Evaluating Ecological Quality Under Dredging Disturbance Using Multiple Macrobenthic Indices in Shellfish Farming Areas of Gamak Bay, South Korea

The protection of the biological diversity and the maintenance of the regional ecological integrity for the Huanghe (Yellow River) Estuary and its adjacent areas are practically significant and valuable. However, frequent human activities and natural climate changes have caused vigorous disturbances on the ecosystem in these sea areas. An objective assessment on the benthic habitat quality (BHQ) of the Huanghe Estuary and its adjacent areas is conducted, using AZTI’s Marine Biotic Index (AMBI) and multivariate AMBI (M-AMBI) based on the data of macrobenthos in May and August 2011. The results show that both the indices do not correlate significantly, and their assessment results are greatly different. All of the samples assessed using the AMBI were “high” or “good”, because the ecological group I (EGI) and the ecological group II (EGII) were dominant macrobenthic ecological groups in the research area. Owing to a low species’ richness and a high individual abundance in some samples, the BHQ levels using the M-AMBI were worse than those of the AMBI. Significant correlations are observed between the M-AMBI, water depth, bottom water salinity and dissolved inorganic nitrogen, thus the M-AMBI could sensitively respond to environmental changes and distinguish influences from uninfluenced stations, but the AMBI could not. The consistent results between the AMBI and the M-AMBI mainly appeared in the uninfluenced (undisturbed or slightly disturbed) stations. Therefore, the M-AMBI is more effective than the AMBI in assessing the benthic habitat quality in the Huanghe Estuary and its adjacent areas. Using the M-AMBI to assess the BHQ of the Huanghe Estuary and its adjacent areas, the results show that 3% of the stations are undisturbed and the BHQs are “high”, and 61% of the stations are slightly disturbed and those of the BHQ are “good”, and the rest are meanly disturbed and those of the BHQ are “moderate”.

Adaptation and application of multivariate AMBI (M-AMBI) in US coastal waters

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.

From a dataset of macrobenthos obtained from 18 cruises from 2004 to 2013 in the Huanghe (Yellow River) Estuary and its adjacent areas, the composition and characteristics of macrobenthos were analyzed, and the applicability of the Shannon-Wiener Index (H′), AZTI’s Marine Biotic Index (AMBI) and multivariate AMBI (MAMBI) for assessing benthic habitat quality was compared. The results showed a total of 203 macrobenthos in the study area. The macrobenthos were dominated by polychaetes, followed by mollusks and crustaceans. The macrobenthic ecological groups were dominated by EGI, EGII and EGIII, which respectively accounted for 31.5%, 36.0% and 21.2% of the total. There were significant differences between the evaluation results of the three indices. The ecological quality status (EQS) levels given by the AMBI were greater than those given by the H′ and M-AMBI. The AMBI could not reflect the differences between 11 sites but the H′ and M-AMBI could do. Moreover, the three indices responded well to the variations in salinity (S) and dissolved oxygen (DO) in the waters. The H′ and M-AMBI also responded sensitively to the differences in physical parameters, such as water depth and sediment texture. The correlation between M-AMBI and environmental pressure gradient data was the strongest. The MAMBI could effectively distinguish degraded conditions from undegraded but the H′ and AMBI could not. Therefore, the M-AMBI reflected benthic habitat health well in the study areas. However, the objectivity of evaluation results of M-AMBI needs further verification by physical, chemical and biological methods. The thresholds also need further discussion.

With the growing global focus on marine environmental conservation and management, it is imperative to evaluate the ecological quality of marine ecosystems accurately. In this study, we employed seven biotic indices, namely the AZTI marine biotic index (AMBI), BENTIX, benthic opportunistic polychaetes amphipods index (BOPA), benthic pollution index (BPI), multivariate AZTI marine biotic index (M-AMBI), abundance biomass comparison (W-value), and Shannon diversity index (H’), to assess the benthic ecological quality in the intertidal zone of Cheonsu Bay, South Korea. Except for the H’ and W-value, the indices (AMBI, BENTIX, BOPA, BPI, and M-AMBI) suggest that the ecological quality at most stations in the intertidal zone of Cheonsu Bay was acceptable. Furthermore, the influx of a large amount of eutrophic freshwater has impacted the intertidal zone of Cheonsu Bay, but the applicability of the seven biotic indices requires further investigation.

