‘Accidentally caught’ rare tiger shark sold for Rs55,000

A rare tiger shark caught by local fishermen was sold off for Rs55,000 at the Karachi Fish Harbour, most likely for preparing ‘finger fish’ and extraction of liver oil, officials of WWF-Pakistan said on Thursday.

The rare marine animal was caught on October 9 by local fishermen about 186km south of Karachi in the Indus Swatch area off Keti Bunder. The specimen measured around 3.8 metres in length and weighed around 550kg.

The tiger shark is a requiem shark known for its ferocious nature and is widely distributed in tropical and subtropical waters of the Indian, Pacific and Atlantic oceans.

Although a large number of tiger sharks have been caught in Pakistani waters previously, their stocks are now dwindling and its capture has become rare. A few specimens are caught every month but are usually small (about 50 to 150 kg). However, catching a large specimen of more than 200 kg is very rare in Pakistan.

Locally known as ‘nar mani’ in Balochi and ‘aiyan more or aiyan’ in Sindhi, tiger sharks are caught mainly by bottom set gillnet and longlines. In addition, they are also caught by handline using live bait and pelagic gillnets.

Although tiger sharks are caught along the entire Pakistan coast, the Indus Swatch area is one of three hotspots, while the other two are off Ormara and Jiwani. The Indus Swatch is a deep canyon at the mouth of the Indus River and has a maximum depth of more than 1,000 meters.

Shark concentrations have been reported from both sides of the canyon up to a depth of 300 metres. Tiger sharks are also reported in shallow coastal waters and in estuary and lagoon areas along the Pakistani coast.

Noor Muhammad, a fishermen trained to collect data for tuna fisheries by WWF-Pakistan, said the gigantic shark was accidently caught and already dead when it was retrieved from the water. “It was too large to be handled and preserved so we used a mechanical lifting device,” he added.

The male tiger shark was brought to the Karachi Fish Harbour where it was weighed and auctioned at Rs55,000 and converted into finger fish for sale in the market. ‘Its liver weighed about 150kg and around 120 litres of oil was extracted, which will be used to smear the hull of fishing boats to keep them smooth and free from fouling organisms,” he added.

Muhammad Moazzam Khan, Technical Adviser (Marine Fisheries) for WWF-Pakistan, said tiger sharks were once common along the coast of Pakistan. However, due to excessive overfishing, especially during 1987 and 2002, shark fisheries almost collapsed.

The tiger shark is a prolific breeder and a female produces about 10 to 80 pups in a litter but due to excessive fishing stock have seriously declined.

The species is considered near threatened, according to the International Union for the Conservation of Nature (IUCN) Red List, because of excessive fishing, including finning, and demand for its meat.

Considering the over-exploitation of sharks, the government of Sindh and Balochistan recently enacted a ban on catching a number of shark species including rare silky, oceanic white-tip, thresher, whales and hammerhead sharks as well as guitarfish and mobulids which are relatives of sharks, he informed.

The tiger shark is a voracious predator and fishermen are very careful when dealing with its entanglement in line gears as it is known for unprovoked attacks.  It is killed using spears and harpoon before being hauled on to a fishing boat. The tiger shark is known to consume a variety of prey including shrimp, crab, lobster, fish, marine mammals, birds, squid, turtles and sea snakes and dolphins and even other sharks.

The tiger shark has been known to eat inedible, floating objects including tires, wood, cans and even stones, therefore, it is also known as a ‘garbage eater’ shark.

Rab Nawaz, Senior Director Programmes for WWF-Pakistan, pointed out that sharks such as tiger sharks are apex predators of the ecosystem of coastal and offshore waters and their decline has disturbed the tropic balance resulting in the appearance of some species which were not found in abundance in the past.

He maintained that WWF-Pakistan initiated studies on shark resources in 2012, which revealed that major shark stocks in offshore waters are depleting whereas sharks harvested by fleets in coastal waters are also under serious threat.

He stressed the need for the implementation of legislations to ensure protection of shark resources which were recently promulgated. “There is also an urgent need for endorsement of National Plan of Action (NPOA) by the provincial governments for protection of the sharks,” he added.