THE SHETLAND ISLES: LONG-TERM OBSERVATIONS ON THE SUBTIDAL MARINE FLORA

IIAN TITTLEY & WILLIAM F. FARNHAM

T~Y,I. & W.F. FARNHAM.2001. The Shetland Isles: Long-term observations on the subtidal marine flora. Arquipklago. Life and Marine Sciences. Supplement 2 (Part B): 1-17. Ponta Delgada. ISSN 0873-4740.

The marine algal flora of Sullom Voe, Shetland, has been surveyed on three occasions in twenty years (1973, 1983, 1993). To date 281 species have been recorded in Shetland, of which 175 species occur in Sullom Voe. The subtidal vegetation of the outer part of the voe is characterised by forest formations of the perennial kelp Lantinaria hyperborea on bedrock and a species-rich epinora on stipes and holdfasts. This community was stable with time despite the wave-exposed conditions there. The subtidal vegetation of the inner, sheltered, voe with a sea-bed of sediment, stone and shell, was characterised by the canopy- forming annual Lantinaria saccharina / longicruris. Comparison of survey results revealed this canopy and associated subflora communities to vary in abundance and extent with time.

Ian Tittley (e-mail: [email protected]) Department of Botany, The Natural History Museum, London SW7 5BD. UK - Williant F. Farnham, Institute of Marine Sciences, University of Portsmouth, Porrsntouth P049 9LY, UK

INTRODUCTION Although accounts of the algal flora of the Shetlands go back almost two centuries (e.g. Shetland is an archipelago of about 100 islands in EDMONSTON1809), studies have been sporadic the Atlantic Ocean lying between 60" and 61°N, and key works are those of B~RGESEN(1903a, b), 170 km north of mainland Scotland and 300 km B~RGESEN& J~NSSON(1905), DIXON (1963). southeast of the Faroe Islands. Although the IRVINE(1962, 1974, 1980) and IRVINEet al. archipelago lies within the cold-temperate region, (1975). The marine algal flora of Shetland is the sea does not freeze due to the warming typical of the species poorer cold temperate North influence of the Gulf Stream (average surface Atlantic Ocean with 281 species recorded (50 temperatures are 4OC in winter and 12°C in Chlorophyta, 101 Phaeophyta, 130 Rhodophyta). summer). The Shetlands contain a mainland Sullom Voe had been scantly studied until the which is 85 km long and incised by deeply construction of Europe's largest oil terminal in the penetrating, fjordic arms (sea-lochs or voes); one 1970s (DUNNET& MCINTYRE1995). Long-term of these, Sullom Voe (Fig. l),is the subject of this surveillance of the intertidal biota of Sullom Voe paper. has been undertaken regularly since 1981 Sullom Voe is a 15 km long, narrow inlet of (MOORE et al. 1995). Studies on the subtidal the sea where there is a gradient of wave-exposure vegetation were initiated in 1973 (TI'ITLEYet al. from extremely wave-exposed to sheltered. A few 1977) as part of a wider study of the algae of rivulets drain into the voe but cause no significant Shetland (IRVINE1974), and repeated in 1983 reduction in salinity. Sullom Voe has a range of (TITTLEYet al. 1985) and 1993 (T~T~LEY& subtidal habitat types, including rocky outcrops, Fr\RNHAM 1997 - unpublished report). extensive sediment areas of shell, stone, sand and The 1993 algal survey of the Sullam Voe silt, and biogenic surfaces such as beds of provided an opportunity to revisit previous study Modiolus (horse-mussel). sites, assess the current status .of the subtidal vegetation, and make comparisons with previous dimensional graphs in which each point represents observations; some results are presented in this a vegetation sample or quadrat. The distances paper. between the points in the graph are taken as an indication of their similarity or difference. METHODS

