Following our report on the Minnows in the Nailbourne last week, it seems that villagers are intrigued to know how it is that fish are once again alive and thriving in the river, given that it can be dry for several years in a row.
One particularly interested resident is Stuart, pictured here checking on the fish at the ford on Mill Lane. He is currently monitoring the fish, water quality and plant life in the Nailbourne and will report his findings to the National Rivers Authority. Like the rest of us, he is very surprised by the variety of fish life suddenly appearing in the river. Stuart says he has found minnows, sticklebacks, eels, shrimps and water snails, all of which would obviously not be found in the bed when the river is dry. So how did they get into the river?
It seems there are two main methods for fish to arrive in a lake or river that has previously been dry. One is for birds or other wildlife to transport the eggs incidentally as they move around the countryside. An alternative possibility is that they may have been there as dormant eggs since the last time the river flooded because some fish eggs can stay viable in mud for many years.
This reasoning may explain some of the new wildlife, but other aspects just remain a mystery. Perhaps surprisingly absent are frogs: none have been seen in the river at all, although being amphibians, they could move from one water course to another more easily than most other river creatures. Grass snakes, which also live on or near rivers, have been spotted swimming down in the meadows.
In terms of water quality, Stuart’s testing indicates the pollution from the sewers is now gone.