The Case of Strangford Lough Biogenic Reef Restoration Joe Breen Marine Division Department of the Environment (NI ) Capacity building workshop for Europe on ecosystem conservation and restoration to support achievement of Aichi Biodiversity Targets Isle of Vilm International Academy for Nature Conservation
Special Areas of Conservation cSAC’s Rathlin • Annex 1 features • Reefs,Sea Caves, Sandbanks Slightly covered Strangford Lough • Annex 1 features • Large shallow inlet & bay, Coastal lagoons, uncovered mudflats & sandflats, reefs • Annex 1 species, common seal Murlough Bay • Annex 1 features • uncovered mudflats & sandflats, Sandbanks Slightly covered, Atlantic salt meadow • Annex 1 species, common seal
A Jewel in the Crown of Nature Conservation
Strangford Lough, a protected area? Conservation Zone Marine Nature Reserve S.P.A. and S.A.C. Also RAMSAR, ASSI, NNR etc...
Communities and substrates – Erwin 1977
Natural undamaged biogenic reef
Damaged biogenic reef
The Main Anthropogenic Impacts
Fishery Conservation measures ‘93 Sites with Modiolus ‘dominant’ (Erwin et al) 1987 Prawn/queen scallop trawling permitted ‘93 King scallop dredging permitted ‘93 Section 14 Oyster Dredging application 2002
Monitoring conducted by DARD Scientists often joint funded by DOE. Mainly Broadscale acoustic methods using RoxAnn and Side scan sonar ground-truthed by video sledge.
RoxAnn Surveys Single beam acoustic discrimination mapping system Source DARD 2002 Year Area Modiolus Area of scattered shell 1993 8.13 3.84 2000 2.1 8.93 Such areas may be the result of physical disturbance to Modiolus clumps, such as trawling activity 2000 1993 There was no significant change between 1993 and 2000 in the area of Modiolus habitat coverage;
S trangford L ough E cological C hange I nvestigation WP1 Nature and Extent of community change within Strangford Lough WP2 The current biological and ecological status of Strangford Modiolus WP3. Commercial fishing WP4. Boating activities WP5. Change in weather patterns-Climate Change WP6. Pollution WP7. Dredging activities and Shore Works WP8. Aquaculture WP9. Harmful Algal Blooms, Diseases and Parasites WP10. Alien species WP11 National Workshop and bringing together of findings WP12 Recommendations to Government
SLECI Survey 2003 SLECI divesite positions 2003 Chapel Island South Island Reagh Island Bird Island Gull Rock Mahee Island Calf Island Rainey Island Sketrick Island Hen Is Trasnagh Island Inisharoan Bird Island Veagh Inishanier Roe Is Conly Island Drummond Island Parton Is Little Minnis Darragh Island Great Minnis Green Island Dunsy Island Dunsy Rock IslandMore Pawle Island Long Island Legend Round Island Other communities Black Rock Modiolus beds Modiolus beds - damaged Island Taggart Mud with dead shell DunnyNeil East Nephrops bed DunnyNeil West Coastline 10mContour Islands Ballyhenry Island Chapel Island Green Island Jackdaw Island Salt Island Shark Island
All factors except mobile gear fishing were excluded as probable cause of reef degradation
What Have DOE done? Commissioned our own independent survey of the current status of all feature interests within Strangford, SLECI Advised DARD that there is and has been credible scientific evidence that bottom fishing reduces complexity and diversity of Modiolus biogenic reefs and hence they are consenting an action which is in breech of the Habitats Regulations The dive survey reveals that there are perhaps only three remaining reefs in the Lough(this includes the areas were boats are excluded) We advisedDARD that in light of this recent evidence they as Competent Authority should invoke the ‘Precautionary Principal’ by banning trawling/dredging until such time as we fully understand exactly what is happening in Strangford Lough. Failure to do so could result in Infraction Proceedings against the UK for permitting damage to a Natura 2000 site. DARD Minister Pearson invoked temporary ban on all mobile fishing activity within Strangford Lough 1st December 2003, immediate effect midnight on day of announcement. Cited precautionary principal.