The surveys were carried out in July / August 1973, July 1983 and August 1993. In the original 1973 survey, the principal features of the algal vegetation of Sullom Voe were recorded by sampling from quadrats along transects; these transect studies were complemented by sampling from 'spot-dive' study sites at pre-selected depths (T~LEYet al. 1977). As the original survey was essentially semi-quantitative and descriptive, transect sampling was not replicated; subsequent reassessment was undertaken in the same manner. Transects were relocated as accurately as previous field data allowed. At each site a rope line was laid from an accessible reference point at high water mark to the subtidal region. The transects were 200 m long and the rope forming the transect line was weighted and marked at 10 m intervals. Depths at these points were recorded at noted times and adjusted to Chart Datum. At each marked 10 m interval, vegetation was cleared from a 1 m X 1 m quadrat beside the transect line and brought back to the laboratory for identification. Where possible, whole stones and cobbles were collected for examination of encrusting algae. Laminarians were weighed wet Fig. 1. Sullom Voe showing transects sites. to assess relative abundance; ages of Lclrl~i~~aria hyperborea plants were ascertained by sectioning stipes and counting annual growth rings (cf. KAIN RESULTS 1963). The results for four of the transect surveys (Fig. 1) are presented below (for other sites see Inner Voe - South Ness T~LEY& FARNHAM 1997). Detrended Correspondence Analysis (DECORANA, a numerical, ordination method) The transect traversed an intertidal area of gently was used to facilitate comparison of quadrat data sloping shingle, boulder and outcropping rocks from the three surveys. A database of species that continued subtidally and, at greater depths presence in quadrats was prepared for the purpose (10 m), gave way to a sea-bed of soft mud and (in TITTLEY & FARNHAM1997). Ordination shell debris. arranges the vegetation samples in relation to each other according to their similarity of species Vegetation description and cor~rpariso~z composition and associated environmental or temporal controls (KENT & COICER1992). The Seventy-nine species were recorded in the three results of an ordination are in this case two- surveys (32 species in 1993,55 in 1983 and 36 in 1973); only a small component (l l species) of the suggests a depth gradient; quadrats at depths of total flora was found on all occasions. less than 10 m (characterised by Lntninaria At shallow sublittoral levels the transect sacharimz / lo~zgicruris)are positioned to the left crossed a canopy of mixed of Fucus serratlcs, of 200, quadrats from deeper waters (often Lniirinaria digitata, L. hyperborea and L. containing Phyllophora crispa) are positioned to saccAnri~~a/lorzgicr~cris(L. saccharina and L. the right. The second axis suggests temporal lotzgicruris may be conspecific cf. SOUTH& differences with most 1973 and 1983 quadrats in T~LEY1986). From 30 m offshore (2-3 m the lower part of the graph (below 200), and 1993 depth) the canopy was solely of L. saccharina / quadrats in the upper part. The ordination does loitgicruris (Fig. 2). In 1993 the Lnrt~inaria not show the quadrats that in 1993 lacked algae. canopy extended to only 90 m offshore (9 m depth), contrasting with 1973 when it was present in all quadrats to 140 m offshore (14 m depth), and 1983 when it was patchily present 80-130 m offshore. The subflora (underflora and epiflora) recorded in shallow waters comprised a diverse species-assemblage but differed in composition in each survey. At 30-80 m offshore (2-8 m depth) only a depauperate underflora was recorded in 1993 compared with species-richer assemblages of 1973 and 1983 (cf. TI'ITLEYet al. 1977, 1985). The principal algae in 1993 were, epiphytes on Lnrminaria blades (e.g. Ectocarplw siliculosus, Myrionenm corurlrtae), and crustose forms such as the Aglaozonia stage of Cutleria nrultifida, Litltotl~ar~zr~ioriglaciale and Pseudolitltodelnm exteizsurtt on stones and shells. At 140-150 m offshore only crustose species were recorded in 1993 in contrast to the foliose and filamentous Fig. 2. Transect 1, South Ness. Kite diagram showing species found previously; in deepest waters at 25- hmirtaria saccharina / longicniris extent and 28 m (160-200 m offshore) vegetation was absent abundance along the transect in the three survey years. in 1993 contrasting with previous occasions (cf. T~LEYet al. 1977, 1985). The red alga Inner Voe - Scarva Taing Pliyllophora crispa that in 1973 and 1983 was commonly present as extensive, detached, mats The transect crossed an intertidal area of shingle 120-200 m offshore, was not recorded in 1993. with rocky outcrops that gave way at shallow sublittoral levels (3 m depth) to a sea bed of gravel, coarse sand and cobble. At 4-5 m depth Ordination (Fig. 3) produced a single cluster of the sea-bed was of mud and sand which continued points. The lack of a clear linear pattern to 100 m offshore. Beyond this point the sea-bed successive points (quadrats along the transect) changed to mud-shell debris and Modiolrcs beds, reflects the patchy mosaic of vegetation crossed and soft mud and shell debris at the greatest by the transect. The first axis of the ordination depths investigated (25-30 m). 026 025

Axis 1 Eigenvalue 0.5506

Fig. 3. Transect 1, ordination of quadrat data. Numbered points represent quadrats (successively joined for 1973 and 1993 transects). 1973, hatched line 35 (inshore) - 49 (offshore); 1983, points unjoined 16 (inshore) - 34 (offshore); 1993, continuous line l (inshore) - 15 (offshore).

Vegetation description and comparison in deepest waters (Fig. 4). Differences in extent of L. saccharina / longicruris canopy were observed Eighty species were recorded during the surveys in each survey occasion (1973 to 110 m offshore; (42 in 1973; 64 in 1983; 18 in 1993) but only 1983 to 50 m offshore; 1993 to 40 m offshore). eight on all oceasions. A diverse subflora of mainly red algae (e.g. In 1993 the principal kelp at sublittoral fringe Phycodrys rubens, Phyllophora crispa, level was L. saccharina / longicruris, contrasting Polysiphonia ebngata, Pterosiphonia parasitica) with mixed Laminaria spp. recorded in 1973 and and the crustose brown algae Aglaozonia and 1983. At greater depths a mixture of L. Pseudolithodermu extensum, was recorded in the saccharina / longicruris and L. lzyperborea was three surveys. Species composition differed on present on all occasions; L. saccharina / each occasion and fewer species were recorded in longicruris was consistently the dominant spwies 1993 than previously. The subflora extended to only 80 m offshore in 1993, compared with 150 m Vegetation descriptiori arzd corirparisor~ in 1973 and 200 m in 1983. Seventy-seven species have been recorded in the surveys (47 in 1993, 48 in 1983, 46 in 1973) but only sixteen species were recorded on all three occasions. In 1993 (and 1973) Laminaria digitata and L. hyperborea successively formed narrow bands on boulders at shallow sublittoral levels, contrasting with 1983 when both were absent. L. saccharinn / lor1gicrlir.i~was predominant in deeper waters offshore on all occasions (Fig. 6). At the greatest depths investigated in the present survey (20 m), macrophytes were absent. Lanlirzarin saccknrina / 1011gicrur.i~beds extended to 80 m offshore in 1993 compared with 190 m in 1983.

Fig. 4. Transect 2, Scarva Taing. Kite diagram showing L.un1inar.i~saccharina / longicrwis extent and abundance along the transect in the three survey years.

Quadrat comparison

Ordination (Fig. 5) produced a graph with a single cluster of points. Quadrats from below 20 m depth are positioned in the top left of the plot and those Abundance from shallow water to the right side of the plot. Quadrats from deep water and lacking in algae in 1993 are not shown.

