I don't fish, but my understanding is that Atlantic salmon are highly esteemed as a prize target, and that the fisherman who can get to Scotland and enjoy both the fishing and the famously picturesque environment has achieved fishing nirvana. Richard Shelton has been able to do this because the region is his home, and though he has fished for salmon, much of his fishing has been for the sake of science rather than for sport or for platter. Among his other duties is Research Director for the Atlantic Salmon Trust, and it is clear that he loves his work and his research subject. He provides a view of both in _To Sea and Back: The Heroic Life of the Atlantic Salmon_ (Atlantic Books), a handsome volume designed to look old, like the natural history volumes that attracted the author when he was a boy. Some of Shelton's book is a look back to a riverine boyhood and the way the curiosity which provoked a boy's poking around for fish in the mud turned into the adult's poking around scientifically. Though the book is based on the remarkable life cycle of the salmon, readers will be happy for digressions on such topics as the evolution of mammalian locomotion in the waters, the edibility of rats and horses, the lives of lampreys that live by "a particularly grisly form of parasitism" (they suck onto a living fish and rasp the flesh away), the beginnings of oceanographic research, and the life of Shelton's wife's grandfather, a ghillie on the Dee. Shelton is a clear writer, and a genial guide to a diversity of subjects.
Since salmon are sequentially freshwater and saltwater fish, their life cycle is complicated, and the words to describe the phases are ancient. The tiny alevin stage is first, then fry, then smolt, then off to sea as true salmon, then return as grilse, then spawning. Salmon do not only grow, they also change shape. Parr need to have bursts of acceleration for hunting in the river and they have a stubby, muscular appearance; smolts need to swim long times and distances, and have a more fusiform shape. Colors also change, and then there are all the other complexities of changing from fresh to salt water and back. It has long been known that salmon return to their own birthing places upriver to spawn and send out their own progeny. This is such an astonishing performance that much research has been done and some answers are ready. The salmon seem to be able to remember smells, and the same hormones that drive increasing muscular activity in the parr also stimulate the central nervous system, possibly so that the brain can make olfactory snapshots of the successive downstream environments. Salmon brains, unlike our own, may have this sort of on-and-off flexibility. The salmon goes to sea with the olfactory memories locked away, and may replay them backward to get home. It may also use an internal compass for navigation, although this may be more useful at sea. Scientists have long known that the "lateral line", a clear marker between upper and lower body in salmon and other fishes, can respond to pressure sensations without actually being touched. It turns out that in salmon, it also carries particles of an iron compound that can respond to the Earth's magnetic field. Shelton introduces us to many naturalists and scientists, past and present. One of his focuses is the famous Victorian naturalist Frank Buckland, who shows up in any account of British biological endeavors of the nineteenth century. Shelton is, in fact, the Chairman of the Buckland Foundation, and Buckland plays a big role in the history of salmon fishing in Britain. Buckland was a real British eccentric, favoring mice on toast for tea, and garden snails, and when he could get it, crocodile. He was, however, a serious naturalist and was disgusted by the way industrial Britain was putting pollutants in the water, writing, "Manufacturers of all kinds of materials, from paper down to stockings, seem to think that rivers are convenient channels kindly given them by nature to carry away at little or no cost the refuse of their works." He knew that chemicals as well as dams and weirs could be obstructions to salmon which needed to migrate upstream and down. He strongly supported sewage treatment, and would have been glad to see that many of the poisoned rivers are now running clean, with salmon returned to them.
Shelton salutes Buckland for his profound love of the environment and his being one of the first to realize how predatory and destructive humans have been to it. His own take on environmental preservation is far from shrill: "It is time to stop wasting fossil fuels, to control the growth of our own population and to manage the living resources of land and sea with love and sensitivity." Maybe someday we will have all the wisdom that salmon do. "If only," Shelton muses, "we were close enough to share the salmon's instinctive ability to profit from the resources of the sea without doing them serious harm."