PROVISIONAL ATLAS of the MARINE ALGAE of BRITAIN & IRELAND
Total Page:16
File Type:pdf, Size:1020Kb
PROVISIONAL ATLAS of the MARINE ALGAE of BRITAIN & IRELAND Edited for the British PhycologicalSociety by Professor T.A. NORTON (University of Liverpool) 1985 BIOLOGICAL RECORDS CENTRE Monks Wood Experimental Station nstitute of Terrestrial Ecology, Nature Conservancy Council, donks Wood Experimental Station, Northrninster House, iuntingdon. Peterborough á NATURALENVIRONMENT RESEARCH COUNCIL INSTITUTEOF TERRESTRIALECOLOGY PROVISIONALATLAS OF THE MARINEALGAE OF BRITAINAND IRELAND Edited for the BritishPhycological Society by ProfessorT A Norton (Universityof Liverpool) 1985 Instituteof TerrestrialEcology NatureConservancy Council BiologicalRecords Centre NorthminsterHouse MonksWood ExperimentalStation PETERBOROUGH AbbotsRipton PEI lUA HUNTINGDONPE17 2LS Printed in Great Britain by NERC Reprographics C NERC Copyright 1985 Published in 1985 by Institute of Terrestrial Ecology Administrative Headquarters Monks Wood Experimental Station Abbots Ripton HUNTINGDON PE17 2LS ISBN 0 904282 89 9 The Institute of Terrestrial Ecology (ITE) was established in 1973, from the former Nature Conservancy's research stations and staff, joined later by the Institute of Tree Biology and the Culture Centre of Algae and Protozoa. ITE contributes to, and draws upon, the collective knowledge of the 13 sister institutes which make up the Natural Environment Research Council, spanning all the environmental sciences. The Institute studies the factors determining the structure, composition and processes of land and freshwater systems, and of individual plant and animal species. It is developing a sounder scientific basis for predicting and modelling environmental trends arising from natural or man-made change. The results of this research are available to those responsible for the protection, management and wise use of our natural resources. One quarter of ITE's work is research commissioned by customers, such as the Department of Environment, the European Economic Community, the Nature Conservancy Council and the Overseas Development Administration. The remainder is fundamental research supported by NERC. ITE's expertise is widely used by international organizations in overseas projects and programmes of reiearch. The Biological Records Centre is operated by ITE, and receives financial support from the Nature Conservancy Council. It seeks to help naturalists and research biologists to coordinate their efforts in studying the occurrence of plants and animals in the British Isles, and to make the results of these studies available to others. Biological Records Centre Institute of Terrestrial Ecology Monks Wood Experimental Station Abbots Ripton HUNTINGDON PE17 2LS 048 73 (Abbots Ripton) 381 CONTENTS Page Foreword ii Introduction Methods Geographical coverage Selection of species iv Uses of the data bank iv Future recording Acknowledgements vi References vii Distribution maps Map 1 Coverage map Maps 2-24 Chlorophyta Maps 25-70 Phaeophyta Maps 71-156 Rhodophyta Index to maps á FOREWORD This ProvisionalAtlas of the MarineAl ae of Britainand Irelandis the resultof the dedicatedefforts of many people. Whilstpart of those effortswas directedspecifically at providingdata for the British PhycologicalSociety's Marine Algal RecordingScheme, a substantialamount of the data used was extractedfrom information assembledfor other purposes. Nevertheless,all the distributional records,from whatever source, have been assessed and validatedbefore theirincorporation into the database summarizedin thisAtlas. Most of the recorders,both professional and amateur,have giventheir time and data freely. The true economiccost of collectingand collating thisinformation by any othermeans would have been prohibitive. As indicatedin the Introduction,the BPS Marine Algal Recording Schemeis to continueuntil it is reckonedthat thereare sufficient species distributiondata to prepare a definitiveAtlas. An additionalobjective is to recordthe locationof specieswith more precision,together with someindication of the habitattype, so that the informationbase for the finalAtlas is of even greateruse than this provisionalatlas. In particular,such informationwill be of considerableuse to the NatureConservancy Council in preparingthe proposedMarine Nature Conservation Review of GreatBritain. As with its terrestrialcounterpart, the purposeof this reviewwill be to classifyand describethe range of marinehabitats, communities and speciesand identifythose sites consideredto be of the highest importanceand which should be conservedie as Sites of Special ScientificInterest, National Nature Reserves or, especially,Marine NatureReserves. This Reviewwill also act as a basisfor adviceon the wider marineenvironment. For many habitats,the marinealgal