Pulsing events and sustainability of Mediterranean deltas  <B>Pulsing events and sustainability of Mediterranean deltas</B><P>J.W. Day1, D. Pont2, P.F. Hensel1 and C. Ibanez3</B><I><P> 1 Department of Oceanography and Coastal Sciences and Coastal Ecology Institute, Louisiana State University, Baton Rouge, USA <BR> 2 CNRS URA 1451, Equipe DESPID, Laboratoire d'Ecologie, Arles, France <BR> 3 Dept. d'Ecologia, Universitat de Barcelona, Barcelona, Spain</I><P> Abstract<P> In deltas, subsidence leads to a relative sea level rise (RSLR) which is often much greater than eustatic rise alone. Because of high RSLR, deltaic wetlands will be affected early by an acceleration of eustatic sea level rise. If there is sufficient vertical accretion, wetlands can continue to exist with RSLR, however lack of sediment input eventually leads to excessive water logging and plant death. Areas with low tidal range such as the Mediterranean and Gulf of Mexico are especially vulnerable to rising water levels because the elevation growth range of coastal vegetation is related to tide range. Reduction of suspended sediments in rivers and prevention of wetland flooding by river dikes and impoundments have reduced sediment input to Mediterranean and Gulf of Mexico deltaic wetlands. This sediment deficit will become more important with an acceleration in sea level rise from global warming. Most sediment input occurs during strong pulsing events such as river floods and storms, and management policies and decisions are especially designed to protect against such events. Management approaches must be reoriented to take advantage of pulsing events to nourish marsh surfaces with sediments. We hypothesize that deltas can be managed to withstand significant rates of sea level rise by taking advantage of pulsing events which lead to high sediment input and that this type of management approach will enhance ecosystem functioning.<P>