The response of phytoplankton, zooplankton and macrozoobenthos communities to change in the water supply from surface to groundwater in aquaculture ponds

Abstract

-Investigating forces driving the structure of aquatic communities has long been an important issue in ecology. In the present study, we focused on the effects of changed water supply for aquaculture ponds on phytoplankton, zooplankton and macrozoobenthos communities during two seasons of rearing common carp. We compared these communities between two types of inflow water: surface sources of watera reservoir pond, two open wells and a small stream and groundwater -deep tube well. Significant changes were observed in environmental variables after the introduction of the groundwater source: oxygen concentration and water hardness decreased, while conductivity, phosphorus and un-ionized ammonia increased. Results revealed that all investigated groups, except Mollusca (macrozoobenthos), decreased in species richness, abundance and biomass due to changed water chemistry, but differed in the level of susceptibility. Rotifera and Cladocera were the most affected showing a sharp decline in density and number of species since 66% of species disappeared from the ponds. The abundance of Copepoda was relatively high although significantly lower under new conditions, with adults being more tolerant to changed inflow water than nauplii larvae. Phytoplankton had the highest potential to replace previous species with newcomers more adapted to changed water chemistry, providing 36 immigrant species, whereas 49 became extinct. Although mainly influenced by fish predation, Chironomidae (macrozoobenthos) were undoubtedly affected by changed water chemistry. These results suggest profound changes in three key ecological groups produced by significant changes of important environmental variables and water quality after the shift from surface to groundwater supply.

Using topsoil translocation from natural wetlands to restore rice field systems

“…It is well established that agricultural activities have substantial effects on zooplankton species (i.e. decreases in species richness and biomass, imbalances in the hatching dynamics; Duli c et al 2014;Gutierrez et al 2017). So, changes in species composition are prone to happen between rice fields and natural wetlands.…”

Natural Biota’s Contribution to Cultured Aquatic Animals’ Growth in Aquaculture Cannot Be Ignored

“…Overall, the biomass of Bacillariophyta, Chlorophyta, Cyanobacteria, Euglenophyta, and Pyrrophyta was 0.07-25.1 × 10 6 ind./L, 1.63-73.2 ind./L, 6.78-54.9 × 10 6 ind./ L, 1.53-11.8 × 10 6 ind./L, and 0.09-0.72 × 10 6 ind./L across seasons, with the relative contributions of 12.5%, 22.5%, 12.5%, 10%, and 2.5%, respectively [33,40].…”

“…For example, the concentration of zooplankton (copepods, polychaetes, protozoans, barnacles, gastropods, ciliatea, hydrozoans, and others) ranged from 124 org/L to 309 org/L, where the copepods (83%) were the most abundant organisms in ponds with organic substrates and fertilization, followed by polychaetes (5%), barnacles (5%), protozoans (3%), ciliate (2%), gastropods (1%), and others (1%) [73]. In the ponds supplied with surface water/groundwater, the biomass of Rotatoria, Cladocera, and Copepoda across the seasons was 14.1-10466 ind./L, 1.7-691 ind./L, and 369-889 ind./L, respectively [40]. Furthermore, Rotifera and Cladocera sharply declined in biomass and abundance (66% of species disappeared) when the ponds changed from surface water to groundwater [40].…”

“…In the ponds supplied with surface water/groundwater, the biomass of Rotatoria, Cladocera, and Copepoda across the seasons was 14.1-10466 ind./L, 1.7-691 ind./L, and 369-889 ind./L, respectively [40]. Furthermore, Rotifera and Cladocera sharply declined in biomass and abundance (66% of species disappeared) when the ponds changed from surface water to groundwater [40].…”

Influence of land development on the ecological status of small water bodies

“…Small water bodies relatively quickly become silted and overgrown with vegetation and consequently disappear. These processes are caused both by natural (ecological succession and periodic rainfall deficiency) and anthropogenic factors (drainage works, cutting down trees and shrubs around water bodies, burning of shore vegetation, sewage discharge and waste storage; Céréghino et al 2008;Dulić et al 2014). Ponds have become more protected, particularly in the Mediterranean regions of Europe, following the recognition of Mediterranean temporary ponds as a priority in the EU (Céréghino et al 2008).…”