Richard Edmonds (UK)
Between Seatown and Eype, on the West Dorset coast (part of the Dorset and East Devon Coast World Heritage Site), there is a remarkable layer of rock known as the Eype Starfish Bed. This is famous for exquisitely brittle starfish (brittlestars) fossils that are usually preserved on the soft, sandy underside of a thick sandstone unit within the Middle Lias. It has been speculated that they became buried during a single storm or possibly even a tsunami event, about 185Ma.
On the outside of the block, the sandstone is relatively soft, but becomes progressively harder the deeper you go. It follows that specimens are highly vulnerable to erosion and rapidly damaged or destroyed if left in the rock, on the beach. The bed itself is located high in the cliffs and, in places, its sharp base is clearly visible. This means that it is only possible to examine and collect specimens from ex situ, fallen blocks. Fortunately, occasional cliff falls bring these large blocks down to beach level and storms also uncover material that has been buried in the talus at the base of the cliff.
There is only one way to collect the brittlestars and that is by cutting out pieces from the flat surface of the blocks containing the specimens. This can be achieved using a hammer and chisel, but this is a difficult and time consuming task, and one that entails a considerable risk of damage to the specimens. As a result, some collectors use stone saws. (In Issue 13, the editor of Deposits magazine reported receiving a complaint from a member of the public at Seatown concerning the use of power tools to collect fossils.
I suspect this relates to the use of stone saws to collect these fossil starfish.) Inexperienced collectors inevitably go for a shallower than necessary excavation, which is usually unsuccessful. Fig. 1 shows several failed attempts. Individual blocks may occasionally contain many starfish and, if removed, the blocks are left pockmarked with hollows that can be very long lasting. Therefore, if a stone saw is used, it is important that all saw marks are removed from the remaining matrix, as they are particularly unsightly. This takes only a few minutes with a hammer and chisel, leaving only a depression on the surface of the block. However, see below as to when you can use stone saws.
One person has expressed a concern to me about the lack of visible brittlestars in these blocks. In management terms, the choice is stark: to leave the specimens to weather out or allow people to collect and save them. If they are left, they are very rapidly damaged or destroyed by the elements. The result would be lots of bits of brittlestars, available for anyone to see at any time, but nothing more. However, at present, most specimens are collected and saved from destruction, while some fragmentary remains can still be seen in the field.
There are specimens in museum collections, although many of these were collected a long time ago. Cleaning techniques have now improved and, if there is a need to acquire more specimens, they are relatively inexpensive – a perfect example costs less than £200. It would almost certainly cost more for a museum or university to send out staff to collect examples, with no guarantee of success.
Furthermore, an active, local collecting community offers the best chance for any specimens of key scientific importance to be recovered before they are destroyed. Local collectors, both amateur and professional, have always played a key role in the recovery of specimens new to science on this rapidly eroding coastline and the collections in many museums are clear evidence of this. Indeed, some years ago, collectors recovered very rare sunstars and cushion stars from a different bed in the area (as ex situ blocks), neither of which had ever been recorded from this site before. One of the sunstars is now within the collection of York Museum, while several other blocks remain with collectors who would like to place them in a world-class, purpose-built museum along with many other superb fossils recovered from the Lower Lias around Charmouth and Lyme Regis.
A potential issue with the Starfish Bed is that, should researchers wish to carry out taphonomic studies on the starfish (the study of death and burial), they would find it very difficult to do this without the help and co-operation of local collectors. Fortunately, I suspect that this would be forthcoming should the need arise. With careful guidance, collectors could easily record the orientation of specimens prior to extraction. In fact, there are examples where several specimens have been recovered together and where the individual specimens and their relationships to each other have been preserved. These blocks, and the information that they contain, would have been lost had they not been collected.
Along the Jurassic Coast World Heritage Site, the approach of the Jurassic Coast Team is that of practical and realistic management, that is, management that works. We believe that the local collecting community, working within our code of good practice on responsible collecting (based on what was English Nature’s but is now Natural England’s) offers the best possible chance for fossils to be collected before they are destroyed. We would rather see fossils recovered as we want to know what is being found and we want important specimens to be made available for scientific study. The West Dorset fossil collecting code was established with just that purpose in mind. The basic requirements of the code are:
- No collecting from in situ (that is the solid rock layers in the cliffs or foreshore) without permission; and
- The recording of specimens of key scientific importance that are found.
Details of the code of conduct and the recording of key scientifically important specimens are available on the Charmouth Heritage Coast Centre website at: www.charmouth.org. If you wish to use stone saws to recover starfish, the National Trust will consent to this activity, but only under licence. Details are available from the area office at The National Trust, West Dorset Office, The Court, The Street, Charmouth, Dorset, DT6 6PG. Tel 01297 561900.
- Get permission from the landowner.
- Only take gravel from the bed of the river.
- Never dig into the banks, as this will cause serious damage the next time the river is in spate.
- Follow the country code.
About the author
Richard Edmonds is Earth Science Manager of the Jurassic Coast Team.