Where is photosynthetic activity highest in lakes?
The littoral zone is the shallow lake margin where sunlight reaches the bottom, allowing rooted macrophytes, attached algae, and phytoplankton to photosynthesize. Plants occupy both the sediment and water column, creating a large photosynthetic surface and structurally complex habitat. Nutrients arrive from shoreline soils, runoff, decomposing vegetation, and sediment recycling, while wave action and animal activity can return them to the water. Consequently, areal primary production is often especially high in the littoral region. The profundal zone lies below effective light penetration and
Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 2-3
