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Volume 4, Annex 4.2 Benthic Ecology - Intertidal Ecology Technical report Triton Knoll Electrical System Environmental Statement, April 2015. Application Document 6.2.4.4.2 Pursuant to: APFP Reg. 5(2)(a) 1

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RWE Innogy UK | Triton Knoll Electrical System, Onshore Crossing Schedule
Volume 4, Annex 4.2 Benthic Ecology - Intertidal Ecology Technical report
Triton Knoll Electrical System
Environmental Statement, April 2015.
1
RWE Innogy UK | Triton Knoll Electrical System, OnBenthic Ecology - Intertidal Ecology Report
Triton Knoll Electrical System
Intertidal Ecology Technical Report
April 2015
Drafted By: RWE Innogy UK Approved By: Kim Gauld-Clark Date of Approval
28/03/2015
Revision A
Triton Knoll Offshore Wind Farm Ltd Auckland House Great Western Way Swindon Wiltshire, SN5 8ZT
T +44 (0)845 720 090 F +44 (0)845 720 050 I www.rweinnogy.com
www.rweinnogy.com/tritonknoll [email protected]
Triton Knoll Offshore Wind Farm Limited Copyright © 2015 RWE Innogy UK Ltd All pre-existing rights reserved.
Liability In preparation of this document Triton Knoll Offshore Wind Farm Limited (TKOWFL), a joint venture between RWE Innogy UK (RWE) and Statkraft UK, subconsultants working on behalf of TKOWFL, have made reasonable efforts to ensure that the content is accurate, up to date and complete for the purpose for which it was prepared. Neither TKOWFL nor their subcontractors make any warranty as to the accuracy or completeness of material supplied. Other than any liability on TKOWFL or their subcontractors detailed in the contracts between the parties for this work neither TKOWFL or their subcontractors shall have any liability for any loss, damage, injury, claim, expense, cost or other consequence arising as a result of use or reliance upon any information contained in or omitted from this document. Any persons intending to use this document should satisfy themselves as to its applicability for their intended purpose. Where appropriate, the user of this document has the obligation to employ safe working practices for any activities referred to and to adopt specific practices appropriate to local conditions.
Triton Knoll Offshore Wind Farm Limited have been awarded EU TEN-E funding to support the development of the Triton Knoll Offshore Wind Farm Electrical System located in both UK Territorial waters and the UK’s Exclusive Economic Zone. The funding which is to be matched will support a number of surveys, engineering reports, and environmental impact assessment studies for the Triton Knoll Electrical System. The studies will form part of the formal documentation that will accompany the Development Consent Order which will be submitted to the Planning Inspectorate. The sum of €1,159,559 has been granted and the process to reclaim this funding is ongoing.
Company Reg No. 2524776 VAT Reg No. 859 6462 70
Report to: RWE Innogy UK Limited
Triton Knoll Export Cable EIA Intertidal Characterisation 2014 Date: June 2014 Project Ref: P014-06-0071/RWE/TKIB2014
Company Registration No. 2524776 VAT REG No. 859 6462 70
Project Name: Triton Knoll Export Cable EIA Intertidal Characterisation 2014 Client Name: RWE Innogy UK Limited
Date: 1st July 2014 Project ref: P014-06-0071/RWE/TKIB2014 Version: 3.0
Precision Marine Survey Ltd
Church Farm, Main Road
Email: [email protected]
Web: www.precisionmarine.co.uk
© Precision Marine Survey Ltd
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Report Title: Triton Knoll Export Cable EIA Intertidal Characterisation 2014 Contents
Page
4. Summary ....................................................................................................................... 17
5. References .................................................................................................................... 19
Appendix 1: Representative Site Photographs ....................................................................... 20
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1. Introduction
Triton Knoll Offshore Wind Farm Ltd (TKOWFL) propose to install offshore cables to connect the consented Triton Knoll offshore wind farm (TKOWF) with the national electricity grid. The proposed landfall for the offshore export cables is near to the village of Anderby on the Lincolnshire coast between Skegness and Grimsby.
