THE ULTIMATE ANGLING BUCKET LIST

separate bucket for reintroduction later where they would be left for a further year, again with ongoing
weekly water chemistry analysis to ensure the pond remained at Class 2 in terms of water quality for
the duration of the heritability experiment.
Meanwhile, as was the established sampling pattern, fish retained for FA measurements first went into
an anaesthetic solution, then into laboratory alcohol for keeping and ultimately having their nine traits
measured and FA levels determined for comparison to the fifty measured immediately after capture a
year earlier.
The hope was that the collective result from each of the two groups would be the same, indicating that
despite improvements in water quality in the pond, FA cannot be reversed.
Initially however, the data did not appear to show this. Despite the water quality improvement in the
pond, the asymmetry differences were greater, which initially had me scratching my head. Then I got
to thinking that this might be because of the extra year's feeding and growth.
To cut a long story short, the one year older fish were typically twenty percent bigger than the other
half of the sample, which mirrored the percentage increase in FA, establishing the fact that while FA
might be halted in extent with water quality improvements, it cannot be reversed. Affected traits as they
grow with the rest of the body continue to reflect the same measure of symmetry difference.
As for the heritability experiment, that also went according to hope and expectation. When the offspring
were eventually netted out to provide FA data, despite the fact that their parent population had come
from a grossly polluted Class 4 watercourse, these fish having been born into a Class 2 environment
and lived for a year with the reduced stress that brings, had asymmetry levels typical of what a Class 2
water should impose on them according to FA measurements taken at other Class 2 sites.
I now had the green light to start analysing the data I had been gathering for a good two years by that
stage from the proposed fifty sites, which while the full data gathering exercise still had quite some way
to go, did at least might give me a feel for the direction things were taking. In fact, after a great deal of
time inputting and analysing data from my minitab statistical analysis package, this looked very
promising indeed.
Plotting FA against water quality
showed a startlingly accurate mirror
image to the point where I could
confidently say that by taking a sample
of sticklebacks from any given location,
it should be possible to say with great
certainty what the water quality at that
site was.
Moreover, by sorting the sample into
different sizes and inferring these to be
representative of different year classes,
it should also be possible to estimate at
what point a problem had started if it
was more recent than the age of the
oldest fish.
Farm run-off stressing the environment
So no more presence or absence
decisions. The data these fish were
recording within themselves could
finally be down-loaded, interpreted, and used to make meaningful statements of a sort which could not
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