February 2007 – Skinny Female Dolphin from Haifa Harbor


The last sighting of the common bottlenose dolphin was in
Haifa Port on Friday February 2nd, at around 3:30pm.

 

Photographed by Yaniv Eliash

Photographed by David Rezek

 

24 hours later, a female common bottlenose dolphin was found dead at Poleg beach – 60 km south of Haifa Port. On Friday night the body was transferred to Michmoret for autopsy, which took place on Saturday morning and its findings are quite thrilling.

Photographed by Ori Asher

 

In the pictures that were taken by Amit Magal and Aviad Scheinin - One can see that the scars on the body and the notches in the edge of the dorsal fin of the carcass match those of the swimming dolphin

 

The dolphin turned out to be 303 cm long– the longest documented female dolphin that ever beached on the Israeli shoreline. Length at maturity for the coastal population in Israel is 250 cm and females are usually smaller than males. Most likely it belongs to the deep water morph, due to its size and coloration.

External body markings leave no doubt that it was the same individual that was sighted inside the Port.

 

IMMRAC president Dr. Dani Kerem before the autopsy in Michmoret – photographed by Aviad Scheinin

 

 

The most important finding was a piece of fishing net that was tightly twisted around the dolphin's modified larynx, known as the 'goose beak'. It is worth mentioning that cetaceans' upper respiratory tract is completely separated from the moth cavity and food passage to the esophagus. The protruding, unattached, cartilaginous 'goose beak' bridges the gap between the nasal passages and the trachea, tightly fitting inside the muscular lower nostril underneath the blowhole and designed to keep anything but air out of the lungs. The twisted piece of netting caused deep necrosis, although it did not perforate the trachea.

 

Within the trachea there was a large amount of frothy yellow-colored fluid.

The net continued into the stomach that felt quite full. Upon checking the stomachs' content at the University of Haifa next morning, a 1/2 kilogram tight ball of fishing net and hooks was found in the otherwise empty stomach.

 

   

IMMRAC chairman Aviad Scheinin shows the fishing net that was found in the dolphin's stomach

 

 

In addition a few external parasites were found on the skin and on the tongue there were two big ulcers. Teeth were worn and quite a few were missing.

    

Ulcers on the dolphin's tongue

 

Tissue samples were taken for pollutant, pathological, genetics and stable isotope analyses. The skeleton was transferred to the University for preservation.

 

Points for consideration:

 

  1. Why did the skinny female dolphin swim 60 km in one day through relatively stormy seas and reached Poleg only to be washed out to the beach?
  2. Could we have freed and extracted such fishing net had we captured the animal and would her condition have been reversible?
  3. When a dolphin seems so skinny, should we capture it and attempt to rehabilitate it, even when it looks lively and performing well?
  4. If we decide to capture a dolphin in such a condition, can we afford the expenses and the manpower needed to treat such an animal for a few months?

 

Unfortunately, the answer to the last question is probably "no".