Hascosay

Site of Special Scientific Interest · 60.6111, -0.9896

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Shetland County

Condition (NatureScot)

Favourable (3)
UnitFeatureConditionArea (ha)Assessed
F1 Dunlin (Calidris alpina schinzii), breeding Favourable — 2005-03-31
F2 Moine Favourable — 2010-08-25
F3 Blanket bog Favourable — 2011-02-08

Climate exposure

This is about exposure to a nationwide pressure this habitat type carries — not a verdict on this site's own management.

Peatland

Peat habitats store centuries of carbon and depend on a stable, waterlogged water table. Warmer, drier summers dry out peat, making it far more vulnerable to wildfire and to carbon release — a pressure that can undo years of restoration work regardless of how well the site is otherwise managed.

Coastal

Coastal habitats are exposed to sea-level rise and storm erosion. Where hard sea defences sit behind them, there's nowhere landward to retreat to — a squeeze that keeps compressing the habitat no matter how well it's managed.

Habitats

Blanket bog

Geology & landscape

Landscape processes: Coastal, Peatland / Mire

Birds & fish recorded

Birds

SpeciesSeason
Arctic tern Breeding
dunlin Breeding
red-throated diver Breeding

Description

HASCOSAY Hascosay Site of Special Scientific Interest (SSSI) is located on a small island, situated in Colgrave Sound between Yell and Fetlar. Hascosay island is no longer inhabited but is still used for grazing. The island is also of importance for its geological features which contribute to the understanding of the geological evolution of Shetland and of the Caledonian Orogenic belt of Britain and Scandinavia. The island is situated on the boundary between the rocks of Yell to the west and Unst and Fetlar to the north and east. Yell is built of highly metamorphosed and migmatised metasedimentary gneisses (sedimentary rocks that have been highly altered and partially melted by intense heat and pressure) which may represent a basement to the major nappes of Unst and Fetlar. The relations of the Moine-like rocks of Yell to the Dalradian sequences of Unst and Fetlar have been interpreted as a ‘slide’ which can best be studied on the southern coast of Hascosay, on either side of Ramna Geo/Grey bearded Man. Hascosay contains some of the finest peatland in Shetland. The extent of gently undulating bryophyte-dominated mire surface is unusual anywhere in Britain. The presence of the bog moss Sphagnum fuscum in such conditions adds to the rarity of the community and confirms the relatively undamaged nature of the blanket bog. The low ridge margins to the pools which are composed of bryophytes but without Sphagnum are a particular feature of Shetland and the site displays these better than any other example recorded in the islands. Dunlin (Calidris alpina schinzii) breed on Hascosay in very high densities. Although populations of this species on small islands can fluctuate hugely, the dunlin on Hascosay remain at the highest density recorded anywhere in Shetland. Other breeding birds of note recorded on the island are red-throated diver (Gavia stellata), Arctic skua (Stercorarius parasiticus), great skua (Stercorarius skua) and Arctic tern (Sterna paradisaea).

Species mentioned

English name
search for this in other sites		 Latin name
search with Google		 IUCN / Red List Type Family
red-throated diver Gavia stellata LC (NonBreeding), LC (Breeding) bird-diver gaviidae
arctic skua Stercorarius parasiticus CR (Breeding) bird-skua stercorariidae
great skua Stercorarius skua VU (Breeding) bird-skua stercorariidae
Arctic tern Sterna paradisaea EN (Breeding) bird-tern laridae
dunlin Calidris alpina EN (NonBreeding) bird-wader scolopacidae
rusty bog moss Sphagnum fuscum LC moss sphagnales

Plant communities

M1 — Blanket bog, Raised bog

Sphagnum auriculatum bog pool community

Erica tetralix, Myrica gale, Carex limosa, Eriophorum angustifolium, Rhynchospora alba, Rhynchospora fusca, Trichophorum cespitosum, Eleocharis multicaulis, Juncus bulbosus, Sphagnum auriculatum, Sphagnum cuspidatum, Sphagnum fallax, Sphagnum magellanicum, Sphagnum palustre, Sphagnum papillosum, Sphagnum pulchrum, Sphagnum subnitens, Cladopodiella fluitans, Gymnocolea inflata, Ordontoschisma sphagni, Drosera anglica, Drosera intermedia, Drosera rotundifolia, Utricularia intermedia, Utricularia minor, Menyanthes trifoliata, Narthecium ossifragum, Potamogeton polygonifolius, Scheuchzeria palustris, Molinia caerulea

