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NATURE AND ENVIRONMENT
Highland Bio-diversity
HIGHLAND BIODIVERSITY Framework Document
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A Draft Framework for Biodiversity in Highland |
COASTS AND FIRTHS
9.1 Highland’s coasts are wonders of natural beauty, and vary from storm-torn seacliff to sheltered sea loch. Unlike much of the rest of the UK coast, Highland’s coasts are relatively unmodified, and have a high value not only for biodiversity, but also in terms of landscape, recreation, enjoyment and also grazing in the case of machair. Coastal areas have a key role in tourism and recreation, with many visitors coming to Scotland specifically to enjoy its coast. This is despite the low profile given to the coast in marketing for tourism, such that the potential is probably far greater. The biodiversity resource: key habitats and species in Highland
9.2 Highland has a long and varied coastline, which supports the whole range of coastal BAP habitats. It is important to note the interdependency of many coastal habitats, such that impacts on one cause knock-on effects on another. For example mudflats depend on soft coasts and salt marshes for the replenishment of sediments, and mudflats also dissipate wave energy, which prevents salt marsh erosion.
9.3 Machair grasslands are found on areas of wind-blown sand, with Scotland having two-thirds of the global resource. The most extensive areas are on the Western Isles, Tiree and Orkney. Highland is the next most significant area, supporting machair in the crofting areas of Sutherland and possibly elsewhere on the west coast. Machair is highly dependent on the traditional system of small scale rotation and low input agriculture and supports diverse plants, high densities of breeding waders, corncrakes, and various insects including the great yellow bumble bee. Whilst of importance, machair systems in Highland are comparatively small, and do not develop the range of habitats and species seen in the islands.
9.4 Coastal saltmarsh is a restricted habitat by its nature, as it mostly occurs in a narrow zone at the top of intertidal mudflats and fringing shores of firths, but in the UK as a whole it has also suffered great losses through land claim. North west Highland is the stronghold for one particular type of saltmarsh (Turf fucoid saltmarsh), for which Highland therefore has particular responsibility. There is also another very restricted type which occurs in the Inner Moray Firth. There are also two examples of cliff top saltings, which are found in only about fifteen places in Scotland and not in the rest of the UK. These are in north Sutherland. Highland has some particularly good examples of transitions from saltmarsh to freshwater habitats, notably at Loch Fleet in Sutherland, which has the best example in the UK of a saline alderwood at the Mound.
9.5 The highest cliffs on mainland Britain are at Clo Mor in Sutherland, with the rest of the north and west coast of Highland having a significant proportion of the UK resource. Steep cliffs are perhaps the most natural environment in the UK, with specialised vegetation and internationally important seabird breeding colonies. The degree of exposure often replicates upland conditions, such that arctic-alpine plants are found at sea level. The best example in the UK of this altitudinal variation is at Invernaver in Sutherland.
9.6 In terms of the range of variation and the size of the systems, Highland is probably the most significant area of Scotland for sand dunes. The best lichen-rich sand dunes in Scotland occur in the Moray Firth.
9.7 Coastal vegetated shingle occurs in a variety of landforms, the commonest being a narrow fringing deposit. The majority of the UK’s shingle occurs in England and Wales. Within Scotland, Argyll, the Solway and Spey Bay have the majority of the resource. Highland is relatively less significant, but there are locally important areas in the Firths, in east Sutherland and in association with sand dune systems.
9.8 Coastal grazing marsh is land that was previously saltmarsh, which is separated from the sea by an embankment and which is periodically flooded with freshwater. There are not thought to be any examples of this in Highland.
9.9 Highland is particularly important for maritime heath, which is a mosaic of species rich grassland and dwarf shrub heath, with distinctive maritime plants such as spring squill and Scottish primrose. Scottish primrose is restricted globally to Highland and Orkney. The majority of the Scottish resource of maritime heath occurs in Highland and Orkney, and in Highland it is concentrated in North Caithness and North Sutherland.
9.10 Also of particular note in Highland, are the only two examples in Britain of coastal juniper scrub. These are at Morrich Mhor and Invernaver.
