At first, it seems like a fairly straightforward conservation tragedy - one of far, far too many. There is a handsome fish found only in the Sea of Cortez (also called the Gulf of California), which is an arm of the Pacific Ocean that extends up to near San Diego, California, and Tijuana, Mexico, between the Baja Peninsula and Mexico's mainland. At the northern tip of this 700 mile long "inlet" is the mouth of the Colorado River.
The fish is called totoaba, and it is a specialized member of the family of fish called drums (Sciaenidae). Once abundant, the fish can grow to a length of about 6 and 1/2 feet and weigh over 220 pounds.
Young totoabas require brackish water, neither as salty as the lower reaches of the gulf, nor as fresh as river water. As it matures, the totoaba prefers more salty water, returning to the brackish region only to spawn, once per year.
The problem? First, the totoaba is over-fished. That is because of the huge value of its swim bladder (an internal organ) in China, where the bladder is used for medicinal purposes. It was estimated in 2013 that 200 bladders fetched $3.6 million. And, the meat is considered a delicacy, also in demand in China and elsewhere.
The story does not end there. The same nets that catch the totoaba also pose a lethal risk to the vaquita, a tiny species of porpoise also found only in the Sea of Cortez. They grow to just under five feet in length and weigh up to about 105 pounds. The vaquitas have become entangled in the nets and drowned, and they are especially vulnerable to net mesh sizes designed to catch totoabas. It is estimated that there may be fewer than 200 to as many as 400 or so left, making them the world's rarest cetacean (the mammals that are whales, dolphins, or porpoises).
Mexico is working hard with limited resources to prevent extinction of both species and is asking the world for help. One method Mexico is toying with worries me, and that is captive breeding, or "farming," of totoaba, to provide the product without taking wild fish. You can buy "legal" totoaba from such farms in trendy Mexican restaurants.
My concern, in part, is that any legal trade in totoaba meat (or swim bladders) will encourage demand and illegal trade. Even as I was typing this blog, news arrived of how an explosive trade in ivory from tusks of long-extinct woolly mammoths is contributing to demand for ivory from ever-decreasing and endangered populations of contemporary elephant species. The mammoth ivory is being uncovered at an unprecedented rate due to melting glaciers in response to climate change.
And China is signatory to the Convention on International Trade in Endangered Species (CITES), which lists both species under Appendix I, prohibiting commercial trade (which at any rate does not threaten the vaquita). Enforcement of existing protection is therefore part of the problem.
But I would argue demand for fish overall contributes to the likely extinction of the vaquita, because, of course, other kinds of fishing activity and netting also put the vaquita at risk, even if the gear used is not so likely to catch vaquitas as the nets used for totoabas. Their mesh is the same size as the vaquita's head.
Totoaba themselves are sometimes imported into the US as "white bass," as well as smuggled illegally into the US, and they are at any rate caught unintentionally (or not) in nets set for other, legally caught species. Can we really blame fishers from impoverished regions for being part of supplying the rest of the world's insatiable appetite for fish?
And then there is our demand for both water and electricity. Historically, the flow of water from the Colorado River maintained perfect conditions for the totoaba's spawning grounds. But, since the completion of the Hoover and Glen Canyon dams, the diversion of fresh water to maintain crops, lawns, golf courses, and other demands - including for cities like Las Vegas and Phoenix, placed in hot deserts where no city should be - at best only the tiniest dribble of polluted fresh water now enters the Sea of Cortez, which means it is too salty for baby totoabas. It is ironic, too, that as climate change seems to lead to extended extreme draught in the US southwest, our demand for water, in part to fight the threat of massive brush and forest fires, comes when there is the least amount available.
Mind you, many decades ago the totoaba was fished so heavily for its swim bladder, back when it was legal, that shorelines were seen to be littered with totoaba carcasses, the bladders cut out for export to China, the meat wasted. Even now, the temptation of earning a few thousand dollars for a single totoaba bladder is a huge incentive for fishermen, and millions of illegal dollars have been made, in the US and elsewhere, from illegal trade in this product.
Time is running out for the vaquita and there is enough blame for its plight, and that of the totoaba, to go around.
Keep Wildlife in the Wild,