Group says infection killed Fraser’s dolphin in Jagna

TAGBILARAN CITY, January 26 (PIA)—First, it was not a bottle nosed dolphin that washed ashore in Pangdan, Jagna, and second, its death is not caused by the cookie cutter shark bites, nor propeller hit. 

This was contained in the necropsy reports which Balyena.org shared to the Marine Wildlife Watch of the Philippines (MWWP) following the news that a dead dolphin was washed ashore in the town, January 22. 

According to balyena.org who did a necropsy before burying the dolphin’s carcass, the dead dolphin was a female Fraser's dolphin.

Police and municipal fisheries and aquatic resources authorities earlier erroneously identified the dolphin as bottle-nosed, measuring an over-all length of 2.2 meters and a girth of 37 centimeters. 

It had inflicted wounds on its body, more prominent of them has been an identified cookie cutter shark bite about five inches from its dorsal fin. 

While observers believed the abrasions on the left side of the animal could have caused the death, Balyena.org in their necropsy report stated that the animal had a severe infection of roundworms (nematodes) in its stomach and tapeworms (cestodes) in its blubber and muscles. 

“The parasitic infection caused ulcerations in the stomach and most likely led to blood loss and eventually to perforation and peritonitis,” the report which was shared by MWWP showed. 

Balyena.org, a non profit non stock organization conducting dolphins and whale research in the Philippines, also added that the two cookie cutter shark bites were not the cause of death. 

Contrary to what most people think, these oval bites are not fatal.

Cookiecutter shark bites on cetaceans are fairly common, Balyena.org, in a separate post on their Facebook account shared. These sharks, Isistius brasiliensis, or the cigar shark, is a member of the Family Dalatiidae or the “sleeper shark” family. 

It is named after the cookie-shaped wounds that it leaves on the bodies of larger fish and marine mammals. These are also known as the cigar shark because of its dark brown and long, cylindrical body shape. It lives in the deep-waters of warmer areas worldwide. And because it emits a greenish glow it is also known as the luminous shark. 

The cookiecutter shark is considered a “facultative ectoparasite which means it feeds on the flesh of other species causing them harm but not death and it is not dependent on these species for survival.” 

The Fraser’s Dolphin that stranded in Pangdan is the second which Balyena.org found there.

Last march 30, 2009, a weakened Fraser’s dolphin stranded in Brgy. Pangdan, Jagna. Responders tried to guide it to deeper waters but it kept swimming back towards shore. The animal died a few hours later. (rac/PIA-7/Bohol)