Phytotechnology : floaters aquatic plant species as potential phytoindicator for europhication in unhealthy aquatic ecosystem

Abstract

Nitrification and eutrophication are two terms that always associated with excess nutrients of nitrogen and phosphorus. Excess nutrients can trigger undesirable eutrophication, resulting in unhealthy algal blooms, spreading of certain aquatic macrophytes, depletion of oxygen and loss of key species leading to degradation of many freshwater ecosystems. Fertilizers, detergents and organic debris are among the sources of excess nutrients for nitrogen and phosphorus. In phytotechnology only aquatic macrophytes can utilize large amounts of nitrogen and phosphorus and remove it from the water bodies. Therefore aquatic plants are excellent indicators of unhealthy environment because they respond to nutrients, light, toxic contaminants, metals, herbicides, turbidity, water level change and salt. The aim of this study is to explore the capabilities of free-floating aquatic plant species as an indicator for eutrophication either at contamination or pollution level in unhealthy freshwater bodies to enable their future enhancement and potential through landscape ecology approach. The effects of nutrients (phosphate, ammonium, nitrate and nitrite), the free-floating macrophytes and locations have been studied on eutrophication level monitoring in aquatic freshwater bodies ecosystem. All species (Lemna minor, Eichhornia crassipes, Spirodella polyrhiza, Neptunia oleracea, Salvinia molesta and Pistia stratiotes) were detected with high level of phosphate at level III which is polluted at all localities (Selangor, Pahang and Kelantan). Ammonium concentration at Selangor range from 0.02 ± 0.02 mg/1 to l.l 4 ± 0.17 mg/I; Pahang range from 0.30 ± 0.10 mg/I to 1.36±0.08 mg/1 and Kelantan range from 0.05 ± 0.02 mg/I to 0.54±0.24 mg/I. Ammonium concentration was varied from class I to class III. The best phytoindicator for excess phosphate were £.minor > E.crassipes > N.o/eracea. Meanwhile, magnificient phytoindicator for excess ammonium were L.minor > S.polyrhiza > E.crassipes. In addition, good phytoindicator for nitrate were S.polyrhiza > E.crassipes > S.molesta. In conclusion, the most reliable phytoindicator for overall experiment were L.minor, E.crassipes and S.polyrhiza. Another interesting results was co-existence of N.oleracea and L.minor in Selangor, E.crassipes and N.oleracea in Pahang and S.molesta and E.crassipes in Kelantan. According to localities, Selangor and Pahang are confirmed with high concentration of phosphate and ammonium. In contrast, Kelantan exhibited with high concentration of phosphate but low level of ammonium. This might resulted from different type of soil from distinct localities. Another interesting result was the co-existence of N.oleracea and L.minor in Selangor, E.crassipes and N.oleracea in Pahang and S.molesta and E.crassipes in Kelantan. The ability of these co-existence species indicate eutrophication phenomenon in aquatic ecosystem were greater and efficient as compared to the existence of floating macrophyte independently. In conclusion, every floater aquatic plant species that has been tested was confirmed as potential phytoindicator to detect eutrophication in unhealthy aquatic ecosystem. Keywords: Floaters aquatic plant species, phytoindicator, eutrophication