Report Number 543 Sabellaria spinulosa reef in The Wash and North Norfolk Coast cSAC and its approaches: Part III, Summary of knowledge, recommended monitoring strategies and outstanding research requirements English Nature Research Reports working today for nature tomorrow English Nature Research Reports Number 543 Sabellaria spinulosa reef in The Wash and North Norfolk cSAC and its approaches: Part III, Summary of knowledge, recommended monitoring strategies and outstanding research requirements R.L. Foster-Smith and V.J. Hendrick Envision Mapping Ridley Building Newcastle University Newcastle upon Tyne NE1 7RU March 2003 A report for the Eastern Sea Fisheries Joint Committee and English Nature Nominated Officer: Conor Donnelly You may reproduce as many additional copies of this report as you like, provided such copies stipulate that copyright remains with English Nature, Northminster House, Peterborough PE1 1UA ISSN 0967-876X © Copyright English Nature 2004 Contents 1. Introduction....................................................................................................................9 2. The Wash .......................................................................................................................9 2.1 The Wash, its conservation status and it’s uses.................................................9 2.2 Background to Wash surveys...........................................................................10 3. Sabellaria spinulosa – General review of the literature ..............................................12 3.1 Distribution......................................................................................................12 3.2 Biotope classification.......................................................................................12 3.3 Biology.............................................................................................................14 3.3.1 Reproduction and development ...........................................................14 Spawning..........................................................................................................14 Settlement.........................................................................................................14 Recruitment ......................................................................................................15 Growth.............................................................................................................15 Maturation........................................................................................................15 3.3.2 Reef development ................................................................................15 3.3.3 Longevity and temporal stability .........................................................16 3.3.4 Fragility................................................................................................16 3.4 Environmental requirements............................................................................17 3.4.1 Temperature.........................................................................................17 3.4.2 Depth....................................................................................................17 3.4.3 Suspended sediment / water movement ...............................................17 3.4.4 Substratum requirements......................................................................18 3.4.5 Salinity .................................................................................................18 3.5 Ecological functioning.....................................................................................18 3.5.1 Reef habitats.........................................................................................18 3.5.2 Associated species................................................................................18 3.5.3 Competitors and predators...................................................................19 3.5.4 Parasites ...............................................................................................19 3.6 Conservation and protection status..................................................................20 3.7 Sensitivity.........................................................................................................20 3.7.1 Sensitivity to natural events.................................................................20 3.7.2 Sensitivity to human activities.............................................................21 Fishing..............................................................................................................21 Aggregate extraction ........................................................................................22 Shoreline development.....................................................................................23 Water quality....................................................................................................23 Chemical contaminants....................................................................................24 4. Review of previous reports..........................................................................................24 4.1 1997 BMP survey.............................................................................................24 4.1.1 Data available.......................................................................................25 4.1.2 Summary of findings............................................................................25 4.2 1999 survey......................................................................................................25 4.2.1 Data available.......................................................................................26 4.2.2 Summary of findings............................................................................26 4.3 2000 survey......................................................................................................27 4.3.1 Data available.......................................................................................27 4.3.2 Summary of findings............................................................................29 4.4 2001 survey......................................................................................................30 4.4.1 Data available.......................................................................................30 4.4.2 Summary of findings............................................................................31 4.5 Summary of data available...............................................................................31 5. Summary of main outcomes from the SeaMap Wash reports.....................................31 5.1 Effective means of detection and sampling .....................................................32 5.1.1 Remote detection through acoustic technologies.................................32 Acoustic Ground Discrimination Systems (AGDS) ........................................32 Sidescan sonar..................................................................................................34 Swath bathymetric systems..............................................................................36 Novel technologies...........................................................................................36 5.1.2 Methods for sampling Sabellaria biotopes..........................................36 Video and digital cameras................................................................................36 Diver observation and sampling ......................................................................37 Grabs, dredges, trawls and infaunal analysis...................................................37 5.1.3 Summary ..............................................................................................38 5.2 Definition of ‘reef’ ...........................................................................................39 5.2.1 Association of S. spinulosa with sediment types.................................45 5.3 Spatial and temporal distribution of S. spinulosa within the Wash and its environs............................................................................................................46 5.3.1 Predicted distribution...........................................................................46 5.3.2 Point sample distribution .....................................................................47 5.3.3 Patchiness.............................................................................................48 5.3.4 Temporal stability ................................................................................50 5.3.5 Disturbance ..........................................................................................51 6. Conclusions on the status of S. spinulosa in the Wash and outstanding issues ...........52 6.1.1 Are reefs a distinct feature? .................................................................53 6.1.2 Are reefs relatively stable or very dynamic? .......................................53 6.1.3 How do reefs relate to other biotopes?.................................................53 6.1.4 How do reefs contribute to productivity and richness?........................54 6.1.5 What is the role of S. spinulosa (particularly reefs) biotopes in the wider ecosystem?.................................................................................54 6.1.6 Are there scales of long term stability given dynamism? ....................55 6.1.7 How should reefs