Based on the macrofauna data (2008-2011) in Xiaoqing River estuary and its adjacent sea, Laizhou Bay of Bohai Sea, China, the AZTI Marine Biotic Index (AMBI) and Multivariate AMBI (M-AMBI) were used for benthic habitat quality (BHQ) assessment. Results showed that BHQ presented an obvious trend of improvement along the direction of stream channel and river mouth, and in the coastal areas. AMBI and M-AMBI were significantly related to environmental pressure gradient data. Therefore, the two indices can well indicate BHQ in the studied area. However, there were significant differences between results of the two indices. In the cases of low taxa number and high abundance of single species, AMBI might overestimate BHQ. We thus adjusted its thresholds to solve this problem. And M-AMBI might overestimate BHQ when benthic assemblage was dominated by the opportunistic species. Then we could raise the weight of AMBI in the calculation of M-AMBI to handle the problem.

IntroductionThe construction of coastal industrial zones has significantly impacted the marine environment, with the extent of these effects varying based on the type of industrial activity. This study compares the environmental impact of two prevalent types of industrial zones along South Korea’s coast: ironworks and shipyards.MethodsWe assessed heavy metal pollution near these industrial zones using the Pollution Load Index (PLI) and Nemerow Pollution Index (Pn). To evaluate the impact of heavy metals and organic matter on macrobenthic communities, we employed redundancy analysis (RDA) and Spearman correlation analysis. Additionally, we used the AZTI’s Marine Biotic Index (AMBI), Multivariate AMBI (M-AMBI), and Benthic Pollution Index (BPI) to gauge the ecological quality of the affected marine environments.Results and discussionOur findings indicated that the biodiversity and abundance of species near shipyards were significantly lower than those near ironworks. Results of PLI and Pn revealed that the ecological risk posed by heavy metals from shipyard activities was significantly higher than from ironworks. The AZTI’s Marine Biotic Index (AMBI), Multivariate AMBI (M-AMBI), and Benthic Pollution Index (BPI) demonstrated that the ecological quality of Asan Bay (ironworks) is better than that of Dangdong Bay (shipyard). RDA analysis identified Lumbrineris longifolia, Ancistrosyllis hanaokai, and Theora fragilis as biological indicators for assessing heavy metal and organic matter pollution. Spearman correlation analysis indicated that BPI and species richness index are effective indicators for evaluating such pollution. Overall, the negative impact of shipyards on the marine environment was significantly more significant than that of ironworks. Our study provides valuable insights for the South Korean government in managing coastal industrial zones and formulating relevant policies.

The ecological status of Karavasta Lagoon (Albania): Closing the stable door before the horse has bolted?

Benthic biotic indices are important ecological tools extensively used to understand the ecological quality of coastal wetlands. The present study aimed to assess the ecological status of Kodungallur-Azhikode estuary for the first time by using widely used benthic indices such as species richness (S), Shannon diversity index (H'log2), BENTIX, benthic opportunistic polychaetes amphipods (BOPA), AZTI's Marine Biotic Index (AMBI) and multivariate AMBI (M-AMBI). In the canonical correspondence analysis, salinity, dissolved oxygen, organic matter, sediment Eh, sediment pH and sand were identified as important variance descriptors. A single species of an opportunist, Americorophium triaeonyx, an amphipod belonging to the ecological group (EG) III, significantly contributed to the total macrofaunal density. Other dominant opportunistic species included Obelia bidentata (EGII), Arcuatula senhousia (EGIII), Cirolana fluviatilis (EGII), Prionospio cirrifera (EGIV) and Capitella sp. (EGV). The overall assessment indicated a 'good to moderate' condition in AMBI, 'good to poor' condition in M-AMBI, 'high to moderate' condition in BENTIX, 'high to poor' condition in BOPA and 'moderate to poor' condition in univariate Shannon diversity index. All the multivariate indices tested in the study were correlated with each other except BOPA and M-AMBI. The group of stations dominated with a sandy substrate and a moderate level of organic content indicated high to good conditions while other stations demonstrated moderate to poor conditions. However, no significant variation in indices tested between seasons was observed. The present study recommends long-term monitoring of benthic macroinvertebrate assemblages with proper taxonomic identification and functional trait analysis for better calibration of indices, which is the key factor for getting better results.