M2 — Blanket bog, Raised bog, Valley mire

Sphagnum cuspidatum/recurvum bog pool community

Empetrum nigrum subsp.nigrum, Calluna vulgaris, Erica tetralix, Myrica gale, Andromeda polifolia, Vaccinium oxycoccos, Carex canescens, Carex magellanica, Carex rostrata, Eriophorum angustifolium, Eriophorum vaginatum, Rhynchospora alba, Aulacomnium palustre, Polytrichum commune, Polytrichum strictum, Sphagnum cuspidatum, Sphagnum fallax, Sphagnum magellanicum, Sphagnum palustre, Sphagnum papillosum, Sphagnum pulchrum, Sphagnum tenellum, Cephalozia connivens, Cephalozia lunulifolia, Gymnocolea inflata, Mylia anomala, Ordontoschisma sphagni, Cladonia impexa, Cladonia uncialis, Drosera anglica, Drosera intermedia, Drosera rotundifolia, Menyanthes trifoliata, Narthecium ossifragum, Agrostis canina, Deschampsia flexuosa, Molinia caerulea

M3 — Blanket bog, Raised bog

Eriophorum angustifolium bog pool community

Empetrum nigrum subsp.nigrum, Erica tetralix, Eriophorum angustifolium, Eriophorum vaginatum, Campylopus brevipilus, Drepanocladus fluitans, Polytrichum commune, Sphagnum cuspidatum, Sphagnum fallax, Sphagnum papillosum, Gymnocolea inflata, Ordontoschisma sphagni, Drosera rotundifolia, Agrostis canina, Molinia caerulea

M15 — Blanket bog, Raised bog, Upland wet heath

Scirpus cespitosus-Erica tetralix wet heath

Empetrum nigrum subsp.nigrum, Calluna vulgaris, Erica cinerea, Erica tetralix, Myrica gale, Vaccinium myrtillus, Carex binervis, Carex demissa, Carex dioica, Carex echinata, Carex nigra, Carex panicea, Carex pilulifera, Carex pulicaris, Eriophorum angustifolium, Eriophorum vaginatum, Schoenus nigricans, Trichophorum cespitosum, Juncus acutiflorus, Juncus articulatus, Juncus bulbosus, Juncus conglomeratus, Juncus effusus, Juncus squarrosus, Luzula multiflora, Huperzia selago, Selaginella selaginoides, Aulacomnium palustre, Breutelia chrysocoma, Pohlia nutans, Campylopus atrovirens, Campylopus flexuosus, Dicranum scoparium, Leucobryum glaucum, Racomitrium lanuginosum, Hylocomium splendens, Hypnum cupressiforme, Hypnum jutlandicum, Plagiothecium undulatum, Pleurozium schreberi, Rhytidiadelphus loreus, Rhytidiadelphus squarrosus, Scorpidium revolvens, Scorpidium scorpioides, Polytrichum commune, Sphagnum auriculatum, Sphagnum capillifolium, Sphagnum compactum, Sphagnum fallax, Sphagnum palustre, Sphagnum papillosum, Sphagnum subnitens, Sphagnum tenellum, Calypogeia fissa, Calypogeia muelleriana, Diplophyllum albicans, Lophozia ventricosa, Ordontoschisma sphagni, Pleurozia purpurea, Aneura pinguis, Cladonia arbuscula, Cladonia chlorophaea, Cladonia coccifera, Cladonia impexa, Cladonia uncialis, Succisa pratensis, Drosera anglica, Drosera rotundifolia, Hypericum pulchrum, Triglochin palustre, Pinguicula vulgaris, Menyanthes trifoliata, Narthecium ossifragum, Dactylorhiza maculata, Euphrasia officinalis, Pedicularis palustris, Pedicularis sylvatica, Polygala serpyllifolia, Trientalis europaea, Potentilla erecta, Galium saxatile, Viola palustris, Agrostis canina, Agrostis capillaris, Agrostis stolonifera, Anthoxanthum odoratum, Danthonia decumbens, Deschampsia flexuosa, Festuca ovina, Festuca rubra, Festuca vivipara, Molinia caerulea, Nardus stricta, Blechnum spicant, Pteridium aquilinum

