European Site Conservation Objectives: Supplementary advice on conserving and restoring site features
River Derwent and Bassenthwaite Lake Special Area of Conservation (SAC) Site Code: UK0030032
Photo: Bassenthwaite Lake, Natural England, Peter Wakely, 1996.
Date of Publication: 7 February 2019
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About this document
This document provides Natural England’s supplementary advice about the European Site Conservation Objectives relating to River Derwent and Bassenthwaite Lake SAC.
This advice should therefore be read together with the SAC Conservation Objectives available here:
Where this site overlaps with other European Site(s), you should also refer to the separate European Site Conservation Objectives and Supplementary Advice (where available) provided for those sites.
You should use the Conservation Objectives, this Supplementary Advice and any case-specific advice given by Natural England when developing, proposing or assessing an activity, plan or project that may affect this site.
The tables provided below bring together the findings of the best available scientific evidence relating to the site’s qualifying features, which may be updated or supplemented in further publications from Natural England and other sources. The local evidence used in preparing this supplementary advice has been cited. The references to the national evidence used are available on request. Where evidence and references have not been indicated, Natural England has applied ecological knowledge and expert judgement. You may decide to use other additional sources of information.
This Supplementary Advice to the Conservation Objectives presents attributes which are ecological characteristics of the designated species and habitats within a site. The listed attributes are considered to be those that best describe the site’s ecological integrity and which, if safeguarded, will enable achievement of the Conservation Objectives. Each attribute has a target which is either quantified or qualitative depending on the available evidence. The target identifies as far as possible the desired state to be achieved for the attribute.
In many cases, the attribute targets shown in the tables indicate whether the current objective is to ‘maintain’ or ‘restore’ the attribute. This is based on the best available information, including that gathered during monitoring of the feature’s current condition. As new information on feature condition becomes available, this will be added so that the advice remains up to date.
The targets given for each attribute do not represent thresholds to assess the significance of any given impact in Habitats Regulations Assessments. You will need to assess this on a case-by-case basis using the most current information available.
Some, but not all, of these attributes can also be used for regular monitoring of the actual condition of the designated features. The attributes selected for monitoring the features, and the standards used to assess their condition, are listed in separate monitoring documents, which will be available from Natural England.
These tables do not give advice about SSSI features or other legally protected species which may also be present within the European Site.
If you have any comments or queries about this Supplementary Advice document please contact your local Natural England adviser or email [email protected]
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About this site
European Site information
Name of European Site River Derwent & Bassenthwaite Lake Special Area of Conservation (SAC)
Location Cumbria
Site Map The designated boundary of this site can be viewed here on the MAGIC website
Designation Date 1st April 2005
Qualifying Features See section below
Designation Area 1832.96 ha
Designation Changes None
Feature Condition Status Details of the feature condition assessments made at this site can be found using Natural England’s Designated Sites System
Names of component River Derwent and Tributaries SSSI; Bassenthwaite Lake SSSI; Sites of Special Scientific Braithwaite Moss SSSI; Buttermere SSSI Interest (SSSIs)
Relationship with other The boundary of this SAC is adjacent to the following sites European or International Lake District High Fells SAC Site designations Borrowdale Woodland SAC North Pennine Dales Meadows SAC.
Site background and geography
The Derwent is a large nutrient poor (oligotrophic) river system within the West Cumbria Coastal Plain National Character Area (NCA Profile 07) and the Cumbria High Fells National Character Area (NCA Profile 08), with high water quality and a natural channel. There is a natural succession of plant communities from source to mouth reflecting a slight increase in nutrient status downstream. The Derwent flows through two lakes (Derwent Water and Bassenthwaite), as does its major tributary the Cocker (Buttermere and Crummock Water). These lakes have a hydrological buffering effect which helps stabilise the flow regimes.
Derwent Water is the broadest and shallowest of the major Cumbrian lakes. The aquatic flora is indicative of a relatively low level, nutrient poor (oligotrophic/mesotrophic) lake. Derwent Water and Bassenthwaite Lake have healthy populations of floating water-plantain Luronium natans in extensive, species-rich beds of aquatic macrophytes. The fish fauna includes vendace, England’s rarest fish.
Bassenthwaite is a large lake with an extensive catchment and consequently is subject to rapid through- flow of water and moderate nutrient status (mesotrophic), and a diverse flora. The shorelines are long and relatively undisturbed compared with other major Cumbrian lakes. The fish fauna includes vendace, England’s rarest fish. Bassenthwaite Lake is also designated as an NNR:
Buttermere is one of the best examples in the Lake District of an oligotrophic (nutrient-poor) lake. It lies on the Skiddaw Slate but its water catchment, like Wastwater, is predominantly on Borrowdale Volcanic rocks. Buttermere is fed and drained by the River Cocker. It is one of the lakes that has been least affected by man. The fish fauna includes Arctic charr, a member of the trout and salmon family which in Page 3 of 79
England is found only in the Lake District. It is an important relic species as it is believed that the population within each particular lake was isolated in that locality after the last Ice Age.
Crummock Water is an oligotrophic lake situated in the same glacial valley as Buttermere. It is a natural lake with a man-made weir at the outlet to provide artificial storage for water supply purposes. The fish fauna includes Arctic charr.
The River Cocker differs from the main river in being smaller with a more stable flow regime and channel substrates. The stable flows enable a rich and varied flora.
Braithwaite Moss, on the flood plain area to the south of Bassenthwaite Lake, supports marsh fritillary butterflies Euphydryas aurinia. It comprises areas of marshy grassland and rushy pasture intimately mixed with smaller areas of woodland and scrub. Devil’s-bit scabious Succisa pratensis, the larval food plant, is found throughout the site.
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About the qualifying features of the SAC
The following section gives you additional, site-specific information about this SAC’s qualifying features. These are the natural habitats and/or species for which this SAC has been designated.
Qualifying habitats:
• H3130 Oligotrophic to mesotrophic standing waters with vegetation of the Littorelletea uniflorae and/or of the Isoëto-Nanojuncetea; Clear-water lakes or lochs with aquatic vegetation and poor to moderate nutrient levels
In the UK, this freshwater habitat is represented in the north and west by lakes with low to moderate nutrient levels. These waters are often vulnerable to acid deposition and nutrient enrichment. Shoreweed Littorella uniflora and water lobelia Lobelia dortmanna are characteristic of shallow lake areas. In deeper water alternate water-milfoil Myriophyllum alterniflorum, and quillworts Isoetes species are found. These lakes usually have healthy salmonid fish populations. Brown trout Salmo trutta are common, although in some lakes species such as arctic charr Salvelinus alpinus (Crummock Water), whitefish Coregonus lavaretus or vendace Coregonus albula (Derwent Water and Bassenthwaite Lake) also occur.
The River Derwent and Bassenthwaite lake SAC contains four of the 12 major lakes of the Lake District, Derwent Water, Bassenthwaite Lake (SSSI), Crummock Water, and Buttermere (SSSI).
Derwent Water is the broadest and shallowest of the major Cumbrian lakes. The aquatic flora is indicative of a relatively low level, nutrient poor (oligotrophic/mesotrophic) lake. Derwent Water and Bassenthwaite Lake have healthy populations of floating water-plantain Luronium natans in extensive, species-rich beds of aquatic macrophytes. In Bassenthwaite Lake it also occurs on muddy lake-shores.
Bassenthwaite Lake is the fourth largest in the Lake District, and the shallowest. These factors combined with an extensive catchment make it subject to a rapid through-flow of water and moderate nutrient status (mesotrophic). It has a relatively undisturbed shoreline and diverse fringing habitats (reedswamp, fen, flood-plain fen, wet grassland, willow scrub and alder woodland). A wide variety of pondweeds Potamogeton spp. are found, including perfoliate pondweed Potamogeton perfoliatus, small pondweed P. berchtoldii and curled pondweed P. crispus, which are widespread, whilst red pondweed P. alpinus, various-leaved pondweed P. gramineus and lesser pondweed P. pusillus are more locally distributed. Uncommon species present in the community are autumnal water-starwort Callitriche hermaphroditica and six-stamened waterwort Elatine hexandra. Much of the shore is of shingle or gravel, but soft peat has accumulated around Bowness Bay. Several sedge species are found in such areas, including a local northern species, water sedge Carex aquatilis. On stony shores common spike-rush Eleocharis palustris is locally abundant amongst species such as globeflower Trollius europaeus, saw-wort Serratula tinctoria and the nationally rare thread rush Juncus filiformis. The lake supports one of only two populations of a rare fish, the vendace, known in Britain, the other being in Derwent Water (in the same catchment).
Bassenthwaite has considerable ornithological interest. The food from an abundance of water plants, sheer size of the lake and diverse fringing habitats support a varied bird fauna. Over 70 breeding species have been recorded around the lake including: little grebe, red-breasted merganser, mute swan and the locally uncommon great crested grebe; sandpipers, sedge warbler, willow warbler and redpoll, reed bunting, grasshopper warbler, redshank, snipe and lapwing. Significant numbers of birds come to the lake in winter to roost and feed. Over 2,000 birds may be present at one time. Species recorded include teal, widgeon, goldeneye, tufted duck and mallard.
Buttermere is one of the best examples in the Lake District of an oligotrophic lake. It lies on the Skiddaw Slate but its water catchment is predominantly on Borrowdale Volcanic rocks. Buttermere is fed and drained by the River Cocker. It is one of the lakes that has been least affected by man, with few people living in the catchment and with negligible water abstraction. As such the lake is an important extant example of this once more typical situation. The shoreline is generally stony but in places maintains vegetation typical of the lakes oligotrophic status. This vegetation consists of a belt of shoreweed Littorella uniflora, common spikerush Eleocharis palustris and reed canary-grass Phalaris arundinacea in Page 5 of 79 shallow water at the lake margin. Beds of quillwort Isoetes lacustris, bulbous rush Juncus bulbosus var. fluitans, alternate water-milfoil Myriophyllum alterniflorum, water lobelia Lobelia dortmanna and, more notably, intermediate water-starwort Callitriche hamulata occur in water to about 3 m depth. The fish fauna includes charr, a member of the trout and salmon family which in England is found only in the Lake District. It is an important relic species as it is believed that the population within each particular lake was isolated in that locality after the last Ice Age. Other fish species include perch, pike, three-spined stickleback, brown trout, eel and salmon. The lake invertebrate fauna is typical of oligotrophic conditions but the great diversity of water fleas, Cladocera, is of special interest.
Crummock Water is an oligotrophic (nutrient-poor) lake with Arctic charr Salvelinus alpinus, which only occur in the Lake District in England. It requires deep cool waters and clean marginal gravels for spawning.
• H3260 Water courses of plain to montane levels with the Ranunculion fluitantis and Callitricho-Batrachion vegetation; Rivers with floating vegetation often dominated by water-crowfoot
Rivers that support characteristic communities of water-crowfoot Ranunculus species, which often dominate the plant community in the river channel. This vegetation occurs in relatively unpolluted waters, in a diverse range of river types. The River Derwent is the finest large oligotrophic river system in England, a watercourse of plain to montane levels with the Ranunculion fluitantis and Callitricho- Batrachion vegetation. This low nutrient status is reflected in the abundance of bryophytes and the absence of aquatic species typical of more nutrient-rich environments.
Qualifying Species:
• S1065 Marsh fritillary butterfly Euphydryas (Eurodryas, Hypodryas) aurinia
The marsh fritillary butterfly Euphydryas aurinia is found in a range of habitats in which its larval food plant, devil’s-bit scabious Succisa pratensis, occurs. Marsh fritillaries are essentially grassland butterflies in the UK, and although populations may occur occasionally on wet heath, bog margins and woodland clearings, most colonies are found in damp acidic or dry calcareous grasslands. In Northern Ireland it occurs in fens and on sand dunes. Management in both wet and dry situations is predominantly by low- intensity cattle or pony grazing. Sheep selectively graze devil’s-bit scabious and are therefore detrimental to marsh fritillary populations, except at very low stocking rates. Burning and mowing are also known to have caused the extinction of populations.
Populations of marsh fritillary vary greatly in size from year to year, and, at least in part, this is related to cycles of attack from parasitic wasps. Adults tend to be sedentary and remain in a series of linked metapopulations, forming numerous temporary sub-populations, which frequently die out and recolonise. Where unable to do this, populations do not seem to be able to persist in habitat fragments. It is therefore essential to conserve a cluster of sites in close proximity.
Euphydryas aurinia has declined dramatically in Europe and is regarded as endangered or vulnerable in most of its European range. On the basis of existing knowledge, the UK and Spain constitute the European strongholds for this species. It is a fully protected species listed on Schedule 5 of the Wildlife and Countryside Act 1981, and has been afforded special protection due to its rarity on a European scale and has been listed under Appendix II of the Bern Convention and Annex II of the EC Habitats Directive.
Braithwaite Moss is notified for its breeding population of Eurodryas aurinia. Due to changes in agricultural practices, 50% of marsh fritillary breeding sites have been lost in Cumbria in the past 20 years, while nationally the population is decreasing by 10% every decade. The site mainly comprises areas of marshy grassland and rushy pasture intimately mixed with smaller areas of woodland and scrub. Devil's-bit scabious Succisa pratensis, the larval food plant for the marsh fritillary, is found throughout the site, and most abundant in the eastern half. The adult butterflies feed on nectar provided by flowers in the species rich grassland. Marsh fritillaries are weak fliers and so benefit from the shelter
Page 6 of 79 provided by the shrubs and areas of woodland that are present. Structural diversity is also important in the grassland for the provision of suitable larval web sites.
The marsh fritillary butterfly for which the site were notified became extinct at this site in 2004 and is the subject of a reintroduction programme. http://www.cumbria- butterflies.org.uk/conservation/marsh_fritillary/.
This site supports the largest area of appropriate habitat, M25 Molinia caerulea – Potentilla erecta mire, in Cumbria. The marsh fritillary population is spread over four habitat patches where numbers fluctuate annually but collectively form a moderate-sized and stable population.
Euphydryas aurinia is also a designated feature of the Cumbrian Marsh Fritillary Site SAC - UK0030126.
• S1095 Sea lamprey Petromyzon marinus
This is a primitive, jawless fish resembling an eel. It is the largest of the lampreys found in the UK. It inhabits North Atlantic coastal waters, estuaries and easily accessible rivers, and is an anadromous species (i.e. spawning in freshwater but completing its life cycle in the sea). Like the other species of lamprey, sea lampreys need clean gravel for spawning, and marginal silt or sand for the burrowing juvenile ammocoetes. Sea lampreys have a preference for warm waters in which to spawn. Features such as weirs and dams, as well as polluted sections of river, may impede migration to spawning grounds. In comparison to River lamprey Lampetra fluviatilis, sea lampreys seem to be relatively poor at ascending obstacles to migration, and are frequently restricted to the lower reaches of rivers.
It has a widespread distribution within the UK, although populations have declined due to pollution and barriers to migration. The Derwent represents sea lamprey in a high-quality oligotrophic river in northern England. The extensive occurrence of gravels and silts in the middle to lower reaches of this river means that it is able to support a large population.
• S1096 Brook lamprey Lampetra planeri
The brook lamprey is a primitive, jawless fish resembling an eel and is the smallest of the lampreys found in the UK. It is a non-migratory species, living entirely in fresh water and occurring over most of the UK in streams and occasionally in lakes. Like other lamprey species, the brook lamprey requires clean gravel beds for spawning and soft marginal silt or sand for the ammocoete larvae.
The Derwent represents brook lamprey in a high-quality, oligotrophic river in northern England. Good populations of the species are known to occur, and this river has features that provide the necessary conditions for both spawning and nursery areas – extensive gravel shoals, good water quality and areas of marginal silt.
• S1099 River lamprey Lampetra fluviatilis
The river lamprey is a primitive, jawless fish resembling an eel. Confined to western Europe, it is found in coastal waters, estuaries and accessible rivers. This species is normally anadromous and migrates from the sea to spawn in silt beds of many rivers in the UK. One population in the UK (Scotland) is, however, known to live entirely in freshwater, and therefore one of a few land-locked populations, seen as having special European importance. The river lamprey is absent from some rivers because of pollution and barriers to migration.
The Derwent represents river lamprey in an oligotrophic river in northern England. Good numbers of this species are known to occur and this river has features that provide the necessary conditions for both spawning and nursery areas – extensive gravel shoals, good water quality and areas of marginal silt.
• S1106. Atlantic salmon Salmo salar
The Atlantic salmon is the largest of our migratory fish and spawns in the least polluted rivers of north- west Europe. It is an anadromous species (i.e. adults migrate from the sea to breed in freshwater). Page 7 of 79
Spawning takes place in shallow excavations called redds, found in shallow gravelly areas in clean rivers and streams where the water flows swiftly. The young that emerge spread out into other parts of the river. After a period of 1-6 years the young salmon migrate downstream to the sea as ‘smolts’. Salmon have a homing instinct that draws them back to spawn in the river of their birth after 1-3 years in the sea. This behaviour has resulted in genetically distinct stock between rivers and even within individual rivers, with some evidence of further genetic distinctiveness in the tributaries of large rivers. It has declined due to over-fishing at sea, pollution and barriers to migration within its spawning rivers. The UK supports a large proportion of the salmon population in the European Union.
The Derwent represents Atlantic salmon populations in north-west England and is a particularly good example of a large oligotrophic river flowing over base-poor geology, providing a contrast to the more mesotrophic River Eden. Low intensity land-use in the catchment means there is good water quality throughout much of the system. This water quality, coupled with the presence of extensive gravel shoals, makes it a particularly suitable river for breeding and enables it to support a large population.
• S1355 Otter Lutra lutra
Otters are semi-aquatic mammals, requiring both good fishing grounds for food and suitable shelter on land for resting and breeding. Once widespread in Europe, the otter population declined sharply during the 1960s and 1970s. It is now showing signs of recovery in the UK and is spreading to repopulate its former areas. The UK, and in particular Scotland, supports some of the largest concentrations of otters in Europe, with both freshwater and coastal populations. It occurs in a wide range of ecological conditions, including inland freshwater and coastal areas (particularly in Scotland). Populations in coastal areas utilise shallow, inshore marine areas for feeding but also require fresh water for bathing and terrestrial areas for resting and breeding holts. Coastal otter habitat ranges from sheltered wooded inlets to more open, low-lying coasts. Inland populations utilise a range of running and standing freshwaters. These must have an abundant supply of food (normally associated with high water quality), together with suitable habitat, such as vegetated river banks, islands, reedbeds and woodland, which are used for foraging, breeding and resting.
