On the coast of the Azov Sea, a mass death of the Azov goby is observed annually, more than ten tons of fish are thrown ashore. A large accumulation of the Azov goby is observed at the end of the Berdyansk Spit, where still living gobies stand near the shore in a strip at a distance of about a hundred meters from the shore.
The phenomenon called the death of a goby is a common thing on the Azov Sea. Its cause is the shallow depth of the Azov Sea, which warms up quickly in summer. At the same time, the oxygen content in sea water drops sharply and Azov fish begins to suffocate. Of all the fish in the Azov Sea, the Azov goby is the first to react to a lack of oxygen. A similar phenomenon is observed in the Azov Sea annually, sometimes several times during the summer.
Sometimes the death of the Azov goby begins earlier than usual. This may be due to the fact that for several weeks there is complete calm on the Azov Sea, the mass of water does not mix. The bottom of the Azov Sea is mainly composed of silt, which oxidizes by absorbing oxygen from the sea water. Since there was no water circulation, the oxygen content in the lower layers of the water begins to decrease, and the goby, which lives near the bottom, begins to move towards the shore, into the higher layers of the water. As a result of this, so many fish gather near the shore that it becomes simply nothing to breathe.
One of the measures to prevent or reduce the negative consequences of this phenomenon is the so-called reclamation of Azov gobies, which reduces the number of fish and allows the rest to survive. Usually in the summer, more than a dozen fishing vessels are busy reducing the number of gobies in the Azov Sea during its mass death.