fisheries is an unknown,” Craig said.

Click here to read the full Bloomberg article.