The River Derwent and Bassenthwaite Lake represent good quality otter habitat in north-west England. Together, the lake and river represent a wide range of suitable conditions for otters in a relatively upland environment.
• S1831 Floating water-plantain Luronium natans
Floating water-plantain is a rare, small, white-flowered water plant only found in Europe. In the UK it is considered a nationally scarce plant. It is found in Wales and central and northern England, growing in lakes, reservoirs, ponds, slow-flowing rivers and canals. Floating water-plantain occurs as two forms: in shallow water with floating oval leaves, and in deep water with submerged rosettes of narrow leaves.
This site represents the northern limit of floating water-plantain in the UK, and its occurrence in relatively shallow, oligo-mesotrophic lakes. Within the site, the species is found in two lakes, Derwent Water and Bassenthwaite Lake. Both of these lakes have healthy populations of the species in extensive, species- rich beds of aquatic macrophytes. In Bassenthwaite Lake it also occurs on muddy lake-shores. These are the only two known sites for Luronium in the Lake District
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Table 1: Supplementary Advice for Qualifying Features: H3130. Oligotrophic to mesotrophic standing waters with vegetation of the Littorelletea uniflorae and/or of the Isoëto-Nanojuncetea; Clear-water lakes or lochs with aquatic vegetation and poor to moderate nutrient levels
Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
Extent and Extent of the Maintain the total extent of the There should be no measurable reduction (excluding any trivial Natura 2000 Standard data entry distribution feature within feature at 1585.72 hectares. loss) in the extent and area of this feature, and in some cases, form of the feature the site the full extent of the feature may need to be restored.
The baseline-value of extent given has been generated using data gathered from the listed site-based surveys. Area measurements given may be approximate depending on the methods, age and accuracy of data collection, and as a result this value may be updated in future to reflect more accurate information.
The extent of an Annex I habitat feature covers the sum extent of all of the component vegetation communities present and may include transitions and mosaics with other closely- associated habitat features. Where a feature is susceptible to natural dynamic processes, there may be acceptable variations in its extent through natural fluctuations.
Where a reduction in the extent of a feature is considered necessary to meet the Conservation Objective for another Annex I feature, Natural England will advise on this on a case- by-case basis. Extent and Spatial Maintain the distribution and A contraction in the range, or geographic spread, of the feature distribution distribution of configuration of the feature, (and its component vegetation and typical species, plus of the feature the feature including where applicable its transitional communities) across the site will reduce its overall within the site component vegetation types, area, the local diversity and variations in its structure and across the site composition, and may undermine its resilience to adapt to future environmental changes.
This may also reduce and break up the continuity of a habitat within a site and how well its typical species are able to move around the site to occupy and use habitat. Such fragmentation can impact on their viability and the wider ecological composition of the Annex I habitat. Smaller fragments of habitat can typically support smaller and more isolated populations which are more vulnerable to extinction. These fragments also
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
have a greater amount of open edge habitat which will differ in the amount of light, temperature, wind, and even noise that it receives compared to its interior.
These conditions may not be suitable for some of the typical and more specialist species associated with the Annex I habitat feature. Structure and Invasive, non- Non-native species categorised Non-native species constitute a major threat to many open Maberly et al., 2016 function native and/or as 'high-impact' in the UK under water systems. Impacts may be on the habitat itself (e.g. (including its introduced the Water Framework Directive damage to banks and consequent siltation) or directly on Derwent Water: Halliday, 1997; typical species should be either rare or absent characteristic biota (through predation, competition and Darwell, 2001 species) but if present are causing disease), or a combination of these. For example, species such minimal damage to the feature as signal crayfish have been responsible for much of the Bassenthwaite Lake: Thackeray decline of native crayfish through competition, habitat damage et al., 2004 and the introduction of crayfish plague. Buttermere: Natural England, The UK Technical Advisory Group of the Water Framework 2007a Directive produces a regularly updated classification of aquatic alien species (plants and animals) according to their level of Crummock Water: Natural impact. In general high impact species are of greatest concern England, 2007b; Darwell and but low or unknown impact species may be included in the Marshall, 2013 target on a site-specific basis where there is evidence that they are causing a negative impact (for example high cover values or abundances). Those taxa considered likely to colonise lakes, are indicated by an ‘L’ in the UKTAG guidance. Examples of such high-impact species may include Water Fern, New Zealand pygmyweed and the zebra mussel.
Derwent Water (River Derwent and Tributaries SSSI) – Crassula helmsii is present and was first recorded in 1992 (Halliday, 1997). Elodea nuttallii and Elodea Canadensis are also present (Darwell, 2001). There is a high level of recreational pressure on the lake from casual and regular users (boating, swimming etc.), as well as organised events (triathlons, swim-runs, swims) and commercial wild swimming tours. As a result, there is a high risk of introducing other Invasive Non-Native Species (INNS), in addition to the risk of spreading Crassula to other water bodies, particularly local ones.
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
Bassenthwaite Lake (Bassenthwaite Lake SSSI) - Crassula helmsii is present and was first recorded in 1997 (Halliday, 1997). Elodea nuttallii and Elodea Canadensis are also present (Thackeray et al., 2004). There is a high level of recreational pressure on the lake from casual and regular users (boating, swimming etc.), as well as organised events (triathlons, swim- runs, swims) and commercial wild swimming tours. As a result, there is a high risk of introducing other Invasive Non-Native Species (INNS), in addition to the risk of spreading Crassula to other water bodies, particularly local ones.
Buttermere (Buttermere SSSI) - No non-native plant species were recorded in a Site Condition Assessment survey (Natural England, 2007a). There is a high threat level to Buttermere of introducing Invasive Non-Native Species (INNS) through recreational pressure (casual and regular users - boating, swimming etc. as well as organised events - triathlons, swim- runs, swims, and commercial wild swimming tours. Particularly Crassula, which is present in Derwent Water and Bassenthwaite, within the River Derwent and Bassenthwaite Lake SAC.
Crummock Water (River Derwent and Tributaries SSSI) - No non-native plant species were recorded in a Site Condition Assessment survey (Natural England, 2007b), which states that “a recent survey of aquatic macrophytes identified a healthy and stable community with no evidence of alien species”. A 2012 survey confirms that “the aquatic macrophyte community includes the important characteristic species noted in the SSSI citation and that the macrophyte community remains stable (Darwell and Marshall, 2013). There is a high threat level to Crummock Water of introducing Invasive Non-Native Species (INNS) through recreational pressure (casual and regular users - boating, swimming etc. as well as organised events - triathlons, swim-runs, swims, and commercial wild swimming tours. Particularly Crassula, which is present in Derwent Water and Bassenthwaite, within the River Derwent and Bassenthwaite Lake SAC.
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
In the lakes where Crassula is present, it may be difficult to meet targets of rare or absent until effective methods of control have been developed.
Structure and Macrophyte Maintain (Buttermere and This is a strongly characteristic structural aspect of this habitat Maberly et al., 2016 function community Crummock Water) or restore feature. It will be a response to water transparency, sediment (including its structure (Derwent Water and type and disturbance. Derwent Water: Halliday, 1997; typical Bassenthwaite Lake) a Darwell, 2001 species) characteristic zonation of macrophytes, with increasing Bassenthwaite Lake: Thackeray depth, represented by Littorella et al., 2004 uniflora then with overlapping zones of Littorella uniflora with Buttermere: Natural England, Lobelia dortmana then Isoetes 2007a spp. Crummock Water: Natural England, 2007b; Darwell and Marshall, 2013
Structure and Macrophyte Maintain (Buttermere and This is a strongly characteristic structural aspect of this habitat Maberly et al., 2016 function community Crummock Water) or restore feature. It will be a response to water transparency, sediment (including its structure (Derwent Water and type and disturbance. Derwent Water: Halliday, 1997; typical Bassenthwaite Lake) maximum Darwell, 2001 species) depth of plant colonisation. This will often be the maximum depth Bassenthwaite Lake: Thackeray colonised by Isoetes, but in richer et al., 2004 waters maximum depth of Potamogeton spp. is also Buttermere: Natural England, important. 2007a
Crummock Water: Natural England, 2007b; Darwell and Marshall, 2013
Structure and Macrophyte Maintain and restore a A hydrosere is a naturally-occurring plant succession which River Derwent and Tributaries function community characteristic and well defined occurs in an area of standing fresh water. Over time, an area of SSSI: English Nature, 1997 (including its structure hydrosere associated with the open freshwater will naturally dry out, ultimately becoming typical water body where this is present woodland. During this change, a range of different wetland River Derwent and
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available) species) habitat types such as swamp and marsh, will succeed each Bassenthwaite Lake SAC: other. English Nature, 2005d
This structure around the margins of the lake creates a buffer Bassenthwaite Lake SSSI: zone that can help protect the lake from a limited amount of English Nature, 1994 sediment and nutrient inputs. It also increases habitat heterogeneity providing additional food sources and refugia. Buttermere SSSI: English Nature, 1975 One of the main features of interest for Derwent Water and Bassenthwaite Lake are the transitions from open water to fen/ swamp/ marsh/ wet woodland. For all the lakes, the transitions from wet to naturally dryer habitats are a very important feature.
Structure and Physical Restore the natural shoreline of Inclusion of hard engineering solutions to lake management function structure - the lakes. may have detrimental effects on lake ecology, replacing near- (including its lake shoreline natural substrates with man-made materials. typical species) Alteration of the shoreline may also result in changes in water movements within the lake, which would have effects on patterns of sediment deposition.
The lakes have varying degrees of existing infrastructure impacting on the natural shoreline. Structure and Physical Maintain (Derwent Water, The distribution of sediment particle size and organic content Maberly et al., 2016 function structure - Buttermere and Crummock influences the biology of the lake and will affect the suitability of (including its lake substrate Water) or restore (Bassenthwaite within-lake habitats for invertebrates and macrophytes, and fish Winfield et al., 1998 typical Lake) the natural and spawning grounds (vendace in Derwent Water and species) characteristic substrate for the Bassenthwaite Lake and Arctic charr in Buttermere and Winfield and James, 2018 lake. Crummock Water).
Substrate is typically sand, Increases in sediment loading from activities in the catchment gravel, stones and boulders with area, including those on the lake shore, may result in the low organic content, but there smothering of coarse sediments. may be a locally high peat content. Increased inputs of leaf litter, as a result of scrub encroachment, may also be cause for concern, as organic-rich sediments may be a poor rooting medium for macrophytes.
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
Structure and Water quality Maintain (Derwent Water, If palaeolimnological techniques or hindcast modelling have Natural England, 2014a function - phosphate Buttermere and Crummock been employed to reconstruct natural background phosphorus (including its Water) or restore (Bassenthwaite concentrations for a particular lake, these can be used to set typical Lake) stable nutrient levels targets, although it may be necessary to accept a small species) appropriate for lake type. deviation from these background conditions. Alternatively, historical water chemistry data may exist for individual lakes. The maximum annual mean Where existing, site-specific water column TP concentrations concentration of TP is: are consistently lower than the standard appropriate for the habitat type, a lower target should be applied to prevent Derwent Water 8 μg l-1 deterioration from current status.
Bassenthwaite Lake 10 μg l-1 Increased loadings of P to a water body are likely to lead to higher algal biomass in the water column, which in turn can Buttermere 5 μg l-1 have significant impacts on the standing water ecosystem through, for example, competition with vascular plants for Crummock Water 5 μg l-1 nutrients and light, changes in pH, oxygen depletion and production of toxins. Decreasing dissolved oxygen and The low target for the latter two increasing ammonia levels are associated with death and lakes reflects their low decay of algal blooms, as is a release of toxins from toxin- productivity and is to prevent producing species. deterioration from current state.
Structure and Water quality Maintain or restore a stable There is an increasing understanding that some standing Maberly et al., 2016 function - nitrogen nitrogen concentration which is waters are sensitive to nitrogen (N) enrichment and (including its <1.5 mg l-1 for all lakes. eutrophication may be driven by increases in N, but site- Barker et al., 2008 typical specific information is usually required to determine whether N species) or P is more important. Where P levels are significantly above their target values and there is evidence that the lake is N limited (for example by N levels falling to negligible levels in summer), N targets should be set in addition to P targets. We recommend that such targets should preferably be developed using site-specific information, but should be based around the threshold of 1-2mg/l identified by Barker et al., 2008 In this situation N targets should be used in combination with P targets to drive a management strategy for the lake that reduces all nutrient inputs. Structure and Water quality Acidity levels should reflect Changes in pH can alter the entire freshwater community Maberly et al., 2016 function - acidity unimpacted conditions, typically present within a water body affecting all trophic levels. (including its a pH of 5.5-7.0 for oligotrophic
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available) typical lakes (Derwent Water, Potential causes of a shift in pH include air pollution and direct species) Buttermere and Crummock application of lime to the water column as an acidification Water) and 7.0-8.0 for amelioration strategy (this should not be carried out). mesotrophic lakes (Bassenthwaite Lake). Acidity levels should reflect unimpacted conditions - values of Acid Neutralising Capacity (ANC) considered to avoid significant impact on characteristic biota are laid out in the site's FCT (these are the same numerical values as used to protect high ecological status under the WFD in the UK). As a guide, pH 5.5-7.0 for oligotrophic lakes and 7.0-8.0 for mesotrophic lakes.
Although, pH naturally fluctuates throughout the year, e.g. snow melt may lead to pulses of acid water, and increased plant biomass in summer may result in large fluctuations in pH, including daytime increases in pH values. Therefore pH is not used as a monitoring target, however its importance in affecting many in lake processes means that the pH of a water body should not be artificially altered.
Upland lakes in catchments with hard rock geology have limited buffering capacity and are thus susceptible to acidification. There may be impacts on invertebrate and fish populations at pH levels lower than 5.5. Structure and Water quality Maintain (Derwent Water) or A wide range of pollutants may impact on habitat integrity Maberly et al., 2016 function - other restore (Bassenthwaite Lake, depending on local circumstance. Good chemical status (including its pollutants Buttermere and Crummock includes a list of EQSs for individual pollutants that are UKTAG, 2010; 2010a; 2012 typical Water) good chemical status (i.e. designed to protect aquatic biota with high levels of precaution. species) compliance with relevant Environmental Quality Derwent Water – No high concentrations of heavy metals or Standards) for all lakes. micro-organic pollutants were detected in the most recent survey.
Bassenthwaite Lake – Had one of the highest concentrations of aluminium of the Cumbrian lakes in 2015, exceeded the WFD UKTAG proposed annual maximum concentration of copper (for low alkalinity lakes), the highest concentrations of lead of the Cumbrian lakes, but below the Environmental Quality Standard (EQS) and exceeded the EQS for zinc. No
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
high concentrations of micro-organic pollutants were detected in the most recent survey.
Buttermere – Exceeded the EQS for zinc, and the micro- organic pollutant diazinon (pesticide) was detected (Maberly et al. (2016) stated that “assuming that the high concentrations enter the lake via specific streams, there is a likelihood that concentrations in those streams will be much higher and possibly causing ecological damage”.
Crummock Water – Exceeded the WFD UKTAG proposed annual maximum concentration of copper (for low alkalinity lakes), exceeded the EQS for zinc and the micro-organic pollutant diazinon (pesticide) was detected.
Structure and Water quality Adequate dissolved oxygen As for species in terrestrial environments, dissolved oxygen Maberly et al., 2016 function - dissolved levels for health of characteristic (DO) is required for respiration by aquatic organisms. (including its oxygen fauna. DO>9mg/l for salmonid Anthropogenic activities leading to phytoplankton blooms and Jones et al., 2008 typical waters. increased loadings of organic matter to lakes can cause species) decreases in the concentration of dissolved oxygen available to support the species present.
Mean dissolved oxygen refers to DO being measured at 0.5m intervals throughout the entire water column where the water column is not stratified and measurements taken at 0.5 m intervals below the thermocline only where stratification occurs.
Deep or sheltered lakes exhibit seasonal stratification of temperature and oxygen levels.
DO>9mg/l is the equivalent of WFD High Ecological status.
Buttermere and Crummock Water: Arctic charr avoid low concentrations of oxygen in the hypolimnion (Jones et al., 2008).Reduction in oxygen concentration at depth for Crummock may be a cause for concern (Maberly et al., 2016).
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
Structure and Water Maintain (Derwent Water, Water clarity or transparency is the major determinant of the Maberly et al., 2016 function transparency Buttermere and Crummock depth of colonisation by macrophytes, therefore, it should not (including its Water) or restore (Bassenthwaite be reduced. This should allow plant colonisation to at least typical Lake) the clarity of water at or to 3.5m, but if maximum depth of colonisation has previously species) at least a depth of 3.5 metres been recorded at greater water depths this should be maintained.
Increased nutrient loads leading to increased algal growth will reduce water transparency, disturbance of the sediment by water sports and bottom feeding fish such as carp and bream also increase turbidity and reduce water transparency. Increased sediment loads to a lake would also have this effect.
Structure and Water quality Chlorophyll a concentration Chlorophyll is the pigment used for photosynthesis by plants, Maberly et al., 2016 function - algae should comply with WFD high and the concentration of chlorophyll in the water column during (including its ecological status and not have a the growing season therefore provides a good measure of the typical negative impact on the abundance of phytoplankton. Phytoplankton is an important species) ecosystem. driver of structure and function in lakes and high phytoplankton levels (algal blooms) are usually associated with nutrient Blooms of blue-green or green enrichment. algae should not occur in low nutrient waters. Dense growths of tufted algae may grow on hard substrates where other plants have difficulty establishing, such as on boulders or cobbles. On the whole this is not a cause for concern. However, formation of floating algal rafts or macrophytes being overgrown with filamentous algae is a cause for concern. Structure and Hydrology At a site, unit and/or catchment Defining and maintaining the appropriate hydrological regime is United Utilities, 2009 function level (as necessary), maintain a key step in moving towards achieving the conservation (including its (Derwent Water, Bassenthwaite objectives for this site and sustaining this feature. Changes in United Utilities, 2018 typical Lake and Buttermere) or restore source, depth, duration, frequency, magnitude and timing of species) Crummock Water) natural water supply can have significant implications for the Darwell and Marshall, 2013 hydrological processes to provide assemblage of characteristic plants and animals present. This the conditions necessary to target is generic and further site-specific investigations may be sustain the feature within the site required to fully inform conservation measures and/or the likelihood of impacts.
