On several occasions I have warned you about the human-caused destruction of the world's oceans. One key aspect of this catastrophe is the collapse of various important fisheries, which has a devastating effect on ocean ecosystems. Eventually, the oceans will be all but dead, almost bereft of animal life. Honestly, marine scientists don't really know how much havoc we're wreaking by overfishing various important species, but as our knowledge grows, we'll learn in the end that the outcome of such wanton destruction is not benign. It never is.

The New York Times has come out with a report detailing the decimation of the Jack Mackerel fishery (species Trachurus murphyi) off the coasts of Chile and Peru. The indiscriminate slaughter of these fish looks just like the destruction of the cod fishery off New England and eastern Canada in the northwest Atlantic in the 1990s. From In Mackerel's Plunder, Hints of Epic Fish Collapse—

TALCAHUANO, Chile — Eric Pineda, a dock agent in this old port south of Santiago, peered deep into the Achernar’s hold at a measly 10 tons of jack mackerel — the catch after four days in waters once so rich they filled the 17-meter fishing boat in a few hours. Mr. Pineda, like everyone here, grew up with the bony, bronze-hued fish they call jurel, which roams in schools in the southern Pacific. “It’s going fast,” he said as he looked at the 57-foot boat. “We’ve got to fish harder before it’s all gone.” Asked what he would leave his son, he shrugged: “He’ll have to find something else.”

[My note — Did you catch that? We've got to fish harder before it's all gone.]

Jack mackerel, rich in oily protein, is manna to a hungry planet, a staple in Africa. Elsewhere, people eat it unaware; much of it is reduced to feed for aquaculture and pigs. It can take more than five kilograms, more than 11 pounds, of jack mackerel to raise a single kilogram of farmed salmon. Stocks have dropped from an estimated 30 million metric tons to less than a tenth of that in two decades. The world’s largest trawlers, after depleting other oceans, now head south toward the edge of Antarctica to compete for what is left.

In 20 years Jack Mackerel landings have declined by over 90%. I was able to dig up this data from the Sustainable Fisheries Partnership.



Source. You can see the rapid decline in Peru and Chile (circled). The other nations are operating "pelagic trawlers" in unregulated international waters (map above).



There is also an interactive graphic at iWatch News which I can't reproduce here. You can read about subsidized overfishing and the like in the New York Times. I should point out that Trachurus murphyi has almost certainly reached commercial extinction, as opposed to existential extincton, yet governments and regulatory bodies are still arguing about quotas.

The South Pacific Regional Fisheries Management Organization (S.P.R.F.M.O) was formed in 2006, at the initiative of Australia and New Zealand along with Chile. Its purpose was to protect fish, particularly jack mackerel. But it took almost four years for 14 countries to adopt 45 interim articles aimed at doing that. Only six countries have ratified the agreement... In 1995 alone, Chileans fished more than four million tons. That is eight times the amount S.P.R.F.M.O. scientists said could be landed in a sustainable way in 2012. From 2000 to 2010, Chile landed 72 percent of all jack mackerel in the southern Pacific... Eduardo Tarifeño, a marine biologist at the University of Concepción, said that Chile now had only sardines in relative abundance. “We have no more jack mackerel or hake or anchoveta,” he said. “Fisheries that produced a million or more tons a year have simply run out from overfishing by big companies.” He added: “If we don’t save jack mackerel today, we won’t be able to do it later. We need a total ban for at least five years.” At the fisheries secretariat in Valparaiso, Italo Campodonico said: “As a marine biologist, I have to agree. We should have a five-year ban. But as a civil servant, I must be realistic. For economic and social reasons, it won’t happen. Outsiders can go fish in other waters. We can’t.” Roberto Cesari, the European Union’s chief envoy to the S.P.R.F.M.O., which meets next week, said he expected ratification of its conditions only in 2013 — seven years into precipitous decline for jack mackerel. The S.P.R.F.M.O. cut voluntary quotas 40 percent for 2011, but China, among others, opted out. Beijing later agreed to reduce by 30 percent. Mr. Cesari said the European Union tries to exert pressure, but its clout is limited. China and Russia, he noted, “are giants.” Bill Mansfield, a New Zealand international lawyer who has chaired the S.P.R.F.M.O. since 2006, said that voluntary restraints had not protected fish stocks and that it was time to put the convention into force. The Santiago meeting must limit the 2012 catch to 390,000 metric tons or less, he said.

I last talked about overfishing of the oceans in my post Nothing Changes On New Year's Day. My point then and my point now is that the wanton destruction just goes on and on. This paragraph from the Times captures the problem perfectly.

“The slaughter was tremendous, unbelievable,” said Juan Vilches, who scouts fish for a large company. “No one had any idea of limits,” he added. “Hundreds of tons were thrown overboard if nets came up too full for the hold. Boats came in so loaded that fish were squashed, their blood so hot it actually boiled.”

No one had any idea of limits. There it is. We could use this sentence as Humanity's Epitaph once the 21st century is over.

Bonus Video — Jack Mackerel schooling. Videos like this will be like pornography to those living in 2050.