Multi-Frequency, Multi-Sonar Mapping of Shallow Habitats - Efficacy and Management Implications in the National Marine Park of Zakynthos, Greece

In this work, multibeam echosounder (MBES) and dual frequency sidescan sonar (SSS) data are combined to map the shallow (5–100 m) benthic habitats of the National Marine Park of Zakynthos (NMPZ), Greece, a Marine Protected Area (MPA). NMPZ hosts extensive prairies of the protected Mediterranean phanerogams Posidonia oceanica and Cymodocea nodosa, as well as reefs and sandbanks. Seafloor characterization is achieved using the multi-frequency acoustic backscatter of: (a) the two simultaneous frequencies of the SSS (100 and 400 kHz) and (b) the MBES (180 kHz), as well as the MBES bathymetry. Overall, these high-resolution datasets cover an area of 84 km2 with ground coverage varying from 50% to 100%. Image texture, terrain and backscatter angular response analyses are applied to the above, to extract a range of statistical features. Those have different spatial densities and so they are combined through an object-based approach based on the full-coverage 100-kHz SSS mosaic. Supervised classification is applied to data models composed of operationally meaningful combinations between the above features, reflecting single-sonar or multi-sonar mapping scenarios. Classification results are validated against a detailed expert interpretation habitat map making use of extensive ground-truth data. The relative gain of one system or one feature extraction method or another are thoroughly examined. The frequency-dependent separation of benthic habitats showcases the potentials of multi-frequency backscatter and bathymetry from different sonars, improving evidence-based interpretations of shallow benthic habitats.

[1]  D. Buscombe,et al.  Probabilistic Substrate Classification with Multispectral Acoustic Backscatter: A Comparison of Discriminative and Generative Models , 2018, Geosciences.

[2]  D. Margaritoulis.  Nesting Activity and Reproductive Output of Loggerhead Sea Turtles, Caretta caretta, Over 19 Seasons (1984-2002) at Laganas Bay, Zakynthos, Greece: The Largest Rookery in the Mediterranean , 2005 .

[3]  Michael Kornaros,et al.  Illegal trawling and induced invasive algal spread as collaborative factors in a Posidonia oceanica meadow degradation , 2011, Biological Invasions.

[4]  B. Chakraborty,et al.  Bathymetric techniques and Indian Ocean applications , 2012 .

[5]  Veerle A.I. Huvenne,et al.  Acquisition and processing of backscatter data for habitat mapping - comparison of multibeam and sidescan systems , 2009 .

[6]  J. Mcilvenny,et al.  Colour Sonar: Multi-Frequency Sidescan Sonar Images of the Seabed in the Inner Sound of the Pentland Firth, Scotland , 2016 .

[7]  Vasilis Trygonis,et al.  Assessment of fish communities in a Mediterranean MPA: Can a seasonal no-take zone provide effective protection? , 2018, Estuarine, Coastal and Shelf Science.

[8]  Ron Kohavi,et al.  Wrappers for Feature Subset Selection , 1997, Artif. Intell..

[9]  P. Avramidis,et al.  Bed diversity in the shallow water environment of Pappas lagoon in Greece , 2012 .

[10]  Philippe Blondel,et al.  Acoustic properties of macrophytes: Comparison of single-beam and multibeam imaging with modeling results , 2012 .

[11]  Ronen Basri,et al.  Hierarchy and adaptivity in segmenting visual scenes , 2006, Nature.

[12]  Daniel Ierodiaconou,et al.  Combining angular response classification and backscatter imagery segmentation for benthic biological habitat mapping , 2012 .

[13]  Philippe Blondel,et al.  Textural analyses of multibeam sonar imagery from Stanton Banks, Northern Ireland continental shelf , 2009 .

[14]  J. Schneider von Deimling,et al.  Validation of automated supervised segmentation of multibeam backscatter data from the Chatham Rise, New Zealand , 2018, Marine Geophysical Research.

[15]  J. Beaudoin,et al.  Setting the stage for multi-spectral acoustic backscatter research , 2017 .

[16]  Elias Fakiris,et al.  An Automatic Target Detection Algorithm for Swath Sonar Backscatter Imagery, Using Image Texture and Independent Component Analysis , 2016, Remote. Sens..

[17]  D. Simons,et al.  Multi-angle backscatter classification and sub-bottom profiling for improved seafloor characterization , 2018, Marine Geophysical Research.

[18]  V. Lucieer,et al.  Do marine substrates 'look' and 'sound' the same? Supervised classification of multibeam acoustic data using autonomous underwater vehicle images , 2013 .