Fig. 6. Transect 3, Oil Terminal. Kite diagram Central Voe - Oil Terminal showing Lantirlaria saccizarina / longicrzrris extent and abundance along the transect in the three survey years. The transect crossed a man-made boulder foreshore that gave way in shallow waters to a A subflora of Uha lactuca, CIzorda filunz, sandy sea-bed. At 4 m depth the sea-bed was of Ectocnrpus spp., Spkacelarin cirrosa and mud and shell debris and changed to soft mud at Plzycodlys rubem occurred beneath the approximately 10 m depth. In deep water (15-20 La~ninariacanopy on all occasions. The filiform m depth) the sea-floor wqs of soft mud and silt. brown algae Dictyosiphon foeiziczilaceus, Stictyosipkort soriferus, Spennatochnus beyond 90 m offshore in 1993 while in 1983 paradoxus and Sauvageaugloia g?a@tlzsianus Coccotylus mazcatus, Polysiphonia elongata, recorded in 1973 and 1983 (cf. T~LEYet al. Plzyllopkora crispa, and R. floridula were 1977, 1985) were not found in 1993. Flocculent present, and in 1973 Potyides rotundus, mats of Rhodothamnielln floridula occurred in Desrnarestia aculeata, Sphacelaria plurttosa and smaller amounts at 70 m offshore in 1993 Chaetornorpha rtlelngor~iu~nwere also recorded compared with 1983. Algae were not found (TI~EYet al. 1977, 1985).

Axis 1 Eigenvalue 0.57

Fig. 5. Transect 2, ordination of quadrat data. Numbered points represent quadrats (successively joined for 1983 and 1993 transects). 1973, points unjoined 29 (inshore) - 41 (offshore); 1983, hatched line 9 (inshore) - 27 (offshore); 1993, continuous line l (inshore) - 8 (offshore).

Quadrat comparison linear but meanders (from shallow to deep water) reflecting the mosaic of communities traversed. Ordination of quadrats (Fig. 7) indicated a depth The second axis suggests a time series, with 1973 gradient with those from deeper waters positioned quadrats positioned at law values, 1983 quadrats at higher values on axis 1; the arrangement of at middle values, and most 1993 quadrats at high successive transect quadrats in the graph is not values. Fig. 7. Transect 3, ordination of quadrat data. Numbered points represent quadrats (successively joined for 1973 and 1993 transects). 1973, hatched line 28 (inshore) - 38 (offshore); 1983, points unjoined 11 (inshore) - 27 (offshore); 1993, continuous line l (inshore) - I0 (offshore).

Outer Voe - Grunn Taing Beyond a narrow inshore band of L. digitata, the principal kelp species on all occasions was The transect crossed a wave-exposed intertidal Laminaria hyperbor.ea which formed an extensive sea-shore of shallowly shelving bedrock which stand of large plants to 200 m offshore (Fig. 8). In extended to 5-6 m below low water level (100 m 1993 plants were aged at (5)-6-(7) years old. offshore). Beyond this point were sporadic areas Patchy gsowths of L, saccharina / longicrur~is of boulder, stones and gravel over bedrock, and grew among the L. I~ypel-bore0canopy along the furthest offshore, patches of sand and small entire transect in 1993, compared with only boulders over bedrock. beyond 100 m in 1973 and 1983. Another kelp, Snccorl~izapolyschides, was found occasionally Vegetation clescl-iption aild cornpcwisolz in the three surveys, where sand is temporarily Fifty-nine species have been recorded in the three washed away from the bedrock. susveys (41 in 1973, 32 in 1983, and 39 in 1993). The subflora in all surveys comprised (Table Twenty species have been found on all occasions; 1) a species-rich assemblage on LalninalYa seven are unique to this site. kyper.Dol-ea stipes, and a species-poorer assemblage on bedrock and stones beneath the L. which a clear depth- or time-series could not be hyperborea canopy. discerned.

