Ecosystem monitoring in the Cretan Sea
The objective of this component is to maintain a long time series of biogeochemical, biodiversity and ecosystem measurements in the Cretan Sea. These observations are essential reference points in the study of global change impacts on marine ecosystem biogeochemistry and biodiversity. For this purpose, since 2010, the Institute of Oceanography of HCMR initiated repeated research vessel (R/V) visits in the Cretan Sea next to the POSEIDON E1-M3A fixed platform. The variables measured through the R/V repeated visits are: temperature, salinity, fluorescence (as proxy of Chlorophyll-a), light transmittion, oxygen, inorganic nutrients, pH, total alkalinity, dissolved inorganic carbon, as well as plankton stock and composition from virus to zooplankton. Later on (2011) the R/V visits at this location were complemented with an array of two sediment traps (to analyze among others the organic, inorganic carbon and nitrogen fluxes), and a year later (2012) with an acoustic Doppler current profiler (ADCP) to estimate zooplankton vertical migration. Since 2016 repeated research vessel (R/V) visits are also performed at monthly frequency next to the coastal fixed platform HCB.