The problem began in the 1960-70s, when shocked consumers learned of the numbers of dolphins killed as bycatch by tuna fishermen. In purse seine fishing, pods of dolphin that swam with yellowfin tuna were driven into nets the width of 10 city blocks, which closed in a purse-string action and winched out dolphins along with the tuna. An estimated 6,000,000 dolphins died in this time.
A boycott and downturn in yellowfin sales forced a change in technique. Cork floats were removed, the boats were backed off to let the following net edge fall, and the dolphins swam free above the rim leaving the tuna in the closing nets. Dolphin bycatch reduced by 99%, but still 20,000 dolphins died each year - still the largest globally recorded fishing bycatch.
Under pressure, a dolphin-safe method came in – fish aggregation devices (FADs). Now floats shaped like seaweed, logs and jellyfish, fitted with sonar and GPS systems, monitor numbers of bigeye and yellowfin tuna that ‘aggregate’ around the floats, and let fishermen know where and when to catch them.
Instead of 5-30 metric tons (MT) by purse seining, fishermen now bring in up to 200MT, with less time and fuel wasted in the effort. Not surprisingly this ‘fishing’ method, driven by demand for dolphin-safe tuna, results in bycatch and death of countless juvenile tuna and unwanted fish.
We live in a limited ecosystem, yet still persist in seeing it as limitless. Ocean fish might potentially feed the world, if correctly managed and allowed to grow, but the drive for money means stocks are rapidly dwindling. FADs are not the problem, so much as those who benefit by them.
While other canning companies still sell ‘dolphin-safe’ tuna sourced from FADs, it is easy to see which product the savvy consumer should be buying.
P Edwards (originally published in the "Voices for the Earth" column in The Daily Examiner)