The proposed works require an Environmental Impact Assessment (EIA) to be submitted to support the application for a Development Consent Order under The Infrastructure Planning (Environmental Impact Assessment) Regulations 2009 and as part of this process surveys are required to characterise the intertidal area of the proposed cable landfall to support the EIA. Precision Marine Survey Ltd (PMSL) was commissioned by RWE Innogy UK Limited to undertake a biological survey of the intertidal sediments in the vicinity of the landfall site to characterise the intertidal communities, sediments and habitats within the study area. The survey also aimed to provide an evaluation of biotopes within the area following the UK Marine Habitat Classification (Connor et al, 2004) and highlight the occurrence and distribution of any species and habitats of conservation importance.
1.1 Survey Area
The survey area covers intertidal habitats within the landfall site of the offshore export cables just north of Anderby on the Lincolnshire coast as shown in Figure 1. Beaches along the Lincolnshire coast are typically characterised by medium sands which grade into more varied sands, gravelly sands and mixed sediments further offshore. The intertidal area within the region varies, with more extensive beaches to the north of Mablethorpe where beaches are up to 1km wide and to the south of Skegness where beaches are up to 400m wide. Between Mablethorpe and Skegness beaches are typically narrower, usually less than 150-200m wide, and often exhibit quite steeply shelving profiles.
The surficial sediments in this area have historically been somewhat thinner than those present further the north or south with less than 2m of sandy sediments overlaying boulder clay. The Lincolnshire coast is characterised by large tides (macrotidal) with a tidal range of 6.7m at Skegness from Mean Low Water Springs to the Highest Astronomical Tide and current speeds of 0.05m/s to 1m/s just offshore from Skegness.
Transport of sediment southwards down the coast is a key feature of the area which is subject to significant wave action particularly in relation to waves approaching from the north east which often dominate the wave climate at certain times of the year which can cause considerable beach erosion to the extent that the underlying clay is exposed. Erosion and subsequent lowering of beach height weakens existing defences in the region and in order to maintain beach volume along the coastline, and protect the clay foreshore against further erosion, the Environment Agency currently implements a coastal defence strategy of beach nourishment (the Lincshore scheme) between Mablethorpe and Skegness. This process involves the dredging of offshore material which is subsequently placed on the eroded beaches of the Lincolnshire coast to provide additional protection to the existing defences. The Lincshore project started in 1994 and is now in its fifth phase (2010 to 2015) with annual campaigns typically adding 500,000m3 of sediment to the intertidal area. In
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relation to the current project the areas undergoing beach nourishment include Moggs Eye within the proposed landfall corridor and Huttoft just to the north of the scoping boundary.
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Figure 1. Project survey area.
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2. Methodology
2.1 Survey Methodology
The survey utilised a Phase 1 approach wherein biotopes and notable habitats/species of conservation interest are recorded. The survey was undertaken to cover the export cable corridor landfall and extended across a beach width of over 1km with a 250m buffer either side of the scoping boundary. Survey transects ran from mean high water spring level (MHWS), across the intertidal zone to the mean low water mark (MLWM). The Phase 1 intertidal habitat survey approach was used to identify and characterise the biotope habitats present, and illustrate their zonation across the intertidal area and was undertaken on a transect basis. Surveys were carried out by PMSL and methods for survey followed the standardised Phase 1 mapping methodology as outlined in the Marine Monitoring Handbook (Davies et al. 2001) within procedural guidance No 3-1 (Wyn & Brazier, 2001 and Wyn et al, 2000). For the current survey a series of seven transects were utilised spaced at approximately 250m apart and a systematic route was covered along the transects within each survey area from high water (or the seaward extent of backing dune system) to mean low water along which the distribution of biotopes were recorded. Boundaries between the main habitats/biotopes were recorded along each transect along with other information such as species composition, sediment type and the extent of sub-features and biotopes of conservation importance. The presence of any biotopes of particular interest between transects were recorded as target notes and boundaries logged as appropriate during transits between transects, and the width of the survey area was walked in a systematic fashion from low to high water to assess the level of variability in the area. The survey work was undertaken by a team of two surveyors and led by Dr. James Allen who is one of the authors of the current UK Marine Habitat Classification.
To assist in mapping, each transect was located in the field using an Ashtec/Magellan Promark 3 SBAS/dGPS enabled GPS logger which had transects and site maps/boundaries stored in memory and viewable on screen. A biotope recording database was derived using PC software and input into the GPS loggers to assist in data entry which was backed up by hand written notes. A back-up GPS logger was also used on each survey to prevent possible data loss. Each transect followed the transect line down the shore (allowing for positions of creeks or other obstacles) and extended to the lowest level exposed at low tide for a given tide. Starting at the top of the shore the upper and lower extents of each distinct biotope or habitat along each transect was recorded using the GPS logger. This involved walking down each transect and stopping periodically within each biotope and at the boundaries between habitats to record positions and assess site characterisation data.