2005
ELEMENTS OF THE RESTORATION PLAN (1) Strict protection of the remaining extant Modiolus biogenic reefs and areas where they were previously reported within Strangford Lough through: Maintaining the temporary ban on mobile gear Establishing no-disturbance areas, including disturbance by anchoring, potting and diving (2) Reviewing possible impacts from extant consented activities, e.g. sewage discharges, commercial fishing and aquaculture These measures may require amended and/or new legislation where it is found that existing measures (including voluntary codes of conduct) are found not to be sufficient to control an actual or potential threat to the interest feature.
(2) Monitoring of the effectiveness of protection measures including: Compliance monitoring (policing of banned activities and activities within zoned areas) Detailed reef mapping Monitoring natural recovery
(3) Intervention action . There is a need to identify methodologies aimed at artificially restoring the reef feature in the event of natural recovery failing to achieve a trend towards Favourable Conservation Status (FCS). These will include: Pilot-scale studies to assess whether conditions in areas based on historical presence are currently favourable for Modiolus restoration. Translocation of natural Modiolus reefs. Experimental re-seeding of historical Modiolus reef sites.. This element will require the following lines of research: Production of young mussels for re-seeding. Establishing the most suitable sites for re-seeding and mussel recruitment . Creating favourable sites, through provision of artificial substrate for both wild and laboratory-reared seed.
Strangford Lough Modiolus Restoration Research Project: As part of the delivery of the Restoration Plan
COMMITMENT OBJECTIVES: Modiolus OBJECTIVES: Modiolus 2004 Restoration Plan 2005 Restoration Research Project DARD DOENI 2007 DARD DOENI QUB ‘ My authorities wish to reassure Identify, map and protect the Commission Modiolus reef within 1 Reef Mapping that they are year committed to ensuring no To show evidence of recovery of further Modiolus reefs towards deterioration to ‘ Unfavourable Condition, Monitoring the biogenic Recovering’ within 5 years reefs.’ Second secretary Environment To assess if conditions are Restoration & favourable for restoration using Intervention trials pilot translocation trials To restore Modiolus reefs to ‘Favourable Scientific advice & Recommendations Conservation Status’
Objective 1 Reef mapping Undertaking 1: Identify good condition Modiolus Undertaking 2: Identify poor condition Modiolus Undertaking 7: Determine distributional range of Modiolus
Mapping data collection Method Description Advantage Disadvantage Boundary Using diver mounted Could produce Beds too fragmented Mapping sonar beacon and accurate boundary to find edge DPVs to map the edge maps of habitat of reefs No quantitative data collected Transect mapping 100 m leaded line Quantitative and Does not deliver 20-25 Photo quadrats Qualitative data of clear boundary to a taken Modiolus community reef habitat Historical comparison ROV Video Ray- deployed Ruled out obviously Small area covered unsuitable area without wasting diver Technical difficulties time
1973-2005 2008-2010 North: Dunsey Island to Gransha Point South: Southern tip of Island Taggart to Kate’s Pladdy
Species increasing • Mycale similaris • Balanus crenatus • Liocarcinus corrugatus • Mytilus edulis • Pecten maximus • Ostrea edulis • Antedon bifida • Thyone roscovita
Species decreasing • Spanioplon armaturum • Iophon hyndmani • Protula tubularia • Modiolus modiolus • Aequipecten opercularis • Chlamys varia • Munida rugosa • Thyonidium drummondi • Pyura microcosmus • Corella parallelogramma
Notable species unchanged • Virgularia mirabilis • Sagartiogeton laceratus • Doto cuspidata • Aeolidiella glauca • Arctica islandica • Eucratea loricata • Leptasterias mulleri • Boltenia echinata
Modiolus condition definitions Grade Modiolus Condition 1 Continuous clumps (> 5 Ind. clump -1 ) or > 1 clump m -2 2 Discrete clumps (> 3 Ind. clump -1 ) < 1 clump m -2 Modiolus present ( 0 – 3 Ind. clump -1 ) < 1 clump m -2 3 4 Modiolus absent
North: Dunsey Island to Gransha Point Conclusions South: Southern tip of Island Taggart to Kate’s Pladdy ● Current distributional range has been established ● Since SLECI, (2004) the Modiolus north of Hadd Rock has disappeared (Green Island Passage, Slave Rock). ● Previously unrecorded good condition area revealed (central channel up to Craigyourran)
Recommend
More recommend
