Over the past two decades, stocks of Jack mackerel in the South Pacific have declined by 90%, from 30 million tons to 3 million tons. Many of the fish being netted are juveniles. This is a sad turn of events for one of the world’s richest fishing grounds.
Chile captures three quarters of the Jack mackerel catch. This protein-rich fish tastes similar to sardines and can be used as a tuna-substitute. Because mackerel are smaller-bodied and not top predators, their meat accumulates less toxins and heavy metals.
But only a small percentage of Jack mackerel are eaten directly. The majority of the Chilean bounty is turned into fish oil or fish meal, which is used to feed pigs and aquaculture. Chile is a major world supplier of farmed Atlantic salmon; and it takes four pounds of fish meal to make one pound of farmed raised salmon.
How did the mackerel situation get so bad? A lack of regulations and improvements in trawling technology created a fishing free-for-all. In 2006, New Zealand, Chile, and Australia formed the South Pacific Regional Fisheries Management Organization to protect the fish—but progress has been slow.
A recent report by the International Consortium of Investigative Journalists found that nearly 60 percent of the jack mackerel caught in 2009 failed to meet minimum size requirements. In early 2011, this number edged toward 91 percent.
Daniel Pauly, an oceanographer at the University of British Columbia, sees the decline of Jack mackerel in the southern Pacific as an alarming indicator, calling them “the last of the buffaloes.”
Photo, taken on December 27, 2004 using a Canon Digital IXUS 500, courtesy of Richard Ling via Flickr.