Chris
Mitchell - 13-Sep-2006 - After two weeks of hard
work the Environment Agency is due to complete
its 2006 annual survey of fish populations along
the River Thames on Thursday 15 September.
The survey is carried out annually
along more than 40 miles of the freshwater Thames,
from Hurley to Teddington and forms part of a
national monitoring programme - covering 2,700
miles (4,300km) of watercourses across England
and Wales. The results will provide a picture
of fish populations, and show how healthy our
rivers actually are.
Environment Agency staff have been using a specialised
electro-fishing boat to catch the fish. Two arms
extending from the front of the boat pass an electric
current through the water, which attracts and
momentarily stuns the fish, enabling them to be
caught easily in a net.
Length and weight are then recorded
while scale samples are taken to determine age,
before the fish are returned unharmed back to
the water.
Fisheries team leader, John
Sutton, said: “The information collected in these
annual surveys provides us with a good picture
of the population structure and range of fish
species living in our rivers. It also helps us
to understand environmental factors that influence
the health of our rivers from year to year.”
“This year’s survey will be
especially interesting as it will show what kind
of impact the current drought has had on fish
species in the Thames, and we will be drawing
comparisons with our data from surveys carried
out in 1976 to see whether there are any kind
of similarities.”
