19 Marine Ecology 19 MARINE ECOLOGY 19.1 Introduction 19.1.1 This Chapter assesses the potential impacts of the construction and operational phases of the proposed Hinkley Point C Power Station on marine ecosystems at Hinkley Point and, where appropriate, the wider Bridgwater Bay and Severn Estuary environment. 19.2 Scope of Assessment 19.2.1 The assessment of the potential impacts has been undertaken in accordance with the methods outlined in Chapter 4, Volume 2. Available published data and grey literature have been examined which includes data derived from ongoing impingement and entrainment sampling at the current HPB Station intake screens. To secure the marine science base to support consideration of this development, both in terms of environmental assessment and appropriate engineering design, a range of investigations were instigated by British Energy under the umbrella of the British Energy Estuarine and Marine Studies (BEEMS) process, now adopted by EDF. These surveys were designed to gather baseline data across appropriate temporal and spatial scales for the key ecological components of the surrounding ecosystems. 19.2.2 The geographical extent of the area of interest for the marine ecological assessment is dependent upon the particular organism, its habits, and the type of impact considered critical for it. 19.2.3 The extent of dedicated survey and assessment effort is also dependent upon an understanding of the highly dynamic physical processes that govern the ecology of the Severn Estuary and Bristol Channel (see Chapter 16). 19.2.4 The site for the proposed HPC Station is located within and adjacent to a number of international and national conservation designations that cover a range of marine ecological interests. These designations and the species and habitats for which they are designated have been of prime consideration for the assessment process. Ecological receptors with protected status have been identified. Where a species or habitat is of conservation or general ecological importance, but does not have protected status, it has been discussed in more detail. 19.2.5 Assessment of potential impacts has been undertaken for the construction and operational phases of the development. Following initial assessment, if an impact was indicated to be of moderate significance or greater, mitigation measures have, where possible, been identified to reduce predicted impacts. In some instances, mitigation measures have been an integral aspect of initial project design (e.g. jetty design or cooling water outfall location). 19.2.6 To identify the scope of the issues to be covered in the assessment of potential effects on marine ecology, an initial evaluation of the potential for interactions between defined project HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 1 ENVIRONMENTAL APPRAISAL – VOLUME 2 19 Marine Ecology activities and the receiving environment was undertaken. This resulted in a number of activities being identified which were considered, on the basis of likelihood and known response of the ecological parameters, to potentially result in interactions. These interactions are identified and listed in Table 19.1. The table does not provide an exhaustive list of potential interactions, but solely those for which further assessment work was determined to be necessary. Table 19.1: Marine Ecology - Sources of Potential Interactions with Defined Project Activities for a Range of Key Receptors Receptor Fish Epifauna Epifauna Zooplankton Zooplankton Benthic flora Phytoplankton Phytoplankton Marine mammals mammals Marine Intertidalhabitats Intertidalhabitats (including Sabellaria) Sabellaria) (including Subtidal invertebrates Construction Physical damage to habitats (e.g. construction on the seabed, dredging etc.) Disturbance to habitats and species Changes in water quality Noise impacts (piling and vessels) Operation Loss or change in habitat caused by presence of structures Entrainment and impingement impacts on intake screens Water quality - temperature, flow and chemical impacts from thermal plume Water quality - chemical discharges Maintenance dredging Noise impacts from 2 | HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 ENVIRONMENTAL APPRAISAL – VOLUME 2 19 Marine Ecology maintenance vessels a) Consultation with Regulatory Bodies 19.2.7 Consultation in relation to marine ecology has been undertaken with various stakeholders throughout project development. A summary of key meetings at which the scope of the assessment work was discussed is provided in Table 19.2. This summary does not represent a full account of all meetings held, only those where marine ecology and other marine issues relevant to the assessment process were discussed. Table 19.2: Summary