Posted on February, 20 2013

Tuna fishing using handline is often branded as sustainable. But is it really?

In Mindoro, this certainly is not the case.

Let me explain.

I have had the liberty of being at sea on board tuna handline boats, big and small, on many occasions. Fishing is done primarily at night, mainly drifting but to a lesser extent, also during daytime anchored around Fish Aggregating Devices (FADs).

Normally, each fisher brings 6 reels of fishing lines, 3 to 4 of which he uses, and the rest he sets aside as backup. Between 8 to 10 pm, each fisher deploys 1 to 2 hooks and hauls them every 5 to 15 minutes.

As soon as sufficient baits (20 to 30 per fisher) have been collected, the full fishing operation commences, starting around midnight. Each fisher deploys between 3 to 5 hooks at a time, with soak time ranging from 5 to 15 minutes.

To count the number of hooks deployed each night per fisher, I simply counted the number of drop stones they used. Dropstones are rocks (~1-2 kg) where baited hooks are tied to bring the hooks to the desired fishing depth.

On average, each fisher deploys between 30 to 40 hooks in one night on a catchless operation. If any fish (tuna or marlin) takes the bait, this number of hooks deployed is reduced to 22 to 30 hooks, as fishing operation is halted to facilitate hauling of the catch.

During daytime, fishers will deploy lines another 10 to 15 times, bringing it to an average of 47 hooks per fisher for every 24-hour fishing operation.

Now translate this to the whole fishery off Mindoro with an average of 1,700 fishers (about 60% of the total) going out to fish every day, and you have a total of 79,900 hooks deployed per night!

Or, computed with 240 annual fishing days, the number of hooks deployed by the fishery is 19.2 million hooks per year!

This is equivalent to 6,392 longline boats deploying 3,000 hooks each night!Going back to my earlier question; when can the use of handline be justified as “sustainable”?

The answer is - only when its numbers are regulated to conform to a fishing level that leaves enough tuna to replenish stocks.

Currently, handline fishing in Mindoro is not. It is in the oxymoron state of “sustainable overfishing.”

Posted by Jose Ingles (Jingles)