Is there any relationship between the pH of seawater and any properties of the sand at the beach? If so, what/ why/ how? Context: I am writing a report for my Soil Mechanics course, for which we analysed some sand we collected at the beach, as well as some seawater. One of the key properties to measure - as suggested by both lecturer and lab tutors - was the pH of the seawater, which leads me to believe there might be some relationship. I am aware that the pH of soil affects what kind of plants can grow, but this is a soil mechanics subject, not agriculture (i.e. we also have to find the angle of repose, suction, shear strength, etc...). So why bother with the pH of seawater? I have tried finding relevant material in the textbook for the course [Soil Mechanics and Foundations, Buhdu] but have been unsuccessful. Furthermore, my attempts at online research have lead me as far as finding the best soil pH to grow crops. Any insights will be very much appreciated!