Macroinvertebrate-Derived Multimetric Indices and Physico-Chemical Water Attributes of a Sandy Coastal Ecosystem

Abstract

This study investigated the ecological status of the sandy coastal ecosystems of Riohacha, La Guajira. Using the bioindication capacities of the macroinvertebrates associated with the sandy substrates and the physicochemical attributes of the water. Three different beaches were delimited (A = Gubernation, B = Edifice Majayura and C = Centro Cultural), and sampling was carried out over a period of six months. To identify the macrofauna associated with the sandy substrate, the nucleator methodology was used, whereby it was integrated into the sediment of each specific beach region. For physicochemical attributes, assessments of pH, dissolved oxygen (DO), conductivity, salinity and temperature were carried out. revealed a 97 % correspondence for all beaches. Spearman's correlation between physicochemical parameters and the presence of organisms indicated a strong association with salinity (0.12), while the other parameters showed a significant inverse correlation. Margalef, Simpson and Shannon-Wiener diversity indices showed that the ecological conditions of beach B were better in relation to the other beaches, which can be attributed to a greater uniformity in the distribution of its species. The species that could be considered bioindicators of ecological quality on the beaches studied, because they show greater tolerance to fluctuations in the physico-chemical parameters evaluated, are Arca zebra and Trachycardium muricatum.