Biogeographic classification of the Caspian Sea ...

• Main Authors: Fendereski, Forough, Vogt, Meike, Payne, Mark R., Lachkar, Zouhair, Gruber, Nicolas, Salmanmahiny, Abdolrassoul, Hosseini, Seyed Abbas
• Format: Article in Journal/Newspaper
• Language: English
• Published: ETH Zurich 2014
• Subjects: Sea ice
• Online Access: https://dx.doi.org/10.3929/ethz-b-000093361; http://hdl.handle.net/20.500.11850/93361

Like other inland seas, the Caspian Sea (CS) has been influenced by climate change and anthropogenic disturbance during recent decades, yet the scientific understanding of this water body remains poor. In this study, an eco-geographical classification of the CS based on physical information derived from space and in situ data is developed and tested against a set of biological observations. We used a two-step classification procedure, consisting of (i) a data reduction with self-organizing maps (SOMs) and (ii) a synthesis of the most relevant features into a reduced number of marine ecoregions using the hierarchical agglomerative clustering (HAC) method. From an initial set of 12 potential physical variables, 6 independent variables were selected for the classification algorithm, i.e., sea surface temperature (SST), bathymetry, sea ice, seasonal variation of sea surface salinity (DSSS), total suspended matter (TSM) and its seasonal variation (DTSM). The classification results reveal a robust separation ... : Biogeosciences, 11 (22) ...