The stock of yellowfin tuna has been heavily overfishedOverfished:
A stock is overfished when the stock size has decreased so far that it can no longer produce a maximum sustainable yield. The size of the fish populations is insufficient to reproduce in the long term. in the last 10 years. The [fishing effort] however has declined and the stock seems to be currently within safe biological limits and is not being overfished. The reliability of the [stock estimate] is however very unclear.
Besides, the catching method of longlines is an unselective fishing method. The longline fishery on yellowfin tuna in the Indian Ocean is known for their high bycatch of young tuna and undesired species like seaturtles, seabirds and sharks. In the north-east of the Indian Ocean, shark bycatches of 54% of the total catch weight have been observed.
The IOTCIOTC:
Indian Ocean Tuna Commission, an international organization dedicated to the management of tuna and tuna species in the Indian Ocean and adjacent seas. is responsible for the management of tuna in the Indian Ocean. There are several problems with the management. There is no [catch limit] set and there are no effective tools to oversee and correct the fishing effort. The [illegal fishery] on yellowfin tuna is still considerable: 18-32% of the total catch. Measures to address unwanted bycatch are not taken. The IOTC has made a resolution to deal with the finning of sharks, but due to the lack of surveillance and control at sea, this initiative has little effect.