Jacques Populus

Using EUNIS habitat classification for benthic mapping in European seas: Present concerns and future needs

The EUNIS (European Union Nature Information System) habitat classification system aims to provide a common European reference set of habitat types within a hierarchical classification, and to cover all terrestrial, freshwater and marine habitats of Europe. The classification facilitates reporting of habitat data in a comparable manner, for use in nature conservation (e.g. inventories, monitoring and assessments), habitat mapping and environmental management. For the marine environment the importance of a univocal habitat classification system is confirmed by the fact that many European initiatives, aimed at marine mapping, assessment and reporting, are increasingly using EUNIS habitat categories and respective codes. For this reason substantial efforts have been made to include information on marine benthic habitats from different regions, aiming to provide a comprehensive geographical coverage of European seas. However, there still remain many concerns on its applicability as only a small fraction of Europes seas are fully mapped and increasing knowledge and application raise further issues to be resolved. This paper presents an overview of the main discussion and conclusions of a workshop, organised by the MeshAtlantic project, focusing upon the experience in using the EUNIS habitats classification across different countries and seas, together with case studies. The aims of the meeting were to: (i) bring together scientists with experience in the use of the EUNIS marine classification and representatives from the European Environment Agency (EEA); (ii) agree on enhancements to EUNIS that ensure an improved representation of the European marine habitats; and (iii) establish practices that make marine habitat maps produced by scientists more consistent with the needs of managers and decision-makers. During the workshop challenges for the future development of EUNIS were identified, which have been classified into five categories: (1) structure and hierarchy; (2) biology; (3) terminology; (4) mapping; and (5) future development. The workshop ended with a declaration from the attendees, with recommendations to the EEA and European Topic Centre on Biological Diversity, to take into account the outputs of the workshop, which identify weaknesses in the current classification and include proposals for its modification, and to devise a process to further develop the marine component of the EUNIS habitat classification.

Quantification of Subpixel Cover Fractions Using Principal Component Analysis and a Linear Programming Method: Application to the Coastal Zone of Roscoff (France)

Abstract In this study, principal component analysis and the linear programming method “affine algorithm” were jointly used to provide an unmixing method and to calculate fractions bounds of main seaweeds and intertidal components from mixed pixels. The method was tested using CASI airborne imagery data taken over the Roscoff coastal zone (Brittany, France). The contribution of the number of spectral bands used to identify many component types was also examined. Between four and six components can be distinguished depending on the spectral richness of the original image. The accuracy of fraction cover types was estimated by comparing calculated proportions with ground data. Whatever the number of bands and ground categories, the coefficient of determination R 2 was higher than 0.62. Much more information and more accurate results were obtained with 13 spectral bands (R 2 from 0.81 to 0.96).

The use of SPOT data for wave analysis

Abstract After recalling the various techniques used for wave measurement, this paper concentrates on the possibilities of using SPOT data for large scale wave analysis. Conditions for good wave pattern visibility are discussed from a theoretical point of view. In order to check the theory, examination of a large number of SPOT images was performed concerning the relation between viewing conditions and image quality. Using spectral analysis, a comparison is achieved using available simultaneous in situ directional data and SPOT images of an off shore area in Brittany, France. Major conclusions are that both types of data compare rather well and that SPOT data could be used effectively in the coastal zone, provided that a proper software is designed to process small spatial windows. Recommendations are given for image acquisition procedure.

Remote sensing as a tool for diagnosis of water quality in indonesian seas

Shrimp development in Indonesia, after a decade of strong expansion and intensification, began to be faced with critical problems of mortality. General degradation of coastal waters is likely to be the major reason, and this mainly occurs on sites in the Java Sea which appear as confined seas subjected to high telluric effluent levels and anthropic pressure. Remote sensing provides synoptic vision over large areas. Several scenes were processed for land-use mapping using conventional classification techniques. In this study, this was specifically done to determine water quality. A general empirical relation for the Java Sea, independent of time and place, was found between image and field data, namely pigments and suspended matter. Applying this relation to a new site provides an initial approach to water type and, together with land use mapping, a preliminary assessment of the suitability of the area for shrimp aquaculture development. It also provides guidance for efficient subsequent field sampling. Recommendations are given for use of remote sensing to improve site assessment and monitoring.

An assessment of environmental sensitivity to marine pollutions: solutions with remote sensing and Geographical Information Systems (GIS)

Abstract The environmental sensitivity to oil pollution is addressed in the Loire estuary, an area of very high economical and recreational value. The first part of the paper deals with the evaluation of remote sensing images (SPOT, Landsat Thematic Mapper and ERS-1 radar). The availability of the right images with respect to low tide conditions is discussed. Well-established classifications are used for both visible and radar images, which produce mainly geomorphological information: coastline, sediments, vegetation. Living resources at risk are compiled mostly out of ancillary data, i.e., maps and reports. These two types of information lead to ranking the shoreline in terms of its ecological sensitivity. Man-made objects and human activities are also incorporated. After collecting all relevant data, we examine in a second part how to merge them and produce environmental sensitivity maps, using both CAD (Computer Assisted Design) and GIS (Geographic Information Systems) tools.

Application of airborne imaging spectrometry system data to intertidal seaweed classification and mapping

The aim of this paper is to test the ability of imaging radiometers to describe the principal seaweed and seagrass beds along the coast of Brittany (France). In this work we used CASI, an instrument with programmable narrow bands. On the ground, regions of homogeneous vegetation cover were mapped using differential GPS positioning. Ground spectra were recorded with a field spectroradiometer (Spectron SE 590), for substratum and different species. Their analysis shows variations in relation to pigment characteristics, vegetation structure and environmental conditions. An algorithm sequence based on field work and according to the technical sensor characteristics, was developed to discriminate the dominant species. The classified CASI image was compared with ground data. The main results are the following: (a) the visible wavelengths allow good discrimination between green, red and brown algae. (b) the infrared wavelengths allow separation of two main types of brown species, seagrasses and the identification of floating seaweed.