Sensitivity of a tropical micro-crustacean (Daphnia lumholtzi) to trace metals tested in natural water of the Mekong River

http://repository.vnu.edu.vn/handle/VNU_123/28913

Metal contamination is one of the major issues to the environment worldwide, yet it is poorly known how exposure to metals affects tropical species. 

We assessed the sensitivity of a tropical micro-crustacean Daphnia lumholtzi to three trace metals: copper (Cu), zinc (Zn) and nickel (Ni).

Both, acute and chronic toxicity tests were conducted with metals dissolved in in situ water collected from two sites in the lower part of the Mekong River.

In the acute toxicity test, D. lumholtzi neonates were exposed to Cu (3-30 mu g L-1), Zn (50-540 mu g L-1) or Ni (46-2356 mu g L-1) for 48 h.

The values of median lethal concentrations (48 h-LC50) were 11.57-16.67 mu g Cu L-1, 179.3-280.9 mu g Zn L-1, and 1026-1516 mu g Ni L-1. I

n the chronic toxicity test, animals were exposed to Cu (3 and 4 mu g L-1), Zn (50 and 56 mu g L-1), and Ni (six concentrations from 5 to 302 mu g L-1) for 21 days.

The concentrations of 4 mu g Cu L-1 and 6 mu g Ni L-1 enhanced the body length of D. lumholtzi but 46 mu g Ni L-1 and 50 mu g Zn L-1 resulted in a strong mortality, reduced the body length, postponed the maturation, and lowered the fecundity.

The results tentatively suggest that D. lumholtzi showed a higher sensitivity to metals than related species in the temperate region.

The results underscore the importance of including the local species in ecological risk assessment in important tropical ecosystems such as the Mekong River to arrive at a better conservational and management plan and regulatory policy to protect freshwater biodiversity from metal contamination.

Title:	Sensitivity of a tropical micro-crustacean (Daphnia lumholtzi) to trace metals tested in natural water of the Mekong River
Authors:	Dao Thanh-Son Le Nam Vu Bui Ba Trung
Keywords:	Acute toxicity Life history traits Mekong River water Sensitivity Trace metals
Issue Date:	2017
Publisher:	ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
Citation:	ISIKNOWLEDGE
Abstract:	Metal contamination is one of the major issues to the environment worldwide, yet it is poorly known how exposure to metals affects tropical species. We assessed the sensitivity of a tropical micro-crustacean Daphnia lumholtzi to three trace metals: copper (Cu), zinc (Zn) and nickel (Ni). Both, acute and chronic toxicity tests were conducted with metals dissolved in in situ water collected from two sites in the lower part of the Mekong River. In the acute toxicity test, D. lumholtzi neonates were exposed to Cu (3-30 mu g L-1), Zn (50-540 mu g L-1) or Ni (46-2356 mu g L-1) for 48 h. The values of median lethal concentrations (48 h-LC50) were 11.57-16.67 mu g Cu L-1, 179.3-280.9 mu g Zn L-1, and 1026-1516 mu g Ni L-1. In the chronic toxicity test, animals were exposed to Cu (3 and 4 mu g L-1), Zn (50 and 56 mu g L-1), and Ni (six concentrations from 5 to 302 mu g L-1) for 21 days. The concentrations of 4 mu g Cu L-1 and 6 mu g Ni L-1 enhanced the body length of D. lumholtzi but 46 mu g Ni L-1 and 50 mu g Zn L-1 resulted in a strong mortality, reduced the body length, postponed the maturation, and lowered the fecundity. The results tentatively suggest that D. lumholtzi showed a higher sensitivity to metals than related species in the temperate region. The results underscore the importance of including the local species in ecological risk assessment in important tropical ecosystems such as the Mekong River to arrive at a better conservational and management plan and regulatory policy to protect freshwater biodiversity from metal contamination. (C) 2016 Elsevier B.V. All rights reserved.
Description:	TNS07039 ; SCIENCE OF THE TOTAL ENVIRONMENT Volume: 574 Pages: 1360-1370 Published: JAN 1 2017
URI:	http://repository.vnu.edu.vn/handle/VNU_123/28913 http://www.sciencedirect.com/science/article/pii/S0048969716317417
ISSN:	0048-9697 1879-1026
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