Anastasia Tsirika

Using Earth Observation to update a Natura 2000 habitat map for a wetland in Greece.

The European Habitats Directive 92/43/EEC has defined the need for the conservation of habitats and species with the adoption of appropriate measures. Within the Natura 2000 ecological network of special areas of conservation, natural habitats will be monitored to ensure the maintenance or restoration of their composition, structure and extent. The European Space Agencys GlobWetland project has provided remotely sensed products for several Ramsar wetlands worldwide, such as detailed land cover-land use, water cycle and inundated vegetation maps. This paper presents the development and testing of an operational methodology for updating a wetlands habitat map using the GlobWetland products, and the evaluation of the extent to which GlobWetland products have contributed to the habitat map updating. The developed methodology incorporated both automated and analyst-supervised techniques to photo-interpret, delineate, refine, and evaluate the updated habitat polygons. The developed methodology was proven successful in its application to the wetland complex of the Axios-Loudias-Aliakmon delta (Greece). The resulting habitat map met the European and Greek national requirements. Results revealed that GlobWetland products were a valuable contribution, but source data (enhanced satellite images) were necessary to discriminate spectrally similar habitats. Finally, the developed methodology can be modified for original habitat mapping.

A survey of the benthic flora in the National Marine Park of Zakynthos (Greece)

Abstract We studied the composition of the benthic marine macroflora in Laganas Bay (National Marine Park of Zakynthos, Ionian Sea, Greece). Seasonal samples were collected by SCUBA-diving from April 2001 to February 2003. A total of 182 taxa at specific and infraspecific rank of macroalgae was found, 146 of which are new records to Zakynthos Island and 12 to the Greek coasts. The vegetation of most of the rocky substrata is characterized by species of the canopy-forming genus Cystoseira, while that of soft bottoms is characterized by large meadows of Posidonia oceanica. Two other phanerogams (Cymodocea nodosa and the lessepsian immigrant Halophila stipulacea) also occur on soft bottoms, the former developing dense meadows, while the latter occurs in only a restricted area. The invasive green alga Caulerpa racemosa var. cylindracea was of frequent occurrence on hard and soft substrata.

Preliminary results of field and culture studies of Porphyra att. ad. leucosticta thuret in le jolis from the Gulf of Thessaloniki

Porphyra att. ad. leucosticta has been studied in the field, biotope of Epanomi, Gulf of Thessaloniki and under laboratory conditions. This species has been occured in the field from December 1996 to April 1997. The reproductive mode of the blade phase has been studied by using light microscope. Blade phase produced three types of spores: zygotospores, spermatia and monospores. The number of zygotospores and spermatia produced by each mother cell was 8 (a/2, b/2, c/2) and 32 (a/4, b/2, c/4), respectively. In exceptional cases the number of spermatia in each spermatangium was 64 (a/4, b/4, c/4). The zygotospores developed in culture by a unipolar growth mode into conchocelis plants and by a bipolar growth mode into blade plants. The monospores developed in culture by a bipolar growth mode into blade plants.

Marine Animals’ Ethology as a New Product in Recreational SCUBA Diving Market

Recreational SCUBA diving market is a rapidly developing industry, which during the last years focuses among others in the observation of marine fauna and flora. An innovative approach towards this direction is to study whether animal, and particularly fish behaviour, can contribute to the development of SCUBA diving tourism. The principal two axes of the current survey were the enhancement of SCUBA diving safety (via the promotion of swallow waters biocommunities) and the marine life protection (via environmental awareness). The two study areas are located in Chalkidiki peninsula (Greece, North Aegean Sea). The preliminary part of this study demonstrated a non significant difference between males and females regarding their age, their diving experience (training level and hours of diving) and their diving preferences (depth and type of sea bottom). Nesting and agonistic behavior of three Labridae fish (Symphodus ocellatus, Symphodus cinereus, Xyrichthys novacula) were used as motivation factors in the three testing hypotheses. Among those three hypotheses, diving in shallow rocky bottom aiming at the observation of Symphodus ocellatus seems to be the most attractive for the divers. As a general remark, briefing is a very useful tool that can inform, but also orientate the customers. Additionally, the very poor knowledge of Mediterranean undersea wildlife, especially by the recreational SCUBA diving staff should be mentioned. As a conclusion, the current approach can be used for the enhancement of SCUBA diving product (i.e. promotion of specialties such as Fish Identification) or increase of SCUBA diving equipment (i.e. underwater cameras).

Predicting soil properties for sustainable agriculture using vis-NIR spectroscopy: a case study in northern Greece

Soil Spectral Libraries facilitate agricultural production taking into account the principles of a low-input sustainable agriculture and provide more valuable knowledge to environmental policy makers, enabling improved decision making and effective management of natural resources in the region. In this paper, a comparison in the predictive performance of two state of the art algorithms, one linear (Partial Least Squares Regression) and one non-linear Cubist), employed in soil spectroscopy is conducted. The comparison was carried out in a regional Soil Spectral Library developed in the Eastern Macedonia and Thrace region of Northern Greece, comprised of roughly 400 Entisol soil samples from soil horizons A (030 cm) and B (30-60 cm). The soil spectra were acquired in the visible – Near Infrared Red region (vis-NIR, 350nm2500nm) using a standard protocol in the laboratory. Three soil properties, which are essential for agriculture, were analyzed and taken into account for the comparison, namely Organic Matter, Clay content and the concentration of nitrateN. Additionally, three different spectral pre-processing techniques were utilized, namely the continuum removal, the absorbance transformation, and the first derivative. Following the removal of outliers using the Mahalanobis distance in the first 5 principal components of the spectra (accounting for ~99.8% of the variance), a five-fold cross-validation experiment was considered for all 12 datasets. Statistical comparisons were conducted on the results, which indicate that the Cubist algorithm outperforms PLSR, while the most informative transformation is the first derivative.

Challenges in Recreational SCUBA Diving in the Mediterranean Sea: Posidonia oceanica Meadows

Posidonia oceanica is an endemic Mediterranean ecosystem which is widely distributed along the Greek coasts, and is considered a biotic index of good water quality. Apart from the ecological interest of Posidonia meadows, these habitats can be an attractive pole for recreational SCUBA diving activities. A total of 255 divers (210 males and 45 females) from diving resorts and diving clubs in Sani region (Chalkidiki, North Aegean Sea, Greece) filled in questionnaires. According to the results, only few divers prefer to dive in Posidonia oceanica beds, mainly due to the lack of knowledge. Posidonia diving appears to be a new challenging destination into the Mediterranean basin and this study examines the possibility to increase the value of Posidonia beds as a diving site. The benefits of this are numerous for both the enhancement of the diving industry and the conservation of natural resources. As a general conclusion, the necessity of an appropriate informing and training procedure, through the pre-dive briefing, is underlined.