The smash up of the food web and the chilling waters of the Gulf of Mexico may have led to the untimely deaths of hundreds of dolphins swimming lazily in the region says a report published in Journal PLoS One.
Nearly 186 dead bottlenose dolphins had been found on the beaches between Western Florida and Louisiana.
Half of these peace loving marine animals were baby calves.
Graham A.J. Worthy, a biologist and author from the University of Central Florida said "Unfortunately, it was a 'perfect storm' that led to the dolphin deaths.
“The oil spill and cold water of 2010 had already put significant stress on their food resources. ... It appears the high volumes of cold freshwater coming from snowmelt water that pushed through Mobile Bay and Mississippi Sound in 2011 was the final blow."
Some plausible reasons
The science experts pointed out towards three specific reasons. The bitterly freezing winter spell in 2010, the BP oil spill in April 2011 and chilling freshwater gushing from the thawing snow in January 2011 may be the reason for the high mortality amongst the dolphins.
Another very important factor is that the Northern Gulf dolphins had thin blubber skin layers and were generally unhealthy.
Worthy feels that all the evidence points towards the measly condition of the dolphin bodies.
“What we do know was that there was a cold winter in 2010 which might have affected dolphin food resources, and the BP oil spill occurred in 2010, and there is increasing evidence of spill materials entering coastal ecosystems and negatively impacting the food web,” Worthy said.
The abnormally callous winter of 2010 had been detrimental for the innocent wildlife marine birds, Finfish, manatees and sea turtles too.
Mobile Bay watershed snowfall let an unusually heavy flow of water melt down and come down to the Gulf in January 2011. The dolphins died immediately after the fall in temperature, due to the melt water. Probably these water animals had been unable to cope up with the cold, had succumbed to death and then been washed ashore.
Dolphins can withstand fluctuating temperatures
Dolphins are generally capable of standing up to fluctuating temperatures. Though the oil spill did disturb the food chain of the dolphins, a NOAA (a National Oceanic and Atmospheric Administration )survey in 2011 found the birds were underweight, anemic and already struggling for survival.
Studying all the facts Ruth Carmichael the study leader said, "When we put the pieces together, it appears that the dolphins were likely weakened by depleted food resources, bacteria or other factors as a result of the 2010 cold winter or oil spill, which made them susceptible to assault by the high volumes of cold freshwater coming from land in 2011.”