thorough and systematic survey of the area over a number of years. The Chelmer/
Blackwater Navigation between Chelmsford and Maldon has a rich assemblage of
moving and still-water species, including Platycnemis pennipes. Pyrrhosoma nymphula.
Coenagrion puella and Calopteryx splendens. Unfortunately Erythromma najas now
appears to be absent from the Chelmer/Blackwater, and P. pennipes is present only in
very small numbers.
Fortunately, the Sandon Brook, a tributary to the Chelmer, still has a strong and
apparently secure colony of P. pennipes at Waterhall Meadows, a reserve of The Essex
Naturalists' Trust. J. Chave recorded a remarkable total of thirteen species in this
reserve, including Pyrrhosoma nymphula. Calopteryx splendens. Anax imperator and
Sympetrum sanguineum.
The complex formed by the Navigation and nearby gravel-pits at Ulting has also been
a focus for observers, and if the species - such as Sympetrum sanguineum, and Orthetrum
cancellatum - which are supported by the gravel-pits are added to the locally occurring
moving-water species the whole site supports some sixteen species. Despite this very
impressive total and the continued presence of several scarce and local species, there is
no doubt that the Chelmer/Blackwater complex is steadily declining as a dragonfly
locality. There is an urgent need for further research on the reasons for this so that
conservation measures can be taken. A combination of agricultural run-off and
disturbance by river traffic may well turn out to be the culprits.
(d) Glemsford Pits. Liston
This important S.S.S.I. is on the northern boundary of Essex, and includes one of the
very few dragonfly-rich sites along the Stour. This stretch of the river has a rich Odonata
fauna, including Erythromma najas. Calopteryx splendens, and Coenagrion puella, whilst
nearby flooded pits support a breeding population of the (in Essex) extremely local
Libellula quadrimaculata. In total, thirteen species have so far been recorded from the
site. The importance of the site is further enhanced by its relative isolation - there are
very few high quality dragonfly-sites in Essex north of a line from Bishops Stortford to
Colchester. Whilst the status of this site as an S.S.S.I. affords some protection, it is worth
noting that the Odonata fauna of the pits themselves (particularly in the Melford
Anglers' section) is undoubtedly adversely affected by excessive tree-cover along their
margins. Creation of stretches of open bankside by selective tree-felling would greatly
improve the site for dragonflies.
(e) Roman River Valley. Colchester
This complex site combines habitat diversity with conservation-conscious
management of the river and most of the adjoining terrestrial habitat. The
Conservation Zone includes both the Roman River itself, and a small tributary which
runs from Birch Lake. The upper reaches of the river and this tributary are bounded by
a mixture of open meadows and woodland, including the Roman River Valley reserve of
The Essex Naturalists' Trust. This stretch of the river is distinctive as the breeding site of
Calopteryx virgo, but also supports Pyrrhosoma nymphula and Calopteryx splendens. The
presence of both Calopteryx species in a single stretch of the river is a notable
feature.
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