Leatherback turtle died of pneumonia, but weakened by ingested plastic

A necropsy on a dead leatherback turtle which was brought to the Ċirkewwa quay by the Armed Forces of Malta (AFM) on Wednesday found that the turtle died from pneumonia that developed into a generalised inflammation.

However it was also noted that the animal had been severely weakened by ingestion of plastic material which was found in the intestines, the Environment and Resources Authority said.

The cause of death was issued by Dr Anthony Gruppetta, veterinarian, who performed the necropsy on behalf of Nature Trust Malta. The animal had been found entangled in drift nets, which also left their toll on the animal.

These turtles are the only turtles which feed exclusively on jellyfish and jelly like creatures, and hence are very susceptible to plastics in the sea which they mistake for jellyfish. In fact, a similar case of a dead leatherback turtle was recorded in 2015. 

The leatherback turtle was first noticed between Ras il-Qala and Taħt it-Trunċiera, along the coast close to the Qala quarries, entangled in nets. Subsequently, AFM informed ERA of a report of a huge turtle at sea between Qala and Comino. AFM were asked to land this turtle at Ċirkewwa, and ERA officials proceeded on scene to co-ordinate efforts. 

Upon arrival it was discovered that the turtle in question was a juvenile leatherback female turtle of 1.85m long, which was dead. It weighed 190kgs.

The Civil Protection Department provided assistance to lift the dead specimen from the boat to the quay. The turtle was then transported and a necroscopy carried out to establish the cause of death. ERA also invited the University of Malta to take samples for research purposes. 

This species, Dermochelys coriacae, (Fekruna sewda) is not commonly encountered in the Mediterranean and in Maltese waters and though the last stranding dated July 2015, most of the confirmed sightings of this species around the Maltese date some decades back. The turtles commonly found in Maltese seas are in fact loggerhead turtles (Caretta caretta). 

The leatherbacks that come to the Mediterranean are most probably from the Atlantic sub-population. Leatherback turtles are highly migratory species, crossing the Atlantic Ocean and occasionally entering the Mediterranean Sea. 

Leatherback turtles, along with all the marine turtles, were protected in Malta since 1992 through legislation which at the time reflected the obligations of the Barcelona Convention. This species is also protected under CITES, the Bern & Bonn Conventions and under the Habitats Directive. In the latter it is classified as “Animals of Community Interest in need of Strict Protection”. 

Although their distribution is wide, numbers have seriously declined globally. The northwest Atlantic populations were the ones that generally swam into the Mediterranean, and their normal nesting areas are actuially in the south-eastern USA and the Caribbean Sea. 

Leatherbacks are the largest sea turtle species, and among the heaviest modern reptiles globally. They can grow up to a weight of 900 kgs. They do not have a hard ‘outer’ shell, but a carapace that is elongated and covered by skin and oily flesh which has given this turtle its name; leatherback turtle. 

This turtle has no claws on the flippers which are more elongated and paddle like than in other sea turtles. The leatherback turtle is also quite special as it has the widest geographical range of any of the sea turtles. It tolerates very cold waters unlike other reptiles, due to adaptations in its circulation, high oil content and enormous body size.