FACT, FOLK­LORE OR FIC­TION?

DO AT­LANTIC SAL­MON FEED WHEN MI­GRAT­ING UP­STREAM? THIS EN­THU­SI­AST HAS PLENTY OF REA­SONS TO BE­LIEVE THEY DO

Anglers Journal - - CONTENTS - By C.M. RIP CUN­NING­HAM

There is a com­mon be­lief that At­lantic sal­mon do not feed when mi­grat­ing up­stream. Non­sense, says this en­thu­si­ast, who has the ev­i­dence to back up his hy­poth­e­sis.

Whether it’s called folk­lore, an old wives’ tale or com­mon myth, fishing seems to have more than its share, and some be­liefs are eas­ily dis­proven but rigidly ad­hered to. Take, for in­stance, the be­lief that At­lantic sal­mon do not feed dur­ing their up­stream mi­gra­tion to spawn. Non­sense.

At­lantic sal­mon have mes­mer­ized me since I hooked my first 25-pounder on a big, fluffy White Wulff dry fly at age 10. I can still re­call the fish emerg­ing from its bot­tom cover to in­hale my of­fer­ing. Since then, I have hooked, lost and landed thou­sands more — and I feel strongly that the the­ory about up­stream feed­ing is in­cor­rect. They may also take flies for other rea­sons, but feed­ing should not be ruled out.

My first inkling about the truth came 60 years ago, when an un­cle took me with his fam­ily for a driv­ing/camp­ing trip around Nova Sco­tia. My cousin and I got to hang out in the camp­grounds and forests while Un­cle Woody went sal­mon fishing on the Stewiacke and St. Mary’s rivers. I had only caught trout on flies but had caught a num­ber of salt­wa­ter game­fish on other tackle, and I would rather have been with

Un­cle Woody. I saw a teenage boy with a spin­ning rod and a can of worms in a fly-fishin­gonly spot. He glow­ered at us, then baited the hook and lobbed it out into the river. Within 10 min­utes, he’d hooked and landed a sal­mon of about 7 or 8 pounds. He told us to keep our mouths shut or he’d pound the #%@&! out of us. I didn’t care; I was en­vi­ous of his catch.

What stayed with me about that trip was the ease with which that teenager took a fish, while my un­cle com­plained daily about catch­ing noth­ing. And the fact that worms or other baits are con­sid­ered too ef­fec­tive to al­low them to be used had to mean some­thing, too. If sal­mon don’t eat, then why would there be any dif­fer­ence be­tween Un­cle Woody’s luck and that teenager’s?

Many years later, I watched an an­gler worm-fish a pool on the Laxa Hi­tara in Ice­land and stack up a bunch of sal­mon for the smoker. I con­tin­ued to won­der, If this fish does not eat, why did it in­hale a gob of worms and be­come gut-hooked al­most every time? The be­hav­ior is too close to feed­ing to be in­stinct, ag­gres­sion or any­thing else. If it looks like a duck, walks like a duck …

It’s a slim few an­glers who agree with me. One of them was Lou But­ter­field, a fa­mous Mi­ramichi River an­gler and in­ven­tor of the Whisker (and, I be­lieve, the But­ter­fly). Love him or hate him, Lou caught thou­sands of sal­mon. He be­lieved they would take big in­sects, then crush out the nu­tri­tious in­nards and spit out the re­main­der. He said he had spent hours on sev­eral rivers in Canada’s Gaspé Penin­sula ob­serv­ing this be­hav­ior. From a perch above a crys­tal-clear river, he would lob grasshop­pers to hold­ing fish and watch what hap­pened af­ter a fish would take his of­fer­ings. I have caught many sal­mon on the Mi­ramichi River with chubs in their throats or mouths, yet they still take the fly. That be­hav­ior sounds like feed­ing to me. I have yet to find a parr, but that may be more a func­tion of where I am fishing and where the parr are feed­ing than any dis­crim­i­na­tion on the part of the sal­mon. An­other co­in­ci­dence: In most sal­mon wa­ters where the fish show to any de­gree, they most of­ten do so at the time of day, and un­der the same con­di­tions, when one nor­mally finds good in­sect hatches.

Back in the ’70s, the But­ter­fly was pop­u­lar on the Mi­ramichi be­cause of the high num­ber of gypsy moths. Many an­glers saw fish take a flut­ter­ing gypsy moth off the sur­face. I re­call one oc­ca­sion when sev­eral fish be­ing cleaned had bulging stom­achs crammed with gypsy moths — those were the days when a lot of fish were killed. Feed­ing again, I thought.

I’ll con­cede the point that sal­mon don’t feed in rivers like they do in the ocean en­vi­ron­ment. If they did, they would de­vour far too many of their own young, an evo­lu­tion­ary no-no. How­ever, there’s also the phys­i­o­log­i­cal changes that the fish goes through when mi­grat­ing from salt to fresh wa­ter. In salt wa­ter, the sur­round­ing en­vi­ron­ment is al­ways try­ing to pull mois­ture out of the fish, which ex­pends ap­prox­i­mately 15 per­cent of its en­ergy fight­ing this ten­dency. When a sal­mon en­ters fresh wa­ter, it con­trols the wa­ter that per­me­ates its body through a process called os­moreg­u­la­tion. It al­lows the fish to be far more ef­fi­cient with its en­ergy con­sump­tion in the river.

