A total of 261 bottlenose dolphins have been found stranded between Louisiana and the Florida Panhandles between February 1st and May 31st while 98% of the dolphins were found already dead according to NOAA.
The strandings have prompted a delclaration of an unusual mortality event or UME. Unusual mortality events are defined as a stranding that is unexpected; involves a significant die-off of any marine mammal population; and demands immediate response.
NOAA scientists have said that it is too early to determine what the causes of the high strandings may be but areas that they are investigating are lingering impacts from the 2010 Deepwater Horizon oil spill and salinity changes/pollution from fresh water river run-off coming into the Gulf.
Adding to the problem, this May has gone down as one of the wettest ever recorded in the Midwest which caused flooding in the Mississippi Valley all the way down to the Gulf of Mexico. The flooding has discharged an unusually high amount of freshwater into the Gulf, which impacts the salinity levels in the ocean and impacts dolphins.
While NOAA has not yet officially declared what the problem is, some of the dolphins have been found with freshwater skin lesions. Other than lesions, freshwater can cause dolphins to have eye disorders, abnormal blood chemistry and even end in death.
Even though the majority of flooding has stopped at this point, the worst is not yet over as the dead zone phenomenon could be the largest ever recorded this year due to the extreme amount of water coming from the Midwest and Plains. The phenomenon occurs every year when sources of water pick up excessive nutrient pollution from human activities coupled with other factors that deplete the oxygen required to support most marine life.
NOAA is asking people to immediately call in a stranded dolphin or a dolphin that appears to be in distress or dead in the water. Call the Southeast Marine Mammal Stranding Hotline at 877-WHALE HELP (877-942-5343), or mariners should contact the U.S. Coast Guard on VHF Channel 16 if they do not have cell service. Do not approach or touch the dolphin.
While the amount of rainfall we received this spring is likely tied into climate change, each and every person can do their part by not using fertilizers on their lawns, creating yards with plants that naturally soak up nutrients, and ensuring that waterways are protected by not mowing or cutting plants.