Seasonal Fluctuations in the Vertical Distribution of Meiofauna in Estuarine Sediments

The vertical distribution of meiofauna in estuarine sand and mud sediments was investigated over a period of fourteen months. Statistically significant differences were found between fluctuations of meiofauna inhabiting different depth zones in the top 20 cm of the sediment. The shallow populations are affected more drastically during rimes of adverse conditions but they have the ability to respond rapidly to favourable conditions. It is concluded that a combination of physiological adaptation and changes in species composition, rather than seasonal vertical migrations, are responsible for the observed patterns.