Iranian National Institute for Oceanography and Atmospheric Science
Assessing the impact of physical properties on active reaction changes in the coastal and offshore area is one the most important aspect of marine environment of the Caspian Sea. Therefore, updated techniques and modern instruments have been used in order to evaluating the coastal and offshore area conditions. In the current research, collected data with spatial and temporal variety have been evaluated for investigation on seawater characteristics in the shallow and intermediate layers over the southern Caspian Sea. Some phenomena such as mixing, turbulence, water column stability and stratification are the effective elements on variability of physical and natural structures of the sea. Active reaction and dissolved oxygen as two properties of seawater are very important items for coastal engineering, piping in seabed, breakwaters and port constructions. Thus, in the current study, the above mentioned parameters were assessed over the southern shelf of the Caspian Sea. Vertical and horizontal variations of chemical characteristics such as active reaction of seawater were observed in several stations between coastal and offshore stations across surface, intermediate and deep layers. Results of the field operations showed that the normal values of pH in the study almost varied around 7.9-8 while during some seasons increased ore decreased more than 0.5 units due to human activates.