Description: Abstract. The intertidal macrophyte vegetation of the island of Helgoland (Germany, North Sea) was recently mapped by applying the biotope concept developed by Connor and co-workers in the UK. Having defined the biotopes in the field and having developed a geographical information system, this is a useful method to do regular surveys of the area in order to record the spatial spread of relevant communities on a higher hierarchical level. Additionally, hyperspectral remote sensing methods were applied for the same area in order to develop a tool to receive synoptic spatial data of the whole area including inaccessible sites. This method is promising to detect the patchiness and spatial change of dominant intertidal macrophytes, but the method needs further development. Either of both approaches will be useful to complement the monitoring demands required for the EU WFD.

Description: AbstractHard bottom marine biocoenoses constitute one of the most important and productive ecosystems in the world. The detection of stability or change in different hierarchical levels of these complex systems is difficult but of major international relevance for basic and applied research. World-wide traditional biological field methods created only sparse information regarding the recognition of spatial changes of intertidal biotopes. Remote sensing techniques may help to assess biodiversity change on a high hierarchical level and with a synoptic view of the system, complementing the detailed biological biodiversity studies with their complex spatial information.The marine nature reserve of the island of Helgoland (North Sea, Germany) comprises a large amount of the representative species for northern European rocky coastlines, but the major communities are small-scaled (patches of 10-1000 m2 size) and interwoven. The mapping of these biotopes by airborne remote sensing was the aim of this study in order to develop a method for long-term spatial monitoring of intertidal communities. In July 2002 and September 2003, two data sets of Helgolands coast were acquired with the hyperspectral sensor ROSIS operating at approximately 1m pixel size. The data were radiometrically, atmospherically, and geometrically corrected. Based on ground truth data and detailed spectral analysis, a supervised hierarchical classification scheme was developed to classify the major intertidal communities. Comparisons between the 2002 and 2003 data and between different classification protocols are presented. Simple, cost-friendly machine classification is not possible, but the advanced analysis of the hyperspectral data show a good congruence with a traditionally derived biotope map. The spectral classes are not an exact copy of the mapped biotopes, but represent an even higher hierarchical level of biodiversity and accurately record the patchiness of classes in contrast to the biotope map. The potential and limitations of this spectral approach will be discussed and suggestions for improvement are presented. The method has potential to monitor the spatial change of intertidal communities in the context of the EU-water frame work directive.

Description: The intertidal macrophyte vegetation of the island of Helgoland (Germany, North Sea) was recently mapped by applying the biotope concept developed by Connor and co-workers in the UK. Having defined the biotopes in the field and having developed a geographical information system, this is a useful method to do regular surveys of the area in order to record the spatial spread of relevant communities on a higher hierarchical level. Additionally, hyperspectral remote sensing methods were applied for the same area in order to develop a tool to receive synoptic spatial data of the whole area including inaccessible sites. This method is promising to detect the patchiness and spatial change of dominant intertidal macrophytes, but the method needs further development. Either of both approaches will be useful to complement the monitoring demands required for the EU WFD.

Description: AbstractThis report deals with the use of hyperspectral remote sensing methods in rocky intertidal areas. These methods were evaluated in a pilot study analyzing hyperspectral imagery from the rocky intertidal of Helgoland. The paper discusses the potential of hyperspectral image analysis for monitoring elements of coastal diversity apparent in this area and discusses thepotential and limitations of the method. This is especially relevant for application-oriented monitoring of protected areas and for coastal zone management. The discussed issues also contribute to monitoring works within European programs such as the Water Framework Directive or the Natura 2000 network. The results show that a classification based on aspectral library allows a mapping of the dominant intertidal macrophyte vegetation and general intertidal structures. Limitations remain for separation of mixed vegetation types which cannot be identified without ancillary data sources. One major potential for future use of these methods is their efficiency for high-resolution geospatial data acquisition. The integration of remote sensing techniques in GIS-based automated monitoring systems willhelp to combine different levels of resolution as well as different data sources needed to detect significant changes in structural and compositional coastal biodiversity. The success of this approach also depends on the selection of the best suitable imaging sensor and an appropriate analysis approach which fits the specific needs in the areas of investigation.