Kent and Medway Biological Records Centre

Kent Seaweed Atlas

A provisional historical atlas of seaweeds of Kent,

by Ian Tittley

BladderwrackBladderwrack (Fucus Vesiculosus)
Welcome to this provisional historical atlas of the seaweeds of Kent. Records of seaweeds (marine algae) for Kent go back over 400 years (Tittley, 2005) and a synthesis of all records was first published as an Atlas in 1977 (Tittley & Price, 1977). A total of 184 species were mapped comprising 94 Rhodophyceae - red algae, 51 Phaeophyceae - brown algae, 31 Chlorophyceae - green algae, and 8 from other algal groups. That atlas gave no indication of the temporal nature of species records and simply indicated those records that were confirmed and those that were based on doubtful or drift material. A supplement was published in 1985 (Tittley et al., 1985).

KelpKelp (Laminaria Saccharina)
The present work uses the data mapped in the first atlas but provides more spatial and temporal information, and adds species data to the end of the 20th century. From 1597 to 1999 there are approximately 7500 species records for the county and 281 species are mapped here (141 Rhodophyceae, 82 Phaeophyceae, 47 Chlorophyceae, 11 from other groups). Also included here is geographical information for species excluded in the previous atlas, some of which have been confirmed recently.

Preliminary analysis of species records shows a general trend of few species recorded in the 17th century with most early records from Sheppey and Sheerness, sites that today are species poor compared with elsewhere in Kent. More species were discovered in the 18th and 19th centuries as knowledge of algal taxonomy and floristics developed. This coincided with improved optical technology from the simple hand-lens and microscopes of the 17th century to the more advanced compound microscopes of the 19th century that allowed very small species to be identified. Also by the 19th century information between marine algal specialists and collectors was exchanged more speedily and efficiently using the new national postal system, and collecting increased with coast quick and easy travel by train to the Kent coast.

UlvaUlva (Enteromorpha Sp.)
Records have been taken from a variety of sources including the herbarium of the Natural History Museum (BM) and collections at provincial museums in Kent and elsewhere, the published literature, recent consultancy reports and other grey literature, and personal direct observations. Many recent records have been obtained during meetings of the Kent Field Club, and the Kent Marine Group. The full data set is held at the Kent and Medway Biological records Centre (KMBRC).

Recent fieldwork from the 1960s has been undertaken throughout the county. The Kent coast has a varied ecology and geology including the Thames and Medway estuaries, the saltmarshes of north Kent, Eocene clay exposures of north Kent, the extensive chalk of east and south Kent, and a small amount of Lower Greensand of the Folkestone area and these features determine the nature of the algal communities present. Species diversity is generally low in inner estuaries and in saltmarshes, and increases in outer estuaries and on the clay of north Kent, and increases further on the chalk and greensand of east and south Kent. The mobile shingle of Dungeness, by contrast, is completely lacking in seaweed growth, as are the sandy beaches and banks elsewhere in the county and offshore. Man-made habitats (sea-walls, groynes, ports, harbours and marinas) enhance algal biodiversity in Kent by providing new and different habitats. Much wetland (saltmarsh) has been lost as a result of drainage and land-claim causing a few species to become locally extinct. Removal of chalk cliffs and caves in Thanet from direct contact with the sea by coastal protection has also resulted in the loss of communities and species.

To use the atlas, first choose the Group, then the Genus, then the Species. A new page will then open with information on that species.

References

- Tittley I. 2005. The marine algal flora of Kent: species recorded 1597-1800. Transactions of the Kent Field Club 17: 55-85.
- Tittley I., Fletcher R.L. 1985. Additions to an atlas of the seaweeds of Kent. Transactions of the Kent Field Club 10: 13-11.
- Tittley I. & Price J.H. 1977a. An atlas of the seaweeds of Kent. Transactions of the Kent Field Club 7: 1-80.