DISCUSSION

There exists an extensive body of knowledge on the seasonality, Long-term occurrence, change in abundance and depth distribution, of Laminaria spp. around the coast of Scotland (e.g. WAL~& RICHARDSON1955; WALKER1957). Laminaria occurrence around Shetland was less known until recently (cf. CONNORet al. 1997; TI~et al. 19'77). The results of this field survey agree with the conclusion of WALKER(1958) that the greater abundance of Laminaria spp. occurs at depths of less than 9 m. The present and previous algal surveys have revealed differences in laminarian Fig. 8. Transect 4, Oil Terminal. Kite diagra lrn communities in the inner and outer parts of showing Laminaria hyperborean extent and abundance Sullom Voe, The extensive areas of subtidal along the transect in the three survey years. bedrock in the outer voe provide habitat suited to the strongly anchored, long-lived perennial Table 1 Laminaria hyperborea. The three surveys have Subflora at Grunn Taing shown the species to thrive there despite the Epitlora on Laminaria hyperborea wave-washed conditions which at an extreme can Audouinella purpurea Membranoptera alata cause considerable damage by snapping the stiff Callophyllis cristata Phycodrys rubens stipes (BIR~et al. 1998). WALKER(1958) Ceramium nodulosum Plocamium noted the dominance of L. hyperborea on cartilag incum extensive bedrock in the Orkney Islands. The Cladophora rupestris Polysiphonia stricta inner reaches of Sullom Voe have only a Cryptopleura ramosa Ptilota gunneri restricted area of subtidal bedrock and therefore Derbesia marina Ptilothamnion pzuma . little L. hyperborea. However, the extensive sea- hmtolithOn~ud~~~~~~ Rhodomela con!entoide~ bed of sto&s and shells there, create a Desmarestia viridtr Rhodophyllis divaricata suitable habitat for the fast-growing, opportunist, Haraldiophyllum Sphacelaria radicans bonnemaisonii annual L. saccharina / longicruris and for Filiform Lomentaria clavellosa Ulva lactuca annual brown algae that do not require firm anchorage. Similar assemblages occurred in Underflora on bedrock only sheltered fjords in the Faroes where L. longicruris Hildenbrandia rubra Peyssonnelia dubyi grew on small stones and shells or even Lithothumnion glaciale Phymatolithon rugulosum unattached (TI'ITLEY et al. 1982). With its brittle laminae several metres long, L. saccharina / Snbflora on bedrock and L. hyperborea longicruris is suited to extremely sheltered Membranoptera alafa Ptilota gunneri conditions with little water movement. Phycodrys rubens Ulva lactuca Although the three surveys showed a kelp Polysiphonia stricta canopy to be continuously present throughout the voe, results from transect studies (and also the Quadrat comparison ordination analysis) suggest differences in Ordination (see T~EY& FARNHAM 1997, p.87) stability of the vegetation in the inner and outer presented a single tight cluster of quadrats in voe. The Laminaria hyperborea forests in the outer areas of Sullom Voe appeared stable in Sullom Voe suggest that some kelp communities contrast to the changes in extent and abundance of change more rapidly than others, confirming Laminaria saccharinn / lorzgicr~iriscanopy in the WALKER& RICHARDSON'S(1955) observation inner voe. However, in the outer voe where that L. snccharina is more noticeably seasonal in mobile sand is temporarily washed away from its growth than is L. hyperborea. bedrock, the vegetation on uncovered surfaces is Laruii~aria hyperborea also provides habitat characterised by opportunists such as Saccolhiza for a dynamically stable subflora of epiphytes. polysclzides and L. saccharina / lot~gicr~iris. The associated underflora assemblage on bedrock Changes recorded in the inner voe are probably comprised mainly slow-growing species that also natural and possibly cyclical. WALKER (1956a) formed a dynamically stable facies. The subtidal identified changes in the quantity and composition algal underflora communities, and those at of Laminariaceae in Scotland and showed an 11 locations in the voe without a kelp canopy (see year cycle and coincidence with sunspot activity; T~LEYet al. 1977 for a full description of these WALKER(1956b) suggested that this activity may communities), in general agree with the biotopes influence meteorological conditions and thus the defined by CONNORet al. (1977) from the north marine environment. Elsewhere in the North of Scotland. Atlantic grazing by sea-urchins has significantly The 175 species of algae recorded from reduced the extent of Laminaria stands (TI'ITLEY Sullom Voe (Appendix 1) compares with 199 et al. 1989); this is not the case in Sullom Voe as from the much longer Hardangerfjord in adjacent urchins do not occur in numbers large enough to Norway (JORDE & KLAVESTAD 1963), but deplete the kelp assemblage. To speculate, the considerably exceeds 49 from SkBlafjodur contraction of vegetation from deeper waters (comparable in length to Sullom Voe) in the recorded in the present survey may relate to water Faroes (T~EYet al. 1982). quality and the flushing of the inner basin of These subtidal vegetation surveys, and other Sullom Voe. Although a de-oxygenation event studies over the past twenty years (DUNNET& was recorded in 1978 at the head of Sullom Voe MCINTYRE 1995), have indicated that physical (PEARSON& ELEFTHERIOU1981; STANLEYet al. disturbance caused by construction of the oil 1981), adverse conditions occurred only beneath a terminal has been relatively confined. As shown summer thermocline at 30-35m. by Walker's many studies Larninaria populations The age of the Larnittaria lzyperborea are resilient to disturbance; Lnmitzaria population in the outer voe (5-6-7 years) was Izyperborea at the oil terminal had recovered in slightly more than the 4-5 years reported by 1993 after an absence in 1983. Walker & Richardson (1957) for open sea The Lanzi~zaria forests that occur on the populations in Scotland. Although turnover of temperate sea-shores of the world are biologically individual L. Izyperborea plants has occurred diverse and as a consequence are of considerable between surveys, recruitment has been sufficient conservation importance. They are described by to maintain a broadly similar outward appearance BIRKE'ITet al. (1998) as the marine equivalent of of the kelp bed. WALKER(1958) observed that tropical rainforests in terms of their biological over a year the standing crop of L. Iryperborea is productivity, the numbers of individuals living generally stable until reduced by rough seas and there or dependent on the habitat, and the species by the shedding of old laminae in spring. WALKER diversity present in the habitat. Despite the (1958) also recorded 