Vertical movements by planktonic cyanobacteria and the translocation of phosphorus: implications for lake restoration

Abstract

1. Vertical movements of cyanobacteria during summer stratification were studied in Cauldshiels Loch, a small dimictic temperate lake. 2. Filaments of the three species of cyanobacteria dominant in the summer phytoplankton were recorded moving vertically in both directions, by simple traps deployed just below the thermocline. 3. These phytoplankters could potentially exploit opposing ends of the vertical light/nutrient gradient that existed in the water column during stratification. 4. The hypolimnion and water overlying the sediments were enriched by phosphorus released from the sediments. This internal loading to the lake provides a source of phosphorus available to migrating cyanobacteria to sustain production and growth in the epilimnion. 5. In this study, cyanobacteria filaments moving from the hypolimnion were found to be translocating phosphorus to the epilimnion. 6. Following reduction of external phosphorus loading, utilization of such internal phosphorus sources may delay expected reductions of bloom‐forming cyanobacterial communities, and consequent improvements in other aspects of water quality. Copyright © 1999 John Wiley & Sons, Ltd.

The influence of restoration measures on phosphorus internal loading from the sediments of a hypereutrophic lake

“…The analysis of the variability of SRP and TP concentrations in the interstitial water of Uzarzewskie Lake showed that higher values were noted in summer and autumn periods at the station located in the profundal zone, as phosphorus released by the mineralization of organic matter in the sediments was enriching the interstitial water first; this was also found by Head et al (1999). A similar seasonal variability was recorded in the littoral zone.…”

Blooms also like it cold

“…Physical drivers, like upwelling and mixing events, may also promote blooms that are initiated when water temperatures are cold by providing hypolimnetic nutrients. Several taxa, such as Planktothrix , Dolichospermum , and even Microcystis , respond to lake mixing events that supply nutrients from the hypolimnion across the water column (Head et al 1999; Bormans et al 2016). These hypolimnion‐derived nutrients may then support late fall/early winter cyanobacterial blooms.…”

A novel model for cyanobacteria bloom formation: the critical role of anoxia and ferrous iron

“…Migration velocities appear to be large enough to reach anoxic areas in many systems, but data are limited (Table ). Migration downwards into anoxic waters has been observed (Camacho et al ., ; Camacho, Vicente & Miracle, ; Gervais et al ., ) as well as acquisition of P during migration (Head, Jones & Bailey‐Watts, ). Aphanizomenon has been observed migrating upwards in the anoxic hypolimnion of Lake 227 in the Experimental Lakes Area in north‐western Ontario below the metalimnion (Fig.…”