Gulf of Gabes, inlet, on the east coast of Tunisia, northern Africa. It is 60 miles (100 km) long and 60 miles wide and is bounded by the Qarqannah (Kerkena) Islands on the northeast and by Jarbah (Djerba) Island on the southeast. Except for the Strait of Gibraltar and the Gulf of Venice, it is the only part of the Mediterranean with a substantial tidal range (about 8 feet [2 1/2 m] at spring tides), causing the uncovering of extensive sandbanks at low water. Sponge and tuna fisheries are located at the main ports of Qābis (Gabès) and Ṣafāqis (Sfax). Oil and natural-gas deposits have been found in the gulf, east of Ṣafāqis.