'perennial changes' in cover extensive body of knowledge on kelp forests there and density in Lanlirzaria populations in which are few long-term studies in Britain. Unlike the reductions and gains were noted. BIRKE~Tet al. intertidal monitoring in Sullom Voe that was (1998) discussed the constant change in the undertaken at shorter intervals and therefore spatial mosaic of kelp communities and suggested provides more complete time-series information time-scales of decades to centuries for such on algal populations and communities, these natural dynamic variation. Our observations in subtidal algal surveys only provide snapshots at longer time intervals between which other DUNNET,G.M. & A.D. MCINTYRE.1995. Mon~toringat unrecorded changes may have occurred. an oil terminal: the Shetland experience. Proceeclirrgs of the Xo)vd Society of Echbrrrgh 1038: vi~+ 1-258. ACKNOWLEDGEMENTS EDMONSTON,A. 1809. A view of the crr~cieilt cr11d preseut state of (he Sl~etlcriirlIslarlds. Edinburgh We thank Ronnie Gallagher and BP Exploration and London. vii + 345 pp. Operating Company Ltd., Sullom Voe Oil GUTRY,M.D. 1997. Benthlc, red, brown and green Terminal for the many facilities placed at our algae. Pp.341-367 in: HOWSON,C.M. & B.E. disposal and for considerable support. Shetland PICTON(Eds). The species directory of the rtrari~le farlira and flora of the British Isles and Oil Terminal Environmental Advisory Group is srrrrorr~~clirlgseas. Ulster Museum and The Marine gratefully acknowledged for financial support. Conservation Soclety, Belfast and Ross-on-Wye. The fieldwork could not have been completed vi + 508 pp. without the enthusiastic participation of Lin IRVINE,D.E.G. 1962. The marine algae of Shetland; a Baldock, Jenny Bryant, Frances Dipper, Sarah phytogeographlcal account. British Pl~ycological Fowler, Rob Huxley, Kay Ingleton, Janny Brilletin 2: 18 1-1 82. Mallinson, Chris Spurrier, Karen Webb and Chris IRVINE,D.E.G. 1974. The marine vegetation of the Wood. Shetland Isles. Pp. 107-1 13 in: GOODIER,R. (Eds). The nutrrral erwirorltirent of Sl~etlmld.Proceedi~lps of the Natrrre Conser\wlc~~Corrtrcil Syiilposirrnr REFERENCES held ill Edirrbrtrgh 29-30 Janrrary 1974. Edinburgh. iv + 178 pp. BIRKETr, D.A., C.A. MAGGS,M.J. DRING & P.J.S. IRVINE,D.E.G. 1980. Marine algae. [pp.267-2721. In BOADEN.1998. "Infralittoral reef biotopes with BERRY,R.J. & J.L. JOHNSTON(Eds). The Narrtral kelp species" An overview of dynamic and History ofShetland. Collins, London. 380 pp. sensitivity characteristics for conservation IRVINE,D.E.G., M.D. GUIRY, I. TITTLEY. & G. management of marine SACS. A repor? for the RUSSELL.1975. New and interesting marine algae Scottish Association of Marine Scieuce. Qlreens from the Shetland Isles. British Phycological University of Belfast, Portaferry. 174 pp. Jorrrnal 10: 57-71. BDRGESEN, F. 1903a. Marine algae. Pp.339-532 in: JORDE,I. & N. KLAVESTAD.1963. The Natural History Warming, E. (Eds). Botany of the Faeroes based of the Hardangerfjord 4. The benthonic algal rrporl Danislr investigatior?~.Part II. Copenhagen. vegetation. Sarsia 9: 1-99. 68 1 pp. KAIN,J.M. 1963. Aspects of the biology of La~ilirmria BPIRGESEN, F. 1903b. The marine algae of the hyperborea 11. Age, weight, and length. Jorrrtral of Shetlands. Jorrrnal of Botai~y,Lord011 4 1: 300-306. the Marirw Biological Associatiotr oJ the United B~RGE~EN,F. &H. J~NSSON.1905. The distribution of Kingdorn 43: 129-151. the marine algae of the Arctic Sea and the KENT, M. & P. COKER.1992. Vegetatioi~description northernmost part of the Atlantic Ocean. Appendix, and analysis A practical approach. Bellhaven Pp.1-XXVIII, in: WARMING,E. (Eds). Botany of the Press, London. X +363 pp. Faeroes based rrpolr Danish irwestigarioiw. Parts 1, MOORE,J., P. TAYLOR& K. HISCOCK.1995. Rocky 2 and 3. Copenhagen, Christiania and London. shores monitoring programme. Proceedings of the 1070 + XXVIII pp. Royal Sociefy of Ediihrrgh 103B: 181-200. CONNOR,D. W., M. J DALKIN,T. O HILL, R.H.F. HOLT& PEARSON,T.H. & A. ELETHERIOU.1981. The henthic W.G. SANDERSON. 1997. Marine Nature ecology of Sullom Voe. Proceedings of ~AeRoyal Conservation Review: marine biotope classification Society of Edi~rbrrrgh8OB: 241-269. for Britain and Ireland. Volume 2. Sublittoral SOUTHG.R. & I. TITTLEY.1986. A checklist and biotopes. Version 97.06. JNCC Report No. 230: 1- distribritiolral ii1de.r of the benthic ii~arinealgae of 448. the No~hAtln~rtic Ocean. Huntsman marine DIXON, PS. 1963. The marine algae of Shetland Laboratory and British Museum (Natural History), collected during the meeting of the British St Andrews and London. 76 pp. Phycological Society, August 1962. British STANLEY,S.O., B.E. GRANTHAM,J.W. LOFTLEY& N. Phycological Brilletin 2: 236-243. ROBERTSON,N. 1981 Some aspects of sediment chemistry of Sullom Voe, Shetland. Proceerlirlgs WALKERF.T. 1956a. Periodicity of the Laminariaceae of tkeRoya1 Society of Edirlblrrgh 80B: 91-100. around Scotland. Nature 177: 1246. TJTTLEY,I. & W.F. FARNHAM. 1997. The srrbtidul WALKER F.T. 1956b. The Ln~nirlctric~cycle. Revrre nluri~~ealgal vegetatio~lof Srrllo~rlVoe reassessed - Algologiqrre 3: 179- 18 1. 1993. A report to SOTEAG. The Natural History WALKER F.T. 1957. An ecological study of the Museum, London. l55 pp. Laminariaceae of Ailsa Craig, Holy Island, TITTLEY,I., W.F. FARNHAM,R.L. FLETCHER& D.E.G. Inchmarnock, May Island and Seaforth Island. IRVINE.1985. The subtidal marine algae of Sullom Tra~lsactiovsof the Botarlical Society of Edinblrrgh Voe reassessed. Trarlsactio11s of the Botar~ical 37: 182-199. Society of Edirlbrrrgh 44: 335-346. WALKER F.T. 1958. Some ecological factors RT~LEY,I., W.F. FARNHAM& P.W.G GRAY. 1982. conditioning the growth of the Laminariaceae Seaweeds of the Faroes 2: Sheltered fjords and around Scotland. Acta Adriatica 8 (13): 1 - 13. sounds. Blrlleti~~of the British Mrrserm (Natlrral WALKER F.T.& W.D. RICHARDSON.1955. An History) Botany Series 10: 133-151. ecological investigation of Lanlirlaria clorrsto~~ii TIITLEY, I., W.F. FARNHAM,R.G. HOOPER& G.R. Edrn. (L. hyperborea Fosl.) around Scotland. SOUTH.1989. Sublittoral seaweed assemblages 2: a Jo~rrrlalof Ecology 43: 26-38. transatlantic comparison. Progress ir~ Undenvater WALKERF.T.& W.D. RICHARDSON1957. Perennial Science 13: 185-205. changes of lan~irmriaclolrstorlii Edm on the coasts TIITLEY,I., D.E.G. IRVINE& N.A. JEPHSEN.1977. The of Scotland. Jorrrnal dlr Cor~seil111terrlatior1al pour infralittoral marine algae of Sullom Voe, Shetland. L'Exploratiort de la Mer 22: 298-308. Transactions of the Botar~icalSocie/y of Edirlbrrrgh 42: 397-419. Accepted I2 Jmrrary 2001. APPENDIX l : SPECIES RECORDED FROM SHETLAND AND SULLOM VOE

