FADs and Mining the Ocean of Life

By B. McPherson

FADs are a glaring example of the Law of Unintended Consequences. I’m not talking lava lamps or hoola hoops here. FADs are Fish Aggregation Devices and I have to admit that I was not aware of this particular little horror in our oceans until now. FADs are devices based on the knowledge that fish in the oceans tend to gather around or under logs or other floating debris. Since the outcry in most countries about killing of dolphins in purse seine nets meant to catch tuna, this piece of technology has been increasingly used.

Do you buy “Dolphin Safe” tuna? Do the cans of tuna in your pantry bear the little logo that tells you that you are being a responsible consumer? Mine does and I felt ok about canned tuna, in spite of the high mercury levels, until now.

Fifty years ago the primary method for catching tuna was with poles and hooks into the school of tuna. It was tough, dangerous work but only tuna were caught. Then the fishing industry started using flocks of birds as indicators of a tuna school and moved in quickly to surround the fish with a net that closed like purse strings. They would often trap dolphins which travelled with the tuna schools. Dolphins are air breathers and would drown. The public objected and eventually we were assured that there were ways to catch tuna without catching the dolphins. There were educational films showing the “backing down” of nets allowing the dolphins to swim free. Consumers were reassured that they weren’t killing Flipper when they made their tuna sandwiches.

Humans being the smart, innovative creatures that we are, came up with a more efficient way to catch the tuna than hunting for them on the high seas. They started making artificial floating contraptions that gathered the fish to them like sheep to be shorn. These devices can be equipped to tell the fishing vessels when there are likely to be a good haul of fish. It may be that dolphins are not killed in this exercise, but many other creatures are. They become known as ‘by-catch’ and dead or dying are thrown back into the water as they are sorted out from the commercially salable species.

Can FADs wreck our oceanic ecosystems? We don’t know, but it doesn’t look good. The PEW Environmental Group has this to say:

Moreover, research suggests that networks of thousands of FADs could act as “ecological traps” for open-ocean species by altering their natural distribution patterns, habitat associations, migration, and residence periods. Over time, the proliferation of FAD use may cause widespread alterations in the structure and function of these ecosystems.PEW Environmental Group

There currently are no effective means of regulating the use of these death traps. Some nations seem bent of sieving the oceans of their bounty until little is left. I am sure that the Easter Islanders thought the same way until the reality of their actions was made clear to them.