More on FADs usage and politics / by Francisco Blaha

There still a lot of conversations about FADs and get asked about them a lot, particularly since there is a drive to ban them completely by some NGOs, while others want to go for better designs to reduce risk of entanglement of sharks, sea turtles, and other organisms while reverting from synthetic to biodegradable materials – to reduce marine debris.

In November of last year, I wrote about them from a more technical point of view here. So I explore different aspects today,  there are plenty of FADs design, but the biggest design feature is that FADs can be of 2 sorts: anchored or drifting, and both can have entangling "bits" attached so is no difference there.

Remember that the whole idea of a FAD is to create the illusion of a big "thing" floating so fish congregate underneath. People put all sorts of stuff underneath the floating part to create that illusion. One of the most common pieces of "stuff" you have on board are pieces of nets, so those are the entangling bit, but then… they are not really big, so the impact, while existent, is not massive. 

Originally, we used to put coconut tree leaves all around and make the "body" of bamboo (see the pic above where you see the netting also), but they require way more maintenance.

Making them biodegradable is great regarding marine debris, and if you get the net bit out, the entanglement accidental catch shall be reduced, but so does the life span of the FAD. The companies are putting expensive electronics on them: sun-powered sonars with satellite data transmission devices are more common than ever, and that does not play well with the concept of “biodegradable.”

In any case, it does not actually deviate from what the fact that juvenile YellowFin and BigEye loves hanging out with Skipjacks and as long as you fish with Purse Seiners you’ll catch them all… while at different ratios along the year.

When it comes to canned tuna, the best "eco-friendly" choice is Pole&Line (P&L) caught fish, and then a bit down the scale "FAD-free" purse seine caught fish.

Is being said that the volume of pole-and-line fish is not sufficient to meet the demand, I personally believe that the issue is costing. P&L makes to cans more expensive due to the higher cost of fishing per ton of product (a P&L catches in year what a Purse Seiner Catches in couple of months), and reality seems to be that the bulk of the consumers are not ready to pay X times more for can of P&L caught, just to satisfy their ethics. Hence "FAD-free" makes up the bulk of the "eco-friendly" product.

The interesting point is that "FAD-free" fishing is a return to school fishing, which the fleets were pushed away off by the “dolphin free” campaign in the 70's and early 80's. It is ironic that free school fishing is now being viewed by many NGO's as the more responsible and sustainable.

A truly wicked twist in this saga is that I heard now from various processors that with the influx of "FAD-free" fish, the canneries we are encountering a much higher percentage of fish with really “soft texture,” hence the levels of rejections and downgrading has increased.

A friend that is processing MSC certified skipjack (hence FAD-free), told me that for him MSC stands for Mushy Skipjack Canned :-)

This “soft texture” may have something to do with a higher level of enzymatic reactions, and the higher body temperature of fish caught while actively feeding in a school during the day, as opposed to fish caught while lazily circling a FAD in the very early mornings.

Free school fishing happens when tuna is feeding "out there". Skipjack feed predominantly on small pelagics, micro-crustaceans and some mollusks (squid). Stomach contents show a huge variety tho, so is obviously a highly opportunistic feeder. (It would eat its own juveniles as well)

From the fishes in the Skipjack diet, Scombers and Thyrsitops are quite represented, and both have high enzymatic contents in the stomach, that associated with the high level of enzymes in the stomach of Skipjacks while feeding (which is when are capturing them) is known to be associated with mush and soft meat.

And this is not just on tuna; we hated it when we were doing trawling for Hake and Hoki in the South Atlantic if the fish was feeding on sardines or anchoveta for the same reason, fish became a mush in no time

So, if the level of rejections has increased which means that the fish is sent to the fishmeal factory. Hence, more fish needs to be caught as to maintain production, (which is usually demand driven by contracts), so the whole situation it is going against one of its initial aims:  catching less fish.

I think that if you had FAD closures for longer or 2 or 3 times a year, then it could achieve a balance... With an estimated 80000 to 120000 FADs deployed, there is no "magic bullet" solution for this... or for anything thing else in life actually :-)