Hydrology and Earth System Sciences www.hydrol-earth-syst-sci.net 1027-5606 1607-7938 9 1/2 2005 10.5194/hess-9-67-2005 http://www.hydrol-earth-syst-sci.net/9/67/2005/ http://www.hydrol-earth-syst-sci.net/9/67/2005/hess-9-67-2005.html http://www.hydrol-earth-syst-sci.net/9/67/2005/hess-9-67-2005.pdf 67 80 2005-06-14 Factors influencing fluffy layer suspended matter (FLSM) properties in the Odra River - Pomeranian Bay - Arkona Deep System (Baltic Sea) as derived by principal components analysis (PCA), and cluster analysis (CA) J. Pempkowiak J. Beldowski K. Pazdro A. Staniszewski A. Zaborska T. Leipe K. Emeis Institute of Oceanology, ul. Powstanców Warszawy 55, 81-712 Sopot, Poland Institute of Baltic Sea Research, Seestrasse 15, 18119 Rostock-Warnemuende, Germany Institute of Biogeochemistry and Marine Chemistry, Hamburg University, Bundesstrasse 55, 20146 Hamburg, Germany Factors conditioning formation and properties of suspended matter resting on the sea floor (Fluffy Layer Suspended Matter - FLSM) in the Odra river mouth - Arkona Deep system (southern Baltic Sea) were investigated. <P style="line-height: 20px;"> Thirty FLSM samples were collected from four sampling stations, during nine cruises, in the period 1996-1998. Twenty six chemical properties of the fluffy material were measured (organic matter-total, humic substances, a variety of fatty acids fractions, P, N, &delta;13C, &delta;15N; Li; heavy metals- Co, Cd, Pb, Ni, Zn, Fe, Al, Mn, Cu, Cr). The so obtained data set was subjected to statistical evaluation. <P style="line-height: 20px;"> Comparison of mean values of the measured properties led to conclusion that both seasonal and spatial differences of the fluffy material collected at the stations occured. Application of Principal Component Analysis, and Cluster Analysis, to the data set amended with environmental characteristics (depth, salinity, chlorophyll <i>a</i>, distance from the river mouth), led to quantification of factors conditioning the FLSM formation. The five most important factors were: contribution of the lithogenic component (responsible for 25% of the data set variability), time dependent factors (including primary productivity, mass exchange with fine sediment fraction, atmospheric deposition, contribution of material originating from abrasion-altogether 21%), contribution of fresh autochtonous organic matter (9%), influence of microbial activity (8%), seasonality (8%).