[19]  Dawn J. Wright,et al.  Unified Geomorphological Analysis Workflows with Benthic Terrain Modeler , 2018 .

[20]  S. Somot,et al.  The Biodiversity of the Mediterranean Sea: Estimates, Patterns, and Threats , 2010, PloS one.

[21]  Craig J. Brown,et al.  Multiple methods, maps, and management applications: Purpose made seafloor maps in support of ocean management , 2012 .

[22]  Michele Gristina,et al.  Seagrass meadows (Posidonia oceanica) distribution and trajectories of change , 2015, Scientific Reports.

[23]  Philippe Blondel,et al.  Textural analyses of sidescan sonar imagery from two mound provinces in the Porcupine Seabight , 2002 .

[24]  Yuri Rzhanov,et al.  Construction of seafloor thematic maps from multibeam acoustic backscatter angular response data , 2012, Comput. Geosci..

[25]  Vanina Pasqualini,et al.  Mapping ofPosidonia oceanicausing Aerial Photographs and Side Scan Sonar: Application off the Island of Corsica (France) , 1998 .

[26]  Luciano E. Fonseca,et al.  Remote estimation of surficial seafloor properties through the application Angular Range Analysis to multibeam sonar data , 2007 .

[27]  Tengku Afrizal Tengku Ali,et al.  A Multispectral Bayesian Classification Method for Increased Acoustic Discrimination of Seabed Sediments Using Multi-Frequency Multibeam Backscatter Data , 2018, Geosciences.

[28]  Jaroslaw Tegowski,et al.  Nearshore Benthic Habitat Mapping Based on Multi-Frequency, Multibeam Echosounder Data Using a Combined Object-Based Approach: A Case Study from the Rowy Site in the Southern Baltic Sea , 2018, Remote. Sens..

[29]  M.,et al.  Statistical and Structural Approaches to Texture , 2022 .

[30]  I. Galparsoro,et al.  Broad-scale mapping of seafloor habitats in the north-east Atlantic using existing environmental data , 2015 .

[31]  J. Schneider von Deimling,et al.  Improved Interpretation of Marine Sedimentary Environments Using Multi-Frequency Multibeam Backscatter Data , 2018, Geosciences.

[32]  P. Levin,et al.  Integrated Ecosystem Assessments: Developing the Scientific Basis for Ecosystem-Based Management of the Ocean , 2009, PLoS biology.

[33]  B. Calder,et al.  Angular range analysis of acoustic themes from Stanton Banks Ireland: A link between visual interpretation and multibeam echosounder angular signatures , 2009 .

[34]  Jens Greinert,et al.  The Hyper-Angular Cube Concept for Improving the Spatial and Acoustic Resolution of MBES Backscatter Angular Response Analysis , 2018, Geosciences.

[35]  V. Lucieer.  Object‐oriented classification of sidescan sonar data for mapping benthic marine habitats , 2008 .

[36]  P. Blondel.  Bathymetry and Its Applications , 2012 .

[37]  K. Dunton,et al.  Laboratory investigation of the acoustic response of seagrass tissue in the frequency band 0.5-2.5 kHz. , 2009, The Journal of the Acoustical Society of America.

[38]  Larry A. Mayer,et al.  The limits of spatial resolution achievable using a 30 kHz multibeam sonar: model predictions and field results , 1998, IEEE Oceanic Engineering Society. OCEANS'98. Conference Proceedings (Cat. No.98CH36259).

[39]  Philippe Blondel,et al.  A multi-method approach for benthic habitat mapping of shallow coastal areas with high-resolution multibeam data , 2012 .

[40]  Maria Papatheodorou George Ferentinos George Fakiris Eli Geraga.  The study of an ancient shipwreck using marine remote sensing techniques, in Kefalonia Island (Ionian Sea), Greece , 2015 .

[41]  F. Douvere.  The importance of marine spatial planning in advancing ecosystem-based sea use management , 2008 .

[42]  Luciano E. Fonseca,et al.  Geocoder: An Efficient Backscatter Map Constructor , 2005 .

[43]  Alexandre C. G. Schimel,et al.  Integrating Multibeam Backscatter Angular Response, Mosaic and Bathymetry Data for Benthic Habitat Mapping , 2014, PloS one.

[44]  Iain Parnum,et al.  High-frequency seafloor acoustic backscatter from coastal marine habitats of Australia , 2012 .

[45]  Elias Fakiris,et al.  Quantification of regions of interest in swath sonar backscatter images using grey-level and shape geometry descriptors: the TargAn software , 2012, Marine Geophysical Research.

