Kerkennah Islands and Djerba Off Tunisian Coast
Both the Kerkennah Islands (above) and the island of Djerba (below) are surrounded by greenish tan waters. This coloration may be partially caused by sediments and partially caused by algal growth, as two species of green algae tend to invade this coastal region.
The Kerkennah Islands are a group of islands lying off the east coast of Tunisia in the Gulf of Gabes. The islands are low-lying, at no more than 13 metres above sea level. The archipelago has an area of 160 km2 and a population of 14,400 as of 2006. Djerba, also located in the Gulf of Gabes, is the largest island off North Africa at 514 km². Its largest city is Houmt-Souk, with a population of around 60,000.