At about 7ha, Għadira is tiny by international standards but on a national scale, its ecological value is high. Due to the dry climate, wetlands in Malta are rare and permanent inland bodies of water are almost nonexistent. Because of this, much of the flora and fauna of Għadira tend to be scarce, rare or with very restricted distribution in the country. The aquatic flora includes a species of tassel weed, which appears virtually nowhere else in Malta, and the resident Mediterranean killifish is one of just three or four populations on the Islands.