Aquatic surveys are a specialist area, as some ecologists find taking a stroll in the sun looking for reptiles, for example, much more pleasant than getting wet and bug-bitten, and wading through waist-deep boggy water. How misguided they are. I had a fantastic time!
We had a lot of heavy kit, which consisted of two big baskets of heavy fishing nets, a lot of buckets and what looked to the untrained eye like an ancient relative of R2D2. We rocked up with it on-site only to find a small waterway that normally I wouldn’t have looked twice at. In fact, we initially waddled straight past it. The stream, for want of a better word, was flanked by vastly overgrown nettles and had steep banks with a disappointing trickle of muddy water at the bottom. Nick Monaco, the survey lead, did a cursory exploration of the area and concluded that it was about as close to worst case scenario for an electrofishing survey site as you could get. Wonderful.
R2D2’s great grandfather, more commonly known as an electrofishing battery-powered backpack
Before we began, a local car-boot salesman began chatting to us, clearly intrigued by what two people in bright orange safety gear and waders carrying what appeared to be ghostbusting equipment were doing battling through 3-foot-high nettles to reach chocolate-coloured water. When we explained that we were surveying for fish, he was stunned. So were the fish, but we will come to that! He happily informed us that there were no fish and wished us luck.
He was wrong. We found four species: minnow, three-spined stickleback, stoneloach, and bullhead. So many little fish! The male sticklebacks were in breeding colours and looked beautiful with their flashes of red and bright blue eyes, while the stoneloaches had very fetching moustaches, which are apparently called barbules.
A bullhead fish being measured
A male three-spined stickleback
The survey involved Nick wading in the stream ahead of me with the battery-powered backpack strapped to him. This is a big metal box with a cable and plaited steel strip (the cathode) trailing out of the back into the water. Another cable is plugged into it, at the end of which is a pole with a metal loop. This is the anode. Meanwhile, I was enthusiastically wading behind with a bucket full of stream water to put the fish in. In convoy we made our way up the stream. Nick would sweep the water with the loop, and the current that went through the water shocked and stunned any fish that swam near. As they floated to the surface, Nick would quickly fish them out using an ordinary hand-held fishing net and put them in the bucket I was carrying. I would check that they recovered quickly and the process was repeated.
At the end of the survey we moved the fish to a bigger container with fresh water before measuring the length of each fish individually. We then returned all of them unharmed to their home. It was wonderful to see them all swimming off to become completely out of view in the muddy water, hidden and safe once again.
However, the best fishing was yet to come. Unlike the first, the second site we went to was ideal, and here we found two rather exciting species on top of all the ones we’d previously seen: some rather handsome gudgeon and tench! I found all six species of fish rather beautiful in their own muddy way. I had no idea the simple minnow sported a leopard-print pattern or that stoneloaches and gudgeon looked so charismatic.
Driving home, our arms ached. We’d been attacked by nettles as tall as I am and bitten by an army of mosquitoes, and yet all I could ask was when we could do it all again.
Note: No fish were harmed in the making of this article