How you can help

There are many ways in which you can contribute to the ongoing work to understand and conserve both D. plantarius and its very localised congener, D. fimbriatus in the UK and elsewhere across their European ranges. You can also contribute to understanding of the genus Dolomedes worldwide. These include:

Hands-on involvement in raft spider conservation

D.plantarius is well known at three UK sites but it is possible that other populations remain undiscovered. It is also possible, although unlikely, that some Dolomedes populations currently assumed to be D. fimbriatus are in fact D. plantarius. We are also aware that the distribution of D. fimbriatus, particularly in upland Britain, is incompletely mapped and records for known sites are often out-of-date. If you know of populations of D. fimbriatus in your locality and are unsure whether they are formally recorded, or if their identity has been verified, please contact Helen Smith. Please send with details of the location and habitat and, if possible, photographs of the spiders. Gaining a complete picture of the current status of both Dolomedes species in the UK is a key element in future efforts to safeguard their populations. You can also contribute towards this important task by volunteering to help with surveys of potentially suitable habitat in both East Anglia and Southern England. Thorough surveys that help to confirm the absence of D. plantarius from suitable sites are as important as the discovery of new populations. The likelihood of introducing this species to new areas of suitable habitat to reduce the possibility of extinction in the UK as a whole, requires confirmation of our current understanding of its distribution. If you are interested in taking part in survey work, or are already involved in survey of potentially suitable wetland areas, please contact Helen Smith. As the programme of translocation of D. plantarius to new sites progresses, more volunteers will be needed to help to monitor the success of the new populations. If you are interested in helping with this exciting development of the project, either in East Anglia or in south-east England, please get in touch.


Do you have information about present or past locations for either Dolomedes species in Europe? If so we would love to hear from you with specific information on location and, ideally, photographs of the habitat and the spiders.
Do you have any relevant literature about this species that is not in the main-stream scientific journals? Do you have any data or information about any aspect of the biology of D.plantarius ? All of this information can play a vital role in our understanding of the natural history and distribution of D.plantarius and help in the development of recording and conservation programmes.


Analysis of DNA extracted from small tissue samples of Dolomedes has already made a huge contribution to our understanding of this genus across Europe and to our ability to conserve it. To continue this work we need further samples fo D. plantarius from across its range. As well as continuing with the work on D. plantarius, we also need samples of D. fimbriatus from Britain and continental Europe. These will help us examine the effects of increasing isolation in the fragmented UK populations of this species and improve our understanding of the role of genetics in the comparative ecology of D. fimbriatus and .D. plantarius. We welcome samples of DNA from other Dolomedes species throughout the world, to contribute to the phylogenetic reconstruction of the genus and to our understanding of its evolution and natural history. Even very small tissue samples are sufficient for DNA extraction. Fresh tissue can be obtained from single legs (these re-grow as juvenile spiders change their skins) and gives the best yields of DNA for genetic analysis. However, very useful samples can also be obtained from shed skins without any impact on the spiders themselves. Is also possible to extract DNA from old tissue, such as ethanol preserved, or dry museum specimens. The analysis of old specimens can make a very important contribution to our understanding of temporal changes in the genetic variability of D. plantarius, including quantifying rates of loss of genetic variability in isolated populations (see Andrew Holmes' work). If you have access to specimens of any of the above types, and are able to send them to us, we would be very grateful: please contact Helen Smith. Please ensure that any collection of fresh material complies with any licensing requirements for D.plantarius in the country of origin. For finds of any Dolomedes in the UK, please contact us to check whether the location and specific identity are already known. Please do not collect samples: in the case of possible new populations, we will organise expert help with identification and sampling. In the UK a license is required under the Wildlife and Countryside Act 1981 for any activity that is likely to cause disturbance to D. plantarius. Please contact us if you have any queries about the law in relation to any material to which you might have access. For information on licensing in England click here, in Wales click here and in Scotland click here. Licensing is also required for D. plantarius in some other European countries.


If you have comments or suggestions on any aspect of the Dolomedes study, please contact us.