Effects of imidacloprid on the ecology of sub-tropical freshwater microcosms
Sumon, Kizar Ahmed ; Ritika, Afifat Khanam ; Peeters, Edwin T.H.M. ; Rashid, Harunur ; Bosma, Roel H. ; Rahman, Md Shahidur ; Fatema, Mst Kaniz ; Brink, Paul J. Van den - \ 2018
Environmental Pollution 236 (2018). - ISSN 0269-7491 - p. 432 - 441.
Bangladesh - Freshwater ecosystem - Insecticide - Neonicotinoid
The neonicotinoid insecticide imidacloprid is used in Bangladesh for a variety of crop protection purposes. Imidacloprid may contaminate aquatic ecosystems via spray drift, surface runoff and ground water leaching. The present study aimed at assessing the fate and effects of imidacloprid on structural (phytoplankton, zooplankton, macroinvertebrates and periphyton) and functional (organic matter decomposition) endpoints of freshwater, sub-tropical ecosystems in Bangladesh. Imidacloprid was applied weekly to 16 freshwater microcosms (PVC tanks containing 400 L de-chlorinated tap water) at nominal concentrations of 0, 30, 300, 3000 ng/L over a period of 4 weeks. Results indicated that imidacloprid concentrations from the microcosm water column declined rapidly. Univariate and multivariate analysis showed significant effects of imidacloprid on the zooplankton and macroinvertebrate community, some individual phytoplankton taxa, and water quality variables (i.e. DO, alkalinity, ammonia and nitrate), with Cloeon sp., Diaptomus sp. and Keratella sp. being the most affected species, i.e. showing lower abundance values in all treatments compared to the control. The observed high sensitivity of Cloeon sp. and Diaptomus sp. was confirmed by the results of single species tests. No significant effects were observed on the species composition of the phytoplankton, periphyton biomass and organic matter decomposition for any of the sampling days. Our study indicates that (sub-)tropical aquatic ecosystems can be much more sensitive to imidacloprid compared to temperate ones.
|Effects of periphyton substrates and addition of freshwater prawn (Macrobrachium rosenbergii) on pond ecology and tilapia (Oreochromis niloticus) production
Uddin, S. ; Fatema, M.K. ; Wahab, M.A. ; Azim, M.E. - \ 2007
In: World Aquaculture Society. World Aquaculture, May 09-13, 2005, Bali, Indonesia. - - p. 662 - 662.
|A bioeconomic evaluation of tilapia monoculture and polyculture with freshwater prawn with and without periphyton substrates
Uddin, S. ; Farzana, A. ; Wahab, M.A. ; Fatema, M.K. ; Azim, M.E. - \ 2007
In: 7th Asian Fisheries Forum, 30 November-4 December 2004, Penang, Malaysia, AFF. - - p. 82 - 82.
Technical evaluation of tilapia (Oreochromis niloticus) monoculture and tilapia-prawn (Macrobrachium rosenbergii) polyculture in earthen ponds with or without substrates for periphyton development
Uddin, S. ; Farzana, A. ; Fatema, M.K. ; Azim, M.E. ; Wahab, M.A. ; Verdegem, M.C.J. - \ 2007
Aquaculture 269 (2007)1-4. - ISSN 0044-8486 - p. 232 - 240.
nile tilapia - herbivorous fish - coral-reef - systems - aquaculture - densities - culture - quality - biomass - growth
The effects of periphyton grown on bamboo substrate, on growth and production of Nile tilapia, Oreochromis niloticus (Genetically Improved Farmed Tilapia strain) in monoculture and polyculture with the freshwater prawn (Macrobrachium rosenbergii) were studied and economically evaluated. The experiment had 2 × 2 factorial design: The first factor was presence or absence of substrate for periphyton development, the second factor was related to culture system. The first system was monoculture of the GIFT strain of Nile tilapia stocked at 20,000 fingerlings ha¿ 1, the second system was tilapia¿prawn polyculture with each stocked at 20,000 fingerlings or postlarvae ha¿ 1. Bamboo poles were posted vertically in ponds under substrate treatments. Feed and inorganic fertilizers were applied to all ponds. There were no differences in phytoplankton biomass and primary productivity between the treatments (P > 0.05). The electivity indices indicated that there were low dietary overlaps between tilapia and prawn. Survivals of tilapia and prawn were higher in ponds with bamboo substrate (60% and 35%, respectively) than in the control ponds without substrates (55% and 20%, respectively). Addition of substrate significantly (P <0.05) increased growth and production of both species. In monoculture, substrate contributed 40% to tilapia production, whereas, in polyculture, it contributed 46%. Prawn production was increased by 127%. Highest total yield (2445 kg ha¿ 1 tilapia and 141 kg ha¿ 1 prawn) over a 145-day culture period was recorded in substrate-based polyculture ponds. However, there was conclusive evidence that addition of periphyton substrates resulted in higher fish production and hence, polyculture of tilapia and prawn in periphyton ponds is a promising option for low-input ecological aquaculture.