Biological Monitoring Working Research Articles

Development of a multimetric index based on benthic macroinvertebrates for downstream Jajrud River in Tehran province, Iran

Jajrud River is the main source of drinking water in the East of Tehran. The river originates from heights of the Alborz Mountain in Northern Tehran. In this study, five stations were sampled for water quality assessment in downstream. Brgjhan and Afjeh stations were considered as reference stations. Benthic macroinvertebrate sampling was repeated 3 times at each station with a Surber sampler device and an area of 900 square cm and a mesh size of 250 microns, in four seasons. For the development of MMIDJ (Multimetric Macro-invertebrate Index Downstream Jajrud-MMIDJ) multimetric index based on benthic macro-invertebrate, 25 bio-indicators were compared in the reference stations with the data of two years, 2013 and 2014. The features of the bio-indicators included measurement of components tolerance, composition, richness, and trophic. MMIDJ multimetric index was developed from 6 indices including HFBI (Hilsenhoff Family Biotic Index), BMWP/ASPT (Biological Monitoring Working Party/Average Score per Taxon), NJIS (New Jersey Impairment Score), MMIF (Multimetric Macro-invertebrate Index Flanders), % Ephemeroptera, and BBI (Belgian Biotic Index). Indices selected were significantly correlated with at least one physicochemical parameter and low degree of changes like % Chironomidae, % non-insects, the ratio of EPT (Ephemeroptera, Plecoptera, and Trichoptera) individuals to Chironomidae, and high density. Water quality in MMIDJ multimetric index was classified into four. Index values were from 6 to 30. The water quality improved from 6 to 30. With regard to water quality assessment of Jajrud River using MMIDJ multimetric index, Jajrud River did not have a good quality. Appropriate management actions should be considered in Jajrud River for improvement of the water quality.

Relationships between aquatic biotic communities and water quality in a tropical river–wetland system (Ecuador)

Abstract Many tropical wetlands threatened by land use changes, or modifications in hydrological regime require effective management policies and implementation to protect them. The Abras de Mantequilla wetland, located in the Guayas River Basin in Ecuador, is subject to two major environmental disturbances, i.e., short-term agriculture (rice, maize) on the land around the wetland and the effects of planned infrastructure works of the Baba dam in the upper catchment. Both activities are expected to be the main constraints for the future wetland health. The objective of this study was to provide an initial characterization of the biotic communities of the river and wetland habitats before the dam starts operating. Plankton, macroinvertebrates, fishes and associated physical and chemical variables were sampled at 12 sites during the wet season (February 2011). Biotic metrics (abundance, taxa richness, diversity and evenness) were computed for the aquatic communities in the wetland and the river. A biotic index (Biological Monitoring Working Party-Colombia/adaptation) was applied to the macroinvertebrate community. Relationships between biotic and abiotic variables indicated nutrients, velocity and sediment type as main drivers. Cluster analysis grouped physico-chemical variables according to river or wetland sites. Similarities regarding the taxa composition among sites were explored with non-metric multidimensional scaling method (NMDS), showing clusters for ichthyoplankton and macroinvertebrates. Higher densities of organisms were recorded in the wetland compared with the river. The wetland is an important area of breeding and reproduction for fish communities, with its lentic habitats promoting the development of high densities of ichthyoplankton. In order to achieve sustainable solutions for integrated river–wetland systems, management options should focus on maintaining natural variation in hydrodynamic conditions throughout the entire catchment, as well as implement good practices in agriculture and reforestation using native species. Local and national authorities should support continuous monitoring programmes, taking account of seasonal variation and of future impacts from flow reduction and nutrient enrichment.