Spawning and eggs incubation of herring (Clupea harengus L.) of the Puck Bay origin were carried out. During incubation period measures of the water oxygen content (mg/dm3) and water temperature (°C) had been taken. The particular eggs developing stages were determined in degree-days (°D). Efforts, as to find out whether, rinsed with marine water mixed with milk, eggs are loosing their sticking properties were undertaken. After being sticked to the net, eggs were incubated directly in the bay water and controlled while incubating.