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16 january 2011
I went to the local science library in search of James Prosek's new book Eels, but it wasn't on the shelf. Luckily I found another recent book on eels, Richard Schweid's Eel, which I devoured faster than a steaming unagi bowl. Then, luckily or not as you look at it, I discovered that Eel is only one of a long series on individual common animals, smartly produced by Reaktion Books. I sense a compulsive read through an entire series coming on.
But to start with Eel, a book I was drawn to because its title fish is possibly my favorite food in the world. Schweid's book is in the best traditions of popular-science writing. It's informative, timely, piquant, and elegantly written. It induces new respect for the lowly eel, and at the same time (as is tragically so often the case with writing about wild animals), it alerts us to possible impending ecological doom.
Mmmn. I had to take a break to eat a can of eel. The eel in the can was the end product of a baffling biological process. Adult eels from Asian rivers swam out into the middle of the Pacific Ocean to spawn, in grounds only discovered by scientists within the last 20 years. (For fun, Google "15° N, 140° E": it is seriously in the middle of nowhere, and how eels find it is completely unknown. Even that they find it is mostly an inference.)
Larval eels, born in the open ocean, commence swimming back to Asia. When they reach the mouths of rivers in, say, Korea, some of them are caught by aquabusiness workers. They're still tiny, at the "glass eel" stage of development. They're shipped to Taiwan, grown to maturity in farm ponds, slaughtered, marinated and barbecued to an indescribable deliciousness, tinned, and shipped – mostly to Japan. Thanks to globalism, some of them fetch up in a Vietnamese supermarket in Grand Prairie, Texas, whence I collect them via shopping cart and car.
The process I've just described mirrors one that takes place in the Atlantic, and forms the subject of Schweid's Eel. Anguilla anguilla, a close cousin to my Anguilla japonica, swims down the streams of Europe and North America to breed in the Sargasso Sea. Again, this fact is mostly inference. Nobody's ever seen adult eels in the Sargasso Sea. Nobody's really seen them en route. Inductive reasoning is all that allows us to know that they do, because they can't honestly be doing anything else.
The big picture of eel reproduction was worked out by Danish scientist Johannes Schmidt in the first decades of the 20th century. Schmidt spent about 20 years tracking eel larvae. He drew lines – like isobars, though one might have to call them "isoelvers" – indicating how large the young eels he'd sampled in various Atlantic locales had grown to be. When he found the smallest eels of all, he knew they were spawned nearby, even if he couldn't catch their parents in the act.
For millennia, our ancestors cheerfully grabbed and ate eels in the rivers of Europe, Asia, and America, unaware of the odyssey the fish undertook to get there. Like the migratory birds and insects that enriched their ecosystem, these long-distance swimmers came and went, beyond the scope of humans to do much except sample them (usually in the course of their downstream drive back to the Sargasso or other spawning grounds).
But our love for eel – and I'm guilty as charged – has led to overfishing. Pollution and damming have reduced the habitat of the freshwater eel. In particular, the demand of the food market has meant that far more glass eels are being taken up at the mouths of streams and diverted into aquaculture than can be replaced by wild sources. Eels cannot breed commercially, though crash efforts are underway to encourage them to do so. Every eel we eat must be born in midocean: and fewer eel progenitors every year make it back there to beget them.
As well as containing many gorgeous illustrations, Eel is a fount of facts. Eels, with their four nostrils, have the second-keenest sense of smell in the animal kingdom (next only to dogs). Eels are not kosher. (Perhaps they should be, because they have microscopic scales, but early rabbis couldn't see the scales, so eels are treyf forever.) George W Bush owns a pair of custom-made eelskin boots. I can retain next to nothing of practical use, but I'm going to remember those miscellaneous eel facts till I die.
Schweid, Richard. Eel. London: Reaktion, 2009.