Seagrass mapping and monitoring along the coast of Crete, Greece

International audienceThis research is presented at the job interview in the University of Rostock. Originally based on author's MSc thesis (2009-2011) summarizing research in marine observations using remote sensing and GIS methods. Study object is seagrass Posidonia oceanic (P. oceanica) along the coast of Crete, Greece. The most important facts about seagrass: endemic Mediterranean seagrass, P. oceanica is a main species in marine coastal environment of Greece. P. oceanica is the largest, the most widespread, homogeneous, dense “mattes” forming meadows between 5-40 m in Mediterranean Sea. Seagrass is a component of coastal ecosystems of high importance for the marine life, playing important functions in the marine environment. Seagrasses are subjects to external factors and therefore have environmental vulnerability. The study area is located in General research area: Island of Crete, Greece. Seagrass sampling will be performed at three stations at a depth of 6-7 m: Heraklio, Agia Pelagia, Xerokampos, Crete Island, Greece. The general research objectives of the MSc research includes GIS and environmental analysis: 1) Mapping the extent of the spatial distribution of seagrass P. oceanica along the northern coast of Crete; 2) Monitoring environmental changes in seagrass meadows in the selected fieldwork sites (Agia Pelagia, Xerokampos) over the 10-year period (2000-2010). There are various multi-sources data proposed for using in spatial analysis. data of the previous measurements received during the last year fieldwork, to analyze whether P.oceanica is spectrally distinct from other sea floor types, using differences in the spectral signatures on the graphs in a WASI, the Water Color Simulator software. Other data include satellite images from the open sources (Landsat TM), aerial images, Google Earth; underwater videographic measurements of 3 cameras Olympus ST 8000 made during the ship route (20 total in the selected areas of the research places) resulting in series of consequent images, covering area under the boat path; in-situ measurements of the seagrass in selected spots, using measurement frame and other devices for marine biological research for the validation of the results. Arc GIS vector layers of Crete island and surroundings (.shp files). Hypothesis testis is performed by ANOVA, SPSS. The results of WASI spectral analysis illustrating graphs of the spectral reflectance of different sea floor types (sand, P.oceanica, rocky, etc) at various depths (0.5-4 m), based on the results of 20. Precise, correct and up-to-date information about the seagrass distribution over the coasts is necessary for the sustainable conservation of marine environment