Hydrology influences lake ecosystem functioning in two ways: determining residence time (flushing) and water level
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
fluctuations. Flushing of lakes is important for dilution and removal of nutrients and phytoplankton, and for reduction in sedimentation. The timing of different flushing rates within the year influences the biology of the lake. For example, reduced flushing in summer would encourage bloom conditions.
Modifications of inflows and outlets or changes in hydrology, e.g. from flood control regimes, abstraction and gravel removal can lead to unnatural changes in lake levels.
Evidence of major impacts of drawdown includes stranded marginal vegetation, exposed lake sediments, or signs of former shorelines. Emergent plants may exhibit morphological differences under different hydrological regimes, but this varies between species. Lobelia dortmanna may reduce in abundance with increased drawdown, whilst the terrestrial form of Littorella uniflora may be present in abundance in such situations.
Crummock Water – A weir at the mouth creates additional storage for public water supply for which the abstraction licence is held by United Utilities (UU). Under this licence, UU can abstract water by gravity until the lake level is approx. 1.1 m below weir crest, then it is necessary to pump to maintain both public water supply and compensation flow (Drought Permit/Order required for this action). UU’s Final Statutory Drought Plan (2018) includes a drought option at Crummock Water to allow pumping of from 1.1 to 1.5 m below weir crest and a Habitats Regulation assessment undertaken by UU concluded that this would have no adverse effect on site integrity of the SAC.
As part of the compensatory measures package for Ennerdale Water, this abstraction licence will be revoked. A review of restoration options is currently being undertaken.
Structure and Sediment load Maintain (Derwent Water, Increased sediment loadings may result in clogging of the lake Maberly et al., 2016 function Buttermere and Crummock bed, increased siltation in the basin and deoxygenation of (including its Water) or restore (Bassenthwaite sediments. Blockage of coarser substrates with finer sediment typical Lake) the natural sediment load restricts water flow-through, whilst increases in organic matter
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available) species) increase biochemical oxygen demand.
Examples of causes of increases in siltation include: increased lake productivity, changes in catchment land-use (particularly over-grazing), lake level fluctuations or climatic fluctuations.
Sediment input can also have a potential adverse effect on the spawning grounds for vendace (Derwent Water and Bassenthwaite Lake) and Arctic charr (Buttermere and Crummock Water).
Historic heavy metal input to the lake sediments could easily be disturbed by dredging and other operations. Structure and Supporting Maintain and restore the extent, Include only where applicable. The structure and function of the River Derwent and Tributaries function off-site quality and spatial configuration qualifying habitat, including its typical species, may rely upon SSSI: English Nature, 1997 (including its habitat of land or habitat surrounding or the continued presence of areas which surround and are typical adjacent to the site which is outside of the designated site boundary. River Derwent and species) known to support the feature. Bassenthwaite Lake SAC: Changes in surrounding land-use may adversely English Nature, 2005d Wetlands - Swamp, marsh and (directly/indirectly) affect the functioning of the feature and its fen component species. This supporting habitat may be critical to Bassenthwaite Lake SSSI: Wet woodlands the typical species of the feature to support their feeding, English Nature, 1994 breeding, roosting, population dynamics ('metapopulations'), pollination or to prevent/reduce/absorb damaging impacts from Buttermere SSSI English Nature, adjacent land uses e.g. pesticide drift, nutrient enrichment. 1975
Swamp, marsh and fen are best developed in the River Derwent and Tributaries SSSI around Derwent Water and Crummock Water, and in the Bassenthwaite Lake SSSI around Bassenthwaite Lake. Wet woodland is largely restricted to the margins of Derwent water within the River Derwent and Tributaries SSSI.
Structure and Functional Maintain the natural connectivity The natural isolation of some standing water bodies can function connectivity/ of the water body to other water provide some protection from threats such as pollution and (including its isolation bodies invasive species. Hydrological isolation can also lead to unique typical or diverse species assemblages this may be due to genetic species) isolation or the absence of predators. These water bodies should have their isolated state maintained.
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
In contrast other standing water bodies naturally rely on hydrological connectivity to other freshwater systems for water supply, and can support migratory species.
Hydrological connectivity may also be important for geneflow, and habitat and species resilience. These water bodies should have their hydrological connectivity maintained.
Derwent Water is connected to Bassenthwaite via the River Derwent. Both lakes are connected to tributaries of the Derwent catchment and this connectivity is vital for the migration of Atlantic salmon to headwater spawning sites.
Buttermere is connected to Crummock Water via Buttermere Dubbs. Both lakes are connected to tributaries of the Cocker catchment and this connectivity is vital for the migration of Atlantic salmon to headwater spawning sites.
Structure and Key Maintain or restore the Some plant or animal species (or related groups of such Derwent Water: Darwell, 2001 function structural, abundance of the typical species species) make a particularly important contribution to the (including its influential listed below to enable each of necessary structure, function and/or quality of an Annex I Bassenthwaite: Thackeray et al., typical and/or them to be a viable component of habitat feature at a particular site. These species will include; 2004 species) distinctive the H3130 habitat; species • Structural species which form a key part of the Annex I Buttermere: Natural England, Distinctive lake flora – see habitat’s structure or help to define that habitat on a particular 2007a supporting notes for further SAC (see also the attribute for ‘vegetation community information composition’). Crummock: Darwell and Marshall, 2013 All lakes fauna: • Influential species which are likely to have a key role Petromyzon marinus, sea affecting the structure and function of the habitat (such as Maberly et al., 2016 lamprey; Lampetra planeri, brook bioturbators (mixers of soil/sediment), grazers, surface borers, lamprey; Lampetra fluviatilis, predators or other species with a significant functional role Winfield et al., 1998 river lamprey; Salmo salar, linked to the habitat) Atlantic salmon; Lutra lutra, Winfield and James, 2018 Otter. • Site-distinctive species which are considered to be a particularly special and distinguishing component of an Annex I Derwent Water fauna: habitat on a particular SAC. Vendace; Characteristic
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
invertebrate assemblage with There may be natural fluctuations in the frequency and cover of presence of particular scarce each of these species. The relative contribution made by them species (the leaf beetle Donacia to the overall ecological integrity of a site may vary, and Natural aquatica and the snail Vertigo England will provide bespoke advice on this as necessary. lilljeborgi). The list of species given here for this Annex I habitat feature at this SAC is not necessarily exhaustive. The list may evolve, Bassenthwaite Lake fauna: and species may be added or deleted, as new information Vendace; breeding bird about this site becomes available. assemblage. Flora Buttermere and Crummock The characteristic macrophyte species are distributed in Water fauna: specific bays of the lakes. There should be no loss of species Arctic charr richness of individual bays.
Derwent Water flora: Littorella uniflora, Isoetes lacustris, Isoetes echinospora, Lobelia dortmanna, Luronium natans, Callitriche hamulata, Myriophyllum alterniflorum, Potamogeton polygonifolius, Potamogeton berchtoldii, Potamogeton natans, Nymphaea alba, Juncus bulbosus, Eleogiton fluitans, Nuphar lutea, Other characteristic species: Pilularia globulifera, Elatine hexandra, Utricularia spp., Nitella spp. Sparganium natans, Potamogeton alpinus, P. perfoliatus.
Bassenthwaite Lake flora: Littorella uniflora, Isoetes lacustris, Lobelia dortmanna, Sparganium angustifolium, Luronium natans, Callitriche hamulata, Myriophyllum alterniflorum, Potamogeton berchtoldii, Potamogeton natans, Nymphaea alba, Juncus bulbosus, Nuphar lutea, Persicaria amphibia; Other characteristic species: Elatine hexandra, Nitella spp. Sparganium natans, Potamogeton alpinus, P. perfoliatus, P. gramineus.
Derwent Water and Bassenthwaite lake flora: Luronium natans, floating water-plantain
Buttermere flora: Littorella uniflora, Isoetes lacustris, Lobelia dortmanna, Callitriche hamulata, Myriophyllum alterniflorum, Potamogeton polygonifolius, Juncus bulbosus, Other characteristic species: Carex rostrata, Nitella spp.
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
Crummock Water flora: Littorella uniflora, Isoetes lacustris, Lobelia dortmanna, Subularia aquatica, Sparganium angustifolium, Callitriche hamulata, Callitriche brutia, Myriophyllum alterniflorum, Potamogeton polygonifolius, Juncus bulbosus, Eleogiton fluitans, Other characteristic species: Elatine hexandra, Nitella spp. Sparganium natans.
Fauna Vendace are England’s rarest fish and an important species present in Derwent Water and Bassenthwaite Lake (Maberly et al., 2016, Winfield and James, 2018). Known spawning sites were mapped by Winfield et al., 1998.
Arctic charr are an important fish species in Buttermere and Crummock Water (Maberly et al., 2016).
For both these fish species, the availability of littoral/benthic fauna (including Asellus, bivalves, chironomid larvae and gastropods) and open water zooplankton (especially Daphnia and Bosmina sp.). These are the food sources for the fish.
Structure and Fisheries Maintain a total projected Fish communities may exert a strong influence on overall lake Winfield et al., 2016 function estimate for biomass of total fish ecology and may cause or exacerbate eutrophication (including its production at less than 200kg/ha symptoms. Where fisheries are present it should be a balanced typical (this should take into account the mixed fishery. There should be a presumption against stocking species) growth potential of the resident non-native species, carp and bream. . and stocked fish). Roach and ruffe and dace are introduced species, present in Derwent Water and Bassenthwaite Lake and with the potential to impact on the vendace populations. Supporting Air quality Maintain as necessary, the This habitat type is considered sensitive to changes in air More information about site- processes concentrations and deposition of quality. Exceedance of these critical values for air pollutants relevant Critical Loads and Levels (on which the air pollutants to at or below the may modify the chemical status of its substrate, accelerating or for this SAC is available by using feature relies) site-relevant Critical Load or damaging plant growth, altering its vegetation structure and the ‘search by site’ tool on the Air Level values given for this composition and causing the loss of sensitive typical species Pollution Information System feature of the site on the Air associated with it. (www.apis.ac.uk). Pollution Information System
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
(www.apis.ac.uk). Critical Loads and Levels are recognised thresholds below which such harmful effects on sensitive UK habitats will not occur to a significant level, according to current levels of scientific understanding. There are critical levels for ammonia (NH3), oxides of nitrogen (NOx) and sulphur dioxide (SO2), and critical loads for nutrient nitrogen deposition and acid deposition.
There are currently no critical loads or levels for other pollutants such as Halogens, Heavy Metals, POPs, VOCs or Dusts. These should be considered as appropriate on a case-by-case basis. Ground level ozone is regionally important as a toxic air pollutant but flux-based critical levels for the protection of semi- natural habitats are still under development.
It is recognised that achieving this target may be subject to the development, availability and effectiveness of abatement technology and measures to tackle diffuse air pollution, within realistic timescales. Version Control Advice last updated: N/A Variations from national feature-framework of integrity-guidance: The targets for some attributes listed above include both ‘maintain’ and ‘restore’ objectives. This is because River Derwent & Bassenthwaite Lake SAC is comprised of a number of geographically-separate component sites which are currently in different states of condition. Overall, both objectives will be applicable to the SAC but these will differ between each component site depending on its particular circumstances. Natural England will able to provide further specific advice on request.
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Table 2: Supplementary Advice for Qualifying Features: H3260. Water courses of plain to montane levels with the Ranunculion fluitantis and Callitricho-Batrachion vegetation; Rivers with floating vegetation often dominated by water-crowfoot
Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
Extent and Extent of the Restore the total extent of the See the explanatory notes for this attribute above in Table 1 Jacobs, 2010a; 2010b; 2010c distribution feature within feature to 34.08 hectares of the feature the site
Structure and Biotope Restore the extent and pattern of Watercourses with a high degree of naturalness are governed Jacobs, 2010a; 2010b; 2010c function (habitat) in-channel and riparian biotopes by dynamic processes which result in a mosaic of characteristic (including its mosaic (habitats) to that characteristic of physical habitats or biotopes, including a range of substrate Natural England, 2014b typical natural fluvial processes. types, variations in flow, channel width and depth, in-channel species) and side-channel sedimentation features (including transiently exposed sediments), bank profiles (including shallow and steep slopes), erosion features (such as cliffs) and both in-channel and bankside (woody and herbaceous) vegetation cover. All of these biotopes, and their characteristic patterns within the river corridor, are important to the full expression of the biological community.
A range of physical habitat modifications cause simplification of biotope mosaics, resulting in declines of characteristic biota dependent upon biotopes that have been lost or reduced in extent. Rivers that have sections that are already significantly physically modified should be subject to a process for planning and implementing physical restoration measures. This should be based on restoring natural geomorphological processes (including restoration of hydrological continuity between river and floodplain) as far as possible to allow restoration of characteristic and sustainable biotope mosaics, working within the practical constraints of essential flood protection for people and the built environment.
Excessive levels of livestock grazing denudes the riparian zone, causes artificially high bank instability, and degradation of the fauna and flora of exposed riverine sediments. Low levels of grazing by suitable livestock are important in generating the full expression of riparian biotopes.
The River Derwent and tributaries have been heavily modified
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
in parts, in the past, and have been subject to being straightened, deepened, widened and embanked resulting in the loss of dynamic processes and subsequent loss of range of biotopes which would be associated with an unmodified river.
Implementation of the River Restoration Strategy aims to restore naturally functioning geomorphological processes wherever possible.50 out of 67 reaches were classed by Jacobs (2010) as requiring river restoration interventions.
Structure and Riparian zone Restore a patchy mosaic of A mosaic of natural and semi-natural riparian vegetation types Jacobs, 2010a; 2010b; 2010c function natural woody and herbaceous provides conditions for all characteristic in-channel and riparian (including its (tall and short swards) riparian biota to thrive, creating patches of tall and short riparian typical vegetation (except in upland swards, a mixture of light and shade on the river channel, and species) areas above the natural tree tree root systems and a supply of large woody debris that add line). channel complexity.
The riparian zone should be Patchy tree cover provides shade protection against rising sufficiently wide to act as a water temperature caused by climate change. Between 30 and healthy and functional habitat 50% riparian tree cover is generally considered optimal for in- zone within the river corridor. channel and riparian habitats. Intensive cutting across significant proportions of the riparian zone is not appropriate. Also see above comments on livestock grazing. Structure and Woody debris Restore the presence of coarse Dead woody material that falls into streams (‘woody debris’) Jacobs, 2010a; 2010b; 2010c function woody debris within the structure plays an important role in increasing habitat diversity, providing (including its of the channel (except in upland shelter for fish, supplying a food source for aquatic typical areas above the natural tree invertebrates, and for slowing the passage of nutrients species) line). downstream.
In smaller watercourses, Woody debris is therefore a key feature of healthy rivers. temporary debris dams should be Woody debris should be left in situ, unless there are overriding a feature of channel dynamics. reasons of public safety (for example to prevent flooding or bridge collapse).
Woody debris is scarce in some tributaries of the River Derwent and its presence needs to be restored. In other tributaries woody debris is well represented and this should be maintained where possible.
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
Structure and Water course Restore the natural flow regime The natural flow regime both shapes and sustains Jacobs, 2010a; 2010b; 2010c function flow of the river, with daily flows as characteristic biotope mosaics, affecting factors such as current (including its close to what would be expected velocities and bed hydraulics, water levels and depths, wetted Natural England, 2014b typical in the absence of abstractions area, temperature regime and dissolved oxygen regime, species) and discharges (the naturalised United Utilities, 2009 flow). All parts of the natural flow regime are important, including flushing flows, seasonal baseflows and natural low flows. Natural England and Environment Natural seasonal flow recession is critical in supporting the full Agency, 2016 expression of ephemeral habitats (marginal and riparian vegetation, exposed riverine sediments, ephemeral Natural England, 2009a – headwaters). Available from Natural England on request Any significant impacts on the natural flow regime should be rectified sustainably by reducing flow modifications, not by artificial augmentation, or by altering channel form to fit reduced levels of flow. There should be no increase in the existing level of impact on the natural flow regime, and any significant impacts should be controlled to acceptable levels. Flow targets for WFD high ecological status should be used to avoid deterioration and for restoration where this is technically feasible. These are: <5% deviation at
The natural flow regime of the River Derwent has been altered by many in-channel structures (with impoundment effect) and other factors which change the natural flow regime. The implementation of the River Restoration Strategy (Jacobs, 2010) aims to restore the natural flow regime in these situations where possible and avoid further deterioration.
Within the catchment there are public water supply abstractions from for the West Cumbria Supply Zone from Crummock Water and non-potable water supply from the River Derwent. The EA Review of Consents for abstractions (under the Habitats
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
Directive) in 2009, resulted in modification of the abstraction licences for Ennerdale Water and Dash Beck with short and long term consequences for Crummock Water. In the short term, there will be increased demand whilst in the longer term there will be a revocation of the abstraction licence and associated infrastructure by 2022 (as part of a Compensatory Measures Package for Ennerdale).
In addition, the decommissioning of five water treatment works in the area has also been assessed as having a significant positive effect on water quantity and quality due to increases in flows in the catchment (United Utilities, 2009).
Natural England and Environment Agency have published flow targets for each unit and waterbody (Natural England and Environment Agency, 2016.
Structure and Sediment Restore the natural supply of Coarse sediment supply is essential for the stability of the river Jacobs, 2010a; 2010b; 2010c function regime coarse and fine sediment to the channel and for creating and sustaining key biotopes including (including its river riffles and exposed shingle banks. Coarse sediment supply can typical be interrupted by weirs and other impounding structures, and species) by dredging or extraction, and can result in channel incision and heavy bankside erosion that have consequences for both biodiversity and river management (e.g. flood risk).
Excessive fine sediment supply can lead to the smothering of coarse substrates and the loss of flora and fauna dependent on them (note that impoundment of the river can have the same effects). In upland streams, damage to blanket peat creates enhanced levels of organic particulates that cause considerable change to macroinvertebrate communities. Where fine sediment delivery is a problem, control measures need to be planned in the catchment. In upland areas, the restoration of intact peat bodies is critical in controlling organic sediment load.
