14/02/2005 - Spare a
thought this Valentines Day for the lonely
pearl mussel as the Environment Agency turns
dating agency in an attempt to boost its
sex life.
The North East is one of the last remaining
strongholds for the freshwater pearl mussel
but their numbers are dropping and the solitary
shellfish are being forced to live their
lives in empty beds.
The problem has become so severe that the
Environment Agency has been forced to play
matchmaker by relocating some of the mussels
in the North Tyne and socialising them in
a more confined environment.
Environment Agency conservation officer
Anne Lewis said: "If the pearl mussels
fail to revive their love life then the
entire species will be extinct south of
the Scottish border. We have relocated 40
pearl mussels to Kielder Hatchery and so
far they are thriving which is good news
for the future.
"Ideally we would like to see the
pearl mussels reproduce but their sex-life
is all but a distant memory and as yet,
we have had no results. We are constantly
learning more about the pearl mussel though
and we hope it won’t be long before the
species is showing signs of recovering."
Pearl mussels are one of England’s oldest
river inhabitants and reproduce – in a process
that resembles group sex - by the males
releasing large quantities of sperm into
water which is then filtered by the females.
Fertilised eggs develop in the female’s
brood pouch for several weeks before the
larvae, known as glochidia, are released
into the water. These attach to the gills
of young salmon where they live as harmless
parasites until the following spring when
they drop off.
In healthy populations, many thousand pearl
mussels are found together in beds. They
have a long life-span, become sexually mature
at about 20 years-old and live for over
100 years. However, fertilisation becomes
near-impossible when the dwindling shellfish
populations are some distance apart.
At Kielder Hatchery, the mussels are kept
in a tank with around 7,000 young salmon
which are checked for glochidia.
The pearl mussel is extremely sensitive
to water quality and habitat conditions.
Illegal dredging and increased sedimentation
have all taken their toll on the species.
