As part of our management of Radipole and Lodmoor we monitor fish populations to provide us with biomass estimates and a picture of what species are present and where. We do this by a process called electric (or electro) fishing which uses state of the art equipment to send a pulse of electricity between a cathode and an anode which temporarily stuns any fish between the two electrodes, thereafter allowing them to be easily netted.
As well as providing fish population data we use electro-fishing to catch carp in our restored ditches and new pools at the top of Radipole and move them into the main lake (segregated by mesh fish-fences) where they are a choice quarry for anglers on the lake.
The carp in the lake (common, leather and mirror) are sub-species of fish of Asian extraction, domesticated and introduced to Europe by monks from the13th century onwards as a food fish. Unfortunately, carp are not a desirable species from a nature conservation perspective because their large size, coupled with a bottom feeding habit, stirs up the silt from the lake bed. This turbidity prevents light penetration into the water and so inhibits macrophytic plant growth as photosynthesis is no longer possible, denying food and shelter for an array of inverts, other fish species and has 'knock-ons' up the entire food chain. The use of fish fences/ electrofishing offers a nice compromise between our perspective and that of the anglers.
Today we had our volunteer Richard Wood, (as it happens a keen carp angler) along to act as banks man and pleasingly we didn’t catch any carp, (although I am sure Richard was secretly disappointed) but we did catch plenty more besides.
Quite a number of jack pike.
A few rudd (above) and hundreds of roach (below) on the scales.
Rudd are distinguished from close relatives the roach because as surface feeders their bottom lip protrudes beyond the upper and the start of the dorsal fin is set back from the start of the pelvic fin, whereas the dorsal and pelvic fins are exactly in alignment on a roach.
The remainder of the catch was made up of eels and the odd tiny sunbleak.
But no angling story would be complete without tall tale of the one that got away. A pike of a couple of feet in length was briefly stunned but recovered and 'finned-it' before the net could pass underneath. Over an ale or two this evening it is sure to gain in all dimensions!
Quite... or praise them if you're a carp angler I suppose.
Damn those 13th century monks eh? :-)