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Testing the suitability of the abundance biomass comparison bioassessment method in a Mediterranean river

Guerrero Francisco, Madrid-Vinuesa Francisca, Gilbert Juan Diego, Jiménez-Melero Raquel, del Arco Ana, Parra Gema

Journal of Water and Land Development

2022

Special Issue

49--55

The Water Framework Directive (Directive 2000/60/EC) emphasises the need for simple tools and studies to characterise aquatic ecosystems. A wide range of methods has been developed, including different groups of biota and different taxonomic resolutions. Among these, the abundance biomass comparison (ABC) method is an important methodology widely used in marine benthic systems and well-founded from the ecological point of view. This method - with a slight modification using genera and families instead of species - was applied in a Mediterranean river (Eliche-Frío, northeast of Andalusia, Spain) using the macroinvertebrate community, together with the Margalef richness index and the Iberian BioMonitoring Working Party (IBMWP) to determine the quality of the water. The obtained results show the suitability of the ABC curves method to analyse the macroinvertebrate community and estimate the ecological status of river ecosystems. Although both, the genus and family aggregations, showed a similar trend, the values obtained with the family level indicate a worse state of contamination than those shown with the genus level. The comparison between genus and family levels with other biological indices shows that the evaluation obtained with family aggregation is more similar to those obtained with the Margalef and IBMWP indices than the evaluation based on genera; therefore, we could conclude that this level of taxonomic resolution is adequate for the use of the ABC method in assessing the ecological status of Mediterranean rivers.

Ecological indices as a tool for assessing pollution in El-Dekhaila Harbour (Alexandria, Egypt)

Ismael A. A., Dorgham M. M.

Oceanologia

2003

No. 45 (1)

121-131

Statistical analyses of data concerning the phytoplankton standing crop and biomass were applied as a tool for assessing pollution in El-Dekhaila Harbour. Univariate and multivariate analysis showed a succession of three clusters associated with salinity and temperature variations. The first and third clusters comprised mainly diatoms and dinoflagellates. The second cluster, richer in species, was dominated by brackish water cyanophytes, chlorophytes and euglenophytes. The diversity index ranged from 0.08 to 2.41. A high diversity was associated with high evenness, reflecting the multidominance pattern of cluster (2). On the other hand, multiple correlations between salinity and standing crop, richness and evenness, were negative and significant, but positive with the diversity index. The ABC curve showed that the k-dominance curve for numerical abundance extends above that for the biomass when clusters 1 and 3 are dominant. Both curves coincide more or less for another segment of the curve but when cluster 2 becomes dominant the numerical abundance curve runs below that of the biomass. Such a pattern may indicate unpolluted or moderate to heavily polluted conditions in El-Dekhaila Harbour. The present study reveals that the combination of univariate and multivariate analysis with the ABC curve provides a promising tool for the characterization of phytoplankton dynamics under stress conditions. On the other hand, the phytoplankton community in El-Dekhaila Harbour is stressed not by the inflow of brackish water but rather by the inflow of sea water. This is indicated by the higher diversity and evenness, and by the ABC curve during the dominance of cluster (2).