Europe celebrates its first Maritime Day   Monthly evolution of chlorophyll concentration in the English Channel and North Sea. Arctic monitoring     Envisat ASAR mosaic of the Arctic Ocean for early September 2007, clearly showing the most direct route of the Northwest Passage open (orange line) and the Northeast passage only partially blocked (blue line). The dark grey colour represents the ice-free areas, while green represents areas with sea ice. Marine environment protection     Integration of vessel tracks from the coastal Automatic Identification System (AIS) with Envisat ASAR imagery. The concidence of the reported vessel track (in green) and the observed oil spill (the dark line at the centre of the image) gives an indication of the vessel responsible. Vessel names are blanked out.   Detection of algal blooms in the Norwegian Sea on 19 May 2008. Marine research     Sea surface temperature map acquired on 9 May 2008. Utilising data from Envisat’s Advanced Along Track Scanning Radiometer (AATSR) instrument, as well as other instruments aboard different satellites, ESA provides daily sea surface temperature maps of the European seas in near-real time as part of the agency’s Medspiration project. Release date: 18 August 2008