Marine Natural History of Lee Bay, Lynton, North Devon, UK
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Marine Natural History of Lee Bay, Lynton, North Devon, UK Lee Bay, Lynton. Source: Dan Lay/Lee Abbey Devon, May 2017. Hannah F. R. Hereward1,2,* Rachel Oates3 and Robert D. Sluka 4 1 A Rocha UK, 18/19 Avenue Road, Southall, Middlesex UB1 3BL, UK. 2School of Marine Sciences and Engineering, University of Plymouth, Drake Circus, Plymouth, PL4 8AA, UK. 3 Lee Abbey, Lynton, North Devon, EX35 6JJ, UK. 4Lead Scientist, Marine and Coastal Conservation Programme, A Rocha International, 89 Worship Street, London EC2A 2BF, UK *Corresponding author: [email protected]. Suggested reference: Hereward, H.F.R., Oates, R. and Sluka, R.D., 2017. Marine Natural History of Lee Bay, Lynton, North Devon, UK. 44pp. Summary Lee Bay, Lynton forms part of the North Devon coastline, which is part of the central southern boundary of the Bristol Channel. This coastline terrain is formed of Devonian slate and the Lynton Formation. While much research has been conducted on the geology, geography and archaeology, little research has been conducted on the ecology of the intertidal or subtidal area. This report summarises the intertidal ecological knowledge of Lee Bay, the potential threats to this ecosystem, the active organisations within this area and points to potential further work, especially as this stretch of coastline is part of the Bideford to Foreland Point Marine Conservation Zone, within Exmoor National Park and within the transition zone of the North Devon Biosphere Reserve. This is to provide a baseline for anyone interested in conducting further surveys in the future. Few reports and little data cover this part of the North Devon coastline. However, one report from 40 years ago conducted biological surveys across Exmoor National Park’s rocky shores, including two around Lee Bay. Combined species lists from previous studies and this study’s fieldwork reached 110 intertidal species. Some interesting species of note include: one sandy habitat marine worm (a polychaete - Nephtys sp.), this low number reflects the lack of nutrients retained in the coarse sand that would usually attract polychaetes and other sand dwelling species. Furthermore, six different species of anemone were identified - beadlet (Actinia equina) and snakelocks anemones (Anemonia viridis) being the two most common. In addition, this study also identified two top shells (the thick top shell (Phorcus (Osillinus) lineatus) and flat or purple top shell (Gibbula umbillicalis)). These can be useful climate change indicators. We conclude that Lee Bay has a low to medium species richness and diversity. However, the comparison of the species lists from 40 years ago to the present indicates that the species assemblage has not changed much. In light of various increasing pressures on the UK coastal species and habitats, this is a positive sign for the future of Lee Bay. However, these pressures, including pollution and climate change induced sea warming, are likely to become increasingly prevalent in the coming years. i Table of Contents Summary ........................................................................................ i Introduction .................................................................................. 1 Natural History .............................................................................. 1 Intertidal Marine Ecology ................................................................ 2 North Devon ................................................................................. 4 Aims and Objectives ...................................................................... 7 Methods ......................................................................................... 7 Site Selection - Lee Bay, Lynton ...................................................... 7 Desktop Research .......................................................................... 8 Fieldwork - Habitat Mapping and Species Abundance .......................... 8 Results ........................................................................................ 10 Previous Research on Lee Bay ....................................................... 10 Species Findings .......................................................................... 11 Phase 1 Habitat Survey ................................................................ 14 Discussion ................................................................................... 15 Lee (Abbey) Bay, Lynton .............................................................. 15 Ecology.................................................................................... 15 Conservation Groups and Designated Areas ................................. 18 Threats and Conservation Issues ................................................... 19 Anthropogenic Climate Change ................................................... 19 Pollution .................................................................................. 20 Fishing and Over Harvesting ....................................................... 20 Energy Production ..................................................................... 21 Conclusions and Future Management? ........................................ 23 Acknowledgements ..................................................................... 25 References .................................................................................. 26 Appendices .................................................................................. 31 Appendix 1 – List of species from all surveys identified for the intertidal zone of Lee Bay, Lynton ............................................................... 31 Appendix 2 – List of species from all surveys identified for the subtidal zone of Lee Bay, Lynton ............................................................... 37 Appendix 3 – JNCC Phase 1 biotope descriptions and conservation status within the Bideford to Foreland Point Marine Conservation Zone ........ 40 Appendix 4 – Bideford to Foreland Point Marine Conservation Zone protected features (source: DEFRA, 2016) ...................................... 42 ii Introduction Natural History Ecological science has become extremely specialised and we often assume we know all we need to know about the world around us in order to conserve it. Yet beginning a research project in a location that is new to a researcher or organisation raises many questions as to how to move forward conservation efforts. What species are there? What habitats are even possible to study? What do we already know? Lee Bay, Lynton (herein referred to as Lee Bay) is the home of Lee Abbey Devon, a Christian conference centre (51°13'40.19"N, 3°51'58.66"W) (Figure 1). Significant conservation work has been completed on the land looked after by Lee Abbey Devon (supported by A Rocha UK), but there became a desire to begin to explore how to take better care of the marine environment. In order to investigate marine conservation options for this site, we needed to understand what is there and what has already been done. Time and resources limited the scope of this study and so we focused our field research on one particular habitat, the intertidal zone (defined as the area between the high water mark and low water mark). Literature surveys were completed to understand the wider ecology and to collate any previous data on the species assemblage of Lee Bay. 1 Figure 1. Location of Lee Abbey, Devon (51°13'40.19"N, 3°51'58.66"W) within the UK (A) and the location/boundary of Lee Abbey, Devon including local designations - Exmoor National Park, Bideford to Foreland Point Marine Conservation Zone, North Devon Biosphere Reserve and West Exmoor Coast and Woods Site of Special Scientific Interest, within Devon (B) and within North Devon (C) and a photograph of Lee Bay, Lynton (D). Maps complied with data from the North Devon Biosphere Reserve and OS data with permission from Lee Abbey Devon. Map produced by Hannah Hereward, 2017. Intertidal Marine Ecology The intertidal zone represents the interface of land and sea. This zone is exposed to the elements at low tide and then inundated with seawater at high tide. The assemblage of species in intertidal marine ecology is influenced by this physical environment as well as the interdependence of intertidal organisms and wider scale interactions between all the marine environments (Little et al. 2009). These all interact around four key gradients: sea-to-land, horizontal wave action, particle size and marine- freshwater (Dahlhoff et al. 2002, Raffaelli and Hawkins 2012). Across these gradients, and between interactions of them, abiotic (physical) and biotic (biological) factors play key roles in determining the species assemblages and the unique zonation pattern for each shoreline (Raffaelli and Hawkins 2012). 2 Among the various biotic factors influencing intertidal plant and animal morphological, physiological and (for animals) behavioural mechanisms; aerial exposure and wave action are of particular note (Dahlhoff et al. 2002, Raffaelli and Hawkins 2012). Depending on the location across the sea-to-land gradient, plants and animals will have periods of time when they are emersed (out of the water) potentially causing loss of water (desiccation) through changes in air temperature, humidity, precipitation and evaporation (Thompson et al. 2002; Helmuth et al.. 2006 and references there in). The species assemblage is further influenced by the wave exposure, depending on their ability to be streamlined and avoid dislodgement (Thompson et al. 2002, Helmuth