As an important part of the Bohai economic rim, the Laizhou Bay has been stressed by serious eco-environmental problems in recent years. In this study, the Shannon-Wiener index (H'), AZTI’s marine biotic index (AMBI) and the multivariate AMBI (M-AMBI) were used to assess the ecological quality status (EQS) of the Laizhou Bay according to macrobenthos data collected annually in August 2011-2014. The results showed that the overall benthic habitat quality in the Laizhou Bay was assessed as “Good”. However, 25% of the samples were classified as “Moderate”, “Bad” or “Poor” status under degraded conditions. Ecological group III (EGIII) species which had a certain tolerance to environmental disturbances had a higher proportion in each station, and most of them had appeared the pollution indicator species Capitella capitata. This indicated that the benthic habitat in the Laizhou Bay had been disturbed and polluted to some extent. The comparison of the three indices evaluation result and the RDA analysis showed that the H' and M-AMBI were more suitable when the relative abundance of the single species was high and the macrobenthic community was significantly imbalanced; when the relative abundance of opportunistic species (EGIV and EGV) was high, the AMBI and M-AMBI could reflected the EQS objectively; in an undisturbed and polluted environment, all the three indices could indicate the benthic habitats quality. In summary, the better correlation between the three indices and environmental factors showed that they were well responsive to the tendency of the benthic habitats quality in the Laizhou Bay.

Response of different benthic biotic indices to eutrophication and sediment heavy metal pollution, in fujian coastal water, East China sea

Assessment of the benthic ecological quality status (EcoQs) of Laizhou Bay (China) with an integrated AMBI, M−AMBI, BENTIX, BO2A and feeding evenness index

Structural and functional responses of macrobenthic communities to seasonal hypoxia and implications for ecological quality in Bohai Bay.

Assessment of benthic ecological status in semi-enclosed Daya Bay (China) in regions exposed to human disturbances based on multiple biotic indices

Rongjiang River, the second largest river system in Guangdong Province, flows through the main urban areas of Jieyang and Shantou cities before reaching the South China Sea. Human activities in the surrounding area pose significant threats to this aquatic ecosystem. The ecological status (ES) of the benthic ecosystem of the Rongjiang River estuary has not yet been conducted using indices based on the macrobenthic fauna, which is important for evaluating environmental health. Here, we used four biotic indices (the AZTI’s Marine Biotic Index (AMBI) and Multivariate AZTI’s Marine Biotic Index (M-AMBI), and taxonomic distinctness indices (average taxonomic distinctness Δ+ and variations in taxonomic distinctness Λ+) to appraise the current ES of benthic communities in Rongjiang estuary. Samples were taken from 11 sampling sites located in six general regions: western aquaculture zones, aquaculture zones, Hanjiang River water channel, Shantou City, Shantou Port, and near the ocean. The benthic ecosystem of this estuary is greatly disturbed: the ES of the aquaculture zones and the sites near the Hanjiang River water channel, Shantou City, and close to the ocean was poorer compared with that of other areas; ES was also poorer in winter than in summer. Generalized linear models revealed that Shannon-Wiener index was negatively correlated with dissolved inorganic nitrogen (p < 0.01), M-AMBI was negatively correlated with temperature and dissolved inorganic nitrogen (p < 0.05 and p < 0.01, respectively), and Λ+ was negatively correlated with pH (p < 0.05). The AMBI, M-AMBI, Δ+, and Λ+ indices were suitable for assessing the ES of the benthic ecosystem in an anthropogenically disturbed estuary.