9.11 Seagrass beds occur in intertidal and shallow subtidal areas, usually in sheltered situations such as estuaries, shallow inlets and lagoons, where they form dense beds. The plants of eel grass and tasselweed stabilise the substratum, provide protection from wave action for other coastal habitats, are an important source of organic matter, and provide shelter and a surface for attachment by other species, including the young stages of commercially important fish and crustaceans. Eelgrass is an important source of food for wildfowl. The Cromarty Firth supports probably the largest total area of dwarf eelgrass and narrow leaved eelgrass in Britain (approx 1200 ha). The Moray Firth is another nationally important site.
9.12 Saline lagoons are expanses of coastal water of varying salinity, which are wholly or partially separated from the sea. They are widespread globally but very restricted in Europe. Scotland has 139 examples, of which the majority are in the Outer Hebrides and the Northern Isles. 15 are in Highland.
9.13 Mudflats are found in sheltered intertidal areas, particularly estuaries. They have a high productivity, but low biodiversity. However they provide feeding and resting areas for internationally important numbers of wintering and migratory waterfowl, and are also important nursery areas for flatfish. Although a widespread habitat, the UK extent of the resource has been dramatically reduced by land claim for development. 9.14 Sheltered muddy gravels also occur in estuaries, rias and sea lochs, in areas protected from strong wave action. The habitat is most diverse in the more saline conditions of the lower shore. Good examples of this habitat are rare, but the Sound of Arisaig is a notable location, having high and relatively constant salinity. Here the muddy gravels support an important and diverse community of burrowing animals (for example burrowing anenomes, as well as animals attached to pebbles (for example molluscs). The native oyster (a UK BAP species) is sometimes present in this habitat. 9.15 Tidal rapids are high energy environments resulting from a constriction in the coast line, such as at the entrance to the deep sea lochs of the west coast. These are linked to the sea by narrow rock sills, over which the tide flows. The tidal flow constantly replenishes the food resource, such that the marine communities are very diverse. There are abundant animals fixed on or in the seabed, including soft corals, sponges, mussels and anemones. In shallower waters are kelp and seaweeds characteristic of tide-swept areas. There are good examples at Loch Alsh and the Sound of Arisaig.
9.16 Habitats classified as UK BAP priority habitats which occur in Highland *indicates habitat discussed in another section · Machair · Coastal saltmarsh · Coastal sand dunes · Coastal vegetated shingle · Maritime cliff and slope · Lowland heath (includes maritime heath)* · Mudflats · Reedbeds* · Saline lagoons · Sheltered muddy gravels · Tidal rapids
9.17 Priority BAP species recorded in Highland associated with the coast · Otter, reed bunting · Saltmarsh: endemic eyebright, sea bryum moss, lesser bearded stonewort · Maritime cliff and slope: endemic eyebrights. · Saline lagoons: lagoon seaslug (Tenellia adspersa)? · Sand dunes: lesser bearded stonewort? · Coastal juniper: scrub on the Morrich Mhoir and at Invernaver.
9.18 Some other species of conservation interest White-tailed sea eagle, common seals, grey seals, Scottish primrose, Corynephorus canescens (a coastal grass in Achaidh Mhoir and Sands of Morar, Lochaber, probably introduced), Eleocharis parvula (a grass, Cromarty Firth), oyster plant (Mertensia maritima), purple oxytropis (Oxytropis halleri), Carex maritima (sedge)and Equisetum variegatum (horsetail), Carex recta (sedge, tidal sections of estuaries).
9.19 Key biodiversity objectives for coasts and firths · To maintain and where possible enhance and restore the biodiversity of coastal habitats and species. · To maintain the natural dynamics of coastal processes wherever possible. · To ensure sustainable use of the coastal resource through the promotion of integrated coastal planning. · To promote enjoyment and understanding of the coast, within the carrying capacity of the resource.
