On Saturday, the tail end of heritage week we had a visitor to the Glen from The Local Authority Waters Programme (LAWPRO), Catherine Seale-Duggan …(appropriately @>) came with her Kick test kit
The kick tests involved scooping up river water in a net in three different places, dipping down deep into the river bed. Each time the scoopings are emptied into a shallow white basin and we peer in. We are looking for life forms. And there is so much going on…
A metropolis of waterborne matter and wriggling creatures. I was taken by the blood worm, scarlet with a forked end, not so much a tail as a pair of tiny splayed limbs – small fleshy projections, called parapodia, run all along its body – which it uses to pivot and angle itself forward, in a rhythmic, scripting movement, its powerful front end bulging with the effort, transluscent, the blood worm seems to be made without matter and its name is perfect. Wondering out loud about the rich red colour, CSealeD says it’s the colour of the haemoglobin showing through thin skin, telling us that blood worms don’t need much extra oxygen. The blood worm is common in poor quality water for this very reason, and also features at the bottom, most negative end of the indicators for water quality. I find out more… they have powerful jaws and can give a human a painful bite – perhaps that is, if they grow to their maximum length of 35 cms. Wikipedia tells me “These animals are unique in that they contain a lot of copper without being poisoned…their jaws are unusually strong since they too contain the metal in the form of a copper-based chloride biomineral, known as atacamite in crystalline form. It is theorized that this copper is used as a catalyst for its venomous bite.” So all iron and copper inside the body of blood worm, make for a real metal ninja creature.
We find sticklebacks which delight one Glen walker as he tells us of childhood memories, rubbing his hand along the spine, feeling for the spiky fins, the three fins are clearly visible as she swims, but in the hand they disappear, the walker says the fins behave in the same way as a cat’s fur when startled by a threat, but in this instance perhaps the warm skinned flesh is just too foreign for her defence system and she remains smooth and limp in the hand, he says this one is female as she has no orange spot on the belly. The walker also remembers foot long black eels in the Glen and we all wonder how they could arrive from the sea through the urban obstacle course of today.
We see a Caddis fly larva … looking like a walking piece of rubble… using silk to bind together stones, fish bone, crustacean shell, twigs, bitten off vegetation, and other water borne debris, the Caddis fly larva cobbles together this odd looking costume, living its aquatic life until ready to change element and become moth, air bound and free. The Caddis fly larva is sensitive to water pollution and so her presence in our samples is a happy sign. I read about an artist who presented a Caddis fly larva with gold, opal and turquoise, pearls, lapis lazuli and rubies out of which to build its home in captivity….not a good look in the wild… Caddis fly larvae are one of the most popular items on the menu for our Dipper, who dives under the water and walks along the river bed poking beak into the matter that moves here. In a beautiful cycle one sensitive creature means another can thrive in The Glen.
Our river gets a “moderate” score of -4 on a scale from -9 to +9, not so bad, CSealeD isn’t surprised, we are a tiny urban river, not really passing through farmland, our threats are not from nutrient rich agricultural run off choking the water with algae, but from detergent effluent produced by washing machines, plumbed into extensions and tapped into the wrong drainage system, a common practice that is difficult to monitor or control. Our river often has a detergent smell and the surface often has the opaque sheen of a cataract on the eye, on bad days it’s milky through and through.