The Türkmenbaşy Gulf or Türkmenbaşy Bay (Russian: Туркменбашы Залив Turkmen: Türkmenbaşy aýlagy) is a bay of the Caspian Sea in the coast of Turkmenistan. With the Krasnovodsk Peninsula to the north and the Cheleken Peninsula to the south, the gulf extends westwards into the sea for 46 km and has an 18 km wide mouth. At its northwest corner are the Bala-Ishem salt marshes which mark the mouth of the dried-up Uzboy River. It became part of the Hazar Nature Reserve in 1968. Among the animals in the bay the Krasnovodsk herring (Alosa braschnikowi nirchi) and the Caspian seal deserve mention.