Water Quality Analysis in a Subtropical River with an Adapted Biomonitoring Working Party (BMWP) Index

Abstract

Subtropical rivers in developing countries often lack adequate monitoring, which makes it difficult to comprehensively determine their water quality when faced with different anthropic impacts. There are no proper protocols in the regulations to incorporate indicators and adapt them to different biogeographic regions, limiting the potential success of conservation and restoration of river ecosystems. This study proposes implementing macroinvertebrates as bioindicators of water quality in river ecosystems, and modifying the calibration of the widely used Biomonitoring Working Party (BMWP) index for its adaptation in a subtropical river. The Duero River, Mexico, was used as an example in this study. Data were explored with multivariate statistics, and the water quality and habitat values were averaged to obtain the families’ bioindication values and the index categories. The BMWP adequately described a deterioration gradient from the origin to the river mouth (from fair to extremely polluted), with some intermediate recovery points related to the presence of springs. Its performance was compared with other biological indices and exhibited a positive relationship with all of them. In addition, how BMWP changed over time was analyzed by examining previous samples, and highlighted increased river deterioration over time. A calibrated BMWP will allow for long-term monitoring at a low cost.

Biotic Integrity, Water Quality, and Landscape Characteristics of a Subtropical River

“…Different studies have described significant differences and important changes from the upper to the lower basin in the aquatic macroinvertebrate taxa, which could be related to changes in the physicochemical characteristics of the water by wastewater inputs, changes in habitats, and physical modifications to the channel, including nearby roads [60][61][62]. The values of the BMWP and the % EPT-B indices better reflected the general quality of the river, an aspect also described in other studies [45,[63][64][65]. In terms of composition, families such as Polycentropodidae, Hydrophilidae, Philopotamidae, Helycopsychidae, Heptageniidae, Libellulidae, Sisyridae Ceratopogonidae, and Dugesiidae require high concentrations of dissolved oxygen and, therefore, were found in sites with good quality [5].…”

“…The maximum biodiversity is maintained at intermediate disturbance and resource availability, levels typically found in conserved riverine areas or those with less anthropogenic influence and different substrate types [67,73]. The most frequent families with the largest number of individuals indicate the presence of organic pollution, mainly those related to the consumption of detritus such as Gammaridae, Baetidae, Chironomidae, Hydrachnidia, Asellidae, and Physidae, which were also abundant in altered ecosystems such as urban rivers [45,74]. In relation to habitat quality, the influence of this productive activity results in suboptimal to marginal results, which determine the presence of tolerant macroinvertebrate families [22].…”

“…Hill's number (three Hill number) is proposed by [43] and based on both methods: q = 0 (species richness), q = 1 (Shannon-Wiener index), and q = 2 (inverse Simpson index). Other biological indices selected for the analysis were the percentage of Ephemeroptera (minus Baetidae), Plecoptera, and Trichoptera (EPT-B %) [44] and the Biomonitoring Working Party (BMWP) index adapted for subtropical rivers, which considered the sensitivity or tolerance to pollution of macroinvertebrate families [45,46].…”

Benthic Macroinvertebrates as Bioindicators of water quality in the Copueno River, Morona- Ecuador

“…La especie del orden Megaloptera de la familia Corylidae es la especie más abundante en nuestro estudio esta especie habita en cursos fluviales de corriente alta y los tramos superiores de los ríos donde la calidad del agua por lo general es mejor que los tramos inferiores ya que tienen alta oxigenación (37). Magallón et al (38) presenta resultados similares en la determinación de la calidad de agua en los ríos, Pindo Mirador, Alpayacu, Pindo Grande, ubicados en la provincia de Pastaza, obteniendo como resultado una calidad de agua "Dudosa", y "Aceptable", dentro de su estudio señala que la presencia de las especies Ephemeróptera y Trichóptera se relaciona con la existencia de aguas transparentes, oligotróficas (4), lo que además puede ser favorecido por características físicas propias del lugar, como la presencia de un fondo rocoso, baja profundidad del lecho y rápidas corrientes que contribuyen a una elevada oxigenación (39), donde además (40) argumentan que los sustratos dominados por hojarasca brindan una mayor disponibilidad de recursos, por lo que además de presentar una alta riqueza de especies permiten sostener una mayor densidad de organismos, bajo este argumento se apoya lo encontrado en estudio, donde los macroinvertebrados hallados en la estación 2 presenta que la diversidad fue mayor con respecto a la estación 1 pero, en abundancia fue menor.…”

Indigenous people doing citizen science to assess water quality using the BMWP in rivers of an arid semi-arid biosphere reserve in Mexico

“…On the other hand, the use of alternative monitoring methods with biological indicators (biomonitoring) allows water quality assessments at a lower cost than evaluations based on physicochemical parameters. Biomonitoring has several advantages, as, in addition to being affordable, it offers a high degree of precision 16 , 17 . Biomonitoring has been extensively used in different countries around the world 18 .…”