Within each distinct habitat, the substratum and dominant/characteristic species were identified using a rapid in-situ surface inspection to assess sediment type, geomorphological features and biological features (e.g. worm tubes/casts or burrows). A quick assessment of infauna was also undertaken by sieving sediment through a 1mm mesh sieve. In order to facilitate identification, a representative sample of fauna from sieved sediment was taken if required and placed in sample pots for subsequent analysis. For each transect photographs of characteristic biotopes/habitats within each sector were taken.
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Sedimentary characteristics were described using a rapid in-field assessment technique which included an assessment of sediment type, water content, presence and depth of anoxic layer and any other relevant features. Sediment grain size was assessed in-situ using standardised Wentworth scale sediment comparison guides. Photographs of the wider area, individual habitats and characteristic species (where visible) were taken at each survey transect and cross-referenced with the survey notes and GPS positions. Supplementary information was also recorded such as any indication of natural or anthropogenic impacts (i.e. movement of drainage channels, vehicle tracks, diggings, saltmarsh encroachment, localised erosion and sediment accretion).
During the survey an extended Phase 1 survey was also incorporated which utilised more detailed in situ sediment turnover at a series of sites approximately 50m apart along each transect at which a minimum of two 0.01m2 areas of sediment were dug over and sieved through a 1mm sieve to allow a more thorough assessment of species composition. The location of the survey transects and sites is provided in Figure 2.
This survey information was used to provide an assessment of biotope classification in the field for the main habitats along each transect. Biotope and biotope complex designations were based on the most recent (2004) Marine Habitat Classification for Britain and Ireland – Version 04.05. Mapping and biotope assignations were coordinated by Dr. James Allen at PMSL who was one of the principal authors of the current classification (Connor et al., 2004). As the 2004 version of the biotope scheme was heavily dependent on quantitative data from core samples a number of biotopes or sub-biotopes are based on taxa which may be difficult to identify in the field. As a consequence the field biotope assessment was supplemented and refined where necessary following assessments of voucher specimens in the laboratory.
2.2 Access
All survey staff had extensive experience of using the standard Phase 1 mapping methodologies and, following standard PMSL Health & Safety policy, carried auto inflation lifejackets, wellingtons, suitable weatherproof clothing, navigation instruments (compass/GPS), whistle, mobile phone and VHF radio. The survey team comprised experienced marine biologists/surveyors, with extensive knowledge of surveying in intertidal areas and extensive tidal flats. Following risk assessment prior to the survey all staff were made aware of tidal constraints within the survey area and operation windows identified. Surveys were predominantly undertaken during ebb conditions with any work carried out on the flood tide restricted to the mid-upper shore. Appropriate permissions were obtained prior to survey and access to the intertidal area was from Anderby Creek or Marsh Yard car park. The survey was undertaken from the 29th April to the 1st May 2014 during spring tides.
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Figure 2. Location of survey sites.
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3. Results
The sedimentary environment within the survey area highlighted a range of primarily sandy habitats which occurred throughout the area and in terms of broad sediment distribution the intertidal habitats showed a degree of consistency across the survey area. However, within these habitats was a considerable level of variation with regard to beach morphology and elevation with the shore characterised by a complex series of ridge, runnels and berms highlighting the dynamic nature of the coastline. A selection of representative photographs from the upper, mid and low shore is provided in Figures 3 to 7 whilst photos from each of the survey sites are provided in Appendix 1. A map showing the sediment types at each of the extended phase 1 survey sites is provided in Figure 8 whilst indicative biotope distributions along each transect and for the area as a whole are shown in Figures 9 and 10.
