Grazing Potential—A Functional Plankton Food Web Metric for Ecological Water Quality Assessment in Mediterranean Lakes

Abstract

Grazing potential (GP, in % day−1) was estimated for the plankton communities of 13 Greek lakes covering the trophic spectrum, in order to examine its sensitiveness in discriminating different classes of ecological water quality. Lakes with high GP values exhibited high zooplankton biomass dominated by large cladocerans or/and calanoids while lakes with low GP values had increased phytoplankton biomass and/or domination of small-bodied zooplankton indicating intensive fish predation. GP successfully distinguished among ecological water quality classes (estimated using the phytoplankton water quality index PhyCoI) indicating its potential use as a metric for ecological water quality assessment. As a next step, PhyCoI index was modified to include GP as a metric in order to enhance the phytoplankton-based ecological status classification of lakes incorporating zooplankton as a supporting factor. The PhyCoIGP successfully assessed the ecological water quality in accordance with PhyCoI classification whereas it was significantly correlated with the eutrophication proxy TSISD based on Secchi Depth. Thus, we propose to use the modified phytoplankton index PhyCoIGP for monitoring the ecological water quality of lakes.

Ecological Connectivity in Two Ancient Lakes: Impact Upon Planktonic Cyanobacteria and Water Quality

“…The phytoplankton modified PhyCoI GP index [18] was used to assess ecological water quality of each lake. For the index calculation, we combined six metrics/sub-indices; i.e., the total phytoplankton biomass, the cyanobacterial biomass (according to World Health Organization Guidelines), the modified Nygaard sub-index based on the biomass of indicator taxonomic groups, the modified Nygaard sub-index based on species richness of indicator taxonomic groups, the quality group species Index and the grazing potential of zooplankton.…”

“…The ecological water quality assessment was based on the data of the sampling period June-September. This period is used for the lake ecological water quality assessments based on phytoplankton in the Greece/Mediterranean region [18].…”

“…We examined temporal variation in composition, biomass, alpha diversity, total beta diversity and the species' turnover and nestedness as the means to delineate the potential role of hydrological connectivity upon the phytoplankton assemblages. Species network interactions within each lake were also explored as the means to identify co-occurrence patterns and negative interactions, while the multimetric index PhyCoI GP [18] was applied to compare water quality of the two lakes.…”

Species Richness and Taxonomic Distinctness of Zooplankton in Ponds and Small Lakes from Albania and North Macedonia: The Role of Bioclimatic Factors

“…Here, we made an attempt towards this direction while using crustacean zooplankton. This group of organisms, ubiquitous in lentic habitats, has been recently subjected to renewed interest as an effective bio-indicator of the environmental status of ponds and small lakes [62][63][64][65]. The heuristic procedure was used here to identify minimum adequate models predicting the diversity the crustacean zooplankton assemblages across the 40 waterbodies under analysis provided non-univocal results.…”

Does habitat restoration disturb? A case study of a shallow urban water reservoir in western India using cladoceran zooplankton

“…The potential drivers of such changes can be identified by studying variations in biological communities and their environments and through integrative approaches using functional traits along with species identities (Cairns & Pratt, 1993, Nevalainen & Luoto, 2017). Functional traits include morphological, physiological and life history characters of organisms which directly link taxonomic diversity and ecosystem function (see Webb et al, 2010), and their integration in monitoring frameworks can vastly improve the understanding of the ecological impacts of anthropogenic disturbance (see Mason et al, 2005, Laliberte & Legendre, 2010, Stamou et al, 2019).…”