communitieswill be the prime attributesused in classifyingand assessingsites. We thereforehope that this extra and important requirementin field recordingwill provide a new interestand, indeed,a stimulusto the next phase of marinealgal recordingto achievethe finalAtlas. We recordour particularthanks to the BiologicalRecords Centre at Monks Wood for applyingtheir experienceand expertiseto the collationand presentationof the data and the publicationof this Atlas. However,without the considerableeffort of ProfessorTrevor Nortonand the recordersof the BritishPhycological Society, this Atlascould not havebeen produced; we are indebtedto them. Dr RogerMitchell SarahFowler ChiefScientist Directorate NatureConservancy Council INTRODUCTION A Marine Algae Recording Scheme was launched by the British Phycological Society (BPS), in conjunction with the Biological Records Centre (BRC), in 1971. The aim of the scheme, organised by Professor T A Norton, is to map the distribution of the British seaweeds. It covers all the benthic members of the Chlorophyta, Phaeophyta and Rhodophyta, plus the genus Vaucheria (Xanthophyta). Only attached seaweeds are recorded, drift plants being ignored as their provenance is unknown. A Preliminar Atlas of fifteen species was published by BRC in 1978; since then recording has progressed steadily and a Provisional Atlas of 155 taxa can now be published. Methods The seaweeds, limited by their requirements for both light and secure attachment, are largely confined to shallow waters close inshore. Therefore their distribution, like that of terrestrial organisms, can be recorded and mapped using the Ordnance Survey National Grid Reference System for Great Britain, the Suirbheireacht Ordonais/ Ordnance Survey National Grid for Ireland and the Universal Transverse Mercator Grid (Channel Islands). A standard recording card was produced at the start of the scheme, and was used for field recording by an enthusiastic group including both professional phycologists and amateur collectors. In addition, records have been extracted from the herbarium of the Department of Botany, University College, Galway (GALW), and from papers published since 1950. The accumulated record cards were passed over to BRC towards the end of 1982, and put on to computer file in 1983-84. The following data (if provided by the original recorder) were included for each record: species code number, site name, grid reference (in full), date of record, code number of recorder, source of record. In addition, records made during Nature Conservancy Council (NCC) surveys and held by NCC on computer file were made available to BRC and incorporated into the data bank. Most of the data processing at BRC was carried out by Francesca Griffith and Mrs D M Greene. Maps of all species were plotted from the resulting data. These maps were examined by T A Norton and R Mitchell (NCC) and 155 were selected for inclusion in a Provisional Atlas. The presence of a dot on the map indicates that there is at least one record from that 10 kmgrid square. Only records dating from 1950 onwards have been maPped, although some older records are included in the data bank. Geo ra hical covera e Records have now been received for about 80% of the approximately 1120 squares covering the coastline of the British Isles (map 1). Ireland is the most poorly covered region, especially the north-west although this area offers some of the most promising collecting grounds in the British Isles. For a frequentlyencountered species that is readilyidentifiable, up to 1000 independentrecords have been received.However, as thereis often more than one recordfrom a given 10 km square,there may be only500-600 dots on the map. Selectionof s ecies The 155 speciesmapped in this Atlas were selectedto indicatethe progressof the schemeand to stimulatecollecting in areas where recordsare sparseor completelylacking. The maps are also intended to draw attentionto the distributionpatterns that are emergingso that they may be verifiedor challengedby collectorsdeliberately searchingfor speciesbeyond their recorded limits. Some poorlyrecorded species have been includedto draw attentionto the neglectthat befalls species that are criticalor are laboriousto identify, eg the calcareouscrustose RhodophytaDermatolithon corallinae(map 99) and Ph tolithonlenormandii (map 135). Species that producesmall, inconspicuousplants, eg M rionemastran ulans (map58), or thatinhabit cryptic habitats, eg Tellamiaintricata (map 21) and parasiticplants, eg Choreocolaxol si honiae(map 139) are rarelynoted in passingbut are usuallypresent if lookedfor. A remarkablefeature of the maps is the numberof specieswhich appear to reach their geographicallimits in the BritishIsles, a region whichoccupies a latitudinalrange of littlemore than 10°. In the captionsto the maps,the terms'northern'