Coarse and fine sediment supply should reflect natural supply levels. Fine sediment delivery should not be enhanced by catchment or riparian management practices in ways that lead
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
to siltation problems in the channel or unnaturally high levels of turbidity. There is smothering of the river channel bed with fine sediment due to accelerated erosion and disconnection from sediment sinks.
The natural sediment regime needs to be restored throughout the whole catchment through the Diffuse Water Pollution Plan, Stewardship Schemes, Partnership Projects and actions of the Derwent Catchment Management Group.
Structure and Thermal Maintain a natural thermal Climate change is driving increases in river temperatures which function regime regime to the river subject to a will create stress for a range of characteristic riverine species, (including its changing climate, ensuring that particularly those on the southern limit of their range. This must typical water temperatures should not not be exacerbated by catchment activities that are likely to species) be significantly artificially raise water temperatures further. These may include elevated impoundment, abstraction, discharges, excessive tree removal or maintenance or other activities. Restoration of riparian tree cover to suitable levels will be needed in many cases, particularly in headwater streams, systems affected by alder Phytophthora and river reaches lacking any riparian trees.
Structure and Biological The movement of characteristic Many species, including fish and invertebrates, require natural Jacobs, 2010a; 2010b; 2010c function connectivity biota should not be artificially freedom of movement to complete their life cycle in rivers and (including its constrained. maximise their population size and genetic diversity. typical species) Longitudinal connectivity within the river channel and lateral connectivity between the channel and the floodplain are both critical to a healthy river ecosystem. Constraints to longitudinal movement such as waterfalls and debris dams are a natural feature of rivers and add to the complexity and diversity of the habitat. Natural waterfalls in headwater areas can create unique (often fishless) communities of conservation importance. New artificial constraints to movement should be avoided and existing artificial constraints should be addressed through strategic river restoration as outlined above. Barriers should be removed wherever possible to restore all aspects of habitat integrity - fish passes constitute a partial mitigation measure for longitudinal biological movement and should only be considered where it is not possible to remove the barrier.
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
Where established, they should allow for the passage of as many characteristic species as possible, including fish species such as salmon and lamprey species.
The River Derwent has a number of in-channel structures which form barriers (particularly in low flows) to longitudinal connectivity and can restrict migratory species such as salmon and lamprey species to poor quality spawning areas when large amounts of spawning habitat exist upstream of the structures. The river is also embanked for significant sections which has removed the lateral connectivity of the river and its floodplain.
Implementation of the River Restoration Strategy will restore biological connectivity where possible.
Structure and Invasive, non- Ensure non-native species Non-native species constitute a major threat to many river Natural England, 2014b function native and/or categorised as 'high-impact' in systems. Impacts may be on the river habitat itself (e.g. (including its introduced the UK under the Water damage to banks and consequent siltation) or directly on typical species Framework Directive are either characteristic biota (through predation, competition and species) rare or absent but if present are disease), or a combination of these. causing minimal damage to the feature. For example, species such as signal crayfish have been responsible for much of the decline of native crayfish through The species on the high impact competition, habitat damage and the introduction of crayfish list known to be present include: plague. The UK Technical Advisory Group of the Water Japanese knotweed, giant Framework Directive produces a regularly updated hogweed, Himalayan balsam and classification of aquatic alien species (plants and animals) signal crayfish. according to their level of impact.
In general high impact species are of greatest concern but low or unknown impact species may be included in the target on a site-specific basis where there is evidence that they are causing a negative impact (for example high cover values or abundances). Those taxa considered likely to colonise lakes, are indicated by an ‘L’ in the UKTAG guidance. Examples of such high-impact species may include Water Fern, New Zealand pygmyweed and the zebra mussel.
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
In this SAC, signal crayfish has been recorded in St John’s Beck and the River Glenderamackin. There is no population of native white-clawed crayfish in the Derwent, but they could impact on the general ecology (particularly impacting on the salmon population as St John’s Beck is the best fry nursery in the whole catchment).
Japanese knotweed and giant hogweed are sporadic and Himalayan balsam is abundant within the SAC and wider catchment. In places they are causing erosion of the banksides.
Structure and Key Restore the abundance of the See the explanatory notes for this attribute above in Table 1 English Nature, 1997 function structural, typical species listed below to (including its influential enable each of them to be a Flora typical and/or viable component of the Annex 1 species) distinctive habitat; Above Derwent Water (bryophytes): Hygrohypnum species ochraceum; Pellia epiphylla; Fontinalis antipyretica; F. Flora squamosa; Racomitrium aciculare; Rhynchostegium Diverse flora populations (see riparioides; Hyocomium armoricum Supporting and Explanatory Notes for further information) Above Derwent Water (macrophytes): Myriophyllum alterniflorum; Littorella uniflora
Fauna: Between Derwent Water and Bassenthwaite Lake (lichens Invertebrate fauna including two and bryophytes): Verrucaria spp; Fontinalis antipyretica; nationally rare species: the leaf Amblystegium riparium beetle Donacia aquatica and the snail Vertigo lilljeborgi. Between Derwent Water and Bassenthwaite Lake (macrophytes and riparian higher plants): Callitriche A diverse assemblage of native hamulata; Ranunculus aquatilis; Myriophyllum alterniflorum; fish species including: Lythrum salicaria Petromyzon marinus, sea lamprey; Lampetra planeri, brook Upstream of Cockermouth: Filamentous red alga - Lemanaea lamprey; Lampetra fluviatilis, fluviatilis river lamprey; Salmo salar, Atlantic salmon; Lutra lutra, Above Buttermere (bryophytes): Rhynchostegium riparoides Otter. Schistidium agassizii
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
Between Buttermere and Crummock Water (macrophytes): Myriophyllum alterniflorum; Callitriche hamulata; Littorella uniflora; Juncus bulbosus
Downstream of Crummock Water (macrophytes): Sparganium minimum; Oenanthe crocata
Riparian habitats: Stachys palustris; Dryopteris carthusiana; Carex remota; Schoenoplectus lacustris; Carex rostrata; Eleocharis acicularis; Juncus filiformis; Polygonum minus; Carex vesicaria; C. elata; Phragmites australis; Potentilla palustris; Equisetum fluviatile; Menyanthes trifoliata; Oenanthe fistulosa Structure and Fisheries Restore fish densities at or to a Fish stocking can cause elevated levels of competition and Natural England Technical function level at or below the natural predation that may damage the characteristic biological specialist (pers. Comm) (including its environmental carrying capacity community. Ideally, fishery management should be based on typical of the river, and below historical natural recruitment, with an emphasis on restoring species) levels (this means no stocking to characteristic river habitat in ways that promote natural previously unstocked rivers or recruitment. Exploitation should be controlled to suitable levels, river sections). and net limitations and catch-and-release techniques used where necessary to avoid population impacts. Trout stocking should not elevate densities of adult trout (stocked Fish introductions, exploitation and other removals should not plus natural) to more than 1-3 interfere with the ability of the river to support self-sustaining fish 100m-2, this being the populations of characteristic species. Stocking should be estimated range of natural trout undertaken so as to avoid risks of disease transfer, including densities in SAC rivers. crayfish plague where white-clawed crayfish populations are at risk. Exploitation and removals should not cause significant suppression of characteristic fish species (e.g. Atlantic salmon, eel, and pike) or affect the balance of the fish or wider biological community.
The stocking of carp to still waters immediately adjacent to SAC rivers is undesirable if there is continuity between river and still water during periods of flood and no effective biosecurity measures are in place. Stocking for population conservation purposes should only be considered as an interim measure whilst underlying environmental problems are addressed, and
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
should not be undertaken if natural recovery can be achieved in reasonable timescales. Fish should be sourced to avoid impacts on the genetic integrity of local populations (including sub-catchment genetics where appropriate, e.g. for salmon).
There is no stocking of salmon or trout in the catchment and the Derwent is a wild stocked river which needs to be maintained.
Structure and Vegetation Maintain and restore where Ideally, grazing levels should be managed at low levels across Jacobs, 2010a; 2010b; 2010c function structure: appropriate, grazing activity in whole riparian fields. Where this is not feasible, set-back (including its riparian zone the riparian zone and in the river fencing may be established with access provision for limited typical channel at or to suitably low grazing within the riparian zone. species) levels. Particularly sensitive areas (e.g. exposed riverine sediments likely to support good invertebrate communities) may need to be fenced off to avoid any concentration of livestock activity, even if only present in low numbers. Close bankside fencing that excludes the development of a functional river corridor is not appropriate. Structure and Vegetation Maintain a sufficient proportion of Removal of submerged aquatic vegetation (often called 'weed- function structure: all aquatic macrophytes to allow cutting') might be undertaken for flood risk management or (including its cover of them to reproduce in suitable fishery purposes. Except in situations of extreme flood risk, typical submerged habitat and unaffected by river best practice is for cutting to leave a mosaic of submerged and species) macrophytes management practices. marginal vegetation, and should promote a characteristic diversity of plant species. It is recommended that where appropriate a weed management plan is developed for the site, allowing for higher levels of cutting at flood risk pinch-points, balanced by lower levels of cutting in other stretches.
Any weed-cutting operations should be undertaken to leave a sufficient proportion of in-channel and marginal vegetation in the river to support characteristic biota (in terms of cover, food supply and spawning substrate). Weed-cutting should not interfere with the ability of the river channel to downsize through encroachment of marginal vegetation during the summer flow recession.
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
Structure and Screening of All intakes and discharges likely Intakes and discharges can be responsible for significant function intakes and to trap a significant number of mortalities of fish. Long-distance migratory species such as (including its discharges individuals of characteristic Atlantic salmon sea trout and European eel can be particularly typical species are being adequately susceptible. Archimedes screw turbines are a recent species) screened. development in small-scale hydropower and should also be screened until such times that there is robust evidence that they cause no damage to characteristic fish populations. Structure and Supporting Habitats beyond the site The characteristic biological communities of the site are function off-site boundary upon which dependent on the integrity of sections of river channel, riparian (including its habitat characteristic biological areas, and transitional and marine waters that lie outside of the typical communities of the site depend site boundary. Headwater areas and tributaries may not fall species) should be restored in a state that within the site boundary, yet a range of species characteristic of does not impair the full the site may use these areas for spawning and juvenile expression of the characteristic development and be critical for sustaining populations within biota within the site. the site.
Fully developed riparian zones are essential to site integrity, yet part of this zone may lie outside of the site boundary, particularly if the river channel is operating under natural processes and moves laterally over time within the floodplain. The conditions experienced by long-distance migratory species (such as salmon, sea and river lampreys, and eels) outwith the site (through the saline transition zone, estuary, coastal waters and into the high seas) are critical to the well-being of populations within the site.
Otter and lamprey species are known to, or likely to, use the tributaries, which will also act as refuges from high flow conditions and pollution incidents. Salmon and trout are known to spawn in the headwaters.
Supporting Water Maintain natural levels of Natural alkalinity levels are critical to characteristic biological processes chemistry - alkalinity communities, with many species adapted to certain parts of the (on which the alkalinity alkalinity range. Mass transfers of water can disrupt the natural feature relies) alkalinity regime. Supporting Water quality The natural nutrient regime of the Elevated nutrient levels interfere with competitive interactions Natural England, 2014a processes - nutrients river should be protected, with between higher plant species and between higher plants and (on which the any anthropogenic enrichment algae, leading to dominance by attached forms of algae and a Natural England and Environment feature relies) above natural/background loss of characteristic plant species (which may include lower Agency, 2016
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
concentrations should be limited plants such as mosses and liverworts). Through changes to to levels at which adverse effects plant growth and plant community composition and structure on characteristic biodiversity are they also affect the wider food web, altering the balance unlikely. between species with different feeding and behavioural strategies.
The respiration of artificially large growths of benthic or floating algae may generate large diurnal sags in dissolved oxygen and poor substrate conditions (increased siltation) for fish and invertebrate species. The management focus is typically on phosphorus in rivers, on the assumption that it can be more easily controlled at levels that limit the growth of plant species. However, nitrogen may also be important in river eutrophication and ideally co-limitation would be the management aim.
Any development within the catchment should ensure that appropriate measures are incorporated at the design phase, to ensure that sustainable urban drainage components are included which address water quality impacts as well as flood attenuation.
Targets for phosphorus have been published by NE and EA. Many units are currently not meeting long term targets for phosphorus.
Implementation of the Diffuse Water Pollution Plan, River Restoration Plan and the Catchment Sensitive Farming Initiative will all contribute towards reducing inputs to the river and reduce levels of phosphorus and nitrogen.
Supporting Water quality Organic pollution levels should Organic pollution effects the biota in a number of ways, Natural England, 2014a processes - organic be controlled to levels that have including direct toxicity (from ammonia and nitrite), reduced (on which the pollution minimal impact on the dissolved oxygen levels (from microbial breakdown of organic Natural England and Environment feature relies) characteristic biota H3260 material), and nutrient enrichment. Reducing organic pollution Agency, 2016 feature as follows: levels reduces toxic effects but unmasks enrichment effects.
Unionised ammonia: 0.03m/L as Controlling the continuous input of low levels of organic 95%ile; material is critical to controlling the enrichment effect. The Total ammonia: 0.25mg/L as values given apply throughout the site not just at routine
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
90%ile; sampling points - assessment can be made by modelling Dissolved oxygen: 85% (assuming full mixing of effluents at the point of discharge). saturation as 10%ile. Implementation of the Diffuse Water Pollution Plan, River Restoration Plan and the Catchment Sensitive Farming Initiative will all contribute towards reducing inputs to the river and reduce levels of phosphorus and nitrogen.
Supporting Water quality Maintain levels of acidity at those Acid deposition can cause major changes to flora, fauna and Natural England and Environment processes - acidification which reflect unimpacted ecosystem functioning and affects organisms as diverse as Agency, 2016 (on which the conditions: diatoms, invertebrates and fish. Upland streams are particularly feature relies) susceptible owing to the higher rainfall in these areas. Acid ANC (Acid Neutralising impacts are typically sporadic and tend to be greatest during Capacity): Mean ANC >80 the winter months.
pH (Clear waters with DOC In humic (peat-stained) waters, pH is naturally lower due to the <10mgL-1) – mean > 6.54 presence of weak acids, and the pH standard is correspondingly lower for these waters. However, humic pH (Humic waters with DOC compounds also provide buffering capacity that helps to reduce <10mgL-1) mean >5.1 fluctuations in pH. Acidification lowers dissolved organic carbon . in these waters, reducing the buffering capacity and altering ecosystem functioning.
The values given should be applied throughout the site, not just at routine sampling points.
Note that, in respect of ANC, some allowance may need to be made for anthropogenically elevated levels of humic substances in rivers and streams draining degraded peat bodies - this artificially raises the buffering capacity of the water and may under-estimate the anthropogenic acid load.
Supporting Water quality Achieve at least 'Good' chemical A wide range of pollutants may impact on habitat integrity processes - other status (i.e. compliance with depending on local circumstance. Good chemical status (on which the pollutants relevant Environmental Quality includes a list of Environmental Quality Standards (EQS) for feature relies) Standards). individual pollutants that are designed to protect aquatic biota with high levels of precaution. These values should be applied throughout the site, not just at routine sampling points.
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
Supporting Air quality Maintain and where necessary See the explanatory notes for this attribute above in Table 1 More information about site- processes restore as necessary, the relevant Critical Loads and Levels (on which the concentrations and deposition of for this SAC is available by using feature relies) air pollutants to at or below the the ‘search by site’ tool on the Air site-relevant Critical Load or Pollution Information System Level values given for this (www.apis.ac.uk). feature of the site on the Air Pollution Information System (www.apis.ac.uk). Version Control Advice last updated: N/A Variations from national feature-framework of integrity-guidance: The targets for some attributes listed above include both ‘maintain’ and ‘restore’ objectives. This is because River Derwent & Bassenthwaite Lake SAC is comprised of a number of geographically-separate component sites which are currently in different states of condition. Overall, both objectives will be applicable to the SAC but these will differ between each component site depending on its particular circumstances. Natural England will able to provide further specific advice on request.
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Table 3: Supplementary Advice for Qualifying Features: S1065. Euphydryas (Eurodryas, Hypodryas) aurinia; Marsh fritillary butterfly
Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
Population Population Restore the abundance of the This will ensure there is a viable population of the feature which This attribute will be periodically (of the abundance population to sustainable levels is being maintained at or increased to a level that contributes monitored as part of Natural feature) to be determined as appropriate to its Favourable Conservation Status across its England’s site condition natural range in the UK. Due to the dynamic nature of assessments population change, the target-value given for the population size or presence of this feature is considered to be the Porter, 2007; 2011 minimum standard for conservation/restoration measures to achieve. This minimum-value may be revised where there is evidence to show that a population’s size or presence has significantly changed as a result of natural factors or management measures and has been stable at or above a new level over a considerable period (generally at least 10 years). The values given here may also be updated in future to reflect any strategic objectives which may be set at a national level for this feature. Given the likely fluctuations in numbers over time, any impact- assessments should focus on the current size of the site’s population, as derived from the latest known or estimated level established using the best available data. This advice accords with the obligation to avoid deterioration of the site or significant disturbance of the species for which the site is designated, and seeks to avoid plans or projects that may affect the site giving rise to the risk of deterioration. Similarly, where there is evidence to show that a feature has historically been more abundant than the stated minimum target and its current level, the ongoing capacity of the site to accommodate the feature at such higher levels in future should also be taken into account in any assessment. Unless otherwise stated, the population size or presence will be that measured using standard methods, such as peak mean counts or breeding surveys. This value is also provided recognising there will be inherent variability as a result of natural fluctuations and margins of error during data collection. Whilst we will endeavour to keep these values as up to date as possible, local Natural England staff can advise that the figures stated are the best available. For this feature counting the conspicuous larval webs is a good measure of population
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
density; as well as the more standardised transect counts of adults.
The marsh fritillary butterfly, for which Braithwaite Moss was notified became extinct in Cumbria as a whole in 2004 when the last caterpillar web was collected and brought into captivity for breeding up and cross-breeding with populations collected from western Scotland. These were then reintroduced to this site and others in Cumbria in 2007, and subsequently, the population has been monitored annually. The level at which populations will be considered sustainable needs to be determined.
