Mercury rising while major predators decline and governments do nothing.
On Canada Day, July 1st, news broke of a new discovery of a very old whale. The whale, named Leviathan melvillei by the scientists who discovered it, lived and died some 12 to 13 million years ago. The name literally means Melville’s sea monster, named after the author of Moby Dick, Herman Melville.
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I was fascinated to learn that Leviathan melvillei was a type of sperm whale1, the modern version of which is a species that, only days earlier, I became concerned about due to another recent scientific discovery. But the ancient, long-extinct species was very different from our contemporary sperm whales. For one thing, the ancient whale was extra huge even by whale-standards, with teeth that were up to fifteen inches (36 centimetres) in length. L. melvillei ate, well, anything, including other kinds of whale. Modern sperm whales are benign by comparison, mostly eating giant squid (big, but boneless) crustaceans and small fish.
Leviathan melvillei was at the very tip-top of the food chain in the oceans of long ago, before there were humans to “manage” marine fisheries. By the time humans invented boats and fish nets those fisheries, 12 to 13 million years after L. melvillei left his bones on the sea bottom, were burgeoning with vast numbers of fish and other marine life, from tiny plankton to huge predators. The presence of those predators obviously did not have negative effects on other species. And yet we have systematically and quite intentionally nearly eliminated large predatory fish species.
That fact achieved world-wide media attention a couple of years ago, when scientists were able to report, “Recent estimates indicate that exploitation has depleted large predatory fish communities by at least 90% over the past 50 – 100 years.”2
And yet when, last April, my colleagues fought to provide some level of protection under the Convention on International Trade in Endangered Species (CITES) for some of the large, predatory fish that had suffered the most decline (bluefin tuna and various shark species), they were defeated. The lobby against the proposals was led by Japan, which continues to kill whales and dolphins, large and small, by the thousands in spite of international condemnation.
That brings me to two other very recent events. I finally got to see the Oscar winning documentary film, The Cove, which shows the horrific slaughter of dolphins herded into an isolated cove in Japan.
And, in late June, a report was released that detailed the results of a new five year study of sperm whales, based on the acquisition of skin samples.
While no match for L. melvillei the modern sperm whale is also near the top of the oceanic food chain. The report found that the animals are contaminated by toxins, most a by-product of human (anthropogenic) behaviour, such as industry. This includes mercury, one of the deadliest of substances, found in sperm whales at levels as high as 16 parts per million.
In 1956 it was discovered that in Minamata, Japan, thousands of citizens were sickened, crippled or killed by a severe neurological syndrome caused by mercury poisoning derived from consumption of fish containing trace amounts of mercury. Between 1962 and 1970, the syndrome, popularly called “Minamata disease”, showed up in First Nations people who consumed a high percentage of fish at Grassy Narrows, here in Ontario. The fish were contaminated by mercury illegally discharged by paper mills. Look up “Minamata disease” at the library or on the internet and be prepared for hideous photos of terrible suffering.
We are told that children and pregnant women should avoid fish when mercury reaches only 1 part per million. Whale expert Roger Payne and his colleagues used a sort of dart gun to painlessly remove a tiny sample of skin from about a thousand living sperm whales over a five year period, and found high levels of cadmium, aluminum, chromium, lead, silver, mercury and titanium in the flesh. The whales’ outer skin averaged 2.4 parts per million of mercury.
The threat to humans is twofold. One, as consumers of sea food humans are, like whales and dolphins, atop the marine food chain. Toxins, as one moves up the food chain, “bioaccumulate”, meaning they increase multi-fold. How that happens is beautifully illustrated with graphics in The Cove, and I highly recommend renting the CD version and also viewing the extra feature which details sources of mercury poisoning in humans.
But the other threat is, clearly, to marine life itself. Just as these heavy metals, mostly anthropogenic in origin, threaten us, so do they threaten top-of-the-food-chain predators, which are already greatly reduced by overfishing. And yet they are essential to the ability of the environment to sustain the very food so many of us depend upon so much for our own survival. I haven’t eaten fish in forty years, but for some people, including the folks at Grassy Narrows, sufficient numbers of alternative foods simply don’t exist.
We are attacking ocean life on so many levels, in so many ways, it is hard to track it all. And yet when we look to government authorities and regulatory bodies we see mostly failure to protect dwindling stocks of marine life. There are a few stellar exceptions to be sure, but the general response of humanity to the decline in our planet’s ability to sustain us, our lives, cultures and industries, is to do nothing…or rather, do pretty well all we can to hasten the destruction.
1 There are two living species of sperm whale, the sperm whale (which is what the fictional Moby Dick was) and the much less well-known pygmy sperm whale.
2 See: Myers, Ransom A., and Boris Worm, Extinction, survival or recovery of large predatory fish, Phil. Trans. R. Soc. B 2005, 13 – 20.
Blogging off,
Barry