And while I do not pro­fess to be a marine bi­ol­o­gist, it is pos­si­ble that uric acid in the fish’s sys­tem mit­i­gates the mois­ture ex­trac­tion in salt wa­ter. Uric acid is known to play an im­por­tant part in wa­ter con­ser­va­tion for birds. When the fish en­ters fresh wa­ter, uric acid may chan­nel into its stom­ach, form­ing highly acidic green bile. What lit­tle the fish does eat is quickly dis­solved in this high con­cen­tra­tion of acid — per­haps one of the rea­sons that stom­ach­con­tent ex­am­i­na­tion rarely leads to the kind of con­crete re­sults I saw on the Mi­ramichi.

At the same time, re­search con­ducted mainly for the At­lantic sal­mon aqua­cul­ture in­dus­try shows that At­lantic sal­mon smolts mov­ing from fresh­wa­ter rear­ing tanks to salt­wa­ter grow-out pens go through a pe­riod of anorexia. It is pos­si­ble that the re­verse mi­gra­tion from salt to fresh wa­ter could have the same sort of im­pact on the re­turn­ing adults — an idea that has seen less re­search. Cer­tainly, we know that af­ter win­ter­ing in the river, sal­mon feed ac­tively as they drop down­river. The feed­ing ac­tiv­ity may be a com­bi­na­tion of ac­cli­ma­tion to the en­vi­ron­ment and the lack of spawn­ing hor­monal

changes. What­ever it is, they most cer­tainly are feed­ing as they move back to the ocean.

When At­lantic sal­mon mi­grate from fresh­wa­ter lakes up rivers to spawn, they can be much more ag­gres­sive tak­ers — and, I sus­pect, feed­ers. The rea­son is that they do not have to go through the phys­i­o­log­i­cal changes that fish com­ing out of the ocean do. This is also true of steel­head mi­grat­ing out of the Great Lakes. They are ac­tively feed­ing dur­ing their up­river spawn­ing mi­gra­tion. Like all fish that are pre­par­ing to spawn, they go through sub­stan­tial hor­monal changes that may well af­fect their feed­ing habits, too: the closer to spawn­ing time, the greater the hor­monal im­pact.

In some of these sit­u­a­tions, it is likely that male fish will dis­play ag­gres­sive ten­den­cies to­ward any­thing they see as in­vad­ing their ter­ri­tory. Thus, the com­monly be­lieved the­ory of tak­ing a fly as an act of ag­gres­sion. And yes, the ef­fects of en­vi­ron­men­tal changes, phys­i­o­log­i­cal changes and hor­monal changes cer­tainly lessen the fish’s de­sire to eat, but I do not be­lieve they elim­i­nate it. I be­lieve that in some in­stances, when fac­tors such as wa­ter tem­per­a­ture or baro­met­ric pres­sure might make a sal­mon less in­clined to take in a nor­mal feed­ing pat­tern, some pre­sen­ta­tions will trig­ger a re­flex­ive in­stinct to take.

I ac­knowl­edge that as the an­nual mi­gra­tion sea­son ma­tures, ag­gres­sive ten­den­cies in­crease in male fish. But if ag­gres­sion is the rea­son sal­mon take, why are 99 per­cent of the fish hooked inside the mouth? Wouldn’t more of them be hooked some­where on their head rather than in the corner of the jaw or the roof of the mouth? And it’s also a fact that a sal­mon, af­ter tak­ing a wet fly, will hold it while re­turn­ing to its lie. This is not an ag­gres­sive trait. It could be an in­stinc­tive re­ac­tion based on years as a ju­ve­nile in the river. If that in­stinct prompts the strike, the re­sult is a bug con­sumed.

Does it make sense that a fish could come into the river in June, move to some head­wa­ter pool and hold there un­til late Oc­to­ber to spawn, then re­main in the river un­til April with­out some sort of feed­ing? In some cases, this could mean al­most 10 months of liv­ing off stored fat. In some Great Bri­tain rivers, it can be more than 12 months. Sure, their me­tab­o­lism un­der the ice slows to a crawl, but in the spring, on the trip down­river, they are ac­tively feed­ing.

Al­most ev­ery­thing I have learned about this fish says that it is feed­ing in its up­river mi­gra­tion, too. But old myths are hard to dis­prove. Think about that when you land your next At­lantic sal­mon hooked in the roof of its mouth. Con­ven­tional wis­dom says this was just chance. Re­ally?

Sal­mon As­cend­ing a Falls

Whether sal­mon feed dur­ing their up­stream mi­gra­tion has long been de­bated by an­glers.

Twi­light Sal­mon Fishing

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