After last month’s drop in raw material costs, Thai tuna canners were expected to reduce selling prices, but the fall of $100 a tonne turned out to be temporary.

Prices have now reverted to the $800 level with little chance of weakening.

At the annual tuna conference, which will be held in Bangkok at the beginning of June, there will be considerable interest in the five-year sustainability project following concern over the lowering of average fish size.

For the last two years, high seas vessels have reported a definite drop in the size of fish, which has led to experts warning of overfishing.

That’s a view strongly contested by others who will be pointing out that tuna is still prolific and it is a question of fish movement due to sea temperature, which has made catching more unpredictable.