Current status
The tadpole shrimp occurs in seasonally flooded ponds which dry out completely in summer, eliminating predators and competitors. It has a rapid development and is able to mature from egg to adult in two to three weeks following wetting. The tadpole shrimp is omnivorous, feeding on small aquatic invertebrates, aquatic plants and microscopic particles extracted from sediment. There appears to be a need for nutrient input in the form of herbivore dung. As with other aquatic crustacea, veterinary compounds excreted in livestock dung are potentially highly toxic.
It is currently found in a single ephemeral pond in the north of the New Forest (Hampshire) where it has been regularly recorded since 1934. The only other 20th century records are from the Kirkcudbrightshire coast, but its pond was recorded as lost to coastal erosion in the 1960s. There are 18th and 19th century records from north Kent (now Greater London), Bristol, Christchurch and Glanvilles Wootton in Dorset, Powick and Tewkesbury in Worcestershire. The tadpole shrimp is found across Europe to Russia and the Balkans and from the Middle East to India. However, the taxonomy of the group is in need of revision and the British population may prove to be internationally significant.
In Great Britain this species is classified as Endangered. It is specially protected under Schedule 5 of the Wildlife and Countryside Act 1981.
Current factors causing loss or decline
Potential threats include the introduction of predators (eg fish or ducks), pollution, colonisation of the pond by alien aquatic plants, and exposure to veterinary compounds.
Current action
The New Forest is a SSSI, SPA, Ramsar site and candidate SAC. The land and pond is Crown property managed by Forest Enterprise and is grazed by commoners livestock, regulated through the Court of Verderers under the New Forest Acts 1877, 1949, 1964 and 1970.
Research into the species, its ecology and the management of captive populations is being promoted by the Triops Conservation Group, guided by English Nature's Species Recovery Programme.
Action plan objectives and targets
Maintain the New Forest population in a healthy, dynamic state.
Maintain captive populations for research, public appreciation and, if appropriate, reintroduction.
Proposed actions with lead agencies
Policy and legislation
Where appropriate, include the requirements of the species when preparing or revising prescriptions for agri-environment schemes. (ACTION: NE, MAFF)
Site safeguard and management
Ensure that occupied habitat continues to be appropriately managed. (ACTION: NE, FE)
Ensure that the species is included in site management documents for relevant SSSI's. (ACTION: NE, FE)
Species management and protection
Continue to support a programme of captive breeding. (ACTION: NE)
Investigate the appropriateness and feasibility of reintroductions and, if appropriate and feasible, reintroduce the species to former localities. (ACTION: NE)
Advisory
Advise landowners, managers and commoners of the presence of this species and the importance of beneficial management for its conservation. (ACTION: NE, MAFF)
Future Research and Monitoring
Conduct targeted autecological research to inform habitat management, and to elucidate the effects of veterinary compounds on the habitat of the species. (ACTION: NE, FE)
Survey suitable ephemeral ponds, including locations of former populations, throughout the historic range of the tadpole shrimp. (ACTION: NE, SNH)
Establish a regular monitoring programme for the species. (ACTION: NE, FE, SNH)
Pass information gathered during survey and monitoring of this species to a central database for incorporation in national and international databases. (ACTION: NE, SNH)
Communications and Publicity
Promote opportunities for the appreciation of the species and the conservation issues associated with its habitat. (ACTION: NE)
Links with other action plans
None given.
Publication details
Originally published in: UK Biodiversity Group Tranche 2 Action Plans - Volume VI: Terrestrial and freshwater species and habitats (October 1999, Tranche 2, Vol VI, p131)
Related links
ARKive Visit the ARKive website to view images and further information relating to this species