Sanitary Survey - Review
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Sanitary Survey - Review Taw/Torridge Estuary – 2021 Document No. – J0591/20/06/23 Carcinus Ltd, Wessex House, Upper Market Street, Eastleigh, Hampshire, SO50 9FD. Tel. 023 8129 0095 https://www.carcinus.co.uk/ Cover image: Mouth of the Taw/Torridge Estuary, © Phillip Halling, CC-BY-SA Page | i Carcinus Ltd – Document Control Sheet Client Food Standards Agency (FSA) Project Title Sanitary Survey Review Document Title Review of the sanitary survey of Taw/Torridge Estuary Document Number J0591/20/06/23 Revision 4.2 Date 20 January 2021 Revisions Revision No. Date Comment 1.2 2nd Oct 2020 Draft for Carcinus Review 2.0 23rd Oct 2020 Draft for Food Standards Agency Review 3.1 4th November 2020 Draft for external consultation 4.2 20th January 2021 Final report post-consultation Document QA and Approval Name Role Date Author Joshua Baker Freshwater and Marine 20th January 2021 Ecologist Checked Despina Crabb Administrator & Quality 19th Oct 2020 Assurance Matthew Crabb 20th January 2021 Director Approved Matthew Crabb Director 20th January 2021 Initial Consultation Consultee Date of consultation Date of response North Devon District Council 18 June 2020 30 June 2020 Torridge District Council 18 June 2020 18 June 2020 Environment Agency 18 June 2020 27 June 2020 Consultation on draft report Consultee Date of consultation Date of response Devon and Severn IFCA 09 November 2020 07 December 2020 North Devon Council 09 November 2020 07 December 2020 Page | ii A sanitary survey relevant to the bivalve mollusc beds in Taw/Torridge Estuary was undertaken in 2013 in accordance with Regulation (EC) 854/2004 (which was replaced by retained EU Law Regulation (EU) 2017/625, which sanitary survey requirements now specified in retained EU Law Regulation 2019/627). This provided appropriate hygiene classification zoning and monitoring plan based on the best available information with detailed supporting evidence. In line with regulatory and EU guidance the Food Standards Agency undertake targeted sanitary survey reviews to ensure public health protection measures continue to be appropriate. This report provides a review of information and recommendations for a revised sampling plan if required. Carcinus Ltd (Carcinus) undertook this work on behalf of the FSA. Carcinus accepts no liability for any costs, losses or liabilities arising from the reliance upon or use of the contents of this report other than by its client. Dissemination Food Standards Agency, North Devon District Council, Torridge District Council. The report is publicly available via the Carcinus Ltd. website. Recommended Bibliographic Citation: Carcinus Ltd (Carcinus), 2020. Review of the Taw/Torridge Estuary 2013 Sanitary Survey. Carcinus reports on behalf of the Food Standards Agency, to demonstrate compliance with the requirements for classification of bivalve mollusc production areas in England and Wales under retained EU Law Regulation (EU) 2019/627. Page | iii Contents 1 Introduction .................................................................................................................................... 8 1.1 Background ............................................................................................................................. 8 1.2 Taw/Torridge Estuary Review ................................................................................................. 8 1.3 Assumptions and limitations ................................................................................................... 9 2 Shellfisheries ................................................................................................................................... 9 2.1 Description of Shellfishery ...................................................................................................... 9 2.2 Classification History ............................................................................................................. 11 3 Pollution sources ........................................................................................................................... 12 3.1 Human Population ................................................................................................................ 12 3.2 Sewage .................................................................................................................................. 15 3.3 Agricultural Sources .............................................................................................................. 21 3.4 Wildlife .................................................................................................................................. 24 3.5 Boats and Marinas ................................................................................................................ 24 3.6 Other Sources of Contamination .......................................................................................... 26 4 Hydrodynamics/Water Circulation ............................................................................................... 26 5 Rainfall .......................................................................................................................................... 26 6 Microbial Monitoring Results ....................................................................................................... 27 6.1 Summary Statistics and geographical variation .................................................................... 27 6.2 Overall temporal pattern in results ...................................................................................... 32 6.3 Seasonal patterns of results .................................................................................................. 34 7 Conclusion and overall assessment .............................................................................................. 36 8 Recommendations ........................................................................................................................ 38 8.1 Mussels (Mytilus sp.) ............................................................................................................ 38 8.2 Pacific oyster (Crassostrea gigas) ......................................................................................... 39 8.3 Sampling plan ........................................................................................................................ 39 8.3.1 Location Reference ....................................................................................................... 39 8.3.2 Shellfishery .................................................................................................................... 40 8.3.3 Local Enforcement Authorities ..................................................................................... 40 9 References .................................................................................................................................... 42 Appendices ............................................................................................................................................ 44 Breakdown of population change ............................................................................. 45 Taw/Torridge Estuary Sanitary Survey Report 2013 ................................................. 48 About Carcinus Ltd ................................................................................................................................ 49 Page | iv Contact Us ............................................................................................................................................. 49 Environmental Consultancy .................................................................................................................. 49 Ecological and Geophysical Surveys...................................................................................................... 49 Our Vision .............................................................................................................................................. 49 Page | v List of figures Figure 1.1. Location of Taw/Torridge Estuary. ........................................................................................ 9 Figure 2.1 Mean percentage cover of live mussels plotted over tonnage of total stock within all D&S IFCA survey areas 2012 - 2019 (after Thomas, 2019). .......................................................................... 10 Figure 2.2: Locations of existing classification zones for mussel and Pacific oyster harvesting and their respective RMPs within the Taw/Torridge estuary. ............................................................................. 12 Figure 3.1: Human population density in 2001 and 2011 census Output Areas that intersect the Taw/Torridge hydrological catchment. ................................................................................................. 13 Figure 3.2: Population change between the 2001 and 2011 censuses for Wards and Electoral divisions (based on 2011 boundaries) that are within or partially within the Taw/Torridge hydrological catchment (wards have been clipped to the boundary of the hydrological catchment. 2001 Census data have been transposed to 2011 wards using the UK Data Service’s GeoConvert tool (UK Data Service, 2020) to facilitate comparison. Numbers within wards are identifiers that can be used in combination with Appendix I to provide more detail. ............................................................. 14 Figure 3.3. Locations of all consented