Supporting Distribution of Restore the distribution and A contraction in the range, or geographic spread, of the feature This attribute will be periodically habitat: supporting continuity of the feature and its (and its component vegetation) across the site will reduce its monitored as part of Natural extent and habitat supporting habitat, including overall area, the local diversity and variations in its structure England’s site condition distribution where applicable its component and composition, and may undermine its resilience to adapt to assessments vegetation types and associated future environmental changes. Contraction may also reduce transitional vegetation types, and break up the continuity of a habitat within a site and how Natural England, 2000 across the site well the species feature is able to occupy and use habitat within the site. Such fragmentation may have a greater amount of open edge habitat which will differ in the amount of light, temperature, wind, and even noise that it receives compared to its interior. These conditions may not be suitable for this feature and this may affect its viability.
The S1065 marsh fritillary feature is supported by a suite of habitats found within the site that support it through its life cycle including: Purple Moor-grass and Rush Pasture for the larval food plant and adult nectaring sites and other wetland communities and areas of scrub for nectaring and shelter, as the adults are weak fliers. Structural diversity is also important in the grassland for the provision of suitable larval web sites.
Supporting Extent of Maintain the total extent of the In order to contribute towards the objective of achieving an Natural England, 2008 – habitat: supporting habitat which supports the overall favourable conservation status of the feature at a UK Available from Natural England extent and habitat feature at: level, it is important to maintain or if appropriate restore the on request distribution Purple Moor Grass & Rush extent of supporting habitats and their range within this SAC. Pasture (M23/M25) 33.86
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
hectares The information available on the extent and distribution of supporting habitat used by the feature may be approximate depending on the nature, age and accuracy of data collection, and may be subject to periodic review in light of improvements in data.
Supporting Ground Grazing regime should allow for Sward height should be long enough during spring/ summer habitat: moisture a sufficiently long sward during months that the larval foodplant does not become desiccated structure/ the summer months to avoid (especially important on calcareous grassland sites). function dessication of the Susccisia plants on which the larvae feed. Supporting Soils, Maintain the properties of the Soil supports basic ecosystem function and is a vital part of the habitat: substrate and underlying soil types, including natural environment. Its properties strongly influence the structure/ nutrient structure, bulk density, total colonisation, growth and distribution of those plant species function cycling carbon, pH, soil nutrient status which together form vegetation types, and therefore provides a and fungal:bacterial ratio, within habitat used by a wide range of organisms. typical values for the supporting habitat Soil biodiversity has a vital role to recycle organic matter. Changes to natural soil properties may therefore affect the ecological structure, function and processes associated with the supporting habitat of this Annex II feature. Supporting Vegetation Maintain an abundance of devils- As the feature's larval foodplant, Succisa should be common This attribute will be periodically habitat: composition - bit scabious Succisa pratensis enough in the sward that there will always be a good and monitored as part of Natural structure/ presence of within supporting habitat continuous number of suitable plants for egg-laying; this is England’s site condition function foodplants particularly important on calcareous grassland sites, which are assessments more prone to drought.
Supporting Vegetation Maintain, and where necessary, The larval foodplant grows on calcareous, as well as neutral, This attribute will be periodically habitat: structure - restore appropriate sward grassland, but this habitat is drier and more prone to drought; monitored as part of Natural structure/ sward height conditions, with a typical sward so the sward height should be longer to ensure the Succisa is England’s site condition function height of 8-20 cm on average usable by the larvae. assessments (during summer months) Natural England, 2008 – Available from Natural England on request
Supporting Adaptation Maintain the feature's ability, and This recognises the increasing likelihood of supporting habitat Natural England (2015) Climate processes and resilience that of its supporting habitat, to features to absorb or adapt to wider environmental changes. Change Theme Plan and (on which the adapt or evolve to wider Resilience may be described as the ability of an ecological supporting National Biodiversity
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available) feature and/or environmental change, either system to cope with, and adapt to environmental stress and Climate Change Vulnerability its supporting within or external to the site change whilst retaining the same basic structure and ways of assessments (‘NBCCVAs’) for habitat relies) functioning. Such environmental changes may include changes SACs and SPAs in England in sea levels, precipitation and temperature for example, which Available at: are likely to affect the extent, distribution, composition and http://publications.naturalengland. functioning of a feature within a site. The vulnerability and org.uk/publication/495459459137 response of features to such changes will vary. 5360
Using best available information, any necessary or likely adaptation or adjustment by the feature and its management in response to actual or expected climatic change should be allowed for, as far as practicable, in order to ensure the feature's long-term viability.
The overall vulnerability of this SAC to climate change has been assessed by Natural England (2015) as being high, taking into account the sensitivity, fragmentation, topography and management of its supporting habitats. This means that this site is considered to be one of the most vulnerable sites overall, likely to require the most adaptation action, most urgently.
A site based assessment should be carried out as a priority. This means that action to address specific issues is likely, such as reducing habitat fragmentation, creating more habitat to buffer the site or expand the habitat into more varied landscapes and addressing particular management and condition issues. Individual species may be more or less vulnerable than their habitat itself. In many cases, change will be inevitable so appropriate monitoring would be advisable.
Supporting Air quality Maintain or, where necessary, See the explanatory notes for this attribute above in Table 1 More information about site- processes restore concentrations and relevant Critical Loads and Levels (on which the deposition of air pollutants to at for this SAC is available by using feature and/or or below the site-relevant Critical the ‘search by site’ tool on the Air its supporting Load or Level values given for Pollution Information System habitat relies) this feature of the site on the Air (www.apis.ac.uk). Pollution Information System (www.apis.ac.uk).
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
Supporting Conservation Maintain, and where necessary, Active and ongoing conservation management is needed to This attribute will be periodically processes measures restore the management protect, maintain or restore this feature at this site. Further monitored as part of Natural (on which the measures (either within and/or details about the necessary conservation measures for this site England’s site condition feature and/or outside the site boundary as can be provided by contacting Natural England. assessments its supporting appropriate) which are necessary habitat relies) to maintain and restore the This information will typically be found within, where applicable, English Nature, 2005a structure, functions and supporting documents such as Natura 2000 Site Improvement supporting processes associated Plan, site management strategies or plans, the Views about Natural England, 2014b with the feature and/or its Management Statement for the underpinning SSSI and/or supporting habitats. management agreements.
Purple Moor-grass and Rush pasture, which is the habitat that supports the marsh fritillary butterfly, requires low intensity grazing management to maintain suitable structure and foodplant density for the marsh fritillary. If grazing is too intensive then the sward becomes uniform and the abundance of devil’s-bit scabious is reduced. Conversely, if grazing is insufficient then vegetation becomes too coarse. Optimum grazing regimes alone are not sufficient to control scrub and maintain open areas of Purple Moor-grass and Rush Pasture and so additional scrub control is also required.
Supporting Grazing Maintain and restore a cattle or Cattle grazing is preferable as it produces a less uniform sward; Doyle, 2018 processes pressure pony-dominated grazing regime. also sheep tend to selectively graze the Succisa, which is likely (on which the Stock may be removed May- to be detrimental to marsh fritillary populations. If sheep are feature and/or September, but light continuous used it should be at a very low stocking ration (especially on its supporting cattle grazing is more beneficial calcareous sites, where care should be taken that sites aren't habitat relies) than short-term heavy grazing, overgrazed, resulting in a short sward and increased risk of as long as the correct sward dessication of Succisa plants (if they aren't actually eaten!). structure is maintained and sites Sheep should not graze during the summer months - cattle/ do not become overgrazed. pony grazing during summer may be OK if at a low stocking density. Supporting Water Where the feature or its For many SAC features which are dependent on wetland Natural England, 2014b processes quantity/ supporting habitat is dependent habitats supported by surface and/or ground water, maintaining (on which the quality on surface water and/or the quality and quantity of water supply will be critical, feature and/or groundwater, maintain, and especially at certain times of year. Poor water quality and its supporting where necessary, restore, water inadequate quantities of water can adversely affect the habitat relies) quality and quantity to a standard structure and function of this habitat type. which provides the necessary
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
conditions to support the feature Typically, meeting the surface water and groundwater environmental standards set out by the Water Framework Directive (WFD 2000/60/EC) will also be sufficient to support the achievement of SAC Conservation Objectives but in some cases more stringent standards may be needed to reflect the ecological needs of the species feature. Further site-specific investigations may be required to establish appropriate water quality standards for the SAC.
The Site Improvement Plan for the River Derwent and Bassenthwaite Lake SAC lists water pollution as a potential threat to marsh fritillary (enriching habitat), along with water abstraction and the pressure of hydrological change. Measures listed include: exploring options to prevent future damaging lake drawdown and the hydrological management of Braithwaite Moss.
Version Control Advice last updated: N/A Variations from national feature-framework of integrity-guidance: The targets for some attributes listed above include both ‘maintain’ and ‘restore’ objectives. This is because River Derwent & Bassenthwaite Lake SAC is comprised of a number of geographically-separate component sites which are currently in different states of condition. Overall, both objectives will be applicable to the SAC but these will differ between each component site depending on its particular circumstances. Natural England will able to provide further specific advice on request.
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Table 4: Supplementary Advice for Qualifying Features: S1095. Petromyzon marinus; Sea lamprey and S1096 Brook lamprey Lampetra planeri; and S1099 River lamprey Lampetra fluviatilis
Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
Population Juvenile Restore juvenile densities at Impacts on physical, chemical or hydrological integrity, or from (of the densities those expected under non-native species, may suppress juvenile densities. feature) unimpacted conditions throughout the site, taking into account natural habitat conditions and allowing for natural fluctuations
Population Population Restore the abundance of the This will ensure there is a viable population of the feature which (of the abundance population to a level which is is being maintained at or increased to a level that contributes feature) close to that expected under as appropriate to its Favourable Conservation Status across its unimpacted conditions natural range in the UK. throughout the site (subject to natural habitat conditions and Due to the dynamic nature of population change, the target- allowing for natural fluctuations), value given for the population size or presence of this feature is whilst avoiding deterioration from considered to be the minimum standard for its current level as indicated by conservation/restoration measures to achieve. the latest mean peak count or equivalent. This minimum-value may be revised where there is evidence to show that a population’s size or presence has significantly Lamprey ammocoete populations changed as a result of natural factors or management should have at least 3 age measures and has been stable at or above a new level over a classes. considerable period (generally at least 10 years). The values given here may also be updated in future to reflect any strategic objectives which may be set at a national level for this feature. Given the likely fluctuations in numbers over time, any impact- assessments should focus on the current size of the site’s population, as derived from the latest known or estimated level established using the best available data. This advice accords with the obligation to avoid deterioration of the site or significant disturbance of the species for which the site is designated, and seeks to avoid plans or projects that may affect the site giving rise to the risk of deterioration. Similarly, where there is evidence to show that a feature has historically been more abundant than the stated minimum target and its current level,
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
the ongoing capacity of the site to accommodate the feature at such higher levels in future should also be taken into account in any assessment. Unless otherwise stated, the population size or presence will be that measured using standard methods, such as peak mean counts or breeding surveys. This value is also provided recognising there will be inherent variability as a result of natural fluctuations and margins of error during data collection. Whilst we will endeavour to keep these values as up to date as possible, local Natural England staff can advise that the figures stated are the best available.
Supporting Distribution of Restore the distribution and A contraction in the range, or geographic spread, of the feature Jacobs, 2010a; 2010b; 2010c habitat: supporting continuity of the features and (and its component vegetation) across the site will reduce its extent and habitat their supporting habitat, including overall area, the local diversity and variations in its structure Harvey and Cowx, 2003 distribution where applicable its component and composition, and may undermine its resilience to adapt to vegetation types and associated future environmental changes. transitional vegetation types, across the site Contraction may also reduce and break up the continuity of a habitat within a site and how well the species feature is able to occupy and use habitat within the site. Such fragmentation may have a greater amount of open edge habitat which will differ in the amount of light, temperature, wind, and even noise that it receives compared to its interior. These conditions may not be suitable for this feature and this may affect its viability. Supporting Extent of Restore the total extent of the In order to contribute towards the objective of achieving an Jacobs, 2010a; 2010b; 2010c habitat: supporting river habitat to that characteristic overall favourable conservation status of the feature at a UK extent and habitat of the natural fluvial processes level, it is important to maintain or if appropriate restore the distribution associated with the river type, extent of supporting habitats and their range within this SAC. which supports the brook, river and sea lamprey. The information available on the extent and distribution of supporting habitat used by the feature may be approximate depending on the nature, age and accuracy of data collection, and may be subject to periodic review in light of improvements in data. Supporting Biological See general advice for river Lampreys can pass some potential barriers by attaching Jacobs, 2010a; 2010b; 2010c habitat: connectivity habitat (H3260) themselves to structures or river banks by their suctorial discs structure/ and creeping up by strong bursts of swimming. However, many Lucas et al., 2009 function in-channel structures are known to either completely or partially
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
block access to historical spawning grounds. Kemp et al., 2011
Whilst in-channel structures can artificially generate both siltbeds and clean gravels, both of value to lamprey species, this is not a justification for their continued existence or the construction of new structures. Suitable habitat for lamprey and other species can and should be generated by natural processes - where physical restoration of the channel is required this may involve changes in the distribution of species within the river system.
The River Derwent and Bassenthwaite Lake SAC has many artificial barriers of different sizes and some will not be passable to lamprey species. Abundant small scale barriers, even when passable, can have an adverse cumulative effect on lamprey condition. Passage rate of lamprey over barriers is also dependant on the water flow rates over the weir/barrier. Lamprey passage is low when maximum velocities at the weir/barrier exceed 1.5m/s.
Implementation of the River Restoration Strategy will restore biological connectivity where possible.
Supporting Biotope See general advice for river Habitat conditions for lamprey species vary naturally in rivers. habitat: mosaic habitat (H3260) Some river sections may provide optimal habitat for some or all structure/ life stages whilst others may be largely unsuitable. Adult function lamprey require spawning substrates of coarse material in which to deposit eggs in shallow scrapes (redds). Larval lamprey (ammocoetes) live in silt beds, which are often in channel margins but in relation to sea lamprey are known to occur in deep water in main river reaches.
The advice for H3260 is based on natural river function, which provides a characteristic biotope mosaic that caters for lamprey life stages to a degree characteristic of the river. Supporting Control of See general advice for river Over-grazing of riparian areas can have a dramatic effect on habitat: livestock habitat (H3260) lamprey habitat, trampling marginal siltbeds, eliminating structure/ grazing marginal vegetation and generating excessive loads of fine function activity sediment on spawning gravels.
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
Supporting Fisheries - All exploitation (e.g. netting or Controls on exploitation should include migratory passage habitat: exploitation angling) of lamprey species within territorial waters, including estuarine and coastal net structure/ should be undertaken fisheries, as well as exploitation within the river. function sustainably without compromising any components Lamprey species are not exploited in the River Derwent of the population catchment. Supporting Fisheries - Ensure fish stocking/ The presence of artificially high densities of fish may create habitat: introduction introductions do not interfere with unacceptably high levels of predatory pressure on brook structure/ of fish the ability of the river to support lamprey and ammocoetes of all species. function species self-sustaining populations of the features The management aim is to provide conditions in the river that support a healthy, natural and self-sustaining salmon population, achieved through habitat protection/restoration and the control of exploitation as necessary.
Stocking represents a loss of naturalness and, if successful, obscures the underlying causes of poor performance (potentially allowing these risks to perpetuate). It carries various ecological risks, including the loss of natural spawning from broodstock, competition between stocked and naturally produced individuals, disease introduction and genetic alterations to the population.
Supporting Flow regime See general advice for river The natural flow regime is critical to all aspects of lamprey life habitat: habitat (H3260). cycle. It shapes the characteristic biotope mosaic, maintains structure/ water in critical biotopes (including marginal siltbeds), and function provides adequate flows for migratory passage (which is important not only for river and sea lamprey but also brook lamprey in its shorter distance migrations within the river). Supporting Integrity of See general advice for river Lamprey populations may be dependent on the integrity of habitat: off-site habitat (H3260) sections of river channel, riparian areas and transitional and structure/ habitats marine waters that lie outside of the site boundary. function Headwater areas and tributaries may not fall within the site boundary, yet lamprey (particularly brook and river lamprey) may use these areas for spawning and juvenile development and be critical for sustaining populations within the site. River and sea lamprey require safe passage through coastal waters and estuaries.
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
Supporting Riparian zone See general advice for river Active marginal vegetation including riparian trees provides Jacobs, 2010a; 2010b; 2010c habitat: habitat (H3260) important habitat for lamprey ammocoetes, as it encourages structure/ and stabilises the formation of silt beds in which ammocoetes function burrow.
Riparian trees also add substrate diversity and aid the formation of siltbeds and clean gravels. They also provide temperature gradients in the channel that improves the availability of suitable micro-habitat. Supporting Screening of See general advice for river Adult lamprey and migrating sub-adults (transformers) can be habitat: intakes and habitat (H3260) entrained in intakes and discharges along with other fish structure/ discharges species. function
Supporting Sediment See general advice for river Natural levels of coarse sediment supply are critical to the habitat: regime habitat (H3260) maintenance of high quality spawning habitat for lamprey structure/ species, maintaining bed substrates in optimal condition for function egg-laying and juvenile and adult cover.
Excessive delivery of fine sediment, from the catchment or artificially enhanced bank erosion, can cause siltation of egg- laying sites and juvenile and adult refugia. Supporting Soils, Maintain and where appropriate, Soil supports basic ecosystem function and is a vital part of the habitat: substrate and restore the properties of the natural environment. Its properties strongly influence the structure/ nutrient underlying soil types, including colonisation, growth and distribution of those plant species function cycling structure, bulk density, total which together form vegetation types, and therefore provides a carbon, pH, soil nutrient status habitat used by a wide range of organisms. and fungal:bacterial ratio, within typical values for the supporting Soil biodiversity has a vital role to recycle organic matter. habitat Changes to natural soil properties may therefore affect the ecological structure, function and processes associated with the supporting habitat of this Annex II feature.