[46]  D. Tamsett.  Sea-bed characterisation and classification from the power spectra of side-scan sonar data , 1993 .

[47]  J. Collier,et al.  Interlinking backscatter, grain size and benthic community structure , 2014 .

[48]  S. Vaz,et al.  Quantitative mapping of fish habitat: A useful tool to design spatialised management measures and marine protected area with fishery objectives , 2014 .

[49]  G. Papatheodorou,et al.  Interplay of thrust, back-thrust, strike-slip and salt tectonics in a fold and thrust belt system: an example from Zakynthos Island, Greece , 2016, International Journal of Earth Sciences.

[50]  L. Parson,et al.  TexAn: textural analysis of sidescan sonar imagery and generic seafloor characterisation , 1998, IEEE Oceanic Engineering Society. OCEANS'98. Conference Proceedings (Cat. No.98CH36259).

[51]  Jaime S. Davies,et al.  Identifying deep-sea megafaunal epibenthic assemblages for use in habitat mapping and marine protected area network design , 2010, Journal of the Marine Biological Association of the United Kingdom.

[52]  Brian R. Calder.  Tackling Modern Multibeam Data with CUBE , 2004 .

[53]  J. M. Preston,et al.  Seabed classification of multibeam sonar images , 2001, MTS/IEEE Oceans 2001. An Ocean Odyssey. Conference Proceedings (IEEE Cat. No.01CH37295).

[54]  Carrie V. Kappel,et al.  A Global Map of Human Impact on Marine Ecosystems , 2008, Science.

[55]  Vanina Pasqualini,et al.  Use of SPOT 5 for mapping seagrasses: An application to Posidonia oceanica , 2005 .

[56]  Yuri Rzhanov,et al.  On Importance of Acoustic Backscatter Corrections for Texture-based Seafloor Characterization , 2012 .

[57]  Christopher B. Cogan,et al.  The role of marine habitat mapping in ecosystem-based management , 2009 .

[58]  Philippe Blondel,et al.  The Handbook of Sidescan Sonar , 2009 .

[59]  Craig J. Brown,et al.  Correlation of sidescan backscatter with grain size distribution of surficial seabed sediments , 2005 .

[60]  Alexandre C. G. Schimel,et al.  Combining pixel and object based image analysis of ultra-high resolution multibeam bathymetry and backscatter for habitat mapping in shallow marine waters , 2018, Marine Geophysical Research.

[61]  G. Lamarche,et al.  Recommendations for improved and coherent acquisition and processing of backscatter data from seafloor-mapping sonars , 2018, Marine Geophysical Research.

[62]  Jeroen Steenbeek,et al.  Biodiversity data requirements for systematic conservation planning in the Mediterranean Sea , 2014 .

[63]  Bhavani Narayanaswamy,et al.  Improving marine habitat mapping using high-resolution acoustic data; a predictive habitat map for the Firth of Lorn, Scotland , 2018, Continental Shelf Research.

[64]  J. Boucher,et al.  Processing of high-frequency multibeam echo sounder data for seafloor characterization , 2003 .

[65]  Vasiliki S. Karpouzi,et al.  The Mediterranean Sea under siege: spatial overlap between marine biodiversity, cumulative threats and marine reserves , 2012 .

[66]  N. Pace,et al.  Swathe seabed classification , 1988 .

[67]  J. Clarke.  Multispectral Acoustic Backscatter from Multibeam , Improved Classification Potential , 2015 .

[68]  Philippe Blondel.  Textural analysis of sidescan sonar imagery and generic seafloor characterization , 1999 .

[69]  P. Blondel.  Segmentation of the Mid-Atlantic Ridge south of the Azores, based on acoustic classification of TOBI data , 1996, Geological Society, London, Special Publications.

[70]  Xavier Lurton,et al.  An Introduction to Underwater Acoustics: Principles and Applications , 2010 .

[71]  Karen L. McLeod,et al.  Placing marine protected areas onto the ecosystem-based management seascape , 2010, Proceedings of the National Academy of Sciences.

[72]  Iain Parnum,et al.  High-frequency multibeam echo-sounder measurements of seafloor backscatter in shallow water: Part 2 - Mosaic production, analysis and classification , 2011 .

[73]  Elias Fakiris,et al.  Object-based classification of sub-bottom profiling data for benthic habitat mapping. Comparison with sidescan and RoxAnn in a Greek shallow-water habitat , 2018, Estuarine, Coastal and Shelf Science.

[74]  W. Ryan,et al.  Side-looking sonar backscatter response at dual frequencies , 1996 .