M17 — Blanket bog

Scirpus cespitosus-Eriophorum vaginatum blanket mire

Empetrum nigrum subsp.nigrum, Calluna vulgaris, Erica cinerea, Erica tetralix, Myrica gale, Vaccinium myrtillus, Carex demissa, Carex echinata, Carex nigra, Carex panicea, Eriophorum angustifolium, Eriophorum vaginatum, Rhynchospora alba, Schoenus nigricans, Trichophorum cespitosum, Juncus acutiflorus, Juncus squarrosus, Luzula multiflora, Huperzia selago, Aulacomnium palustre, Breutelia chrysocoma, Pohlia nutans, Campylopus atrovirens, Campylopus flexuosus, Campylopus setifolius, Campylopus shawii, Dicranum scoparium, Leucobryum glaucum, Racomitrium lanuginosum, Hylocomium splendens, Hypnum cupressiforme, Hypnum jutlandicum, Plagiothecium undulatum, Pleurozium schreberi, Rhytidiadelphus loreus, Rhytidiadelphus squarrosus, Polytrichum commune, Polytrichum strictum, Sphagnum auriculatum, Sphagnum capillifolium, Sphagnum cuspidatum, Sphagnum imbricatum, Sphagnum magellanicum, Sphagnum palustre, Sphagnum papillosum, Sphagnum strictum, Sphagnum subnitens, Sphagnum tenellum, Calypogeia fissa, Diplophyllum albicans, Kurzia pauciflora, Lophozia ventricosa, Mylia anomala, Mylia taylorii, Ordontoschisma sphagni, Pleurozia purpurea, Ptilidium ciliare, Scapania gracilis, Cladonia arbuscula, Cladonia coccifera, Cladonia impexa, Cladonia uncialis, Cornicularia aculeata, Drosera anglica, Drosera rotundifolia, Vaccinium vitis-idaea, Pinguicula vulgaris, Narthecium ossifragum, Pedicularis sylvatica, Polygala serpyllifolia, Potentilla erecta, Galium saxatile, Agrostis canina, Anthoxanthum odoratum, Deschampsia flexuosa, Festuca ovina, Molinia caerulea, Nardus stricta

M18 — Blanket bog, Raised bog

Erica tetralix-Sphagnum papillosum raised and blanket mire

Empetrum nigrum subsp.nigrum, Calluna vulgaris, Erica tetralix, Myrica gale, Andromeda polifolia, Vaccinium myrtillus, Vaccinium oxycoccos, Eriophorum angustifolium, Eriophorum vaginatum, Rhynchospora alba, Trichophorum cespitosum, Juncus squarrosus, Aulacomnium palustre, Pohlia nutans, Campylopus flexuosus, Dicranum scoparium, Racomitrium lanuginosum, Hypnum cupressiforme, Hypnum jutlandicum, Plagiothecium undulatum, Pleurozium schreberi, Rhytidiadelphus loreus, Polytrichum commune, Polytrichum strictum, Sphagnum capillifolium, Sphagnum cuspidatum, Sphagnum fallax, Sphagnum fuscum, Sphagnum magellanicum, Sphagnum palustre, Sphagnum papillosum, Sphagnum pulchrum, Sphagnum subnitens, Sphagnum tenellum, Calypogeia muelleriana, Cephalozia bicuspidata, Cephalozia connivens, Cladopodiella fluitans, Kurzia pauciflora, Lophozia ventricosa, Mylia anomala, Ordontoschisma sphagni, Hypogymnia physodes, Cladonia arbuscula, Cladonia gracilis, Cladonia impexa, Cladonia uncialis, Drosera anglica, Drosera rotundifolia, Vaccinium vitis-idaea, Narthecium ossifragum, Rubus chamaemorus, Deschampsia flexuosa, Molinia caerulea

M19 — Blanket bog, Raised bog

Calluna vulgaris-Eriophorum vaginatum blanket mire

Empetrum nigrum, Empetrum nigrum subsp.nigrum, Calluna vulgaris, Erica tetralix, Betula nana, Arctostaphylos alpinus, Vaccinium microcarpum, Vaccinium myrtillus, Vaccinium oxycoccos, Vaccinium uliginosum, Carex bigelowii, Carex binervis, Carex nigra, Eriophorum angustifolium, Eriophorum vaginatum, Trichophorum cespitosum, Juncus squarrosus, Luzula sylvatica, Huperzia selago, Aulacomnium palustre, Pohlia nutans, Campylopus flexuosus, Dicranum fuscescens, Dicranum majus, Dicranum scoparium, Racomitrium lanuginosum, Hylocomium splendens, Hypnum cupressiforme, Hypnum jutlandicum, Plagiothecium undulatum, Pleurozium schreberi, Rhytidiadelphus loreus, Rhytidiadelphus squarrosus, Polytrichastrum alpinum, Polytrichum commune, Polytrichum strictum, Sphagnum capillifolium, Sphagnum compactum, Sphagnum fallax, Sphagnum fuscum, Sphagnum palustre, Sphagnum papillosum, Sphagnum russowii, Sphagnum subnitens, Sphagnum tenellum, Barbilophozia floerkei, Calypogeia fissa, Calypogeia muelleriana, Calypogeia trichomanis, Cephalozia bicuspidata, Diplophyllum albicans, Kurzia pauciflora, Lophozia ventricosa, Mylia anomala, Mylia taylorii, Ordontoschisma sphagni, Ptilidium ciliare, Hypogymnia physodes, Cetraria islandica, Cladonia arbuscula, Cladonia bellidiflora, Cladonia coccifera, Cladonia floerkeana, Cladonia gracilis, Cladonia impexa, Cladonia squamosa, Cladonia tenuis, Cladonia uncialis, Cornicularia aculeata, Cornus suecica, Drosera rotundifolia, Vaccinium vitis-idaea, Pinguicula vulgaris, Narthecium ossifragum, Neottia cordata, Potentilla erecta, Rubus chamaemorus, Galium saxatile, Melanpyrum pratense, Deschampsia flexuosa, Festuca vivipara, Molinia caerulea, Nardus stricta, Blechnum spicant

