Ecology of southern African estuaries: Part XIII. The Palmiet River estuary in the south-western Cape

Abstract

The Palmiet estuary is only 1,67 km in length, but has a relatively large catchment of 539 km². Rain falls largely during winter when it scours the estuary and widens the mouth, but by late summer the mouth narrows and, in some years, may close. The estuary never closes for more than a few months, and salinities are normal. The entire estuary has clear bottom water and high bottom salinities, but the surface waters are usually fresh and darkly stained with humic acid. This permanent stratification allows many marine species to penetrate the estuary.