3.1 Upper Shore Habitats
On the upper shore at (or above) MHWS adjacent to the dune system which backs the intertidal was a band of dry coarse sand or somewhat gravelly sand usually 20 to 30m wide which ran along the length of the survey area. This habitat graded into a narrow strandline habitat around 5 to 10m in width comprising of bands of dry medium sand or gravelly sand with strandline debris and sandier sediment often overlaid a more gravelly substrata. Beyond this a band of more gravelly substratum was present which comprised of gravelly coarse sand or sandy gravel and shingle which sloped steeply down to the mid shore. This area dropped several metres in elevation over a width of around 20 to 30m and extended along the full width of the survey area. Running along the base of this gravel slope was a narrow longitudinal runnel with standing water and mobile rippled sand or gravelly sand. This habitat was typically 2 to 10m in width and periodically punctuated by a series of run- off channels which run down the shore.
These habitats were characterised by impoverished or barren sediments which were subject to either strong wave action or long drying times on the upper shore and no fauna was recorded at any the upper shore sand or gravels habitats during survey aside from occasional terrestrial taxa (insects) at the very upper shore. The runnel at the base of the gravel slope also tended to be very impoverished with invertebrates recorded very rarely. Species present in this area may include very low numbers of amphipods (Bathyporeia sp.), mysids or shore crab. In terms of biotopes the extreme upper shore sand is classified as LS.LSa (Littoral sand) and whilst it is an elevated upper shore sand rather than a mobile sand structured by wave action or tides the barren nature of these sediments mean they also fall under the biotope LS.LSa.MoSa.BarSa (Barren littoral coarse sand). The same is true of the strandline sands or gravelly sands and whilst typical strandline fauna such as Talitrus saltator (sandhoppers) were not observed within/under the strand debris such taxa may be present in some areas (or on a seasonal basis). Consequently, whilst they are essentially barren sands they could also fall under the biotope LS.LSa.St (Strandline). The steep slope running down to the mid shore has been classified as a variant of LS.LCS.Sh.BarSh (Barren littoral shingle) as it has the characteristics of this biotope albeit represented by sandy gravel or gravelly sand rather than shingle. Mobile sands or gravelly sands in the runnel at the base of the slope have been classified as LS.LSa.MoSa.BarSa (Barren littoral coarse sand).
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3.2 Mid Shore Habitats
Beyond the runnel at the base of the gravel slope the beach rises to form a more elevated area of well drained medium or medium to fine sand often with some coarse sand or gravel/shell grit. This area is typically quite mobile and somewhat variable forming a mosaic of more rippled areas alongside flatter dryer sand. This area typically extends for 50 to 100m down the shore and covers much of the mid shore region across the survey area. This habitat is punctuated by a series of shallow channels which run down the shore which vary in width and morphology but are typically characterised by mobile medium/coarse sand or slightly gravelly sand which gradually spread out onto the lower mid shore and grade into the low shore habitats.
These habitats were rather impoverished with relatively few invertebrates recorded, highlighting the dynamic nature of the area. The transects across this area either recorded no fauna (e.g. Transect 2 site 2.4 and Transect 5 site 5.4) or included occasional amphipods (Bathyporeia sp.) and polychaetes such as Scolelepis sp. or occasionally Nephtys sp. along with mysid crustacea (e.g. Gastrosaccus spinifer). Habitats with Scolelepis sp. tended to be relatively patchy and occurred in low numbers but predominantly in more rippled areas often in closer proximity to run-off channels. Run-off channels which traverse this area
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tended to be impoverished with either no fauna or occasional or rare amphipods (Bathyporeia sp.) whilst mobile wetter (less elevated) areas outside the channels may also include occasional Nephtys sp. particularly further down the shore. This habitat was inherently variable and somewhat transitional in places which reflects the variation in beach elevation, presence of run-off channels and differing sediment types. As such it is considered a mosaic of relatively impoverished variants of LS.LSa.MoSa (Barren or amphipod-dominated mobile sand shores) including LS.LSa.MoSa.AmSco (Amphipods and Scolelepis spp. in littoral medium-fine sand) or LS.LSa.MoSa.BarSa (Barren littoral coarse sand) with latter more prevalent in run-off influenced areas.
Figure 4. Mid shore habitats.
3.3 Low Shore Habitats
The well drained sands on the mid shore gradually grade into areas of both wet and dryer well drained sand with areas of more rippled medium to fine sand also present interspersed with some more elevated or dryer sand. These sediments tend to have less coarse material although this is highly variable with some areas exhibiting slightly higher gravel content and some areas of surface grit or occasional small stones. At low water a number of areas include scoured areas with small pools of deeper standing water whilst in areas where run- off channels are present (particularly to the south) the channels spread out and often merge into adjacent channels to form areas of wetter mobile sands or slightly gravelly sand.