M20 — Blanket bog, Raised bog, Valley mire

Eriophorum vaginatum blanket and raised mire

Empetrum nigrum subsp.nigrum, Calluna vulgaris, Vaccinium myrtillus, Carex bigelowii, Eriophorum angustifolium, Eriophorum vaginatum, Trichophorum cespitosum, Juncus squarrosus, Orthodontium lineare, Pohlia nutans, Campylopus flexuosus, Dicranum scoparium, Drepanocladus fluitans, Hypnum jutlandicum, Plagiothecium undulatum, Pleurozium schreberi, Polytrichum commune, Sphagnum capillifolium, Sphagnum fuscum, Sphagnum papillosum, Barbilophozia floerkei, Calypogeia muelleriana, Calypogeia trichomanis, Cephalozia bicuspidata, Cephaloziella hampeana, Diplophyllum albicans, Gymnocolea inflata, Kurzia pauciflora, Lophozia ventricosa, Mylia taylorii, Ptilidium ciliare, Cetraria islandica, Cladonia arbuscula, Cladonia chlorophaea, Cladonia coccifera, Cladonia floerkeana, Cladonia impexa, Cladonia squamosa, Cladonia uncialis, Cornicularia aculeata, Rubus chamaemorus, Deschampsia flexuosa, Festuca ovina

M25 — Blanket bog, Coastal floodplain grazing marsh, Lowland fen, Purple moor grass and rush pasture, Upland acid grassland

Molinia caerulea-Potentilla erecta mire

Salix cinerea, Calluna vulgaris, Erica tetralix, Myrica gale, Vaccinium oxycoccos, Ulex europaeus, Ulex gallii, Carex echinata, Carex flacca, Carex nigra, Carex panicea, Eriophorum angustifolium, Schoenus nigricans, Juncus acutiflorus, Juncus articulatus, Juncus effusus, Juncus subnodulosus, Luzula campestris, Luzula multiflora, Aulacomnium palustre, Pohlia nutans, Calliergon giganteum, Calliergonell cuspidatum, Hypnum jutlandicum, Kindbergia praelonga, Pleurozium schreberi, Pseudoscleropodium purum, Rhytidiadelphus squarrosus, Polytrichum commune, Sphagnum auriculatum, Sphagnum capillifolium, Sphagnum fallax, Sphagnum palustre, Sphagnum papillosum, Sphagnum subnitens, Calypogeia fissa, Cephalozia bicuspidata, Lophocolea bidentata, Lophozia ventricosa, Angelica sylvestris, Carum verticillatum, Hydrocotyle vulgaris, Achillea ptarmica, Centaurea nigra, Cirsium palustre, Eupatorium cannabinum, Pulicaria dysenterica, Serratula tinctoria, Cardamine pratensis, Lobelia urens, Succisa pratensis, Valeriana officinalis, Equisetum palustre, Lotus pedunculatus, Hypericum pulchrum, Hypericum tetrapterum, Mentha aquatica, Scutellaria minor, Menyanthes trifoliata, Narthecium ossifragum, Epilobium palustre, Dactylorhiza maculata, Rumex acetosa, Ranunculus acris, Ranunculus flammula, Filipendula ulmaria, Potentilla erecta, Rubus fruticosus agg., Galium palustre, Viola palustris, Agrostis canina, Agrostis capillaris, Agrostis curtisii, Agrostis stolonifera, Anthoxanthum odoratum, Danthonia decumbens, Deschampsia cespitosa, Festuca ovina, Festuca rubra, Holcus lanatus, Molinia caerulea, Nardus stricta, Phragmites australis, Dryopteris carthusiana, Osmunda regalis