Miraculous Brook Trout

1890547_10152630464659344_2089064443005018923_oThe god Manitou, according to Iroquois legend, was so taken with the brook trout’s sleek beauty that he declined to eat it, throwing it back into the stream he’d plucked it from and leaving his fingerprints as jewel-like speckles on the fish’s back and sides. Although small by most standards – eight inches at maturity is normal in the majority of the Northeast’s streams, and over twelve inches is remarkable anywhere south of Labrador – the brook trout has a big reputation. It is popular enough to have been chosen the official state fish for eight states, including Vermont, New Hampshire, and New York, and it is legendary among fishermen for its energetic fight and its delicate, tasty flesh.

The brookie, also known as the speckled trout or the squaretail, is actually not a trout at all. It’s a char, which means it’s more closely related to the coldwater fishes north of the 50th parallel – the arctic char and the grayling – than it is to the commonly stocked rainbow and brown trout. It is one of the world’s loveliest animals, with its bright flecks of luminous color and the mysterious rune-like patterns that bedeck the dorsal side of its fusiform shape. Through most of the year it is dark with hints of silver, but in October it takes on the glow of a north-country autumn: the intense oranges and reds of the maples; the varied yellows and subtle golden hues of birch, beech, and ash, even the blue of the sky. It is a noble predator, as much a master of the liquid realm as a dolphin or an otter, as fierce and merciless as a wolf or a catamount.

The brookie is also noble in another respect; a finicky elitist, it can survive only in the purest of water. Unlike the more adaptable (and hence more widespread) brown and rainbow, which can live in murkier streams and ponds and can tolerate warmer temperatures, the brook trout needs champagne water: clean, cool, fresh, and well-aerated. The brookie’s Latin name – salvelinus fontinalis, “spring-dwelling char” – is absolutely fitting. Its ideal summer habitat is clear, spring-fed, pH-neutral water at temperatures between 55 and 65 degrees Fahrenheit. At the end of a millennium that has been characterized by extensive development, deforestation, and pollution, this means that wild brookies can only live in the purest of waters, in the streams, ponds, and headwaters of forested or montane ecosystems.

* * *

My wife and I returned to Vermont seeking just such a place, after a decade of living in New Mexico, California, and three overseas countries. We bought a house on approximately thirteen acres of forested land, and part of that acreage – a fertile bottomland hollow directly below the house – was an old beaver dam that had blown out and become overgrown with a tangle of willow scrub, redosier dogwood, and buckthorn. Somewhere beneath all this vegetation a tiny stream burbled; the sound of trickling water was one of the things that drew us to the property. One day in late spring I was poking around in the overgrown hollow, trying to get a better sense of the underlying contours of the land, when I spotted a fleeting shadow in the stream. For the first time it occurred to me that the rivulet – our own little brook – might be home to a population of salvelinus fontinalis. It was spring-fed, cold and clear. But it was quite a small stream, two or three feet across at its widest point, anywhere from ankle to shin deep, with a few knee-deep pools. Was it really big enough to host wild trout?

I watched the stream from then on. Occasionally I thought I saw something – a dark lightning-quick form darting across a pool; a tiny pulse of shadow disappearing under a rock – but I could never be sure. It seemed unlikely that they would venture this far upstream, so close to the source. Even after several weeks of observation, when I’d established to my own satisfaction that there were indeed brookies in the stream, I was met with disbelief all around.

“That brook’s too small,” said Richard, a carpenter and self-styled ecology expert who was working on our house. “It probably dries up in August, or shrinks down to a real trickle. You sure what you saw wasn’t a frog?”

I assured him that what I’d seen was a squaretail fingerling. I’d crept up to the bank and watched it hold in the shallow current long enough to make out the telltale rune patterns on its back. Richard didn’t argue, but I could tell by the look in his eyes that he didn’t quite believe me. Nevertheless, I knew what I’d seen. There were brookies in our stream. What a stroke of good fortune! It meant that the water was pure, that it ran year-round (brookies won’t live in a seasonal flow), and that our own little watershed was home to one of the noblest creatures in North America. It also boded well for earl-summer days on the deck: brook trout are ravenous eaters, feeding on over eighty genera of aquatic insect, the most common being mayfly, caddis, various midges, and – best of all, from our perspective – black fly larvae.

* * *

Contrary to Richard’s prediction, the stream did not dry up in August. The volume fell off slightly, but the source of the springs feeding the brook was robust enough to provide a year-round flow. One day in late October I was sitting on the deck reading when some movement in an open stretch of the brook caught my eye. I got up and walked down into the hollow to get a closer view. Something big was shimmying up through the shallow riffles, displacing a good deal of water. At first I thought it was a muskrat, but taking a closer look I saw that it was a trout: a mature brookie eight or nine inches long. I couldn’t believe it: a full grown brook trout in our little trickle! It seemed impossibly out of scale, and in some of the shallower stretches its wriggling back stuck completely out of the water. Maybe there’s something wrong with it, I thought; some nervous disorder brought on by acid rain or whirling disease that caused it to flee the safety of the deeper water downstream.

