Assessing the ecological quality of the Port Blair coast (South Andaman, India) using different suites of benthic biotic indices

Abstract

Six benthic biotic indices (Shannon–Wiener H′log2, W-statistics, BOPA, BENTIX, AMBI and M-AMBI), based on different ecological principles, were applied to assess the health of variously disturbed tropical intertidal habitats of the Port Blair coastline. A total of 243 replicate samples were collected during the dry period (January, February and March) of 2014–2016. Temperature, salinity, dissolved oxygen, sediment pH, total organic matter content and texture were analysed. A high mean abundance of opportunistic species (Orbinia sp. 748, Capitella singularis 237 and Armandia sp. 114 ind. m−2) was observed at Phoenix Bay, a gradual decline in diversity at Junglighat and a comparatively high diversity and moderate biomass at Wandoor, reflecting a human pressure gradient. Results showed an annual decline of benthic quality from 2014 to 2016 (good to moderate). Overall BOPA failed to distinguish the magnitude of disturbances, while the rest of the indices classified the benthic quality from undisturbed/high (WD), slightly disturbed/good (JG), to moderately disturbed/moderate to poor (PB). The subjective analysis demonstrated that the urban centres corresponded to disturbed benthic communities of dominant first and second order opportunistic species, while sensitive (EGI) and indifferent (EGII) were associated with the least disturbed or undisturbed site. The study successfully demonstrated the performance of temperate indices in intertidal habitats against the mild organic enrichment. However, for an effective assessment, setting natural reference conditions and sampling in stable dry periods (strong seasonality in tropics) is desirable. In order to test the performance of biotic indices, a long-term monitoring approach of taking abiotic and biotic descriptors into account is recommended.

Macrobenthic community of an anthropogenically influenced mangrove associated estuary on the East coast of India: An approach for ecological assessment

“…77: high, 0.77-0.53: good, 0.53-0.38: moderate, 0.38-0.20: poor, and <0.20: bad). Procedures adopted to estimate indices scores, algorithm, boundary limits, and community health/ ecological quality classifications were based on the WFD scale of indices detailed by Equbal et al (2017).…”

“…Large-scale variability in the environmental parameters and ecological quality status of the benthic habitat at each station (or zone) could be attributable to the heterogeneous MES (Elliott and Quintino, 2007). Temporal variation of macrobenthic communities was evident through either increased or decreased benthic indices depending upon life strategy (r-selected and k-selected) and niche performance (sensitive, indifferent and tolerant) of the individual species (Equbal et al, 2017). The improved sample quality between premonsoon and winter is suggestive of satisfactory performance by the benthic indices during stable, less turbulent, and low seasonal impact periods (Kröncke and Reiss, 2010;Karakassis et al, 2013;Sigamani et al, 2015;Bae et al, 2016;Chan et al, 2016;Feebarani et al, 2016;Mulik et al, 2017).…”

“…The applied biotic indices evaluated the benthic quality status by discriminating the highly disturbed from the less disturbed areas of the estuary. While the robustness of the M-AMBI (compared to AMBI) in sample quality assessment was explained by several researchers (Khan et al, 2014;Equbal et al, 2017;Pandey et al, 2021), a few others have observed its reverse performance due to lack of reference conditions and spatial benthic variability, heterogeneity within the estuarine complexes (Sigamani et al, 2015). According to Borja and Tunberg (2011), both AMBI and M-AMBI are sensitive to detecting humanmediated disturbances modified by natural disturbances.…”

What role do environmental and anthropogenic factors play in the variability of benthic macrofauna in the northern lagoon of Tunis?

“…But AMBI which is one of the most widely used biotic indices in European countries (Borja et al 2007) seems to be less sensitive than BENTIX due to the different design of each index (Salas et al 2006, Pranovi et al 2007, Blanchet et al 2008. That prompted some authors to recommend readjustment of BENTIX threshold boundaries for quality classification to be more consistent with the other biotic indices (Equbal et al 2017). Even more, AMBI robustness could be reduced in case of low number of species and/or individuals (Afli et al 2008b), such as the case of the northern lagoon of Tunis.…”