(see also those in section on the Seas) · Climate change is most significant issue. Sea level rise anticipated as a result of global warming. Low lying coasts most likely to be affected. On or near soft coasts will cause reworking of coastal sediments; generally outer firths will lose sediments and inner firths will gain sediments. Salt marshes will move inland, where topography and land-use permit. · Climate change likely to increase both storm intensity and frequency, leading to coastal erosion. Already pressure for improvements to coastal defences. · Inadequate planning to assess impact of climate change both on the natural heritage and on man made environment. Some modelling been carried out in England using airborne radar to assist mapping. · Highland has more natural coast than much of mainland Scotland. In some areas artificial constraints to natural processes include sea defences, recreational use, agricultural use. · Ongoing developments for oil and gas industry, other built development, fish farming, coastal recreation cause land claim, disturbance to wildlife, pollution. Significant EU investment in new coastal infrastructure eg roads, bridges, piers. · Agricultural improvement has resulted in alteration or loss of coastal habitats. See Farmlands section for trends in crofting land which affect machair. · Increasing demand for clean beaches has lead to increases in use of mechanical beach-cleaning machinery- damage to fauna, upsets natural processes. “Blue flag” standard demands use of machinery. · Extraction of sand and shingle, often for agricultural use under permitted development rights. Can cause erosion and loss of vegetation. This needs to be more clearly flagged up in relation to climate change. · Coast is a key recreation resource, great benefit to tourism industry. Highland tends to be marketed for its mountains rather than its coast however. Great marketing potential. Rising demand for green tourism. Seabirds and cliffs key asset. · Recreational pressure a potential issue for sand dunes, needing careful management, with disturbance and localised erosion a problem in the past in some areas ( Achmelvich and Clachtoll). Some dunes affected by golf courses, also habitat loss. Spread of scrub not a problem on Highland sand dunes, generally do not need intervention. Caravan sites on sand dunes been an issue in the past, but no known current proposals. · Key issue for salt marshes is grazing pressure. Many salt marshes are designated, but management agreements needed to ensure appropriate grazing level continues. · Key issue for Lowland/maritime heath is grazing levels. Work on Hoy established that enhancement of both agricultural viability and biodiversity interest possible by varying the shepherding. No additional costs. May be applicable elsewhere. · Seagrass beds vulnerable to wasting disease caused by slime mould, not occurred recently, environmental stress likely to weaken resistance to it. Most at risk from land claim, increases in turbidity, nitrate concentrations, oil, oil dispersants. · Coastal water quality improving, as effluent loading on marine environment has been reducing. Sewage dumping at sea now eliminated. Water quality will be improved further by various EC Directives including the Water Framework Directive. · Greatest pollution problems now from diffuse sources such as agriculture. Further improvements likely with integration of range of water related/pollution control legislation under EU Water Framework Directive. · Sand and shingle systems and maritime heath identified as key habitats for action.
9.21 Current mechanisms for promoting biodiversity · Moray Firth Partnership · Cromarty Firth Liason Group · Rural Stewardship Scheme. · Minch Project (recently finished) · Special Areas for Conservation, other statutory conservation designations, SNH management agreements, SNH grants, nature reserve management.
· See those for farmlands which encompass machair. · “Blue flag” beach status currently demands mechanical rubbish clearance. Amend regulation to allow hand picking of rubbish. · Review the guidance to local authorities on managing recreation on sand dunes. · Promote integrated coastal management, including production of shoreline management plans. · Planning for climate change.
9.23 Potential practical opportunities for enhancing biodiversity and its sustainable use · Promote greater enjoyment and understanding of the coast. · Market the coast of Highland as a visitor resource. · Promote grazing methods used for maritime heath on Hoy. · Interpretation of traditional farming/crofting practices. · Interpretation of archaeological remains and links with the environment in coastal areas. · Schools project looking at bumble bees. · Encourage wider support for and recognition of importance of small scale agricultural units, also encourage use of vacant and under-utilised crofts. · Encourage appropriate grazing levels for individual units based on their carrying capacity and their ability to produce home-grown feeds and proportion of species rich grasslands. · Promote grazing methods used for maritime heath on Hoy. · Encourage use of cattle where appropriate and native breeds with local wintering using locally grown fodder. · Machair projects. · Monitoring of dynamic change to coast. · Local management of areas- Local Nature Reserves? · Integrate databases. · Look at whole river/ sealoch systems and their management- demonstrate benefits of integrated management, establish monitoring base.. · Sand dunes- identify areas which demonstrate dynamic processes.
9.24 Survey/Research information and requirements · Comprehensive surveys exist of sand dunes, machair and saline lagoons. Incomplete survey of salt marshes. · Survey of sea cliffs (high priority) and shingle needed.
9.25 Sources of Further Information Coastal Cells in Scotland HR Wallingford 2000 (look at coastal erosion) Guide to managing coastal erosion in beach/dune systems SNH 2000 |