But the next day there was another one, equally out of scale with the tiny stream, and then several more made their way up into the hollow. All displayed similar behavior, wriggling up through the shallows and then holding in the deeper pools to gather their energy. In the pools they would splash around playfully, chasing each other and flashing silver as they rolled sideways in energetic riffs along the banks. These shenanigans confirmed what I’d already suspected: the fish were spawning. I sat on the deck for hours, training my binoculars on the open stretch of brook to view the festivities. At one point there must have been twenty fish in the stretch of water visible from the deck, rolling and splashing and churning the surface.

It seemed odd that brook trout would spawn so late in the year. Rainbow trout spawn in the spring so their fry have the advantage of an entire season of feeding before facing the deprivation of the colder months. How would the brookie offspring survive the icy brutality of a Vermont winter? Winter is a dangerous time for trout; their habitat is much reduced due to decreased water flows, and subsurface ice, known as anchor or frazil ice, can force them out of their over-wintering pools. There’s not much to eat, and the spring break-up of the ice cover is a chaotic and hazardous event, with bursting ice dams leading to sudden surges of ice and water that can crush or mortally damage sluggish winter trout. Concerned, I turned to Nick Karas’ excellent study of salvelinus fontinalis, appropriately titled Brook Trout.

Brookies can get away with spawning in the fall because their fry have a long incubation period – one designed to get them through the winter. When you think about it, it makes a lot of sense given the duration and harshness of the northern winters: the eggs are timed to hatch just after snowmelt, in time for the arrival of food, yet before most of the major aquatic predators are active. Female  brookies construct their redds in fine gravel where there is a constant upwelling of fresh water, which keeps the eggs aerated throughout the winter months. The total number of eggs varies from 100 to as many as 5,000 in a large female. The incubation period also varies greatly, from 144 days in 35-degree water to 48 days in 50-degree water. I calculated the time from spawning to hatch; if I assumed an average water temperature slightly above 35 degrees (a reasonable figure, I thought, given the fluctuating temperatures in the month or so before winter’s true arrival), the eggs in our little brook should hatch in a little over four months. That meant some time in early to mid March, right around the time the snow cleared.

After the ice melted off I checked the brook frequently. For weeks I saw no sign of life, and I began to conclude that the previous fall’s spawning had for whatever reason failed. But consulting Karas’ book once again I learned that the hatched larvae remain protected within the gravel of the redd for up to 80 days, gaining strength before they venture up into the open water. And indeed, on a crisp day in mid-April my worries about the viability of salvelinus fontinalis in our watershed were triumphantly dispelled. Peering into the tiny riffle where the brook exits the hollow, I spotted a little school of half a dozen new hatchlings wriggling in the light current. They were pin-thin and only as long as the smallest joint on my pinky finger, but they were already identifiable as brookies by the mottled patterns on their backs and sides. Success!

Curious about how far upstream the spawning run had reached, I walked the brook to its source, half a mile uphill through a shady stand of hemlocks and yellow birch. After a few hundred yards the pitch of the terrain increased; in some places I had to climb steep stretches of granite ledge where the water broke into chattering cascades. These waterfalls seemed far too steep and lengthy for spawning trout to have passed, and I didn’t really expect to see any more fry upstream of them. But in the pools above each there were fry. There were fry in pools no bigger than a birdbath; there were fry in sections of the stream no wider than my outstretched fingers. There were fry within a few feet of the spring that bubbled up out of the ground giving birth to the main flow of the brook.

* * *

For the rest of that spring I watched the brookies whenever I could. The insect hatches began, a succession of awakenings triggered by rising water temperatures. First came some tiny caddis, then the black flies (which the brookies seemed to devour with delightful greed), then the glorious undulating clouds of exquisitely poised mayflies. The deck turned out to be a perfect observation platform; with binoculars I would watch all the tiny pools in the brook come alive with rising fish. The whole life cycle of the brook trout is miraculous – not only that the fish can make it so far upstream, passing such daunting natural barriers in their quest to propagate, but that the timing of the incubation period makes it possible for the precious and vulnerable fry to survive until the bounty of the spring insect hatches.

Even the year-old fingerlings were adept predators; more than once that spring I saw one cock an eye to a tiny caddis dribbling along the surface and then rocket completely out of the water like a miniature Orca to snap it up, slicing back into the pool with a proud little flourish of its tail.

You think you’ve seen everything and then the brookie comes up with another way to amaze you. I have a friend with a beautiful spring-fed pond; for years its held a healthy population of salvelinus fontinalis. But the fish wouldn’t show themselves for months at a time, and just as he would resign himself to the idea that they were finally gone for good they would start surfacing again. One day he put on a mask and snorkel and caught a flimpse of the brookies swimming into the little gravelly holes at the head of the pond – literally following the springs underground, which is undoubtedly where they were spawning as well. I sat on the bank of the same pond and watched as a pair of second-year trout no bigger than my index finger followed the path of a dragonfly zigzagging across the surface. It seemed a quixotic enterprise for the fish – the dragonfly was nearly as big as them and moving fast, like a low-flying helicopter – but suddenly one of the fingerlings leapt out of the water with acrobatic precision and knocked the dragonfly onto the meniscus.  Before it had a chance to right itself the other fish grabbed the enormous insect by its tail and wrestled it under, where the two brookies quickly plucked it apart and polished it off.

This article originally appeared in Northern Woodlands.
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