Supporting Vegetation See general advice for river Species such as signal crayfish can have a serious effect on Natural England, 2014b habitat: composition: habitat (H3260) lamprey habitat and may predate heavily on brook lamprey and structure/ invasive non- ammoecoets of all lamprey species if present at high densities. function native species Chinese mitten crab is also of concern, not only in the lower reaches of main river but due to its potential to migrate long
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
distances upstream.
Signal crayfish are known to occur in St John’s Beck and the River Glenderamackin.
Supporting Water quality See general advice for river Brook lamprey may be affected by acidification in low alkalinity habitat: - acidification habitat (H3260) headwaters. Maps of critical loads provide an indication of structure/ acidification hotspots. function Supporting Water quality Restore the natural nutrient Nutrient enrichment can lead to loss of substrate condition for habitat: - nutrients regime of the rivers, with any spawning, egg development and ammocoete growth, due to structure/ anthropogenic enrichment above benthic algal growth and associated enhanced siltation and function natural/background sediment anoxia. concentrations limited to levels at which adverse effects on the Lamprey species may be affected by both episodic and chronic features are unlikely. organic pollution. Episodic pollution causes direct mortalities whilst chronic pollution affects substrate condition through the build-up of excessive microbial populations. Supporting Woody debris See general advice for river Woody debris is an important component of river habitat for Jacobs, 2010a; 2010b; 2010c habitat: habitat (H3260) lampreys as well as the wider biological community. It structure/ encourages characteristic heterogeneity in biotopes, provides a function mosaic of substrates types that lamprey species need to fulfil their life cycle. Supporting Adaptation Restore the features’ ability, and See the explanatory notes for this attribute above in Table 3 NATURAL ENGLAND, 2015. processes and resilience that of their supporting habitat, to Climate Change Theme Plan and (on which the adapt or evolve to wider supporting National Biodiversity feature and/or environmental change, either Climate Change Vulnerability its supporting within or external to the site assessments (‘NBCCVAs’) for habitat relies) SACs and SPAs in England [Available at http://publications.naturalengland. org.uk/publication/495459459137 5360]. Supporting Air quality Maintain or, where necessary, See the explanatory notes for this attribute above in Table 1 More information about site- processes restore concentrations and relevant Critical Loads and Levels (on which the deposition of air pollutants to at for this SAC is available by using feature and/or or below the site-relevant Critical the ‘search by site’ tool on the Air its supporting Load or Level values given for Pollution Information System habitat relies) this feature of the site on the Air (www.apis.ac.uk).
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
Pollution Information System (www.apis.ac.uk). Supporting Conservation Restore the management Active and ongoing conservation management is needed to English Nature, 2005b processes measures measures (either within and/or protect, maintain or restore this feature at this site. Further (on which the outside the site boundary as details about the necessary conservation measures for this site Natural England, 2014b feature and/or appropriate) which are necessary can be provided by contacting Natural England. its supporting to restore the structure, functions habitat relies) and supporting processes This information will typically be found within, where applicable, associated with brook, river and supporting documents such as Natura 2000 Site Improvement sea lamprey and/or their Plan, site management strategies or plans, the Views about supporting habitats. Management Statement for the underpinning SSSI and/or management agreements. Supporting Water Where the feature or its For many SAC features which are dependent on wetland processes quantity/ supporting habitat is dependent habitats supported by surface and/or ground water, maintaining (on which the quality on surface water and/or the quality and quantity of water supply will be critical, feature and/or groundwater, maintain and where especially at certain times of year. Poor water quality and its supporting necessary, restore water quality inadequate quantities of water can adversely affect the habitat relies) and quantity to a standard which structure and function of this habitat type. provides the necessary conditions to support the feature. Typically, meeting the surface water and groundwater environmental standards set out by the Water Framework Directive (WFD 2000/60/EC) will also be sufficient to support the achievement of SAC Conservation Objectives but in some cases more stringent standards may be needed to reflect the ecological needs of the species feature. Further site-specific investigations may be required to establish appropriate water quality standards for the SAC.
Version Control Advice last updated: N/A Variations from national feature-framework of integrity-guidance: The targets for some attributes listed above include both ‘maintain’ and ‘restore’ objectives. This is because River Derwent & Bassenthwaite Lake SAC is comprised of a number of geographically-separate component sites which are currently in different states of condition. Overall, both objectives will be applicable to the SAC but these will differ between each component site depending on its particular circumstances. Natural England will able to provide further specific advice on request.
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Table 5: Supplementary Advice for Qualifying Features: S1106. Salmo salar; Atlantic salmon
Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
Population Adult run size Restore the population to that Impacts on physical, chemical or hydrological integrity, or from CEFAS, ENVIRONMENT (of the expected under un-impacted non-native species, or from exploitation in freshwater or marine AGENCY, 2003. feature) conditions, allowing for natural and coastal waters, may suppress adult run size. fluctuations. CEFAS and NRW, 2016 Stocking may also artificially augment adult run size, and may This should include a seasonal mask environmental problems or generate impacts on naturally ENVIRONMENT AGENCY, 2017 pattern of migration characteristic spawned individuals. The Conservation Limit should be based of the river and maintenance of on the adult run size required to fully utilise all parts of the the multi-sea-winter component. catchment that would be suitable for spawning and juvenile As a minimum, the Conservation development under unimpacted conditions. Limit for the river system should be complied with. The Conservation Limit for the River Derwent is a deposition rate of 3.93 million eggs/annum. This was exceeded in 2013 (144 %) and not reached in 2014 (82 %). The numbers declined in 2015 (56 %) but improved in 2016 (although still under the conservation limit). The annual assessment report including 2016 data shows that the CL has only been met in 3 years out of the last 5. The salmon population is on a declining trend. The effects of low numbers of returning adult salmon in 2014, 2015 and 2016, and the effects of Storm Desmond, are still to be observed in the population in the coming years. The records show that whilst there is likely to be a small recovery in the multi-sea winter fish, the grilse numbers have continued to decline. Electrofishing data has also shown a decline in fry and parr numbers in some parts of the catchment.
Population Juvenile Restore juvenile densities at Impacts on physical, chemical or hydrological integrity, or from (of the densities those expected under non-native species, or from exploitation of spawning adults in feature) unimpacted conditions freshwater or marine and coastal waters, may suppress throughout the site, taking into juvenile densities. account natural habitat conditions and allowing for natural fluctuations
Population Spawning Restore the distribution of After a year or more at sea, adult salmon return from their English Nature, 2005d (of the distribution spawning to reflect unimpacted feeding grounds back to their river. Once it is time for them to
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available) feature) conditions through the site, and spawn they will migrate upstream to the areas of the SAC avoid reductions in existing where they were born to spawn themselves. These spawning levels. areas may be in small tributaries of river systems where there is clean gravel and a good flow of fresh clean water. Maintaining these spawning areas is critical to the successful reproduction and long-term viability of this feature.
The principal tributaries for salmon spawning and nursery grounds are the Rivers Greta, Glenderamackin and Marron as well as St John’s, Naddle, Whit and Sandy Becks. The Greta- Glenderamackin, with its tributaries St John’s and Naddle Becks, act as the prime salmon fry and parr production area in the Upper Derwent catchment.
Supporting Distribution of Maintain, and where necessary A contraction in the range, or geographic spread, of the feature habitat: supporting restore, the distribution and (and its component vegetation) across the site will reduce its extent and habitat continuity of the feature and its overall area, the local diversity and variations in its structure distribution supporting habitat, including and composition, and may undermine its resilience to adapt to where applicable its component future environmental changes. Contraction may also reduce vegetation types and associated and break up the continuity of a habitat within a site and how transitional vegetation types, well the species feature is able to occupy and use habitat within across the site the site. Such fragmentation may have a greater amount of open edge habitat which will differ in the amount of light, temperature, wind, and even noise that it receives compared to its interior. These conditions may not be suitable for this feature and this may affect its viability.
Supporting Extent of Maintain, or where necessary, In order to contribute towards the objective of achieving an Natural England, 2009a – habitat: supporting restore the total extent of the overall favourable conservation status of the feature at a UK Available from Natural England extent and habitat habitat(s) which support the level, it is important to maintain or if appropriate restore the on request distribution feature (at/to]: extent of supporting habitats and their range within this SAC.
Rivers and streams: 133.56 km The information available on the extent and distribution of length supporting habitat used by the feature may be approximate depending on the nature, age and accuracy of data collection, Standing open water: 1,415 and may be subject to periodic review in light of improvements hectares in data.
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
Supporting Biological See general advice for river Freedom of movement throughout the river system is critical to Jacobs, 2010a; 2010b; 2010c habitat: connectivity habitat (H3260) all life stages of salmon. Barriers to adult migration have structure/ cumulative effects on the ability of individuals to reach Newton et al., 2017 function spawning grounds and need to be considered in combination.
The River Derwent and Bassenthwaite Lake SAC has many artificial barriers of different sizes. There are fish passes on some of the larger structures. However, even if salmon can pass the barriers, there may be a loss in their condition and increased levels of predation whilst negotiating the barrier.
The River Derwent River Restoration Strategy includes removal of some priority structures.
Supporting Biotope See general advice for river Within the river, a characteristic habitat mosaic shaped by habitat: mosaic habitat (H3260) natural processes provides the diversity of water depths, structure/ current velocities and substrate types necessary to fulfil the function spawning, juvenile, adult and migratory requirements of salmon as well as other characteristic species. Some river sections will be naturally sub-optimal for some salmon life stages, and this is just a characteristic of the river.
The species requires adult holding areas (generally pools of at least 150 cm depth, with cover from features such as undercut banks, vegetation, submerged objects and surface turbulence), spawning habitat (stable, clean gravel/pebble-dominated substrate without an armoured layer and with <10% fines in the top 30cm, and with 15-75cm of overlying water), nursery habitat (for fry, water of <20 cm deep and a gravel/pebble/cobble substrate; for parr, water 20-40 cm deep and similar substrate).
Close juxta position of biotopes is needed to allow easy movement of individuals between suitable areas of the channel under different flow conditions and with age.
Supporting Flow regime See general advice for river The natural flow regime is critical to all aspects of the salmon habitat: habitat (H3260). life cycle, including migratory passage through the estuary and structure/ up the river to spawning grounds, egg incubation in redds, fry
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available) function and parr habitat quality and extent, and downstream smolt migration.
Supporting Riparian zone See general advice for river High riparian tree cover is beneficial to salmon, in terms of habitat: habitat (H3260) physical habitat provision and combatting increasing structure/ temperatures caused by climate change. However, the extent function of tree cover needs to be optimised to provide suitable conditions for the whole characteristic biological community.
Supporting Sediment See general advice for river Natural levels of coarse sediment supply are critical to the habitat: regime habitat (H3260) maintenance of high quality juvenile and salmon habitat, structure/ maintaining spawning gravels and characteristic biotope function mosaics.
Excessive delivery of fine sediment, from the catchment or artificially enhanced bank erosion, can damage gills, impair vision and cause siltation of spawning and nursery areas.
Supporting Soils, Maintain, and where necessary, Soil supports basic ecosystem function and is a vital part of the habitat: substrate and restore the properties of the natural environment. Its properties strongly influence the structure/ nutrient underlying soil types, including colonisation, growth and distribution of those plant species function cycling structure, bulk density, total which together form vegetation types, and therefore provides a carbon, pH, soil nutrient status habitat used by a wide range of organisms. and fungal:bacterial ratio, within typical values for the supporting Soil biodiversity has a vital role to recycle organic matter. habitat Changes to natural soil properties may therefore affect the ecological structure, function and processes associated with the supporting habitat of this Annex II feature.
Supporting Thermal See general advice for river Water temperature can affect egg development, fish survival, habitat: regime habitat (H3260) feeding and growth. structure/ function
Supporting Vegetation See general advice for river Species such as signal crayfish can have a serious effect on habitat: composition: habitat (H3260) salmon habitat and can predate heavily on salmon juveniles if structure/ invasive non- present at high densities. Chinese mitten crab has the potential function native species to migrate long distances up rivers and damage marginal
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
habitats used by both adult and juvenile salmon.
Signal crayfish are known to occur in St John’s Beck (the most productive salmon fry nursery on the Derwent) and the River Glenderamackin.
Supporting Water quality See general advice for river Salmon are highly sensitive to acidification stress. habitat: - acidification habitat (H3260) structure/ function
Supporting Water quality Restore the natural nutrient In addition to the wider ecosystem effects of eutrophication that Natural England, 2009a – habitat: - nutrients regime of the river, with any have a detrimental effect on salmon habitat, enrichment can Available from Natural England structure/ anthropogenic enrichment above place salmon at a competitive disadvantage, for instance on request function natural/background relative to brown trout. Salmon are efficient foragers that are concentrations limited to levels at adapted to low productivity environments, and increased which adverse effects on the productivity makes efficient foraging obsolete. feature are unlikely. Eutrophication and episodic pollution causes direct mortalities, Unionised ammonia: 0.03m/L as whilst chronic pollution affects substrate condition through the 95%ile; build up of excessive microbial populations. Total ammonia: 0.25mg/L as 90%ile; Salmon are particularly sensitive to reduced dissolved oxygen Dissolved oxygen: 85% levels, in the water column and within the gravel substrate of saturation as 10%ile. spawning redds (nests).
See Table 1 for site specific Salmon are particularly sensitive to ammonia so organic inputs targets. are acutely toxic to the fish in addition to lowering the dissolved oxygen or causing increased eutrophication.
Implementation of the Diffuse Water Pollution Plan, River Restoration Plan and the Catchment Sensitive Farming Initiative will all contribute towards reducing inputs to the river and reduce levels of phosphorus and nitrogen.
Supporting Woody debris See general advice for river Woody debris is an important component of river habitat for habitat: habitat (H3260) salmon as well as the wider biological community. structure/ function
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
Supporting Adaptation Restore the feature's ability, and See the explanatory notes for this attribute above in Table 3 NATURAL ENGLAND, 2015. processes and resilience that of its supporting habitat, to Climate Change Theme Plan and (on which the adapt or evolve to wider supporting National Biodiversity feature and/or environmental change, either Climate Change Vulnerability its supporting within or external to the site assessments (‘NBCCVAs’) for habitat relies) SACs and SPAs in England [Available at http://publications.naturalengland. org.uk/publication/495459459137 5360]. Supporting Air quality Maintain or, where necessary, See the explanatory notes for this attribute above in Table 1 More information about site- processes restore concentrations and relevant Critical Loads and Levels (on which the deposition of air pollutants to at for this SAC is available by using feature and/or or below the site-relevant Critical the ‘search by site’ tool on the Air its supporting Load or Level values given for Pollution Information System habitat relies) this feature of the site on the Air (www.apis.ac.uk). Pollution Information System (www.apis.ac.uk). Supporting Conservation Maintain, and where necessary Active and ongoing conservation management is needed to English Nature, 2005b processes measures restore the management protect, maintain or restore this feature at this site. Further (on which the measures (either within and/or details about the necessary conservation measures for this site feature and/or outside the site boundary as can be provided by contacting Natural England. This its supporting appropriate) which are necessary information will typically be found within, where applicable, habitat relies) to maintain or restore the supporting documents such as Natura 2000 Site Improvement structure, functions and Plan, site management strategies or plans, the Views about supporting processes associated Management Statement for the underpinning SSSI and/or with the feature and/or its management agreements. supporting habitats. Rivers and streams naturally provide a diversity of habitats for plants and animals. Some of these habitats are directly connected with the physical form of the channel and its banks; others are created by the vegetation which the river’s form supports. The river’s natural structure and form should be maintained. This will support a natural flow regime that will help conserve the geomorphological features of interest. It will also ensure the provision of resting pools for fish, conserve the quality of the riverbed as fish spawning habitat, and avoid the creation of artificial barriers to the passage of migratory fish. Natural barriers to the movement of fish (such as waterfalls)
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
should be left alone. Where artificial modifications have occurred - such as weirs and impoundments, embankment, straightening and dredging – the restoration of natural channel profiles and dynamics is desirable where appropriate.
Any new infrastructure, such as road and rail bridges should be carefully designed to avoid the constriction of the river or blockage of its floodplain. Opportunities should be taken to create additional riparian areas where flooding is acceptable, in order to reconnect the river with its floodplain.
Management should maintain the natural flow regime of the river or stream, including natural erosion and sedimentation processes, in order to meet the requirements of the full range of flora and fauna it supports. Abstraction levels should be managed to protect the characteristic flow regime, including seasonal base flows and flushing flows. Compensation flows are generally not an acceptable alternative to reducing abstraction, and river transfers may also have an undesirable effect on river ecology.
Bank-side vegetation should be allowed to develop, allowing characteristic plants to flourish. The characteristic aquatic plant communities associated with in-channel vegetation should be allowed to flourish, including fringing emergent vegetation and beds of submerged plants. Any cutting of vegetation should aim to leave at least 50% of the channel vegetated, comprising an active marginal fringe and a mosaic of submerged and floating beds that are allowed to flower and set seed.
Rivers and streams are susceptible to the introduction of invasive plant and animal species. Surrounding Japanese knotweed and Himalayan balsam should be controlled.
The maintenance of good water and sediment quality are essential to maintaining a healthy river system. Management should minimise pollution of the river from point and diffuse sources, including discharges of domestic and industrial effluent, and run-off from agriculture, forestry and urban land.
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
Effluents entering the river directly or indirectly should be treated to reduce the levels of phosphorus contained within them to concentrations that will not lead to a proliferation of algae or the disappearance of characteristic plants and animals. Organic pollution should also be controlled to avoid de-oxygenation of the water or any toxic effects on aquatic animals and plants. Siltation of the river bed can smother and infill coarse gravels, which can affect fish spawning success.
Riparian areas and the wider catchment need to be managed sensitively to avoid excessive run-off of soil particles and nutrients into the river. Ploughing should not be allowed to destabilise river banks and an unploughed strip of at least 2m should be left adjacent to the riverbank.
Supporting Control of See general advice for river Over-grazing of riparian areas can have a dramatic effect on processes livestock habitat (H3260) salmon habitat. (on which the grazing feature and/or activity its supporting habitat relies) Supporting Fisheries - Ensure exploitation (e.g. netting Controls on exploitation should include migratory passage CEFAS, 2016 processes exploitation or angling) of Atlantic salmon is within territorial waters, including estuarine and coastal net (on which the undertaken sustainably without fisheries, as well as exploitation within the river from rod Environment Agency, 2017 feature and/or compromising any components fisheries. its supporting of the population, including multi- habitat relies) sea winter fish and seasonal There are byelaws to limit rod fishing on the Derwent. components of the adult run.