Nomenclature and citation mostly follows Gumv (1997) * = Voucher specimens at BM 7 = Recorded from Sullom Voe in 1973 8 = Recorded from Sullom Voe in 1983 9 =Recorded from Sullom Voe in 1993

Species without asterisks are not represented by specimens at BM; species without 7,8,9 have been recorded for Shetland but not Sullorn Voe.

Bangiophyceae (Rhodophyta) Aglaothantnion bipinrlatrtm (P Crouan & H Crouan) Feldman-Mazoyer Aglaotltan~nionhookeri (Dillwyn) Magg & Hommersand) Aglaotl~amnionpriceanrtin Maggs, Gutry & Rueness Aglaothan~i~ionroserrnl (Roth) Maggs & L'hardy-Halos Aglaothainnion sepositrtnl (Gunnerus) Maggs & Hommersand Ahrtfeltia plicata (Hudson) Fries A~ltithan~niorzellafloccosa (0 F Muller) Whittick Asparagopsis armata Harvey palkenbergia stage] A~tdorrir~elllaalariae (J6nsson) Woelkerling Arrdouinella daviesii (Dillwyn) Woelkerling Arrdoltiriella nlen1branacea (Magnus) Papenfuss Al~douinellaparvda (Kylin) Dixon Audouinella prtrplcrea (Lightfoot) Woelkerling Audouirzella sec~rndata(Lyngbye) Dixon Arcdouitzella virgatrcla (Harvey) Dixon) Barlgia atroprcrpurea (Roth) C Agardh Boergeseniella frrttic~rlosa(Wulfen) Kylin Bor1rrernaisor~ia/tarnifera Hariot [Trailliella phase] Bror~gniartellabyssoides (Goodenough & Woodward) Schmitz Callithanznion coryn~bosrtm(J E Smith) Lyngbye Callithan~niongra~lrrlatrrrn (Ducluzeau) C Agardh Callithan~r~iotttetragorlrrnz (Withering) S F Gray Callocolax neglect~~sBatters Callophyllis cristata (Turner) Kutzing Ca2lopl1yllislaciniata (Hudson) Kiitzing Catenella caespitosa (Withering) L Irvine Cerami~cnlcimbricrrn1 H Petersen Ceranlirlrn desloi~gcltatnpsiiDuby Ceramirttn diaplzatmnt (Lightfoot) Roth Ceranlirinl nodrrlos~trn(Lightfoot) Ducluzeau Ceranlillm slz~rttleworrhia~~~rm(Kuetzing) Rabenhorst Ceranzirmz stricfnnl sensrr Harvey Ceratocolax hartzii Rosenvinge Cltondrrrs crisprrs Stackhouse Choreocolax polysiphoniae Reinsch Clzylocladia verticillata (Lightfoot) Blidingia Coccofylus trltrzcatrrs (Pallas) M Wynne & J Heine Colacodictyon reticulatum (Batters) J Feldmann Corallirla ofJicinalis Linnaeus Cordylecladia erecta (Greville) J.Agardh Cruoria pellita (Lyngbye) Fries C~yptoplertraramosa (Hudson) Lily Newton Cystoclorrirr~~rprrrprtrerrm (Hudson) Batters Delesseria sanguir~ea(Hudson) Lamouroux Dilsea carnosa (Schmidel) Kuntze Dlrmontia contorta (S Gmelin) Ruprecht Erytl~rocladiairregrtlaris Rosenvinge Eryrl~roglossrrnr1aciniatrr111 (Lightfoot) Maggs & Hommersand E~ythrofrichiacartlea (Dillwyn) J Agardh Fosliella sp. Frrrcellaria Irrn~bricalis(Hudson) Lamouroux Gelidirrm prrsillrrm (Stackhouse) Le Jolis Gloiosipko~~iacapillaris (Hudson) Berkeley ? Gracilaria gracilis (Stackhouse) Steentoft, L Irvine & Farnham Griffithsia corallinoides (Linnaeus) Trevisan Halarachnio~zlig~tlatrrtn (Woodward) Kuetzing Halosacciocolax-kjellr~~anii S Lund Halrrr~rsflosc~tloslrs(Lightfoot) Kiitzing Haraldiophyllrrr~lborti~et~taiso~lii (Kylin) A Zinova Helmirtthora divaricata (C Agardh) J Agardh Heterosiplronia plzmosa (Ellis) Batters Hildenbrandia crorranii J Agardh Hildenbrandia rrtbra (Sommerfeldt) Meneghini Hypoglossrnn hypoglossoides (Stackhouse) F Collins & Hervey Kallymenia reruj5ortnis (Turner) J Agardh Lithophyllrrm crouanii Foslie Lithophyllum incrustans Phillippi Litkopkyllrmr orbicrrlatrrm (Foslie) Foslie Lithothamr~ionglaciale Kjellman Litkotka~~~rzior~sor~deri Hauck Lor~~er~tariaarticrclata (Hudson) Lyngbye Lon~entariaclavellosa (Turner) Gaillon Lonrentaria orcadensis (Harvey) Taylor Mastocarprrs stellatris (Stackhouse) Guiry Meiodisczrs spetsbergetwis (Kjellman) Saunders & McLachlan Melobesia r~vmbranacea(Esper) Lamouroux Membrartoptera alata (Hudson) Stackhouse Nen~alionheln~i~~tftoides (Velley) Batters Nitopltyllrrn~prtnctatrrn~ (Stackhouse) Greville Odonthalia der~tata(Linnaeus) Lyngbye Osn~rcndeahybrida (De Candolle) Nam Osmrtr~deapir~natijda (Hudson) Stackhouse Palntaria palr~rata(Linnaeus) Kuntze Peysso~zeliad~rbyi P Crouan et H. Crouan Pltycodrys rrrbens (Linnaeus) Batters Phyllophora crispa (Hudson) Dixon Phyllophora psertdoceranoides (S Gmelin) P Newroth & A R A Taylor Phyn~atolifhoncalcarerrn~ (Pallas) Adey & McKibbin Pltyr?tatolithor~laevigatrun (Foslie) Foslie Pkyrnatolithon larnii (Lemoine) Chamberlain Pliyyn~atolitlzonlenorntandii (Areschoug) Adey Phy~~~atolifhortpurprtrertrn (P Crouan & H Crouan) Woelkerling & L lrvine Plty~ymafolitho~zfenrie (Rosenvinge) Duwel & Wegeberg Ploca~~~irrnrcartilagine~nn (Linnaeus) Dixon Plrrn~ariaplunlosa (Hudson) Kuntze Pr~eophyllrm~carrlerpae (P Crouan & H Crouan) P Jones & Woelkerling Prreopl~yll~rir~cor!fervicola (Kuetzmg) Chamberlain Polyides rotlrndrts (Hudson) Greville Polysiphor~iaatlailtica Kapraun & J Norris Polysiphor~iabrodiaei (Dillwyn) Sprengel Pol.ysiphorlia elol~gatu(Hudson) Sprengel Polysipho~riaeloizgella Harvey Po1)aiphor~iaJibrata(Dillwyn) Harvey Pol)lsiphor~iafibrillosa(Dillwyn) Sprengel Pol~~siphor~iajrcoides(Hudson) Greville Polysipl~or~ialairosa (Linneaus) Tandy PolysipAoilia r~igra(Hudson) Batters Polysiphoi~iastricra (Dillwyn) Greville Porphyra ari~plissiii~a(Kjellman) Setchell & Hus Porphyra Ielrcosticta Thuret Porphyra rri~~bilicalis(Linnaeus) Kiitzing Porphyropsis coccir~ea(Areschoug) Rosenvinge Porphyrostron~irtrrlciliare (Harvey) M Wynne Pterosiphoi~iaparasitica (Hudson) Falkenberg Pterothan~nioitplrrrizrtla (Ellis) Nageli Ptilota grnrr~eriP Silva, Maggs & L irvine Prilithatmior7 pirrina (Dillwyn) Thuret Rhodomela coilfervoides (Hudson) P Silva Rhodorilela I~~copodioides(Linnaeus) C Agardh Rhodophyllis divaricata (Stackhouse) Papenfuss Rkodophysen~aelegai~s (J Agardh) Dixon Rhodotl~aiititiellaJorid~rla(Dillwyn) J Feldmann Sahlingia srrbiittegra (Rosenvinge) Kornmann Scagelia prrsilla (Ruprecht) Athanasiadis Sciitaiafirrcellata (Turner) J Agardh Seirospora iitterrlrpta (J E Smith) Schmitz Spennothan~i~iol~repem (Dillwyn) Rosenvinge S~yloi~en~aalsidii (Zanardini) K Drew Titanoderinu colnllii~ae(P Crouan & H Crouan) Woelkerling, Chamberlain & P Silva Titai~oderri~ap~csf~rlaf~rr~t (Lamouroux) Nageli

