 This has led geologists to the understanding that at some point in time, there was a great deal of change occurring on the banks of the Damariscotta River that influenced the creation of such substantial middens.Oysters tend to like warmer, brackish waters – at some point in time, salty, cold oceanic water breached the Johnny Orr sill, mixed with warmer, less salty riverine water and created an environment that could sustain oyster populations about 2400 B.P..