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During two cruises of the MEDUZA experiment conducted in July 2003 and May 2005 various data were obtained over the deepest part of the southern Adriatic Pit. Temperature, salinity, light transmission and fluorescence were measured in July 2003. During May 2005, except CTD measurements the samples were taken for laboratory determination of phytoplankton pigments with HPLC technique. During both cruises irradiance and radiance were measured at 14 wavelengths in the range 340-715 run with optical probe to about 100 m depth. Bad weather conditions during both cruises caused interruption of measurements that continued after 24 to 48 hours. Stormy conditions have resulted in a slightly different structure of the water column. In the periods of measurements recorded were diurnal rhythms in a series of parameters, caused by solar radiation cycles in the surface layers as well as fluctuations in the deeper layers under the influence of the internal tide. Meteorological conditions and changes in sea level are also described. The analysis included the principal component and correlation analysis between the measured and derived parameters in order to establish a link between the in-situ pigments and multispectral data. During both cruises diurnal vertical oscillations were observed in biotic and abiotic parameters. Chlorophyll pigments prevailed over other pigments preventing other pigments to be distinguished spectrally. Regression models for chlorophyll a were established from radiance and reflectance ratios. [ABSTRACT FROM AUTHOR]

The invasive algae in the Mediterranean Caulerpa taxifolia and Caulerpa racemosa var. cylindracea have gained much interest in the Adriatic Sea due to their fast spread and negative impacts on native seaweed species. Lack of accurate mapping and its overall high costs represent some of the major difficulties for successful detection and subsequent environmental management. Remote sensing techniques couM provide a quicker, more accurate and more cost efficient approach to mapping these invasive species. In order to allow for classification of remotely sensed data, we have collected and analyzed hyperspectral reflectance profiles of both invasive Caulerpa species in the Adriatic and the native Caulerpa cf. laetevirens species from the southeastern Atlantic coast of the United States. We have measured distinctive spectral features for spectroscopically distinguishing between these species, which is particularly interesting in the areas where these native and invasive species coexist. The initial results suggest that it might be possible to distinguish between the species based on their spectral reflectance profile. These results wouM have to be verified with samples taken from more populations in different phenological phases of the seaweed growth and other environmental conditions. [ABSTRACT FROM AUTHOR]