Could artificial plant beds favour microcrustaceans during biomanipulation of eutrophic shallow lakes?
DAVID BALAYLA; THOMAS BOLL; CAROLINA TROCHINE; ERIK JEPPESEN
Lugar: Berlin; Año: 2017
Introductionof artificial plants may facilitate the transition from a turbid to a clearwater state in shallow lakes, particularly when plant establishment is delayed.We investigated the usefulness of artificial plants as a restoration tool in anexperimental setup mimicking open submerged plant beds with high (80%, HPD) andlow (20%, LPD) density in shallow Lake Vaeng, Denmark, having undergonebiomanipulation in the form of extensive fish removal. Biological measures ofthe fish, and of both free-swimming (FSZ) and plant-attached zooplankton (PAZ)within the experimental beds and in the lake, were obtained from before, duringand after biomanipulation. We found that zooplankton measures (density, biomassand Cladocera:FSZ zooplankton) were significantly larger in the HPD beds,before and during fish removal, while the effect of plants was not significant,with low fish biomass after biomanipulation. On PAZ, these effects were lesspronounced and only significant after biomanipulation. Zooplankton was largerat HPD in all years, for both FSZ and PAZ.Inconclusion, artificial plant beds acted as an effective zooplankton refugeagainst fish, particularly for the FSZ at HPD and in the years with high fishdensities, providing further evidence that artificial plant beds could assistlake restoration efforts.