of Consultation Meetings Undertaken to Determine Scope and Nature of Marine Ecological Assessment and Survey Work Date Attendees Consultee Discussion/Comments 20/08/08 Natural England Marine ecology issues discussed – some gaps identified in (NE), Environment initial data review. Coastal processes and coastal protection Agency & also discussed. Possible need for offshore surveys Countryside Council identified. Fisheries data to be requested from CCW, for Wales (CCW) identification of coastal workshop attendees required, methods for offshore surveys to be discussed with NE. Environment Agency identified a lack of sufficiently detailed water quality data. Also discussed coastal monitoring and defence issues and management of discharges. 22/09/08 CCW Water dependant features within the assessment area Correspondence should be detailed as previously suggested in consultation. 03/11/08 NE Terrestrial ecology and marine ecology scoping meeting with the purpose to discuss and agree scope of proposed surveys. The proposed sampling design for the local scale surveys was presented at this meeting. NE confirmed it was content with range and scope of proposed surveys, but requested that a full 12 month survey period was applied for certain key species, specifically fish. It was discussed that shad (protected Annex II species under the Habitats Directive, see Section 19.3) abundance tends to peak in July/August and therefore likelihood of catching this species increases during these months so sampling was extended to cover this period. 16/01/09 NE and CCW CCW comments on marine ecology methodology were received on 09/02/09. NE comments on marine ecology were received on 12/02/09. Other than extension of surveys as decided at the 03/11/08 meeting no other changes to survey design were requested. 11/03/09 CCW, NE, Marine Authorities Liaison Group Meeting was held to Environment Agency discuss consents and estuary issues. and Sedgemoor District Council (DC) HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 3 ENVIRONMENTAL APPRAISAL – VOLUME 2 19 Marine Ecology Date Attendees Consultee Discussion/Comments 24/06/09 Environment Agency, Meeting held to discuss Marine Authorities. Discussed Royal Haskoning, offshore investigations, shore access arrangements and Sea NE, Somerset County Protection Group. Also discussed, water abstraction and Council, Marine and discharge, soil, groundwater and ground gas, surface and Fisheries Agency and marine water. West Somerset Council 28/07/09 Environment Agency, Status presentation on studies regarding shore access, sea Marine Fisheries protection wall, abstraction and discharge, water quality, Agency, English contaminated land, groundwater, ground gas. Heritage, West Somerset Council, Somerset County Council, ARUP 19.3 Legislation 19.3.1 This section describes the main marine ecological legislative and planning policy considerations in relation to the proposed development. Such legislation and planning policy provide control to the types of development which can be conducted within the marine environment and can set out the measures and processes that should be implemented to protect designated sites and biodiversity interests. a) Legislation and Policies Relevant to the Marine Biodiversity and Conservation Interests of the Study Area i International Conventions Ramsar Convention of Wetlands of International Importance 1971 19.3.2 The Convention provides the framework for national action and international co-operation for the conservation and considerate use of wetlands and their resources. Suitable wetlands are designated for inclusion in the List of Wetlands of International Importance. In order to promote the conservation of Ramsar sites, the UK implements the Convention through the Sites of Special Scientific Interest (SSSI) system, with some overlap with Special Area of Conservation (SAC) and Special Protection Area (SPA) sites (see section on ‘EC Habitats Directive’ below). The Ramsar Policy Statement 2000 offers Ramsar Sites equivalent protection to Natura 2000 sites. Of relevance to the proposed development is the Severn Estuary Ramsar designation. 19.3.3 The Severn Estuary Ramsar site is designated due to a combination of a number of attributes including; the large tidal range, presence of Annex I habitats protected under the Habitats Directive (see text for ‘EC Habitats Directive’ below), the presence of unusual estuarine communities (reduced diversity and high productivity), the run of migratory fish between the sea and river via the estuary, the fish of the whole estuarine and river system (which is one of the most diverse in Britain) and wildfowl and wader assemblages and species/populations of 4 | HINKLEY POINT C PRE-APPLICATION CONSULTATION