Water quality assessment in mosquito breeding habitats based on dissolved organic matter and chlorophyll measurements by laser-induced fluorescence spectroscopy

Abstract

Rapid urbanization and its associated pollution can affect water quality in mosquito breeding habitats and, as a result, the ecology and control of mosquito vectors. To understand the effects of pollution on mosquito vectors, an accurate assessment of water quality in breeding habitats is needed. Presently, water quality assessment of mosquito breeding habitats is usually based on the measurement of individual physicochemical parameters. However, several parameters are sometimes difficult to interpret or may not give a clear picture of the overall water quality of the breeding habitats, especially when the pollutants are in complex mixtures. This study employed the use of Laser-Induced Fluorescence (LIF) spectroscopy to assess water quality in breeding habitats of Anopheles, Aedes, and Culex mosquitoes in urban areas in Cape Coast, Ghana. The LIF spectra, using a 445-nm diode laser, were measured from field-collected water samples in the laboratory. The LIF spectra showed the presence of dissolved organic matter (DOM) and chlorophyll in the breeding habitats. The DOM and chlorophyll fluorescence signals were normalised by the Raman vibrational signals to determine water quality in each habitat. The overall water quality was better in Aedes breeding habitats than in Anopheles and Culex breeding habitats. The poor water quality in Anopheles and Culex breeding habitats was due to the presence of high fulvic acid and chlorophyll content, which often reflect pollutants from anthropogenic sources. Anopheles and Aedes habitats were made up of mainly An. coluzzii and Ae. aegypti respectively while Culex species were identified to genus level. The results add up to the growing concern about the breeding of Anopheles in polluted habitats. The study demonstrated for the first time the ability of LIF spectroscopy to assess water quality in mosquito breeding habitats.

Effects of bacterial composition and aquatic habitat metabolites on malaria vector larval availability in irrigated and non-irrigated sites of Homa Bay county, western Kenya

“…This could be due to the presence of algae matter which acts as food for the immature to support their growth. This is consistent with other studies that observed that algae was used as food for mosquito larvae [73][74][75][76].…”

Entomological Survey and Temephos Susceptibility of Aedes, Culex and Anopheles in Naena Muktipura Mimika Papua

“…This aligns with previous reports (22) identifying similar breeding sites like puddles, ditches, and shrubs in rural areas. Notably, the water in these Culex breeding sites was often polluted with organic compounds and complex mixtures (24).…”

Study of mosquito (Culicidae) larvae and characterisation of water bodies in urban and periurban areas

“…It could be expected that chemical parameters would change continuously, resulting in the observed variability; therefore, the association of ecophysicochemical parameters and larval number may also change. All sites surveyed are located in or near disturbed areas, where changes in water quality due to organic and nutrient pollution can affect the replacement of native mosquito species or their adaptation to polluted breeding habitats (Huzortey et al 2022).…”

“…All sites surveyed are located in or near disturbed areas, where changes in water quality due to organic and nutrient pollution can affect the replacement of native mosquito species or their adaptation to polluted breeding habitats (Huzortey et al. 2022).…”