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The species composition of the low shore areas was inherently variable and often quite sparse but typically characterised by low numbers of polychaetes such as Nephtys sp. (predominantly Nephtys cirrosa) along with amphipods (Bathyporeia sp.), and occasional mysids (Gastrosaccus spinifer) or juvenile swimming crabs (Liocarcinus sp.). Arenicola marina was also present in low numbers exhibiting a variable or patchy distribution. Densities werepredominantly low (<1 per m2) although some areas had somewhat higher densities – most notably just south of transect 3 as shown in Figure 6. Areas of the low shore at the base of run-off channels tended to have somewhat coarser sediments and were generally more impoverished with few fauna aside from occasional Bathyporeia sp. Deeper pools or standing water in scoured areas at low water often had mobile fauna such as hermit crabs, Gammaridae amphipods or large swimming isopods such as Idotea linearis.
In terms of biotopes this transitional habitat forms a mosaic of rather impoverished variants of LS.LSa.FiSa.Po (Polychaetes in littoral fine sand) or the sub-biotope LS.LSa.FiSa.Po.Ncir (Nephtys cirrosa dominated littoral fine sand) along with LS.LSa.MoSa (Barren or amphipod- dominated mobile sand shores) with the latter more prevalent in run-off areas.
Two small biotopes of note were recorded just above low water between transects 1 and 2 and transect 5 and 6 where small areas of relict piddock beds in exposed harder material were present (Figure 7). Between transect 1 and 2 this appeared to be a compact peaty substrate whilst between transects 5 and 6 exposed boulder clay was recorded. Both areas were relatively small (<100m2) with patches of this underlying firmer substrate exposed between areas of sand. The harder material was typically covered in holes formed by boring bivalves (piddocks) likely to include Barnea candida or Petricola pholadiformis. These appeared to be relict piddock beds and whilst shells were sometimes visible within the holes there did not appear to be any live animals present. Such areas are likely to have been colonised previously and subsequently covered by sand and periodically uncovered by wave action or tidal scour.
Whilst these habitats do not appear to support live piddock beds the nearest MNCR biotopes in terms of the habitat which cover such habitats are LR.HLR.FR.RPid (Ceramium sp. and piddocks on eulittoral fossilised peat) and LR.MLR.MusF.MytPid (Mytilus edulis and piddocks on eulittoral firm clay) respectively. It is noted that the characterising species associated with these biotopes were not present.
A summary of the overall biotope distribution is provided in Figure 10 which highlights the general biotope structure within the survey area and also highlights topographic features such as run-off channels and transitional areas with mosaics of biotopes. The boundaries were interpolated from information gained during the transect surveys and also notes and boundaries recorded when traversing the survey area to identify areas of channel features and other features such as areas with increased densities of Arenicola marina. Given the rather transitional nature of many of these habitats, sparse infaunal communities and the complex topography within the survey area the derived boundaries should be considered indicative rather than definitive and illustrate more general patterns in community type and habitat. Given the dynamic nature of the area it is also likely that some habitats/biotopes are inherently transient or likely to vary in position and extent over time.
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Figure 5. Low shore habitats.
Figure 6. Low shore areas with increased density of Arenicola marina.
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Figure 7. Relict Piddock beds.
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Figure 8. Sediment type at survey sites.
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Figure 9. Indicative biotope distribution along survey transects.
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Figure 10. Indicative biotope distribution across the survey area.
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Table 1. Summary of species and sediment types at survey sites.
Site Latitude Longitude Sediment Arenicola
marina Scolelepis sp. Nephtys sp.
Gastrosaccus
spinifer
Idotea
linearis
Bathyporeia
sp.
Gammaridea
sp.
