The Kuialnyk Estuary formerly known as Andriivskyi Lyman, is an estuary of the Velykyi Kuialnyk on the northwest coast of the Black Sea, one of the group of Odesa estuaries, located north of Odesa. On the southeast coast of the estuary there is the Kuialnytskyi mud resort, on the banks of the estuary beaches. The water level in the estuary and its salinity are regularly changed. In recent years the estuary has been rapidly become shallow.