16 | AUGUST/SEPTEMBER 2019| TCFF
Speaking of persisting, being more
than somewhat obsessed with mayfly
spinners, recent successes have elevated
this fly to my number-one go-to river pat-
tern. One of the reasons a spinner is so
incredibly effective is that it must be one
of themost readily available food forms,
a fact brought to my attention by one of
my fishing mates. Genetically, trout are
predisposed to taking helpless prey above
all else, so if you consider that most – at
least for the female spinners of the
species – will eventually land up back on
the water, they are sitting ducks for fish.If you compare this to a trout feeding
on hatching duns, which can evade fish
by flying from the surface, spinners are
much easier prey – vulnerable and inert,
both when they fall to the surface and
when they eventually sink and drift
subsurface. Another reason that makes
them almost the perfect phase of insect
to imitate is that they have a distinct
shape and they make a large light
impression on the surface, both fea-
tures that will not get lost on a hungry
fish.Due to my past lack of effective
patterns, I have quite a lot of experi-
ence casting parachute patterns to fish
feeding on spinners, thinking the para-
chute would at least work, sometimes.
Don’t waste your time; these are com-
pletely ineffective. On the Bushman’s,
towards the end of the recent season,
there were four good trout feeding heav-
ily on top, halfway down a pool. I had a
parachute on so I cast that over them, but
it was ignored. As it was late afternoon
when most spinner falls occur, I tied on a
small spinner pattern and immediately
started picking them off, catching three
in just a few minutes.H
aving fished for a good few sea-
sons now, I have come to believe
the current thinking that there is
such a thing as global warming. I per-
haps needed a bit more convincing than
most, but having recently watched a pro-
gramme on the subject where the person
being interviewed was very much of the
opinion that we humans are not influenc-
ing global warming in any meaningful
way and that it is rather the sun and
sunspots that are creating a warmer
period in the planet’s history, I am at
least now sold on that idea.I’ve fished a series of trout streams
in the Berg over a period of 20 years
around the same date, keeping records
of stream temperatures. These records
illustrate a remarkable change of tem-
peratures. For example, I fished the
Lambonja stream at Cathedral Peak on
4 and 5 April 1998 with a water tem-
perature of 10 degrees. For those who
don’t believe our streams ever get that
cold, I remember my fishing buddy
Lance, who was wading wet, complain-
ing bitterly about how the cold water was
burning his legs to the extent that he
could only wade for a few minutes before
having to get out to warm up again. I
fished the same stream on 13 and 14 April
this year and the water temperature was
20 degrees. Sure, there are many factors
that influence small stream temperatures,
but if you look at the statistics, water
temps arerising. Or perhaps the seasons
are running later? Nowadays summers
seem to be lasting longer and our winters
are shorter and milder.FORUM: FRESH WATER
The good news is that although trout
are a cold-water species, they do have
over a hundred generations of offspring
that will be genetically adapted to local
conditions, so will undoubtedly be better
able to cope with, among other things,
our warmer conditions. If you believe
what the experts tell you about trout,
these fish that were feeding heavily and
full of vigour in 20-degree water, were at
most just 4 degrees away from going belly
up. This may explain the very noticeable
fact that the fishing was on in the morn-
ings when it was cold and the fish took
advantage of the more suitable condi-
tions. By late afternoon, the water was
at its warmest having been hammered
by the sun all day, so the fishing was flat
by comparison.Our Berg streams are particularly vul-
nerable to overheating as they often flow
out in the open with no real canopy of
trees to shade them from the sun. Where
I believe the danger of warm water will
be felt for our local trout is during their
spawning periods, which may become
shorter or cease altogether due to the
delicate eggs which can be destroyed by a
rise in temperature. If the current global
warming trends persist and increase,
some of our more marginal streams may
cease to sustain trout completely.Changing Waters
IAN COURYER talks global warming and the effects of warmer
water temperatures on our local trout streams.“NOWADAYS SUMMERS
SEEM TO BE LASTING
LONGER AND OUR
WINTERS ARE SHORTER
AND MILDER.”