Liocarcinus
1.2 53.262271 0.325026 Sandy Gravel/Gravelly Sand
1.3 53.262396 0.325762 Clean Medium/Fine Sand (some Coarse Sand) O O
1.4 53.262499 0.326585 Sl. Gravelly Medium/Fine Sand F
1.5 53.262651 0.327348 Sl. Gravelly Medium/Fine Sand R
1.6 53.262662 0.327795 Sl. Gravelly Medium/Fine Sand O# O R*
2.1 53.264874 0.326568 Sl. Gravelly Medium/Fine Sand O# O R* R*
2.2 53.264680 0.325885 Sl. Gravelly Medium/Fine Sand R# R
2.3 53.264562 0.325157 Sl. Gravelly Medium/Fine Sand R P+
2.4 53.264460 0.324367 Sl. Gravelly Medium/Fine Sand
2.5 53.264309 0.323568 Sl. Gravelly Medium/Coarse Sand
2.6 53.264234 0.323048 Sl. Gravelly Medium/Coarse Sand
3.1 53.266982 0.325135 Clean Medium/Fine Sand (some Coarse Sand) O# O F
3.2 53.266855 0.324418 Clean Medium/Fine Sand (some Coarse Sand) O O
3.3 53.266744 0.323690 Clean Medium/Fine Sand (some Coarse Sand) O O
3.4 53.266636 0.322843 Clean Medium/Fine Sand (some Coarse Sand) O
3.5 53.266434 0.322091 Gravelly Coarse Sand
4.1 53.269087 0.323557 Sl. Gravelly Medium/Fine Sand O R
4.2 53.268937 0.322741 Sl. Gravelly Medium/Fine Sand
4.3 53.268829 0.321959 Medium - Coarse sand (Sl. Gravelly) R
4.4 53.268662 0.321265 Gravelly Coarse Sand
4.5 53.268556 0.320457 Sl. Gravelly Medium/Coarse Sand
5.1 53.271368 0.322453 Clean Medium/Fine Sand (some Coarse Sand) O# O R R*
5.2 53.271147 0.321735 Clean Medium/Fine Sand (some Coarse Sand) O
5.3 53.270965 0.320981 Sl. Gravelly Medium/Fine Sand O
5.4 53.270851 0.320149 Gravelly Coarse Sand
5.5 53.270751 0.319600 Gravelly Coarse Sand
6.1 53.273422 0.320945 Sl. Gravelly Medium/Fine Sand O* O R* R
6.2 53.273206 0.320249 Sl. Gravelly Fine to Coarse Sand O
6.3 53.273043 0.319568 Sl. Gravelly Fine to Coarse Sand O
6.4 53.272888 0.318789 Gravelly Coarse Sand O
6.5 53.272709 0.318071 Medium - Coarse sand (Sl. Gravelly)
7.1 53.274877 0.316644 Medium - Coarse sand (Sl. Gravelly)
7.2 53.274976 0.317455 Sl. Gravelly Medium/Coarse Sand
7.3 53.275157 0.318212 Clean Medium/Fine Sand (some Coarse Sand) O O
7.4 53.275331 0.318988 Clean Medium/Fine Sand (some Coarse Sand) O
7.5 53.275413 0.319721 Clean Medium/Fine Sand R# O O
Abundances refer to the SACFOR scale (S: Super Abundant; A: Abundant; C: Common; F: Frequent; O: Occasional; R: Rare)
* in adjacent pools
Site coordinates in decimal degrees Latitude and Longitude WGS84
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4. Summary
The habitats and biotopes recorded during the survey indicate that the proposed landfall for the export cable is situated in a dynamic section of coastline characterised by mobile sands or gravels which is typical for moderately exposed coastal areas. The area is known to be subject to strong wave action and subsequent erosion of surficial sediments with high levels of sediment transport. This leads to the development of a complex system of berms, ridges and runnels with a topography which exhibits a high level of temporal variability as highlighted by topographic studies undertaken for the Lincshore project (Environment Agency, 2013). Large scale changes in sediment structure and topography may occur over relatively short timespans e.g. following storm events whilst small scale changes are likely to occur continually which was evident during survey in terms of variation in areas of run-off channels from one day to the next. The high levels of erosion and sediment transport down the coast is currently being mitigated by a long term beach nourishment project undertaken by the Environment Agency (the Lincshore project) whereby dredged material is added to the foreshore on an annual basis and the 2014 Lincshore campaign included works at Moggs Eye and Huttoft within the study area which took place shortly after the current survey.
Given the dynamic nature of the area the invertebrate communities present were relatively impoverished, particularly on the upper shore, with the main species including amphipod and mysid crustacea (Bathyporeia sp., and Gastrosaccus spinifer) along with polychaetes such as Nephtys species (e.g. N. cirrosa) and Scolelepis sp. (predominantly Scolelepis squamata). Low densities of the lug worm Arenicola marina were also evident primarily on the lower shore although these are likely to be transient in nature. One example of the slipper limpet (Crepidula fornicata) was also recorded which is a subtidal species and presumably either washed ashore or introduced in dredged material.
