Species point records from 1978-79 SWBSS Upper Bristol Channel sublittoral survey

Published by:
Joint Nature Conservation Committee
Last updated:
15 December 2015
Topic:
Environment
Licence:
Open Government Licence

Summary

This survey was carried out to describe the range of sublittoral habitats and the communities of plants and animals present adjacent to the coast of the upper Bristol Channel. On the north side, from the east side of Swansea Bay to Llantwit Major and on the south side, at Porlock Bay, Minehead and Watchet. 16 sites were surveyed by diving within 43 km of coastline. All of the sites, except Gore Point on the west side of Porlock Bay, included a very small number of species of algae and animals compared to open coast areas of south-west Britain. Algae were only recorded above Chart Datum level. Animal communities were similar from site to site with stable rock surfaces at most sites dominated by Sabellaria spp. (mostly S. alveolata) and at some sites by Dendrodoa grossularia, Mytilus edulis or Polydora ciliata. A small variety of sponges, hydrozoans and bryozoans were also present in large amounts. Mobile or scoured substrata were characterised by Balanus crenatus and Pomatoceros triqueter. Moving west to east along the coast reveals a gradual reduction in the number of conspicuous species with a sharp reduction across Swansea Bay resulting in highly impoverished communities here. Along the majority of the coast studied, it is suggested that the circalittoral zone extended above the Chart Datum level and that the upward extent of the sublittoral zone, based on the presence of sublittoral algae, extended to about 2.5 m above Chart Datum compared to about 1 m on the open coast. The presence of extensive areas of sand and of sand in suspension during strong tidal flow, is considered to be important in the development of large colonies of Sabellaria alveolata. This and previous surveys emphasise the importance of S. alveolata as a dominant species. Records currently considered sensitive have been removed from this dataset.

More from this publisher

All datasets from Joint Nature Conservation Committee

Related datasets

Search

Data links

Link to the data Format File added Data preview
1978-79-SWBSS-Upper-Bristol-Channel-sublittoral-survey.csv CSV 15 December 2015 Preview

Additional information

View additional metadata
Added to data.gov.uk
2018-05-17
Access contraints
no limitations
Harvest GUID
fb0c4d54-6e89-46da-9c25-3fc5d9ce999f
Extent
Latitude: 51.49697531° to 51.17923974°
Longitude: -3.74449187° to -3.274701341°
Spatial reference system
Dataset reference date
2007-04-25 (publication)
Frequency of update
Responsible party
Digital and Data Solutions, JNCC (custodian)
ISO 19139 resource type
dataset
Metadata language
eng
Source Metadata
XML
HTML

Contact

Enquiries

Digital and Data Solutions, JNCC

Freedom of Information (FOI) requests

JNCC Freedom of information requests for this dataset