An additional 11 short-finned pilot whales (Globicephala macrorhynchus) have been found dead in the Florida Keys on Sunday, according to officials. The whales are believed to have originated from a pod, totaling 51 members, that became stranded in the shallow waters of the Everglades National Park, last week, prompting the coordination of intense rescue efforts.
According to the stranding coordinator for the National Oceanic and Atmospheric Administration (NOAA) Fisheries, Blair Mase, the carcasses of the dead whales were spotted at approximately 1 p.m. on Snipe Point, north of Sugarloaf Key. Speaking to reporters during a conference call, Mase delivered the following news:
“We think these are from the same group… We expected this would happen.”
The 11 dead whales were originally spotted by workers for the Florida Fish and Wildlife Conservation Commission. However, NOAA officials are slated to head out to the area on Monday to perform necropsies, in the hope that post-mortem examination might reveal the mysteries of their deaths.
In an official statement, the NOAA indicates that the death tally has now reached 22, with a further 29 pilot whales still unaccounted for. In looking back at previous mass stranding events, the organization predicts the outlook for the missing whales to be “bleak.”
The first batch of whales were discovered on Tuesday, with 11 deaths reported. An additional ten whales died the following day, with officials electing to euthanize four of the creatures, whilst just a single death occurred on Thursday.
What are the Possible Causes of the Strandings?
The last group of whales to have been found alive in the area were moving just five miles offshore on Friday. The group – comprising of 20 whales – were described as swimming in a labored and disorganized fashion; the NOAA suggests this could have been caused by exhaustion, dehydration or malnutrition. Unfortunately, the whales seemed to be heading southward, towards the location where the deceased whales were sighted Sunday.
As yet, no definitive cause for the stranding has been concluded. According to Mase, such types of incidents can be caused by both natural and manmade factors. The team is currently considering the possibility that a virus is spreading through populations of dolphins and whales throughout the Atlantic.
Morbilliviruses are serious pathogens of cetaceans, including whales, dolphins and porpoises, resulting in pneumonia, skin lesions and brain infections. According to a recent study published in the May 2008 issue of the online journal Emerging Infectious Diseases, morbillivirus outbreaks have not been observed in pilot whales in the western Atlantic. However, antibodies to the virus have been identified in 86 percent of two species of pilot whales, including Globicephala melas and G. macrorrhynchus. An additional study also established that 93 percent of stranded long-finned pilot whales were seropositive for the virus, suggesting it to be relatively widespread amongst pilot whales.
According to the Associated Press, scientists are currently awaiting the pathology results of the necropsies to determine whether there were any signs of morbillivirus.
When Mase was asked whether the Navy’s sonar activities could have affected the pilot whales’ behavior, she indicated that the NOAA were currently awaiting a response from Navy officials regarding the matter, alongside details of their recent activities in the region.
Social Creatures of the Sea
The NOAA Fisheries Service confirmed that a total of 11 whales were discovered dead on Sunday, all of which were young females or calves; two of the members were pregnant. The whales were found on a small beach, several feet from one another. They were all emaciated and malnourished, but officials have not outlined the cause of their condition.
Short-fined pilot whales inhabit the open oceans, scavenging for fish, octopus and squid at depths in excess of 1,000 feet. Males typically reach lengths of up to 24 feet, whilst females have an average length of about 12 feet, with adult individuals weighing between 1,000 to 3,000 kilograms.
The whales are highly social creatures and form polygynous relationships, often traveling in groups of between 25 and 50 members. This social behavior is partly responsible for causing the mass stranding incidents, as members of a particular pod are inclined to follow sick and injured whales, in turn, becoming beached themselves.
Meanwhile, the NOAA is requesting any individuals that encounter dead or injured whales, off the coast of southern Florida, make immediate contact with them on 1-877-WHALE-HELP.
By James Fenner