Scientists predict this year’s Gulf of Mexico dead zone will be the largest ever.
The forecast predicts the dead zone will reach its maximum extent later this summer and cover an area of about 24,400 square kilometers (9,400 sq. miles) off the coast of Louisiana and Texas. This is about the size of the combined land area of New Jersey and Delaware, or the size of Lake Erie.
Forecasters are calling for such a large area because of record-breaking floods from the Mississippi River, which are delivering excess nutrients, particularly nitrogen and phosphorus, into the Gulf. These nutrients create large algae blooms which, upon decomposition, suck oxygen out of the water.
Dead zones are areas of this hypoxic water in which fish, shrimp and crabs are stressed and can sometimes die due to oxygen starvation. Scientists, led by Nancy Rabalais, have mapped the size of the Gulf dead zone since 1985:
It’s worth noting that dead zone forecasting is not an exact science, as we saw in 2009. There are several caveats to this year’s forecast, as always:
- This predictions discounts the effect of large storm events which will temporarily disrupt the physical and biological system attributes promotes the formation of the low oxygen zone in bottom waters.
- The predictions assume continued above average discharge through June and July
- Unusual weather patterns affecting coastal winds, as experienced in 2009, may skew the prediction to be lower.
Nevertheless, given the extraordinary river flows this year, it’s a good bet the forecasters are correct that this year’s dead zone will be large.