Ecotoxicity and Ecosystem Health of a Ramsar Wetland System of India

Abstract

In this study one economically important Ramsar wetland system of India, Vembanad wetland system, is studied to determine the environmental pollution. Six surface sediment samples collected from two extreme zones of the wetland system were analyzed for heavy metals such as Copper, Zinc, Manganese, Cadmium, Lead, Nickel and Mercury. Highest metal concentration was found at industrial zone and lowest concentration was detected at southern upstream of the wetland system. The results showed that the pollution level is significant in the industrial zone. Comparison of the results with different sediment quality guidelines indicated ultra high degree of contamination in the industrial zone. The numerical value of degree of contamination, pollution load index, sum of toxic units, enrichment factor and geo-accumulation index confirmed the above fact. Based on National Oceanic and Atmospheric Administration guidelines, the health of the ecosystem was seriously impaired with frequent occurring of biological effects in the industrial zone. The percentage of heavy metal calculated with respect to the industrial zone as the base line and the correlation analysis with organic matter indicated that, mobility of the specific metal has higher impact on its concentration at the fresh water region of the wetland

Ecosystem health assessment of three inland water bodies in South-west, Nigeria based on fish diversity, pollution status, ecological and health risk indices

“…The EF normalizes the level of the measured potentially harmful elements with respect to a reference metal such as Fe, Al or Zn (Mediolla et al, 2008). In this study, Fe was used as the reference metal or normalizer because of its abundance in Nigerian soils and natural sources (98%) vastly dominate its input (Ndimele and Kumolu-Johnson, 2012;Nasir and Harikumar, 2011). The crustal abundance data of Bowen (1979) were used for all EF values.…”

“…where Cmetal and Cnormalizer are concentrations of heavy metal and normalizer (Fe) in the sediment and in the earth's crust. The EF value is used to distinguish the magnitude of contamination resulting from either the natural or anthropogenic influence (Nasir and Harikumar, 2011).…”

Distribution of Arsenic and Mercury in the Aquatic Ecosystem of the Five Chilean Reservoirs

“…Metal concentrations in sediments and in river waters can be easily altered by deposition and remobilization processes. Heavy metals have a propensity to adsorb from aqueous phases to fine suspended particles and are transported along the water course, where they can pose a health risk to benthic organisms if toxic levels are reached, resulting in lower taxonomic diversity, lower reproduction rate, reduced growth or even death 8,9 . According to Filgueiras,10 not even 1% of the pollutants released in water remain in the aqueous phase; the rest are deposited in sediments.…”

“…According to Filgueiras,10 not even 1% of the pollutants released in water remain in the aqueous phase; the rest are deposited in sediments. Since sediment is an important sink for heavy metals that contaminate the water and acts as a habitat and important food source for aquatic biota, its quality provides essential information to assess the pollution status of aquatic ecosystem, as it reflects the long term status 8 . Mercury and arsenic discharged into the aquatic environment can damage aquatic species, ecosystems and consumers due to their toxicity and cumulative behavior 11 .…”