March 24, 2014 By: Simon Blanford

fly fishing science

photo by John Juracek

The amount of scientific research that gets carried out on fish—how they live, how they move, how they evolve, even how they taste—is huge. A quick search for ‘fish’ in a database of journal papers (the end point of biological research and the basic currency of scientists) from last year found some 16,000 individual studies. That’s 44 papers on fish published every day.

Perhaps this shouldn’t surprise. Fish are the most numerous vertebrates on the planet. Studying them is important and the discoveries can change the way we view our world. Fish are used as animal models for all sorts of physiological, ecological and evolutionary studies. They also happen to be one of the most important sources of protein for many peoples and the targets of a recreational sport that spans the globe. Fish, in short, fill our thoughts.

Since fly fishing’s main purpose is to extract life from water, fly fishermen want to know all sorts of things about that life. What kind of fish live in this water? How many are there? What do they eat? How big do they grow? How do they interact with—and even change— their environment? Understanding of the ‘way of a trout with a fly’ has created ranks of anglers who are intensely curious about the behavior of the fish they catch, and of the prey on which they base their imitations. All fly fishermen, to a certain extent, are natural historians. Many take it to the point of being taxonomists: the differences between Baetids are as obvious and compelling to them as the differences between a beagle and a basset hound are to dog lovers.

But modern modern biology has shed its softer edge, has become a rigorous science full of math both in theory and practice. Despite the voracious latinizing that overtook fly fishing in recent decades, there’s a certain tension, a degree of wariness when the language of biology is used in our conversations. As a biologist and a fisherman, that tension puzzles me, if only because of the wealth of knowledge hidden in all that data.

There is no doubt that biology’s seriousness—especially its cold, analytical perspectives—can be off-putting. Its reductive nature and jargony language doesn’t easily cross into relaxed debate. Badly communicated science will kill a conversation as quick as a change in the wind can end a mayfly hatch . My car mechanic (if that isn’t giving the man too grand a title) sent me into a torpor by explaining that the transmission “wouldn’t torque over the spark plugs because the fuel injection was leaking in manifold ways over the coiled carbonara.” Or at least that’s what it sounded like to me. I’d like to understand, I really would. But the non-mechanic in me suspected that he was obfuscating over the state of my lemon’s inner workings —using his peculiar argot as a way to hide something that even he didn’t completely understand.

And so it is with science and fly fishers. Intertwined with our wariness of jargon is the suspicion that such an unburdening of science could diminish or even make mundane the wonder we feel for what we see and catch. We prefer that the conversation continue rather than that it arrive at any sort of conclusion. In fact, Einstein said that “the process of scientific discovery is a continual flight from wonder.” But does the detail implicit in science really unweave the rainbow?

fly fishing science

photo by John Juracek

These days most “science,” of course, comes to us over the Web or via teasers on our favorite news channel. But the translation from scientific journal paper to the soundbites of media is a process that invariably diminishes, trivializes, and often confuses the research.

With all that in mind, I think it’s is time to have another go at distilling current biology and science for fishermen. Over the next few months I’ll provide observations on the stuff that normally turns off the non-scientific mind, in as digestible a form as possible: why some fish are easier to catch than others; on fish and their various personalities; on whether they can learn that your carefully tied green drake is bad for them, how individual fish specialize in what they eat. There will be snippets on the adipose fin, fish vision and, for want of a better expression, ‘left-handedness’ in fish. We’ll also touch on broader subjects: invasive species, trophic cascades and the impact of catch and release.

I hope the discussion will help you see further into the complex world inhabited by the fish we try to catch. A little insight never hurts, especially when you can see the fish and it isn’t eating your fly.  With luck, some of the knowledge I’ll impart will become more than trivia—it may actually help you catch a fish or two.