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WELTZ: Salmonids are able to shrink body length in colder temps

Hot off the news wire this week: trout shrink! A group of Norwegian and Finnish scientists have recently observed that during cold temperatures, salmoniods can reduce their body length up to 10 per cent. It is believed that they do this by reducing the gel in their vertebral disks.

Add this new revelation to the fact that a fish’s whole metabolism slows down in relation to dropping temperatures. Along with the fact they can also change their skin colour to adapt to their surroundings (science has documented that trout call change colour completely in 36 hours), and one gets a glimpse into what science has named functional ecology. Fish are also able to change colour to hide from predators, regulate food intake and digestion with metabolism along with conserving energy by reducing body size.

After reviewing all this data, one question stands out in my mind. How big was my friend Dave Rice’s 44 inch, fly caught, Thompson River Steelhead, before it shrank? One can only guess.

The report

The ice is off our Lower Mainland lakes but it will take a day or two of sunny skies to get the fish feeding actively again. If you are going try a slow retrieve or troll with: Big Black, Woolly Bugger, Micro Leach, Sixpack, Dragonfly Nymph, Halfback, Doc Spratley, or Zulu.

Our Lower Mainland beach and estuary fisheries for sea-run cutthroat are likely your best bet until all the high water recedes. Try: Epoxy Minnow, Tied Down Minnow, Muddler Minnow, Clouser’s deep Minnow, Lioness, Grizzly King, Mickey Finn, Coachman, Knudson’s Spider, Zulu, Purple Joe, or Borden Special.

The Fraser River and soughs are slow to fair for cutthroat and dolly varden. For cutthroat try: Rolled Muddler, Mickey Finn, Eggo, Tied Down Minnow, Epoxy Minnow, Winter Stone, Flesh Fly, Professor, Lioness, Coachman, Zulu, Chez Nymph. For dolly Varden try: Large (#4 to #1) Eggo, Dolly Whacker, Bucktail, Epoxy Minnow, Big Black, Muddler, or Zunker.

The Vedder River should be fishable, and good for steelhead, dolly varden and rainbow, by the weekend. For steelhead try: big Black, Popsicle, Steelhead Nightmare, Polar shrimp, GP, Thor, Squamish Poacher, Kaufmann Stone, Purple Peril, or Eggo. For rainbow try: Rolled Muddler, Mickey Finn, Eggo, Flesh Fly, Kaufmann Black Stone, Black Gnat, Zulu, Chez Nymph, Big Black, Sixpack, or Renegade.

The Stave River is good for rainbow and cutthroat.

The Chehalis River is fair for steelhead and cutthroat. The Harrison River is fair to good for cutthroat, and rainbow.

You can find more at “The Reel Life Press” by Jeff Weltz