Environmental monitoring at Havsul-1

Transcription

1 Environmental monitoring at Havsul-1, Marie-Lise Schläppy, Aleksej Shashkov, Mathias Andersson, Yuri Rzhanov, Ilker Fer and Erling Heggøy Presented by Dominique Durand Uni Research

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3 Why wind farms at exposed places? Wind resource High average wind speeds Competing activities Avoided by merchant vessels Low activity from trawl fisheries on rocky sea bed

4 Potential impacts of offshore wind farms Sea current and wave patterns Sea bed disturbances during construction: impact on benthic communities, fish stocks, loss of food sources, alterations in productivity and composition Noise generated during construction especially the noise stemming from pile driving. Kill or injure fish and marine mammals, hearing loss and disorientation. Species may abandon areas ranging up to several kilometers from the construction site, impact on spawning and juvenile stages of many species Bird: risk of collisions with the wind turbine blades. Migration barrier

5 Baseline & monitoring program Before After Control Impact design Havsul Reference area Two years baseline BACI design One reference area Ålesund Explore and mitigate the possible negative impacts of offshore wind farms on the marine environment

6 Havsul-1 MultiBeam bathymetry

7 Wave regime at Havsul Storm events Golmen 2007 Dahlgren et. al., in press

8 Typical Havsul seabed Havsul habitat Most common habitat Species rich Hard to sample Little known Kelp with epifauna Uncrusted algae Sea urchins/ sea stars Demersal fish

9 New species discovered in the Havsul area Offshore high energy sites Remote Unknown fauna & ecology Impact hard to predict

10 Methods used for baseline study (marine biology) Grab samples in the deeper soft bottom areas Kelp samples for associated fauna Video image data for rocky surface areas (ROV) Passive fishing gear (use of local fishermen) Marine mammals (harbor porpoise) noise detectors (C-pods) Haul-out site seal count (airborne)

11 Results from the Havsul baseline Porpoise Detection Positive Minutes Buoyancy C-Pod Photo: Mathias Andersson Acoustic release Ballast 1st time in Norway: paper in prep.

12 Wind speed (m/s) DMP/ day DPM/ day Results from the Havsul baseline Porpoise Detection Positive Minutes Havsul: 2012 Jun-Sep monthly averages ca DPM/day (Andersson, et. al. unpubl) Belgium: Oct-May monthly averages ca DPM/day (Haelters et. al. 2010) Wind farm sites Control sites Havsul: no correaltion between DPM/day and wind regime Wind speed June July August September Date

13 Results from the Havsul baseline Seabed video data (ROV) Mosaic from video Biological data extraction from mosaic Predictor data (e.g. seabed ruggedness) from multibeam swaths General linear models to test what factor (e.g. ruggedness) explains distribution of features (e.g. sea urchins)

14 Results from the Havsul baseline Seabed video data Sea star abundance (from video transects) positively correlated to ruggedness Flattening seabed for foundations may remove sea star habitat Benthic Terrain Modeller = ruggedness (from multibeam data)

15 Results from the Havsul baseline Seabed video data Kelp abundance positively correlated to Aspect (slope direction/light) Shading southerly slopes may degrade kelp habitat

16 Conclusions from the Baseline study Few hypotheses on impact Video data from ROV: appropriate method for assessing impacts in high-energy rocky-shore habitat Small and quick boats are able to use weather windows Risk of using moorings and other fixed instruments Marine operations largely limited to summer due to weather (and light at high latitudes)

17 Hypotheses on impacts Monitoring not implemented in Norcowe Limited research to developing proper methodological approaches Removal of trawling pressure gives a significant positive impact that shades away the possible impacts of the wind farm itself Mill s mast can be seen an artificial reef with possible positive impact on biodiversity and local genetic pool Impact of noise is still a subject of speculation due to lack of data

18 Perspectives Integrated Ocean Monitoring Network of continuous measurements Cable-based observatories, drifters, Ferrybox, HF radars, fixed moorings, Dynamical baseline to account for accelerating «natural changes» while increasing knowledge for better sustainable management From monitoring of targeted species to assessing ecosystem functions and services Assessing effects on the ecosystems as a whole

19 Published papers Shashkov, A., Dahlgren, T. G., Schlappy, M.-L., Rzhanov, Y. (2012). Usage of Video-mosaic for Computer Aided Analysis of North Sea Hard Bottom Underwater Video for Baseline Study of Offshore Windmill Park. Center for Coastal and Ocean Mapping, paper Dahlgren, T. G., Schlappy, M.-L., Shashkov, A., Andersson, M. H., Rzhanov, Y., & Fer, I. (2014). Assessing the Impact of Windfarms in Subtidal, Exposed Marine Areas. In M. A. Shields & A. I. L. Payne (Eds.), Marine Renewable Energy Technology and Environmental Interactions (pp ). Dordrecht: Springer Netherlands. Schlappy, M.-L., Shashkov, A., & Dahlgren, T. G. (2014). Comparison of manual and semi-automatic underwater imagery analyses for monitoring of benthic hardbottom organisms at offshore renewable energy installations. Continental Shelf Research, 83(C), Shashkov, A., Dahlgren, T. G., Rzhanov, Y., & Schlappy, M.-L. (2015). Hydrobiologia, 756(1),

20 Thanks