Supporting Fisheries - Ensure fish The presence of artificially high densities of other fish creates processes introduction stocking/introductions do not unacceptably high levels of predatory and competitive pressure (on which the of fish interfere with the ability of the on juvenile salmon. The management aim is to provide feature and/or species river to support self-sustaining conditions in the river that support a healthy, natural and self- its supporting populations of the feature sustaining salmon population, achieved through habitat habitat relies) protection/restoration and the control of exploitation as necessary.
Stocking represents a loss of naturalness and, if successful, obscures the underlying causes of poor performance
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
(potentially allowing these risks to perpetuate). It carries various ecological risks, including the loss of natural spawning from broodstock, competition between stocked and naturally produced individuals, disease introduction and genetic alterations to the population.
The River Derwent is a wild fishery, so any fish stocking would be unacceptable.
Supporting Fisheries - Ensure fish The management aim is to provide conditions in the river that processes introduction stocking/introductions do not support a healthy, natural and self-sustaining salmon (on which the of salmon interfere with the ability of the population, achieved through habitat protection/restoration and feature and/or river to support self-sustaining the control of exploitation as necessary. its supporting populations of the salmon. habitat relies) Stocking represents a loss of naturalness and, if successful, obscures the underlying causes of poor performance (potentially allowing these risks to perpetuate). It carries various ecological risks, including the loss of natural spawning from broodstock, competition between stocked and naturally produced individuals, disease introduction and genetic alterations to the population.
The River Derwent is a wild fishery, so any salmon stocking would be unacceptable.
Supporting Integrity of See general advice for river Salmon populations are dependent on the integrity of sections processes off-site habitat (H3260) of river channel, riparian areas, and transitional and marine (on which the habitats waters that lie outside of the site boundary. feature and/or its supporting Headwater areas and tributaries may not fall within the site habitat relies) boundary, yet salmon may use these areas for spawning and juvenile development and be critical for sustaining populations within the site.
Fully developed riparian zones are essential for salmon habitat, yet part of this zone may lie outside of the site boundary, particularly if the river channel is operating under natural processes and moves laterally over time within the floodplain.
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
The conditions experienced by salmon on their marine migration (through the saline transition zone, estuary, coastal waters and into the high seas) are critical to the well-being of populations within the river, and vice versa.
Supporting Screening of See general advice for river Salmon can be seriously affected by inadequate screening on processes intakes and habitat (H3260) their adult and smolt migrations, as well as on their smaller (on which the discharges juvenile dispersion movements between spawning grounds and feature and/or nursery areas. its supporting habitat relies) Supporting Vegetation See general advice for river In rivers where it naturally occurs, submerged and marginal processes structure: habitat (H3260) vegetation is an important element of juvenile salmon habitat. (on which the cover of feature and/or submerged its supporting macrophytes habitat relies) Supporting Water Where the feature or its For many SAC features which are dependent on wetland processes quantity/ supporting habitat is dependent habitats supported by surface and/or ground water, maintaining (on which the quality on surface water and/or the quality and quantity of water supply will be critical, feature and/or groundwater, maintain, or where especially at certain times of year. Poor water quality and its supporting necessary, restore water quality inadequate quantities of water can adversely affect the habitat relies) and quantity to a standard which structure and function of this habitat type. provides the necessary conditions to support the feature. Typically, meeting the surface water and groundwater environmental standards set out by the Water Framework See Table 1 for site specific Directive (WFD 2000/60/EC) will also be sufficient to support targets. the achievement of SAC Conservation Objectives but in some cases more stringent standards may be needed to reflect the ecological needs of the species feature. Further site-specific investigations may be required to establish appropriate water quality standards for the SAC.
Version Control Advice last updated: N/A Variations from national feature-framework of integrity-guidance: The targets for some attributes listed above include both ‘maintain’ and ‘restore’ objectives. This is because River Derwent & Bassenthwaite Lake SAC is comprised of a number of geographically-separate component sites which are currently in different states of condition. Overall, both objectives will be applicable to the SAC but these will differ between each component site depending on its particular circumstances. Natural England will able to provide further specific advice on request.
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Table 6: Supplementary Advice for Qualifying Features: S1355. Lutra lutra; Otter
Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
Population Anthropogenic Reduce levels of mortality as a High numbers of otter casualties within or adjacent to SAC (of the mortality result of anthropogenic (man- catchments will adversely affect the condition and viability of feature) made) factors so that they are the population and mitigation measures should be initiated as not adversely affecting the quickly as possible. Causes of mortality may include roads, overall abundance and viability accidents with fishing equipment (nets, lobster creels), of the population. poisoning, pollutants, hunting and acidification/contamination of water courses (which reduces fish populations). It should be noted that otters are also a European protected species, and that it is an offence to deliberately disturb, capture, injure or kill an otter. Population Population Maintain or restore as This will ensure there is a viable population of the feature which (of the abundance [all necessary the continued is being maintained at or increased to a level that contributes feature) sites] presence of an actively- as appropriate to its Favourable Conservation Status across its breeding otter population within natural range in the UK. the SAC, whilst avoiding deterioration from current levels Due to the dynamic nature of population change, the target- as indicated by the latest mean value given for the population size or presence of this feature is peak count, estimate or considered to be the minimum standard for equivalent. conservation/restoration measures to achieve. This minimum- value may be revised where there is evidence to show that a population’s size or presence has significantly changed as a result of natural factors or management measures and has been stable at or above a new level over a considerable period (generally at least 10 years). The values given here may also be updated in future to reflect any strategic objectives which may be set at a national level for this feature. Given the likely fluctuations in numbers over time, any impact- assessments should focus on the current size of the site’s population, as derived from the latest known or estimated level established using the best available data. This advice accords with the obligation to avoid deterioration of the site or significant disturbance of the species for which the site is designated, and seeks to avoid plans or projects that may affect the site giving rise to the risk of deterioration. Similarly, where there is evidence to show that a feature has historically been more abundant than the stated minimum target and its current level, the ongoing capacity of the site to accommodate the feature at
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
such higher levels in future should also be taken into account in any assessment. For otters, it is difficult to estimate population size. It could be assumed that where there is a high frequency of positive signs in an area, such as a large number of spraints (of several ages), that otters are likely to be occupying the site. Breeding will be indicated by the presence of natal dens, cub sightings and intensive otter activity (e.g. feeding, sprainting, pathways through vegetation). DNA analysis of spraints is now being used as a technique for identifying otters.
Supporting Distribution of Restore the distribution and A contraction in the range, or geographic spread, of the feature habitat: supporting continuity of the feature and its (and its component vegetation) across the site will reduce its extent and habitat supporting habitat, including overall area, the local diversity and variations in its structure distribution where applicable its component and composition, and may undermine its resilience to adapt to vegetation types and associated future environmental changes. transitional vegetation types, across the site. Contraction may also reduce and break up the continuity of a habitat within a site and how well the species feature is able to occupy and use habitat within the site. Such fragmentation may have a greater amount of open edge habitat which will differ in the amount of light, temperature, wind, and even noise that it receives compared to its interior. These conditions may not be suitable for this feature and this may affect its viability.
Supporting Extent of Restore the total extent of the In order to contribute towards the objective of achieving an habitat: supporting habitats which support the overall favourable conservation status of the feature at a UK extent and habitat feature: level, it is important to maintain or if appropriate restore the distribution extent of supporting habitats and their range within this SAC. river habitat to that characteristic of the natural The information available on the extent and distribution of fluvial processes associated supporting habitat used by the feature may be approximate with the river type; depending on the nature, age and accuracy of data collection, standing open water; wetland and may be subject to periodic review in light of improvements habitats - fen, marsh and in data. swamp
Supporting Abundance of Restore an abundance of It should be noted that otters are highly mobile and are likely to habitat: breeding and natural breeding and resting spend their time within wider territories, where designated sites
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available) structure/ resting places sites within the site. only form a proportion of their range and make a contribution to function their wider requirements.
Otters are a European protected species, and it is an offence to disturb their resting places. Otters will often use many holts at any one time. They may give birth in one, but raise their young in another. Important features of a successful breeding site are the availability of food, limited disturbance and safety from the risk of flooding. It is important to consider the whole site and not just the known holts as appropriate management will influence all of these factors.
Some natal den structures have a limited lifespan (e.g. hollow tree trunks, piles of timber etc.) and if alternative opportunities for natal dens are limited, suitable replacements can be created or constructed. Maintaining dense bank vegetation, areas of reed etc. will ensure that there are suitable areas for resting couches.
Supporting Availability of Restore an abundance of dense For rivers, most of the floodplain is outside the boundary of the habitat: refugia bankside vegetation to limit site, yet the integrity of the interest feature will often be structure/ significant disturbance to dependent upon the quality of the adjacent habitat outwith the function animals boundary of the site. This is likely to be the case where bankside vegetation may be an important barrier to disturbing activity but may lie adjacent to and outside the boundary. Nevertheless it will be important to maintain, or in some cases, to restore dense bankside cover.
Supporting Food Maintain fish biomass within In freshwater, key fish prey sources for otters include eels, habitat: availability expected natural levels for the salmonids, roach and sticklebacks. Frogs can also form an structure/ supporting habitat (subject to important part of the diet, depending on the habitat and time of function natural fluctuations). year. Crayfish and water beetles may also form part of the diet, as well as an occasional waterbird (young coots, moorhens, ducks) or mammal (rabbits, water voles - although this is uncommon).
The diet of coastal otters may include eelpout, rockling, butterfish, lumpsuckers and an occasional crab.
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
The diet of otters varies depending on the availability of prey, which in turn varies with the time of year. There should be a diverse range of food sources available throughout the year, within the normal expectations of each particular water course.
It should be noted however, that otters may take prey from adjacent fisheries which are stocked to an artificially high level, especially where there are numerous stocked gravel pits on a floodplain. This can lead to artificially high prey densities adjacent to European sites, which might be expected to, in turn, result in artificially high densities of otter on the designated sites. This highlights the importance of biosecurity around stocked fisheries, and if implemented at all artificial still water fisheries on a floodplain might result in a legitimate reduction in otter density.
Supporting Habitat quality Maintain, and where necessary, Dense bank vegetation, marshes and reedbeds are important Kruuk et al., 1998 habitat: - river habitat restore the quality of supporting for otters, but they will use a long stretch of river and this won't structure/ river habitat features, based on necessarily fall within a protected site. function the advice for H3260 habitat, based on natural river function, Dense bank vegetation and reedbeds are favoured as resting which provides a characteristic areas, but otters will often travel some distance to a preferred biotope mosaic that caters for 'couch' and this will not necessarily be along the edge of the otters. river. The structure and quality of bankside vegetation, reedbeds and other nearby habitats should be maintained, particularly where there is evidence of use by otters. However, it is thought that the most significant determinant of otter usage of a habitat is the abundance of prey (Kruuk et al., 1998)
Supporting Habitat quality Restore the quality of Smaller tributaries of larger river systems (streams, becks etc.) Kruuk et al., 1998 habitat: - waterway supporting waterways habitat are extremely important for otters and have been shown to structure/ habitat features such as the smaller have been used more frequently by otters than larger rivers function tributaries and headwaters of (Kruuk et al., 1998). This is thought to be in part due to the Derwent. differences in fish density and preference for hunting in shallow water with areas of riffles and boulders.
Supporting Habitat quality Maintain, and where necessary For a coastal site to be suitable for otters, an essential habitat: [coastal sites]: restore the overall availability component is the presence of easily accessible freshwater for structure/ Freshwater and quality of supporting bathing. This enables sea-salt to be washed from the animals’
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available) function availability freshwater habitat (i.e. the fur to maintain its insulative properties, something which is number of streams or water important to allow otters to swim and fish in cold water. bodies on or near the site) Such habitat may be outside of the site boundary but still used by animals associated with the SAC. Due to the distance otters can range, this attribute can only be indicative for a site.
Supporting Soils, Restore the properties of the Soil supports basic ecosystem function and is a vital part of the habitat: substrate and underlying soil types, including natural environment. Its properties strongly influence the structure/ nutrient structure, bulk density, total colonisation, growth and distribution of those plant species function cycling carbon, pH, soil nutrient status which together form vegetation types, and therefore provides a and fungal:bacterial ratio, within habitat used by a wide range of organisms. typical values for the supporting habitat Soil biodiversity has a vital role to recycle organic matter. Changes to natural soil properties may therefore affect the ecological structure, function and processes associated with the supporting habitat of this Annex II feature.
Supporting Water flow Restore the natural flow regime Permanent or long-lasting reductions in flow may affect the Jacobs, 2010a; 2010b; 2010c habitat: [rivers] of the river to that close to what availability and diversity of prey. This could lead to otters structure/ would be expected in the moving into new areas, increasing the likelihood of conflict with Natural England, 2014b function absence of abstractions and other otters. discharges (the 'naturalised' United Utilities, 2009 flow). This may also alter they prey targeted by otters as they may hunt for low-preference food such as birds, rabbits, fish carrion Natural England and Environment See Table 1 and Table 2 for site or for frogs, depending on the time of year. Agency, 2016 specific targets. The natural flow regime of the River Derwent has been altered Natural England, 2009a – by many in-channel structures (with impoundment effect) and Available from Natural England other factors which change the natural flow regime. The on request implementation of the River Restoration Strategy (Jacobs, 2010a; 2010b; 2010c) aims to restore the natural flow regime in these situations where possible and avoid further deterioration.
Within the catchment there are public water supply abstractions from for the West Cumbria Supply Zone from Crummock Water and non-potable water supply from the River Derwent. The EA Review of Consents for abstractions (under the Habitats Directive) in 2009, resulted in modification of the abstraction
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
licences for Ennerdale Water and Dash Beck with short and long term consequences for Crummock Water. In the short term, there will be increased demand whilst in the longer term there will be a revocation of the abstraction licence and associated infrastructure by 2022 (as part of a Compensatory Measures Package for Ennerdale). In addition, the decommissioning of five water treatment works in the area has also been assessed as having a significant positive effect on water quantity and quality due to increases in flows in the catchment (United Utilities, 2009).
Natural England and Environment Agency have published flow targets for each unit and waterbody (Natural England and Environment Agency, 2016.
Supporting Water quality/ Restore water quality and For many SAC features which are dependent on wetland Natural England, 2014b habitat: quantity quantity to a standard which habitats supported by surface and/or ground water, maintaining structure/ provides the necessary the quality and quantity of water supply will be critical, Natural England and Environment function conditions to support otters. especially at certain times of year during key stages of their life Agency, 2016 cycle. Poor water quality and inadequate quantities of water See Table 1 and Table 2 for site can adversely affect the availability and suitability of breeding, specific targets. rearing and feeding habitats.
Typically, meeting the surface water and groundwater environmental standards set out by the Water Framework Directive (WFD 2000/60/EC) will also be sufficient to support the SAC Conservation Objectives but in some cases more stringent standards may be needed to support the SAC feature. Further site-specific investigations may be required to establish appropriate standards for the SAC.
The main impact of water chemistry on this feature is its effect on the food supply. For example, moderate levels of levels of eutrophication may increase certain fish populations, but excessive eutrophication can be detrimental. Excessive acidity in watercourses may also affect fish populations. Impacts from toxic pollutants can be devastating and were the major cause of otter population declines in the 50s, 60s and 70s.
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
Any development within the catchment should ensure that appropriate measures are incorporated at the design phase, to ensure that sustainable urban drainage components are included which address water quality impacts as well as flood attenuation.
Implementation of the Diffuse Water Pollution Plan, River Restoration Plan and the Catchment Sensitive Farming Initiative will all contribute towards reducing inputs to the river and reduce levels of phosphorus and nitrogen.
Supporting Adaptation and Restore the feature's ability, See the explanatory notes for this attribute above in Table 3 NATURAL ENGLAND, 2015. processes resilience and that of its supporting Climate Change Theme Plan and (on which the habitat, to adapt or evolve to supporting National Biodiversity feature and/or wider environmental change, Climate Change Vulnerability its supporting either within or external to the assessments (‘NBCCVAs’) for habitat relies) site. SACs and SPAs in England [Available at http://publications.naturalengland. org.uk/publication/495459459137 5360]. Supporting Air quality Maintain or, where necessary, See the explanatory notes for this attribute above in Table 1 More information about site- processes restore concentrations and relevant Critical Loads and Levels (on which the deposition of air pollutants to at for this SAC is available by using feature and/or or below the site-relevant the ‘search by site’ tool on the Air its supporting Critical Load or Level values Pollution Information System habitat relies) given for this feature of the site (www.apis.ac.uk). on the Air Pollution Information System (www.apis.ac.uk). Supporting Connectivity Ensure there are no significant Barriers such as roads, weirs etc. can generally increase the processes within and to artificial barriers to the safe risk of harm to animals as they traverse or avoid them. If these (on which the the site passage and movement of barriers are considered a problem then mitigating measures feature and/or otters into, within and away could be taken. its supporting from the site. habitat relies) Otter populations within the SAC are dependent on the integrity of sections of river channel, riparian areas, freshwater still- waters, floodplains and transitional and marine waters that lie outside of the site boundary.
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
Headwater areas and tributaries may not fall within the site boundary, yet otters may use these areas for feeding and these will be critical for sustaining populations within the site.
Boundaries to river SACs often follow the first break of slope on the bank, with the result that much of the riparian habitat will lie outside the SAC, particularly if the river channel is operating under natural processes and moves laterally over time within the floodplain. It is possible that holts of otters that form part of the population for a SAC may lie on the adjacent floodplain outwith the boundary of the SAC.
Supporting Conservation Maintain, and where necessary, Active and ongoing conservation management is needed to English Nature, 2005b processes measures restore the management protect, maintain or restore this feature at this site. Further (on which the measures (either within and/or details about the necessary conservation measures for this site Natural England, 2014b feature and/or outside the site boundary as can be provided by contacting Natural England. its supporting appropriate) which are habitat relies) necessary to maintain or restore This information will typically be found within, where applicable, the structure, functions and supporting documents such as Natura 2000 Site Improvement supporting processes Plan, site management strategies or plans, the Views about associated with the feature Management Statement for the underpinning SSSI and/or and/or its supporting habitats. management agreements.