Fucophyceae (Phaeophyta) Acirletospora criizira (Harvey) Kornmann Acrothris grncilis Kylin Alaria esclrlei1ta (Linnaeus) Greville Ascophyllrcin r~odosrrri~(Linnaeus) Le Jolis Asperococcrrs coinpressus W J Hooker Asperococc~rsfisrrrlos~o(Hudson) W J Hooker Asperococcrrs brrllosm Lamouroux Chilior~en~aocellat~rin (Kuetzing) Kuckuck Cl~ilioi~en~areptans (P Crouan et H Crouan) Sauvageau Chorda fillrm (Linnaeus) S tackhouse Cl~ordariaflagellifonri~is(0 F Muller) C Agardh Cladostepltlrs spoizgiosrts (Hudson) C Agardh Colporneitia peregrina (Sauvageau) C Agardh Cr&~ia iizrrlt~jida(Mertens) De Notaris [includes Aglaozonia stage] Desri~arestiaaclrleata (Linnaeus) Lamouroux Desti~arrstialigldata (Lightfoot) Lamouroux Desrnarrstia viridis (0 F Mliller) Lamouroux Dictvosiphorr choi.daria Areschoug Dictyosiphor~foerricrrlcrcerrs (Hudson) Greville Dicfyota dicl1otorrru (Hudson) Lamouroux Ectocarprrs fascicrrlatrrs Harvey Ectocarprrs silicrrlosrrs (Dlllwyn) Lyngbye Elachistaflnccida (Dillwyn) Areschoug Elc~histafircicola(Velley) Areschoug Elachistn scrrtrrlcrta (J E Smith) Duby Errdodic@orr i~festarrsGran Errdesiire virescerls (Berkeley) J Agardh Frlcrrs cerarroides Linnaeus Frrcrrs distichrrs Linnaeus Iirrcrrs evairescerrs C Agardh Frrcrrs sermtrrs Linnaeus Frrcrrs spiralis Linnaeus Frrcrrs i~esicrrlos~rsLinnaeus Girarrdia sphacelarioides Derbks & Solier Gor1orreii1aaecidioides (Rosenvinge) P Pedersen Halidry siliqrrosa (Linnaeus) Lyngbye Hecatoirenra iiracrrlarzs (F Collins) Sauvageau Herporrerrra velrrtiirrriir (Greville) J Agardh Hii~~airthaliaelorrgata (Linnaeus) S Gray Hirrcksia grarrrrlosa (J E Smith) P Silva Hir~cksialrirlcksiae (Harvey) P Silva Hincksia ovata (Kjellman) P Silva Hir~cksiasairdriarra (Znanrdini) P Silva Hincksia secrrrlda (Kuetzing) P Silva Istlniroplea splraerophora (Harvey) Kjellman Lanriiraria digitata (Hudson) Lamouroux Lanrirraria hyperborea (Gunnerus) Foshe Lanrirrariu loi1gicnrris De la Pyla~e Lanriiraria sacchariiru (Linnaeus) Lamouroux Lanrinariocolas torrrerrtosoides (Farlow) Kylin Leathesia difSorr11is (Linnaeus) Areschoug Leptorrerirutellafascicdata (Reinke) P Silva Litosiphorr laririrrariae (Lyngbye) Ha~vey Mesogloia larrosa P Crouan & H Crouan Mesogloia verrrricrrlata (J E Smith) S Gray Mikrosypl~arpol)~sip/~or~iaeKuckuck Mikrosyphar porphyrae Kuckuck Myriactrrla a,rschougii (P Crouan & H Crouan) G Hamel Myriactrrla clarrdestirra (P Crouan & H Crouan) J Feldmann Myrior~eirracorrnlnae Sauvageau Myrionerrra papillosrtr~rSauvageau Myrioizeirra strarlgrrlarrs Greville Myriotrichia clavaefor~i~isHarvey Pehetia cailalicrrlata (Linnaeus) Decaisne & Thuret Petalonin fascia (0 F Miiller) Kuntze Petrodenira iiracrrlifor7ire (Wollny) Kuckuck Phaeostrnrira p~rstrrlosr~rirKuckuck Pilayella littoralis (Linnaeus) Kjellman Pogotricl~~rnrfiliforrrreReinke Protectocarprrs speciosrrs (BGrgesen) Kommann Pserrdolithodernra exterrsrm (P Crouan & H Crouan) S Lund Punctaria latifolia Greveille Punctaria plantagitlea (Roth) Greville Punctaria tenuissima (C Agardh) Greville Ralfsia verrucosa (Areschoug) Areschoug Saccorhiza polysclzides (Lightfoot) Batters Sauvageaugloia chordariaeformis (P Crouan & H Crouan) Kylin Sauvageaugloia grt$/?thsiana (W Hooker) Kylin Scytosiphon lomentaria (Lyngbye) Link Sorocarpus microntorus (Bory) P Silva Spermatochnus paradoxus (Roth) Kiitzing Sphacelaria arctica Harvey Sphacelaria cirrosa (Roth) C Agardh Sphacelariafiisca (Hudson) S Gray Sphacelaria ntirabilis (Batters) Prud'homme van Reine Sphacelaria nana Kiitzing Sphacelaria plumigera Hauck Sphacelaria pktmosa Lyngbye Sphacelaria rigidztla Kuetzing Sphaerorn'chia divaricata (C Agardh) Kylin Spongonenta tomentosum (Hudson) Kutzing Sticyrosiphon gri$/?thsianus (Le Jolis) Holmes & Batters Stictyosiphon sorijems (Reinke) Rosenvinge Stictyosiphon tortilis (Ruprecht) Reinke Stilophora tenella (Esper) P Silva Stragularia clavata (Harvey) G Hamel Streblonema breve (Sauvageau) De Toni Streblonema fasciculatum Thuret Streblonema parasiticum (Sauvageau) Levring Streblonema s~haericum(Derbss & Solier) Thuret Ulonema rhizophora Foslie