The biotopes recorded were typical of moderately exposed mobile sands and gravels and included quite impoverished variants of LS.LSa.MoSa (Barren or amphipod-dominated mobile sand shores) including LS.LSa.MoSa.BarSa (Barren littoral coarse sand) and LS.LSa.MoSa.AmSco (Amphipods and Scolelepis spp. in littoral medium-fine sand) which tended to form mosaics on the upper mid shore dependant on elevation, mobility and proximity to run-off channels (the latter generally being more impoverished). On the lower shore were extensive areas of LS.LSa.MoSa (Barren or amphipod-dominated mobile sand shores) and LS.LSa.FiSa (Polychaete / amphipod dominated fine sand shores) including impoverished variants of LS.LSa.FiSa.Po.Ncir (Nephtys cirrosa dominated littoral fine sand) which tended to be rather poorly defined and often rather transitional in nature.
These communities are typical for this section of the Lincolnshire coast and similar communities and species were identified in this area during surveys for the Lincshore project (Allen and Allen, 2008) which also recorded relatively sparse invertebrate communities. Quantitative sampling undertaken for the Lincshore project also recorded a sparse meiofaunal community including nematodes and interstitial worms such as Protodriloides chaetifer along with other taxa such as nemerteans (ribbon worms) although given their small size such taxa are rarely recorded during in-situ biotope assessments. Two small areas of exposed harder clay or peat were also recorded during survey which showed evidence of previous colonisation by piddocks.
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These habitats are included in the UK Biodiversity Action Plan (Peat and Clay Exposures with Piddocks) which includes biotopes such as HLR.FR.RPid (Ceramium sp. and piddocks on eulittoral fossilised peat) and LR.MLR.MusF.MytPid (Mytilus edulis and piddocks on eulittoral firm clay). Peat or clay exposures with piddocks have been recorded elsewhere along the east coast including the Wash and along the Holderness coast north of the Humber which also has extensive subtidal examples in exposed boulder clay ridges. However, in the context of the current survey these areas were rather small with relict piddock beds as opposed to more established beds recorded elsewhere. Given the dynamic nature of the area (and ongoing beach nourishment which aims to stop the erosion of beach sediments lying on top of the clay) these habitats are likely to be transient in nature becoming periodically exposed and then re-covered by surficial sands. Aside from these small scale features the survey area contained no other rare species or habitats of conservation interest and the area appears to be typical for moderately exposed sand and gravel beaches on the east coast.
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5. References
Allen, J.H. & Allen, M.S.J. 2008. Lincshore Coastal Defence Strategy: Environmental Monitoring 2007. Report to The Environment Agency. Institute of Estuarine and Coastal Studies. University of Hull.
Connor, D.W., Allen, J.H., Golding, N., Howell, K.L., Lieberknecht, L.M., Northern, K.O. and Reker, J.B. 2004. The Marine Habitat Classification for Britain and Ireland Version 04.05. JNCC, Peterborough.
Davies, J., Baxter, J., Bradley, M., Connor, D., Khan, J., Murray, E., Sanderson, W., Tumbull, C. and Vincent, M., 2001. Marine Monitoring Handbook. Joint Nature Conservation Committee.
Environment Agency. 2013. Coastal Morphology Technical Note Lincshore. TN002/L/2013.
Wyn, G. and Brazier, P. 2001. Procedural Guideline No. 3-1 - In situ intertidal biotope recording. In Davies J., Baxter J., Bradley M., Connor D., Khan J., Murray E., Sanderson W., Turnbull C. & Vincent M. 2001. Marine Monitoring Handbook, 405 pp.
Wyn, G., Brazier, D. P. and McMath, A. J. 2000. CCW handbook for marine intertidal Phase 1 survey and mapping. CCW Marine Sciences Report: 00/06/01.
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Site 1.1 Site 1.2
Site 1.3 Site 1.4
Site 1.5 Site 1.6
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Site 2.1 Site 2.2
Site 2.3 Site 2.4
Site 2.5 Site 2.6
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Site 3.5
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Site 4.5
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Site 5.5
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Site 6.5
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