KARACHI: In a moving demonstration of changing attitudes to threatened marine species, fishermen looking for tuna 158 kilometres south-west of Karachi safely released a giant manta ray back into the sea after it got entangled in their fishing net recently, according to officials of the World Wide Fund for Nature-Pakistan (WWF-P).

The species had a disc size of about 1.5 meters. It was the first release of a giant manta ray by fishermen who had to lose their net in a half an hour long rescue effort, they told Dawn on Sunday.

“The giant fish was released by boat captain Ameer Badshah and his colleagues while they were fishing in 1034 meters deep waters,” said WWF-P technical adviser on marine fisheries, Mohammad Moazzam Khan.

He said the captain had received training from the organisation on how to rescue threatened marine species. Another giant manta ray was spotted north of Churna Island more than a month ago, he said.

About the past records of the species, he said the fish was reported for the first time from the Karachi coast in 1878 by Francis Day, a pioneer ichthyologist who also served as the inspector general of fisheries in India and Burma (Myanmar).

Later, it was mentioned in the accounts by Tombazi in 1934. He used to hunt the species behind the Churna Island.

He said: “Though many scientists included this species in their list after that, the credit for the first authentic record of its occurrence goes to Dr Rahimullah Qureshi, the founder director of the marine fisheries department, who found it off the coast of Ormara, Balochistan, in 1949. The specimen had a disc size of about 6.5 meters.

“Since then, the marine fisheries department has only one record of its occurrence and that was in 2010. It had about three meters of disc size,” he said.

A gentle giant

According to Khan, the giant manta ray feeding on small planktonic shrimp only is considered to be a gentle marine creature as it poses no threat to humans.

“The area north of Churna Island is its main concentration area in Pakistan where it has been found basking and feeding. Right now, if caught incidentally fishermen sell it for use in the fish meal while its liver oil is used for smearing the hull of the fishing boat,” he noted.

The fishermen trained by the organisation have rescued and released a number of marine species (that got entangled in fishing nets) over the past two years that includes whale sharks, three mantas, 10 rays and hundreds of marine turtles.

Giant manta ray, scientifically known as Manta birostris, the largest living ray that can grow up to a disc size of seven meters, are found in all major oceans, in tropical, subtropical as well as temperate waters.

Within this broad range, however, actual populations appear to be sparsely distributed and highly fragmented, according to local marine experts who regard the species’ local presence as ‘rare’.

The global conservation status of the species is ‘vulnerable’, says the International Union for Nature Conservation (IUCN) Red List of Threatened Species website.

With an ability to jump out of water, the species swims mainly on the surface of the sea in a pattern similar to the flight of a kite.

“The rate of population reduction appears to be high in several regions, as much as 80pc over the last three generations and globally a decline of 30pc is strongly suspected. Sustained pressure from fishing (both directed and by-catch) has been cited as the main cause of the decline. The situation is aggravated by the species’ extremely low reproductive output (one pup per litter),” says the website.

Dive tourism involving this species is a growing industry, according to the website, suggesting responsible development of such industries as they can also negatively impact individual behaviour, entire populations and critical habitat of this species.

Published in Dawn, March 7th, 2016