Touria Bajjouk

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).

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.

Bathymétrie issue des images hyperspectrales - côte ouest de La Réunion

Cette bathymetrie est issue d’une fusion entre le MNT Litto3D Lidar a 1 m et les images hyperspectrales de resolution spatiale 40 centimetres apres traitement de la colonne d’eau. Cette correction a permis le calcul d’une bathymetrie a tres haute resolution spatiale sur l’emprise des images.