Supporting Water quality : [Reduce/Avoid] the presence of The major cause of the decline in otter populations in the 60s processes Toxic pollutants affecting the site, and 70s was toxic chemicals such as dieldrin and related (on which the chemicals which are potentially toxic to pesticides. Contaminants that might have an effect on otters feature and/or otters. may have an indirect effect (e.g. on food supply - organic its supporting pollution, eutrophication, acidification from mine waste and acid habitat relies) rain), a mainly direct effect (e.g. oil spillage, radioactivity) or effects of bioaccumulation (e.g. metals, especially mercury, cadmium and lead; pesticides and PCBs). PCBs, organochlorine pesticides and heavy metals all being seen as detrimental to otters, although the use of many of these is now banned.
Supporting Water quantity/ Where the feature or its For many SAC features which are dependent on wetland processes quality supporting habitat is dependent habitats supported by surface and/or ground water, maintaining (on which the on surface water and/or the quality and quantity of water supply will be critical,
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available) feature and/or groundwater, maintain, or especially at certain times of year. Poor water quality and its supporting where necessary, restore water inadequate quantities of water can adversely affect the habitat relies) quality and quantity to a structure and function of this habitat type. standard which provides the necessary conditions to support Typically, meeting the surface water and groundwater the feature. environmental standards set out by the Water Framework Directive (WFD 2000/60/EC) will also be sufficient to support See Table 1 for site specific the achievement of SAC Conservation Objectives but in some targets. cases more stringent standards may be needed to reflect the ecological needs of the species feature. Further site-specific investigations may be required to establish appropriate water quality standards for the SAC.
Version Control Advice last updated: N/A Variations from national feature-framework of integrity-guidance: The targets for some attributes listed above include both ‘maintain’ and ‘restore’ objectives. This is because River Derwent & Bassenthwaite Lake SAC is comprised of a number of geographically-separate component sites which are currently in different states of condition. Overall, both objectives will be applicable to the SAC but these will differ between each component site depending on its particular circumstances. Natural England will able to provide further specific advice on request.
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Table 7: Supplementary Advice for Qualifying Features: S1831. Luronium natans; Floating water-plantain
Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
Population Population Maintain, or where necessary This will ensure there is a viable population of the feature which (of the abundance restore the abundance of the is being maintained at or increased to a level that contributes feature) population at/to a level which is as appropriate to its Favourable Conservation Status across its above the baseline population, natural range in the UK. whilst avoiding deterioration from its current level as indicated by Due to the dynamic nature of population change, the target- the latest mean peak count or value given for the population size or presence of this feature is equivalent. considered to be the minimum standard for conservation/ restoration measures to achieve. This minimum-value may be revised where there is evidence to show that a population’s size or presence has significantly changed as a result of natural factors or management measures and has been stable at or above a new level over a considerable period (generally at least 10 years). The values given here may also be updated in future to reflect any strategic objectives which may be set at a national level for this feature.
Given the likely fluctuations in numbers over time, any impact- assessments should focus on the current size of the site’s population, as derived from the latest known or estimated level established using the best available data. This advice accords with the obligation to avoid deterioration of the site or significant disturbance of the species for which the site is designated, and seeks to avoid plans or projects that may affect the site giving rise to the risk of deterioration. Similarly, where there is evidence to show that a feature has historically been more abundant than the stated minimum target and its current level, the ongoing capacity of the site to accommodate the feature at such higher levels in future should also be taken into account in any assessment.
Unless otherwise stated, the population size or presence will be that measured using standard methods, such as peak mean counts or breeding surveys. This value is also provided recognising there will be inherent variability as a result of natural fluctuations and margins of error during data collection. Whilst we will endeavour to keep these values as up to date as
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
possible, local Natural England staff can advise that the figures stated are the best available.
Supporting Distribution of Maintain, and where necessary, A contraction in the range, or geographic spread, of the feature English Nature, 1994 habitat: supporting restore the distribution and (and its component vegetation) across the site will reduce its extent and habitat continuity of the feature and its overall area, the local diversity and variations in its structure English Nature, 1997 distribution supporting habitat, including and composition, and may undermine its resilience to adapt to where applicable its component future environmental changes. Contraction may also reduce vegetation types and associated and break up the continuity of a habitat within a site and how transitional vegetation types, well the species feature is able to occupy and use habitat within across the site the site. Such fragmentation may have a greater amount of open edge habitat which will differ in the amount of light, temperature, wind, and even noise that it receives compared to its interior. These conditions may not be suitable for this feature and this may affect its viability.
Supporting Extent of Maintain, and where necessary, In order to contribute towards the objective of achieving an Environment Agency Catchment habitat: supporting restore the total extent of the overall favourable conservation status of the feature at a UK Data Explorer: extent and habitat habitats which support the level, it is important to maintain or if appropriate restore the https://environment.data.gov.uk/c distribution feature at/to: extent of supporting habitats and their range within this SAC. atchment-planning/
Derwent Water: 529 ha The information available on the extent and distribution of Natural England, 2009a – supporting habitat used by the feature may be approximate Available from Natural England Bassenthwaite Lake: 524 ha depending on the nature, age and accuracy of data collection, on request and may be subject to periodic review in light of improvements in data. Natural England, 2009b – Available from Natural England Derwent Water and Bassenthwaite Lake have healthy on request populations of floating water-plantain Luronium natans in extensive, species-rich beds of aquatic macrophytes. In English Nature, 2005d Bassenthwaite Lake it also occurs on muddy lake-shores.
Discrete populations of L. natans must be greater than 50 m apart. Ideally, hydrological connectivity should be maintained or restored between populations. Many habitats where it is present may be subject to periodic major disturbance events and these may be important in enabling populations to persist at a site. Thus, there may naturally be considerable fluctuations in population size at a given site between monitoring visits and
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
so only major fluctuations should be noted.
Supporting Habitat Ensure the supporting water Luronium is intolerant of competition and occurs in a range of Darwell, 2001 habitat: structure bodies are sufficiently free of freshwater habitats – oligotrophic and mesotrophic lakes, slow structure/ other competing vegetation to flowing rivers and associated floodplain pools and small pools function allow space for this early in heathland. There are also large populations in a number of successional species to thrive. disused or recently restored canals.
The Invasive Non Native Species (INNS) Crassula helmsii, is found in both Derwent Water and Bassenthwaite Lake, and has been recorded occupying the same habitat as L. natans, it may be considered a threat to the success of this species in the lakes Darwell, 2001.
Supporting Soils, Maintain, and where necessary, Soil supports basic ecosystem function and is a vital part of the habitat: substrate and restore the properties of the natural environment. Its properties strongly influence the structure/ nutrient underlying soil types, including colonisation, growth and distribution of those plant species function cycling structure, bulk density, total which together form vegetation types, and therefore provides a carbon, pH, soil nutrient status habitat used by a wide range of organisms. and fungal:bacterial ratio, within typical values for the supporting Soil biodiversity has a vital role to recycle organic matter. habitat Changes to natural soil properties may therefore affect the ecological structure, function and processes associated with the supporting habitat of this Annex II feature.
Supporting Substrate Maintain, and where necessary, Fine unconsolidated sediments are an unsuitable rooting habitat: restore a habitat substrate medium and plants may be subject to uprooting. Conversely, structure/ characterised by cohesive where sediment is too coarse and mineral there may be function sediments which are not too scouring and poor root anchorage. coarse
Supporting Vegetation Ensure the following invasive These alien plant species are highly competitive and will impact Darwell, 2001 habitat: composition: non-native species are absent negatively on Luronium, which is not competitive. Other structure/ invasive non- from the site or being contained introduced species may have effects on ecosystem functioning function native species at a level which does not through the food web or via direct effects on the plant significantly affect the feature; community, e.g. artificially large waterfowl populations or non- Crassula helmsii, Hydrocotyle native crayfish species. ranunculoides, Myriophyllum aquaticum, Azolla filiculoides, The Invasive Non Native Species (INNS) Crassula helmsii, is
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
found in both Derwent Water and Bassenthwaite Lake, and has been recorded occupying the same habitat as L. natans, it may be considered a threat to the success of this species in the lakes Darwell, 2001.
Supporting Vegetation Ensure supporting habitat is free Excessive overhanging vegetation both results in shading of habitat: structure of shade or competitive aquatic vegetation and large inputs of organic matter in the structure/ vegetation; taller species form of leaf litter. function associated with Luronium patches should be no more than occasional.
Supporting Water clarity Maintain, or where necessary, Elevated turbidity levels as a result of, for example, high boat habitat: restore a high degree of water traffic densities, high phytoplankton densities, or the presence structure/ clarity, typically to a depth of of benthic-feeding fish will have adverse impacts on submerged function 1.5m (for rivers, heathland pools plant communities. Although Luronium may occur in naturally and canals) or >5 m (for lakes) dystrophic waters with humic staining, this may be exacerbated by acidification, reducing water clarity further.
Supporting Water levels/ Maintain and where necessary In shallow pools and similar sites plants often flower and fruit Natural England, 2009a – habitat: hydrology restore, water levels which are on draw-down zones as summer water levels recede. These Available from Natural England structure/ sufficient to maintain or restore processes should not be artificially interrupted, but will vary on request function populations; in shallow pools, greatly from year to year depending on weather. natural fluctuations in water level should be allowed to occur. Hydrological connectivity should be maintained or restored between populations. Many habitats where Luronium natans is present may be subject to periodic major disturbance events and these may be important in enabling populations to persist at a site.
Supporting Water quality/ Where the feature or its For many SAC features which are dependent on wetland habitat: quantity supporting habitat is dependent habitats supported by surface and/or ground water, maintaining structure/ on surface water and/or the quality and quantity of water supply will be critical, function groundwater, maintain, or where especially at certain times of year during key stages of their life necessary, restore water quality cycle. Poor water quality and inadequate quantities of water and quantity to a standard which can adversely affect the availability and suitability of breeding, provides the necessary rearing and feeding habitats. conditions to support the feature. Typically, meeting the surface water and groundwater
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
See Table 1 for site specific environmental standards set out by the Water Framework standards. Directive (WFD 2000/60/EC) will also be sufficient to support the SAC Conservation Objectives but in some cases more stringent standards may be needed to support the SAC feature. Further site-specific investigations may be required to establish appropriate standards for the SAC.
Luronium populations are present across a wide range of habitats with a corresponding range of water chemistry. This suggests that its tolerances to most water chemistry parameters are not especially demanding although links between presence/persistence and water quality are not yet understood. As such the water quality targets set out for freshwater habitats should be sufficient to protect populations from adverse impacts.
Supporting Adaptation Maintain, and where necessary, See the explanatory notes for this attribute above in Table 3 Natural England (2015) Climate processes and resilience restore the feature's ability, and Change Theme Plan and (on which the that of its supporting habitat, to supporting National Biodiversity feature and/or adapt or evolve to wider Climate Change Vulnerability its supporting environmental change, either assessments (‘NBCCVAs’) for habitat relies) within or external to the site SACs and SPAs in England Available at: http://publications.naturalengland. org.uk/publication/495459459137 5360
Supporting Air quality Maintain or, where necessary, See the explanatory notes for this attribute above in Table 1 More information about site- processes restore concentrations and relevant Critical Loads and Levels (on which the deposition of air pollutants to at for this SAC is available by using feature and/or or below the site-relevant Critical the ‘search by site’ tool on the Air its supporting Load or Level values given for Pollution Information System habitat relies) this feature of the site on the Air (www.apis.ac.uk). Pollution Information System (www.apis.ac.uk). Supporting Conservation Maintain, or where necessary, Active and ongoing conservation management is needed to Natural England, 2009a – processes measures restore the management protect, maintain or restore this feature at this site. Further Available from Natural England (on which the measures (either within and/or details about the necessary conservation measures for this site on request
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available) feature and/or outside the site boundary as can be provided by contacting Natural England. its supporting appropriate) which are necessary Natural England, 2009b – habitat relies) to maintain or restore the This information will typically be found within, where applicable, Available from Natural England structure, functions and supporting documents such as Natura 2000 Site Improvement on request supporting processes associated Plan, site management strategies or plans, the Views about with the feature and/or its Management Statement for the underpinning SSSI and/or English Nature, 2005b supporting habitats. management agreements. English Nature, 2005c Natural waterbodies such as lakes are an integral part of the landscape and are as important for their physical characteristics as they are for the wide range of aquatic plant and animal species they support. Management should aim to retain their natural characteristics such as the lake shape and shoreline profile. Their conservation value is largely determined by structural diversity and water quality.
Management should minimise pollution of the lake from point and diffuse sources, including discharges of domestic and industrial effluent, and run-off from agriculture, forestry and urban land. Effluents entering the lake directly or indirectly should be treated to reduce the levels of phosphorus contained within them to concentrations that will not lead to a proliferation of algae or the disappearance of characteristic plants and animals. Organic pollution should also be controlled to avoid de-oxygenation of the water or any toxic effects on aquatic animals and plants. The wider catchment needs to be managed sensitively to avoid excessive run-off of soil particles and nutrients which may smother stony beds and plants and, reduce water depth in shallow lakes.
The habitats within this site are highly sensitive to inorganic fertilisers and pesticides, applications of which should be avoided both within the site itself and in adjacent surrounding areas.
Where artificial modifications have occurred - such as embankment and dredging – the restoration of natural lake shore and bed profiles is desirable where appropriate
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
Sympathetic management of water levels is necessary for the maintenance of optimal water depths throughout the year, according to the requirements of the plant and animal species present. Water level management should take into account the requirements of submerged aquatic plants that are restricted to areas where there is sufficient light for growth and minimal wave action. Changes in water levels can also alter nutrient regimes. Management should maintain the habitats associated with shallowly sloping margins that are not too exposed to wave action, where stands of emergent plants may develop. The maintenance of structural diversity within and between stands of aquatic vegetation (including emergent, floating and submerged vegetation) provides valuable habitat.
The control or removal of the natural aquatic vegetation, or the introduction of bottom feeding coarse fish that uproot plants and disturb lake sediments, can lead to a decrease in aquatic plants in favour of algae. Indeed, lakes are susceptible to the introduction of many invasive species such as non-native crayfish and Australian swamp stonecrop, an introduced plant, and some management may be necessary to control these where they occur.
Lakes and their surroundings are often also a popular environment for recreational activities such as angling and boating which should be managed sympathetically to avoid conflict with the management of the lake for nature conservation.
Supporting Disturbance The duration, intensity and/or The loss or reduction in the disturbance regime (for example, processes from human frequency of disturbance events grazing, water-level fluctuations, flood scouring, dredging and (on which the activity should not affect the boat traffic) that would normally arrest succession is particularly feature and/or environmental conditions significant. its supporting necessary to support the feature habitat relies) The introduction or spread of INNS via human activity, which can impact or outcompete Luronium should be avoided through the use of strict biosecurity measures.
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Attributes Targets Supporting and Explanatory Notes Sources of site-based evidence (where available)
Supporting Regeneration Maintain, or where necessary This implies effective ageing and recruitment of plants. processes restore, the regenerative ability of (on which the the population, indicated by a feature and/or range of different plant sizes its supporting being present. habitat relies)
Supporting Regeneration Ensure that, in shallow pools, An increase in the presence of perennial vegetative plants may processes (sexual) there is a sufficient number of be associated with prolonged wetness or site permanence. In (on which the flowering and seeding plants the case of populations of annual plants in shallow pools it is feature and/or each year important to obtain evidence of sexual reproduction. The mere its supporting presence of plants only confirms the quality of seed set from habitat relies) previous generations. However, the degree of seed dormancy in L. natans is unknown and repeated recruitment from the seedbank without effective replenishment will reduce the long- term stability of the population.
Supporting Regeneration Maintain and where necessary, Canal populations are sterile clones that only reproduce Natural England, 2009a – processes (vegetative) restore sufficient areas of shallow vegetatively. Available from Natural England (on which the and still water for the on request feature and/or development of ascending Where populations reproduce principally, or exclusively, its supporting stolons bearing chains of through vegetative means, evidence of regeneration may be habitat relies) plantlets, and for the production difficult to observe. Perennial populations should exhibit a of floating leaves. range of plant sizes as this implies that there are a range of different aged individuals.
Version Control Advice last updated: N/A Variations from national feature-framework of integrity-guidance: The targets for some attributes listed above include both ‘maintain’ and ‘restore’ objectives. This is because River Derwent & Bassenthwaite Lake SAC is comprised of a number of geographically-separate component sites which are currently in different states of condition. Overall, both objectives will be applicable to the SAC but these will differ between each component site depending on its particular circumstances. Natural England will able to provide further specific advice on request.
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References
BARKER T., HATTON K., O’CONNOR M., CONNOR L. AND MOSS B. 2008. Effects of nitrate load on submerged plant biomass and species richness: results of a mesocosm experiment. Fundamental and Applied Limnology, 173, 89-100.
CEFAS, EA, 2003. Annual assessment of Salmon Stocks and Fisheries in England and Wales 2003.
CEFAS, EA & NRW. 2016 Salmon Stocks and Fisheries in England and Wales in 2015 Preliminary assessment prepared for ICES, March 2016. Accessed at: (https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/525662/Annual_Salmon_ Stock_Status_Report_2015_final.pdf)
DARWELL, A. 2001. Aquatic Macrophyte Survey 2000. Report to the Lake District National Park Authority and Environment Agency.
DARWELL, A. MARSHALL, T. 2013. Macrophyte survey of Crummock Water in response to proposed drought powers. Report to United Utilities.
DOYLE, S. 2018. 2018 Marsh Fritillary larval web count report. Unpublished report.
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ENGLISH NATURE. 2005a. Views About Management: Braithwaite Moss SSSI. https://designatedsites.naturalengland.org.uk/PDFsForWeb/VAM/2000423.pdf
ENGLISH NATURE. 2005b. Views About Management: River Derwent and Tributaries SSSI. https://designatedsites.naturalengland.org.uk/PDFsForWeb/VAM/2000214.pdf
ENGLISH NATURE. 2005c. Views About Management: Bassenthwaite Lake SSSI. https://designatedsites.naturalengland.org.uk/PDFsForWeb/VAM/1003782.pdf
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