The Trout Season From a Scientist’s Perspective 

​The following enlightening write up is courtesy of my good friend Ryan Weaver who knows a helluva lot more about Trout than I do. He is currently managing one of the Trout farms at Katse Dam in Lesotho and he has given me permission to publish his article that he wrote for the Cape Piscatorial Society. I stand by my opinion  that there are literally hundreds of streams out there that hardly ever get fished, and that morally I have no issues with fishing in the closed season on these streams. It is a very different story on the heavily pressured rivers of the Cape or the Natal Midlands. 

A CPS Season Change, 

by Ryan Weaver
There is nothing more exciting than that first outing onto your favourite section of river at the beginning of the new river season. For me it’s usually to a spot where I ended the previous season having some or other score to settle with a particularly large or tricky fish that got the better of me. The cold winter months have been spent in-doors reading up on new techniques and refining the old favourite flies to something that, in my mind, no fish could possibly refuse. In fact hell, they may as well give up now because I recon I’m so well prepared for the new season they don’t even stand a chance! When we first moved to the du Toit’s Kloof I was so eager to get out onto the streams each year that I developed a tradition of putting a line onto a stream, any stream, come hell or high water on the first of September. This is not too difficult for me as I am fortunate enough to have some incredible rivers within casting range of my back stoep. The unfortunate part is that hell and high water inevitably seemed to culminate in full force to deter me year after year with our little mountainous kloof getting a good drenching of Cape winter rain either on or the day before the opening of the river season and it was very seldom that I found myself throwing my line onto anything that even vaguely resembled a sensibly fishable piece of water. Nevertheless in true piscatorial perseverance my tradition continued much to the bemusement of my employer, staff and family who became accustomed to seeing a shivering, but beaming fool of an angler come traipsing back onto the farm each first of September.
My first decent day’s actual fishing usually only came a few weeks later once the raging torrents had subsided, the kayakers packed up and moved on and the fish finally come out to show themselves again. The water would still bring a numbing ache to the legs, but it was fishable and presented a whole new challenge: Last season’s pools and channels had shifted substantially meaning that the lunker I sought out was long gone. I don’t blame him though as he would most likely have been ground into fishy nothingness by the tumbling boulders that get shifted around by the momentous water volumes that gush down these narrows kloofs over the closed season. In fact it has always amazed me that these little mountain trout can actually manage to spawn and have their fry hatch and survive in such a hostile environment. It’s a wonder they aren’t born with crash helmets and a wild penchant for high speed extreme intercourse! 
Given the size of the fry that we see frequenting the shallows of the Kraalstroom and Elandspad during the early season I have another theory which, over the past three years, I have confirmed through observation. Our wild river trout in the Western Cape are not spawning, as was traditionally believed, in early winter like their hatchery and still water restrained cousins, but are rather waiting to the end of winter once the rivers are full and there is safe access to suitably calm nesting areas that are unlikely to be turned back into monster hydraulic grinders by continual winter rain. It has happened three years in a row now that my first outing of decent fishing on our local rivers has proven that: 1. My newly concocted flies are as unreliable as the previous season’s ones were; 2. The trout are completely safe and need not fear my newly acquired piscatorial prowess and; 3. They’re way too obsessed with various stages of courtship to be interested in my carefully constructed creations. In fact I find myself feeling like a naughty peeping Tom caught watching in rapt fascination as beautiful fourteen-inch fish pair up side-by-side, do their gentle flank touching mating dance and proceed to spawn right in front of me. In fact it usually puts me off fishing completely as I know, from my work at the hatchery, that the energy reserves left in these fish are likely to be so low after spawning that an encounter with an over-eager angler’s fly will have a good chance of killing them. 
Trout, like their pacific salmon (oncorhynchus spp) cousins, go into a period of fasting prior to spawning during which time all their energy reserves are used for migration and gonad development. A recently spawned fish can have used up to 92% of its lipid (fat) reserves and 63% of its protein reserves with the muscle cell bulk now being mostly comprised of water. We see this classically with snoek in the Cape at certain times of the year where these fish (no matter how fresh) are “pap” because of the high water content in the flesh.  Luckily our trout recover condition fairly quickly after spawning and go on a bit of a binge feed to recover the lost weight. During this time they are easy to catch and the likelihood of catching decent size fish in early season is very good. This usually happens around the end of September to early October in our rivers and can be seen in the catch reports that come flooding in over the various online fishing forums. 
My concern is, and I’d like the Cape Piscatorial Society committee to seriously consider this, that our late spawning fish are being put under unnecessary stress by eager early season anglers and that their fragile nesting areas are being trampled by said anglers too. This year I took a new approach to the start of season which I have found very rewarding. Instead of going down to the river with rod and newly tied assortment of flies in tow I carry a camera and watch patiently to see if our next generation have left the nursery yet. They suffer enough pressure from the predatory smallmouth bass that seem to march relentlessly higher and higher up the Elandspad each summer. Given this and that stricter regulations are being imposed on the trout farms as far as escapee management goes (60 micron filters on outflow channels makes for really small escapees!) We should pay serious attention to managing our existing wild spawning stocks. We have an incredibly unique and beautiful strain of rainbow trout in our freestone streams. With Jonkershoek having introduced Brooke, Brown, Cut-throat and Rainbow into many of our local rivers in the late 1800s and the very restricted window periods available to these fish to spawn in these rivers it is quite likely that what we have now is a hybrid of those originally stocked (but that’s a whole other discussion). As Douglas Hey so well put it “Trout are as much a part of South Africa as the oak trees are of Stellenbosch – not to be planted in wilderness areas where they do not already occur, but to be valued where they are established.” So let us consider a change of season to accommodate both the angler and his late spawning prey.  Committee: How about 1st June to 30th September?

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