Publications by authors named "Hong T Pham"

3 Publications

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Reversible and irreversible transgenerational effects of metal exposure on nine generations of a tropical micro-crustacean.

Environ Pollut 2021 May 17;276:116631. Epub 2021 Feb 17.

School of Environmental Science and Technology, Hanoi University of Science and Technology, No 1 Dai Co Viet Street, Hanoi, Viet Nam. Electronic address:

Micro-crustaceans are important grazers that control the algal blooms in eutrophic lakes. However, we know little about how these key species may be affected by long-term exposure to contaminants and when the transgenerational effects are reversible and irreversible. To address this, we investigated the effects of lead (Pb, 100 μg L) exposure on morphology and reproduction of Moina dubia for nine consecutive generations (F1-F9) in three treatments: control, Pb, and pPb (M. dubia from Pb-exposed parents returned to the control condition). In F1-F2, Pb did not affect morphology, and reproduction of M. dubia. In all later generations, Pb-exposed M. dubia had a smaller body and shorter antennae than those in control. In F3-F6, pPb-exposed animals showed no differences in body size and antennae compared to the control, suggesting recoverable effects. In F7-F9, the body size and antennae of pPb-exposed animals did not differ compared to Pb-exposed ones, and both were smaller than the control animals, suggesting irreversible effects. Pb exposure reduced the brood size, number of broods and total neonates per female in F3-F9, yet the reproduction could recover in pPb treatment until F7. No recovery of the brood size and number of broods per female was observed in pPb-exposed animals in the F8-F9. Our study suggests that long-term exposure to metals, here Pb, may cause irreversible impairments in morphology and reproduction of tropical urban micro-crustaceans that may lower the top-down control on algal blooms and functioning of eutrophic urban lakes.
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http://dx.doi.org/10.1016/j.envpol.2021.116631DOI Listing
May 2021

Changes in the Magnitude of the Individual and Combined Effects of Contaminants, Warming, and Predators on Tropical Cladocerans across 11 Generations.

Environ Sci Technol 2020 12 17;54(23):15287-15295. Epub 2020 Nov 17.

Department of Environmental Engineering, Thuyloi University, 175 Tay Son, Dong Da, Hanoi 116705, Vietnam.

A massive challenge in ecotoxicology is assessing how the interaction of contaminants, climate change, and biotic stressors shapes the structure and functions of natural populations. Furthermore, it is not known whether contemporary evolutionary responses to multiple stressors across multigenerations may alter the interaction of these stressors. To address these issues, we exposed to lead (Pb, 50 μg/L) under two temperatures (25 and 28 °C) with/without predator cues from climbing perch () for 11 generations (F1-F11). We assessed changes in fitness, including development time, adult size, lifespan, fecundity, and neonate production. We found strong negative effects of Pb, elevated temperature, and predator cues on the fitness of . Strikingly, Pb-induced reduction in the performance of was stronger at 25 °C and in the absence of predator cues. The individual and interactive effects of Pb, temperature, and predator cues on were stronger across F1-F9 and generally leveled off in F10-F11. Our results highlight the high vulnerability of to multiple stressors, thus weakening top-down control on algal blooms in eutrophic lakes. Our study underscores the importance of integrating evolutionary responses in realistic ecotoxicological risk assessments of contaminants interacting with climatic and biotic stressors.
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http://dx.doi.org/10.1021/acs.est.0c05366DOI Listing
December 2020

Development of metal adaptation in a tropical marine zooplankton.

Sci Rep 2020 06 23;10(1):10212. Epub 2020 Jun 23.

Department of Ecology, University of Science, Vietnam National University, Hanoi, 334 Nguyen Trai, Thanh Xuan, Ha Noi, Vietnam.

Tropical marine ecosystems are highly vulnerable to pollution and climate change. It is relatively unknown how tropical species may develop an increased tolerance to these stressors and the cost of adaptations. We addressed these issues by exposing a keystone tropical marine copepod, Pseudodiaptomus annandalei, to copper (Cu) for 7 generations (F1-F7) during three treatments: control, Cu and pCu (the recovery treatment). In F7, we tested the "contaminant-induced climate change sensitivity" hypothesis (TICS) by exposing copepods to Cu and extreme temperature. We tracked fitness and productivity of all generations. In F1, Cu did not affect survival and grazing but decreased nauplii production. In F2-F4, male survival, grazing, and nauplii production were lower in Cu, but recovered in pCu, indicating transgenerational plasticity. Strikingly, in F5-F6 nauplii production of Cu-exposed females increased, and did not recover in pCu. The earlier result suggests an increased Cu tolerance while the latter result revealed its cost. In F7, extreme temperature resulted in more pronounced reductions in grazing, and nauplii production of Cu or pCu than in control, supporting TICS. The results suggest that widespread pollution in tropical regions may result in high vulnerability of species in these regions to climate change.
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http://dx.doi.org/10.1038/s41598-020-67096-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7311422PMC
June 2020