Assessment of the ecological quality status of sediment at the organic shrimp farming ponds in Ca Mau province by applying the abundance/biomass comparison (ABC) method on nematode communities

Nematode communities in the Tam Giang’s organic shrimp farming ponds, Nam Can district, Ca Mau province were investigated in three seasons (March - dry, July - transfer and November - rainy season). Results showed that the average abundance (inds/10 cm2) ranged from 221.67 ± 122.08 to 2539.33 ± 1403.33 in the dry season. The tranfers and rainy season also showed a high density, from 1020.00 ± 354.30 to 7254.67 ± 5454.39, 822.00 ± 1086.17 – 4608.33 ± 1302.02, respectively. Total dry biomass (µg/10 cm2) of nematode communities in Tam Giang’s organic shrimp farming ponds varied from 51.11 ± 28.64 to 450.87 ± 49.53 in the dry, from 412.93 ± 291.87 to 1607.25 ± 507.42 in the transfer and ranged 49.54 ± 39.36 to 1874.09 ± 3033.16 in the rainy season. The following results were also recorded that abundance/biomass comparison (ABC) method has been used successfully for detecting the ecological quality status of sediment (EcoQ) in Tam Giang’s organic shrimp farming ponds. The results indicated that unfavourable deflections (stress) in EcoQ of Tam Giang’s organic shrimp farming ponds throughout the dry - transfer - rainy season. More specifically, the EcoQ of Tam Giang’s organic shrimp farming ponds has been classified as lightly stressed in most seasons, excpet for the transfer season which has been recognized as the highest EcoQ depending on its ABC curves and W values. Although EcoQ in the Tam Giang’s organic shrimp farming ponds has always been clear, information on Received 05-01-2017, accepted 14-08- 2017, published 12- 9-2018 Author: Tran Thanh Thai, Nguyen Thi My Yen, Ngo Xuan Quang- Department of Environmental Management and Technology, Institute of Tropical Biology, Vietnam Academy of Science and Technology, Le Dieu Linh - Ton Duc Thang University - [email protected] the main cause effected biomass between natural stress or pollution stress remains uncertain.

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Assessing Changes in Ecological Quality Status of Sediment in Tri An Reservoir (Southeast Vietnam) by using Indicator of Nematode Communities

VNU Journal of Science Natural Sciences and Technology ◽

10.25073/2588-1140/vnunst.4973 ◽

2020 ◽

Vol 36 (1) ◽

Author(s):

Tran Thanh Thai ◽

Pham Thanh Luu ◽

Tran Thi Hoang Yen ◽

Nguyen Thi My Yen ◽

Ngo Xuan Quang

Keyword(s):

Rainy Season ◽

Dry Season ◽

Maturity Index ◽

Ecological Quality ◽

Nematode Communities ◽

Ecological Quality Status ◽

Freshwater Habitats ◽

Index Value ◽

Quality Status ◽

Better Than

Nematode communities in Tri An Reservoir (Dong Nai Province, Southeast Vietnam) were explored in the dry season (March) and pre-rainy season (July) of 2019 and analyzed to evaluate their usage as bioindicators for ecological quality status of sediment. Nematode communities consisted of 23 genera belonging to 19 families, 8 orders for the dry and 24 genera, 17 families, 8 orders for the pre-rainy season. Several genera dominated in Tri An Reservoir such as Daptonema, Rhabdolaimus, Udonchus, and Neotobrilus indicated for organic enrichment conditions. The percentage of cp3&4 and MI (Maturity Index) value in the dry season was higher than that in the pre-rainy season expressed the ecological quality status of sediment in the dry season were better than those in the pre-rainy season. Furthermore, the result revealed that MI and c-p% composition can be used to evaluate the ecological quality status of sediment efficiently. Keywords: Bioindicator, ecological quality status of sediment, freshwater habitats, maturity index, nematodes, reservoir.

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The THE ECOLOGICAL QUALITY STATUS OF THE ORGANIC SHRIMP FARMING PONDS: USE OF A NEW BIOTIC INDICES

VNU Journal of Science Natural Sciences and Technology ◽

10.25073/2588-1140/vnunst.4733 ◽

2018 ◽

Vol 34 (2) ◽

Author(s):

Trần Thành Thái

Keyword(s):

Farming Systems ◽

Shrimp Farming ◽

Food Sources ◽

Biotic Index ◽

Natural Food ◽

Ecological Quality ◽

Wet Season ◽

Tropical Regions ◽

Ecological Quality Status ◽

Quality Status

In spite of the development and widespread dissemination of the model organic shrimp farming systems, the biological communities in the organic shrimp farming ponds have still very limited. Therefore, we conducted a field survey for macrobenthic communities (MC) of the Tam Giang‘s organic shrimp farming ponds (TGOSFP) located in Tam Giang commune, Nam Can district, Ca Mau province during three seasons in 2015 (March - dry, July - transfer and November - wet season). The results indicated that the MC have characterized by high density and slightly diversity that is a rich natural food sources for shrimp in the TGOSFP. Further more, the present study is a first attempt to use of new indices (AMBI - AZTI’s Marine Biotic Index) on MC for determining the ecological quality status of sediment (EcoQ) in the TGOSFP. The following results were also recorded with an undisturbed and slightly disturbed EcoQ in the TGOSFP and the general EcoQ would likely be improved between three seasons. The success of AMBI for detecting EcoQ in Vietnam is specific to this study, but AMBI was likely to improved, in particular tropical regions.

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A A COMPARISON OF THE APPLICABILITY OF THE SHANNON-WIENER, AMBI AND M-AMBI INDEX FOR ASSESSING ECOLOGICAL QUALITY STATUS OF SEDIMENT IN AN ORGANIC SHRIMP FARMING PONDS, NAM CAN DISTRICT, CA MAU PROVINCE

VNU Journal of Science Natural Sciences and Technology ◽

10.25073/2588-1140/vnunst.4762 ◽

2018 ◽

Vol 34 (3) ◽

Author(s):

Tran Thanh Thai ◽

Le Hai Dang ◽

Ngo Xuan Quang

Keyword(s):

Environmental Variables ◽

Wiener Index ◽

Shrimp Farming ◽

Biotic Index ◽

Ecological Quality ◽

H Index ◽

Ecological Quality Status ◽

Quality Status

The Shannon-Wiener Index (H′), AZTI’s Marine Biotic Index (AMBI) and multivariate AMBI (M-AMBI) were applied as a comparative applicability in assessing the ecological quality status of sediment (EcoQ) of eight an organic shrimp farming ponds (OSFP), Ca Mau province. There were obvious differences between the evaluation results of three indices in the eight OSFPs through three seasons. The EcoQ given by the AMBI and M-AMBI were higher than that given by the H’ index. These indicated that H’ index may also be more sensitive to environment disturbances than the AMBI and M-AMBI. Furthermore, the EcoQ given by the M-AMBI was a neutralization between that given by the H’ and AMBI indices. Because there are no environmental variables data available in this study, the H′ index was really more sensitive to environment disturbances than the AMBI and M-AMBI, that have yet to be fully elucidated. A analyses three indices with environmental variables gradient data also need further investigation to potentially increase the precise answer of this issue.

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