THE yellowfin tuna, found in tropical waters including PNG, is reaching its “full level of exploitation”, according to a scientist from the Secretariat of the Pacific Communities (SPC), Dr Shelton Harley.
The big-eyed yellowfin’s assumed state in the near future is despite the fact that …“tropical tuna species can spawn throughout the year provided the conditions are good enough for them”.
The species is caught with the long-line and purse seine.
“… and so at the moment, we are finding that the level of mortality – the amount that we are taking from the stock – is too high for the big-eye.
“The big-eye has been over-fished,” Dr Harley said.
He said the albacore – found in temperate waters – was doing well because most Pacific Island fisheries allowed it to breed before they are fished and so have high spawning chances.
The big-eye, however, is being fished as they are spawning and their juveniles are always in the risk of being caught around fresh aggregating devices.
“With their type of migratory behaviours they have little chance to spawn,” Dr Harley said.
On the other hand the albacore and the bluefin (also a temperate tuna) have spawning grounds they migrate to.
President of PNG Fishing Industry Association and RD Tuna Cannery’s Pete Celso said they were looking into expanding the supply base for the fish resource.
However, he said this would be dependent on expert advice from marine scientists.
“Through the industry we can look into research that can expose us to other options. We need the scientist to assist us,” he said.
For the skipjack tuna (also found in tropical waters) Dr Harley said they (SPC) believed it was doing well in terms of breeding.
The other type of tropical tuna is the skip jack.