Turtle Mortality in Fishing Operations in Pakistan - Paper 4 in Proceedings of the Regional Symposium on Sea Turtle Conservation in Asia

Citation
Moazzam M, Nawaz R (2015) Turtle Mortality in Fishing Operations in Pakistan - Paper 4 in Proceedings of the Regional Symposium on Sea Turtle Conservation in Asia. IOTC, Olhao, Portugal
Abstract

There are a number of threats being faced by a dwindling population of marine turtles in Pakistan, of which entanglement in various fishing gears is considered to be the most serious threat. In order to enumerate the extent of mortality and to devise a strategy to reduce interaction of turtles with fishing operations, a study was initiated in October 2012. Monitoring of fishing operations was done in coastal and offshore areas of Pakistan which revealed that in the pelagic gillnet operations in the offshore water maximum numbers of turtles get enmeshed resulting in mortality in some cases. It is heartening that the majority of such turtles survived enmeshment. Mortality was observed only in 3 % cases which is mainly because of the poor heaving process and improper handling onboard fishing vessels. A study on seasonal variation of entanglement in the offshore gillnets fisheries revealed a bimodal pattern. A major peak of entanglement was noticed during October-December with the maximum in November. Another smaller peak of entanglement was observed during February and April. It was also observed that in the offshore waters, Olive Ridley turtles (Lepidochelys olivacea) enmeshment were of more common occurrence (85 %) than green turtles (Chelonia mydas). An analysis of the size frequency data of the enmeshed turtles indicates that almost all green turtles were observed to be juveniles having the carapace length ranging between 11 cm and 31 cm whereas almost all Olive Ridley turtles were observed to have carapace length longer than 36 cm. A study on the spatial distribution indicates that turtle enmeshment is more common in the offshore waters as compared to coastal areas.
Turtle enmeshment was also observed in neritic water gillnetting. A large number of turtles are enmeshed in monofilament net along Sindh and Balochistan coast; however, in almost all cases turtles were observed to be alive which is mainly because of shorter duration of the operation and light weightiness of the gear. Turtles were observed to hinder some fishing operations including encircling of breeding schools of catfish and large croakers by gillnet; therefore, fishermen either remove the turtles or kill them in such operations. The maximum number of turtles killed in one such operation was noticed to be 5. It may be pointed out that encircling of breeding school of fishes area is an event of very rare occurrence and usually repeated after a few years.
Turtles are usually not trapped in seine net operation because these nets are laid down only if no turtle is observed in the area. Even if a turtle is entrapped in the seine net it is released immediately because it hinders the operation of the net. No mortality was observed in the seining operations. In shrimp and fish trawling turtles are seldom caught but because of short duration of the operation, such turtles are released without any harm to them. Therefore, no or insignificant mortality occurs in shrimp trawl fishery of Pakistan. Similarly no turtle mortality was observed in other fishing operations including longlining and estuarine set bag net operations along Pakistan coast.
A programme for creating awareness among fishermen for the reducing interaction of turtles and fishing operations was initiated in October 2012. Fishermen were trained to release enmeshed turtles safely to reduce their mortality. The programme, in the beginning, faced some resistance from the fishermen, however, now almost all fishermen especially those engaged in pelagic gillnet fisheries release the turtles safely without wasting time and injuring the enmeshed turtles. It is estimated that in the pelagic gillnet fisheries about 25,000 to 30,000 turtles are safely released annually.