Ecology

The Mysterious Case of the Missing Fish

If you stand on a bridge for long enough around here someone will come past who will stop to bemoan the passing of the fish.  They will tell you about the trout they tickled in childhood and the salmon their grandfathers netted when times were hard.  They may also tell you how they outwitted the game keeper in their youth.

The only trout we’ve seen in our stream, that was more than an inch long, arrived in a bucket taken from the boot of a car, caught elsewhere by a friend’s grandson and rehomed in our stream, never to be seen again.

Accepted wisdom blames acid rain, too many pine trees, insecticides washing off the backs of the sheep, the reduced use of lime on the fields, too much sewage running into the water, not enough sewage running into the water, over fishing, weirs, flooding and sheep dip.

Now, we’ve just acquired a trail camera which we’ve placed by the stream in an isolated open area (most of our stream has cover) and guess what the first thing we spotted was — not an otter (sadly)

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European Otters

but a mink who appeared to be (guess what?)…  Fishing!

Monk by jsutcliffe

Mink!  by jsutcliffe (CC BY- NC-SA 2.0)

The following day, shortly after dawn, we spied a heron patrolling the same stretch of water. What are they up to, if there are no fish?  I know they do eat frogs.  Or are they the reason that there are no fish?

Lots of the streams in this area have pasture right down to the water’s edge so that any fish that there might be have no cover from overhanging vegetation which is what they need to hide from these dastardly predators.

The problem is what to do about it.  Bring back the game-keeper?  I know what he’d do!

The predators that the game-keepers used to kill are perhaps more common than we thought — we just don’t get up early enough these days to see them.

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