The Red River Rescuers are a group of like-minded people who want to help increase the biodiversity of the Red River Valley Local Nature Reserve and other areas by managing swathes of this once heavily industrialised area to restore areas of habitat being encroached by succession species such as gorse and willow. The members of the group come from a wide variety of backgrounds and new members are always welcome! We are keen to record any species within the Red River catchment area to help our conservation efforts.
Steve Jones presents at the BDS Spring Meeting 2024
Watch Steve's presentation to learn all about the Red River Valley, its history and wildlife.
The Story That Sparked The Group's Formation
From the early 1960s through to the early 1990s Cornwall was recognised as a stronghold for the Scarce Blue-tailed Damselfly – Ischnura pumilio, a nationally scarce insect. The species, which was at one stage thought to be on the verge of extinction in the UK, made use of the many water bodies that were produced as a result of the large scale mining of both tin & china clay in Cornwall. Frequently these water bodies had a shallow depth of water with a slight flow, overlaying a fine silt, and usually had very little emergent vegetation growing in them, ideal conditions for I.pumilio.
With the decline in mining in the county these sites were abandoned but the contaminated mineral content of the tailings which persisted meant that natural vegetation was slow to colonize them. As a result I.pumilio, a species which colonizes relatively new sites before dying out as vegetation takes hold, found the tin streaming valleys of west Cornwall in particular provided unusually long term habitats such as those typified by the Red River Valley near Camborne.
However by the mid 1990’s, after perhaps 40 years, natural vegetation finally began to take hold at these sites in a big way. As a result, in the period 1995 to 2008 the Red River Valley, which had once boasted at least 9 breeding sites for I. pumilio, (including Bell Lake Marsh), was reduced to just one breeding colony at Great Wheal Seaton, (a decline mirrored elsewhere in the county including the Carnon Valley). Great Wheal Seaton remains a typical example of a tin streaming site, supporting a strong colony of Scarce Blue-tails and as such perhaps provides a benchmark for rating other I.pumilio sites in the county.
A visit to Great Wheal Seaton may produce a tally of 6 to 10 I.pumilio on a good day, a total which may appear small compared with other species, but which never the less is significant given that it represents the tip of the iceberg. In June 2006 a group of students from Liverpool University led by Katherine Allen visited Great Wheal Seaton everyday throughout the whole month. Each day was spent marking recently emerged I. pumilio adults with a unique number along their wings. Over the course of a month well in excess of 300 I.pumilio were marked in this way, a sizeable population. This total of 300 for the site suggests that recording 6 to 10 a day is a good indicator of a sizable population for this species. Measured in these terms, Bell Lake Marsh once had a sizeable population of Scarce Blue-tailed Damselflies which were first noted by Pat Paton in 1964, but sadly the species has not been recorded at the site since July 1995.
The work being carried out by the Red River Rescuers at Bell Lake Marsh will hopefully restore the habitat to it’s former condition so that it is much more open, with areas of shallow water over bare sediment. We will do this by removing extensive areas of willow that threaten to engulf and shade out the site. In the drier areas we will be removing gorse and expanding the water area by digging out, (down to about 30cm), shallow extensions to create bare, open stretches of aquatic habitat. We will also be pulling Birch saplings & Lesser Reedmace from the existing marsh to prevent these species from taking hold and becoming dominant. There is also a threat of sedge spreading across the marsh so we will be digging it out wherever possible. Our hope is that the Scarce Blue-tail will then return to the site with Great Wheal Seton acting as a reservoir from which to recolonise areas like Bell Lake Marsh.
While our focus will be on Bell Lake Marsh we will also spend a day at Great Wheal Seaton removing willow & gorse and pulling Lesser Reedmace to keep those species in check before any decline in the Scarce Blue-tail Damselfly becomes critical.
With the decline in mining in the county these sites were abandoned but the contaminated mineral content of the tailings which persisted meant that natural vegetation was slow to colonize them. As a result I.pumilio, a species which colonizes relatively new sites before dying out as vegetation takes hold, found the tin streaming valleys of west Cornwall in particular provided unusually long term habitats such as those typified by the Red River Valley near Camborne.
However by the mid 1990’s, after perhaps 40 years, natural vegetation finally began to take hold at these sites in a big way. As a result, in the period 1995 to 2008 the Red River Valley, which had once boasted at least 9 breeding sites for I. pumilio, (including Bell Lake Marsh), was reduced to just one breeding colony at Great Wheal Seaton, (a decline mirrored elsewhere in the county including the Carnon Valley). Great Wheal Seaton remains a typical example of a tin streaming site, supporting a strong colony of Scarce Blue-tails and as such perhaps provides a benchmark for rating other I.pumilio sites in the county.
A visit to Great Wheal Seaton may produce a tally of 6 to 10 I.pumilio on a good day, a total which may appear small compared with other species, but which never the less is significant given that it represents the tip of the iceberg. In June 2006 a group of students from Liverpool University led by Katherine Allen visited Great Wheal Seaton everyday throughout the whole month. Each day was spent marking recently emerged I. pumilio adults with a unique number along their wings. Over the course of a month well in excess of 300 I.pumilio were marked in this way, a sizeable population. This total of 300 for the site suggests that recording 6 to 10 a day is a good indicator of a sizable population for this species. Measured in these terms, Bell Lake Marsh once had a sizeable population of Scarce Blue-tailed Damselflies which were first noted by Pat Paton in 1964, but sadly the species has not been recorded at the site since July 1995.
The work being carried out by the Red River Rescuers at Bell Lake Marsh will hopefully restore the habitat to it’s former condition so that it is much more open, with areas of shallow water over bare sediment. We will do this by removing extensive areas of willow that threaten to engulf and shade out the site. In the drier areas we will be removing gorse and expanding the water area by digging out, (down to about 30cm), shallow extensions to create bare, open stretches of aquatic habitat. We will also be pulling Birch saplings & Lesser Reedmace from the existing marsh to prevent these species from taking hold and becoming dominant. There is also a threat of sedge spreading across the marsh so we will be digging it out wherever possible. Our hope is that the Scarce Blue-tail will then return to the site with Great Wheal Seton acting as a reservoir from which to recolonise areas like Bell Lake Marsh.
While our focus will be on Bell Lake Marsh we will also spend a day at Great Wheal Seaton removing willow & gorse and pulling Lesser Reedmace to keep those species in check before any decline in the Scarce Blue-tail Damselfly becomes critical.