Restoration cases with hydrophytes (those which develop all their vital functions inside the water or very close to the water surface, e.g., flowering) are less abundant compared to those using emergent plants. Here, I synthesize the latest knowledge in wetland restoration based on revegetation with hydrophytes and stress common challenges and potential solutions. The review mainly focusses on natural wetlands but also includes information about naturalized constructed wetlands, which nowadays are being used not only to improve water quality but also to increase biodiversity. Available publications, peer-reviewed and any public domain, from the last 20 years, were reviewed. Several countries developed pilot case-studies and field-scale projects with more or less success, the large-scale ones being less frequent. Using floating species is less generalized than submerged species. Sediment transfer is more adequate for temporary wetlands. Hydrophyte revegetation as a restoration tool could be improved by selecting suitable wetlands, increasing focus on species biology and ecology, choosing the suitable propagation and revegetation techniques (seeding, planting). The clear negative factors which prevent the revegetation success (herbivory, microalgae, filamentous green algae, water and sediment composition) have to be considered. Policy-making and wetland restoration practices must more effectively integrate the information already known, particularly under future climatic scenarios.

Epilimnetic colonies of Gloeotrichia echinulata were harvested from 200–300 I of water in Lake Erken with filtration through appropriate plankton nets (200 or 70 μm). Phosphate uptake characteristics, phosphorus (P) status and photosynthesis of the colonies were determined twice a week during July and August 1991. Phosphate uptake was analysed according to the simple force- flow relationship of Falkner et al . ( Arch. Microbiol ., 152, 353–361, 1989). The threshold concentration of P uptake below which uptake ceases for energetic reasons, was constantly much higher than the epilimnetic soluble reactive phosphorus (SRP) concentration, so that the planktonic colonies were unable to acquire any Pin the epilimnion. Neither did organic P seem to be a source of P for planktonic colonies. Gloeotrichia echinulata has a unique life strategy in comparison to other common genera of bloom-forming cynanobacteria. Its P assimilation and growth are completely separated both in time and space; growth is preceded by benthic P assimilation. Epilimnetic growth was based solely on internally stored P and growth rates fitted the Droop model well. Depletion of stored P restricts the length of the planktonic phase to 15–20 days under ‘optimal’ growth conditions. Wind-induced surface drift seemed to be the most important loss factor from the epilimnion. Massive recruitment of P-rich benthic colonies accounted for two-thirds of total net internal P loading observed between mid-July and mid-August (3.8 mg P m ⁻² day ⁻¹ ).