Chlorophyceae Acrochaete leptochaete (Huber) R Nielsen Acrochaete viridis (Reinke) R Nielsen Acrochaete wittrockii (Wille) R Nielsen Blastophysa rhizopus Reinke Blidingia minima (Ktitzing) Kyh BolbocoEeon piliferum N Pringsheim Bryopsis hypnoides Lamouroux Bryopsis plumosa (Hudson) C Agardh Capsosiphonfiilvesce~~(C Agardh) Setchell& N Gardner Chaetomorpha linzm (0F Muller) KKiiing Chaetomorpha inediterranea (Kiitzing) Kiltzing Chaetomorpha rnelagotlium (Weber et Mohr) Kiitzing Cladophora albida (Nees) Kittzing Cladophora dalmatica Kutzing Cladophora hutchinsiae (Dillwyn) KBtzing Cladophora pygmaea Reinke Cladophora rupestris (Linnaeus) Kiitzing CIadophora sericea (Hudson) Kiltzing Codiumji-agile (Suringar) Hariot ssp. atlanticum (Cotton) P Silva Derbesia marina (Lyngbye) Solier [including Halicystis stage] Enteromorpha clathrata (Roth) Greville Enteromorpha compressa (Linnaeus) Nees Enteromorphaflexuosa (Wulfen) J Agardh Enteromorpha intestinalis (Linneaus) Nees Enteromorpha inuscoides (Clemente y Rubio) Cremades Etzteromorphaprolifera (0 F Miiller) J Agardh Enteromorpha ralfsii Harvey Entocladia perforans (Huber) Levring Epicladia flustrae Reinke Eugomontia sacculata Kommann Ochlochaeteferox Thwaites Ostroebium queketii Bomet & Flahault Percursaria percursa (C Agardh) Rosenvinge Prasiola crispa (Lightfoot) Kutzing Prasiola stipitata Jessen Phaeophila dendroides (P Crouan & H Crouan) Batters Pringsheimiella scutata (Reinke) Marchewianka Pseudodicfyon itzflahrnz Ercegovic Pseudendocloniumfucicola (Rosenvinge) R Nielsen Rhizoclonium tortnosum (Dillwyn) Kutzing Spongonwrpha arcta (Dillwyn) Ktitzing Spongonenza aeruginosa (Linnaeus) van den Hoek [Chlorochytrium inclusum stage] Ulothrixflacca (Dillwyn)Thuret Ulothrix speciosa (Harvey) Kiitzing Ulva lactuca Linnaeus Ulva rigida C Agardh Ulvariafusca (Postels & Ruprecht) Ruprecht Ulvella lens P Crouan & H Crouan Ulvopsis grevillei (Thuret) Gayral Urospora pszicilliforms (Roth) Areschoug