The history of Cornish seaweed observers

One of the delights of dabbling in rock pools is to meet scuttling crabs, glistening anemones, darting fish and a whole range of amazing shells. All of these are set amongst a colourful array of seaweeds, red, green and brown, which provide shelter and food for so much of our marine fauna both on rocks and fringing our creeks.

Over 640 British seaweed species have been identified; some 400+ occur in Cornish waters and nearly 300 different species have been found within the Helford VMCA. Who are the people that have made these discoveries?

The very first published work on British seaweed was prepared in Cornwall. This is not so surprising when the geographical position of Cornwall is considered, together with its rias, different aspects and varied geology, offering a multitude of rock pools. Indeed experts on the study of marine Algae, such as Dr Juliet Brodie in the Natural History Museum have recently extolled the richness of the far South West of Britain. It follows that Cornwall has attracted national specialists for many of the faunal, floral and fungal groups. However, John Stackhouse went a step further and adopted a small west-facing cove in Mounts Bay and built Acton Castle so that he could have easy access to what has become known as Stackhouse Cove (SW5428). His illustrated work on Nereis Britannica was first published in 1797.

In the 19th century, extensive, annotated collections were formed by R. W. Smitham and R. V. Tellam, and two large albums of pressed specimens are in the Royal Cornwall Museum, Truro. Some years ago these were loaned to J. H. Price, then in the Botany Dept of the Natural History Museum. R. V. Tellam published a list for East Cornwall in the Penzance Natural History and Antiquarian Society and in the same year (1884) and in the same publication John Ralfs included a list for West Cornwall.

The published compilation taking account of all previous sources for the 19th and 20th centuries, including the compilation by E. M. Holmes is in The Victoria History of the Counties of England (1906). J.H. Price himself made extensive lists and collections from many Cornish shores. He undertook extensive recording on the shores of the Lizard peninsula and published this in two parts in Cornish Studies No 7 (for 1979) and No. 8 (for 1980). One co-author was a Museum colleague, S. Honey and the other was C. E. Hepton who made previous records available as well as taking part in fresh field work. Also included are the Helford surveys initiated by the Helford VMCA by Pamela Tompsett and the Cornish Biological Records Unit arranged by Stella Turk.

2003 saw the publication of a national Atlas and Seaweed Checklist for Britain and Ireland by Gavin Hardy and Michael Guiry but this unfortunately missed many records from Cornwall and as is the way of published checklists there are many more additions needed immediately.

In 2006 the HVMCA Group published The Marine Algae of the HVMCA, a checklist with records of the date and place of seaweeds found. Geographically the Helford River fits comfortably within a single kilometre square on the Ordnance Survey map. So this is assuredly the place to state that this square arguably has more species of seaweed than any other British square.

If you have a beginners interest in seaweeds, the various and readily available Pocket Guides are helpful. More precise identification information can be found on-line and in detailed publications from the Natural History Museum and Field Studies Council.

Dr Juliet Brodie will be visiting Cornwall again at the lowest tidal cycle in June 2009 and there will be opportunities to join her workshops. Please email Pamela if you are interested and wish to book a place.

Stella M Turk and Pamela E Tompsett

Extract from HVMCA newsletter No.37 Autumn 2008

© Helford Voluntary Marine Conservation Area