Accumulation and Distribution of Metals in Bolboschoenus maritimus (Cyperaceae), from a South African River

Abstract

The Diep River is a major freshwater ecosystem in the Western Cape, South Africa. Although it is surrounded by many sources of metal pollution, the actual metal levels in this river system are unknown. Wetland plants are known to accumulate metals and may possibly be used as biomonitors of metal contamination in a river system. One such species, the sedge Bolboschoenus maritimus, is found in abundance along the banks of this river. The aim of this study was to investigate and monitor the degree of metal contamination in the water and sediments of the lower Diep River, as well as to study the seasonal accumulation and distribution of metals in B. maritimus, and the use thereof as biomonitor species. Two sampling sites were used: one site above the wetland section of the river, receiving runoff mainly from agricultural lands (site 1), and one site close to the river mouth (site 2), exposed to several possible pollution sources. Water, sediment, and plant (root, leaf and stem) samples were collected seasonally for 1 year and analyzed for Al, Zn, Cu, and Fe. There was greater bioaccumulation of metals by plants at site 2, due to greater bioavailability of metals. B. maritimus was shown to be a root accumulator of metals. Seasonal fluctuations in root, stem, and leaf metal concentrations did not follow seasonal sediment concentration patterns. However, using B. maritimus as test species did provide valuable additional information to sediment and water analyses. More extensive research is needed to conclude whether this species is an effective biomonitor in the lower Diep River environment.

Trace metal bioindication and phytoremediation potentialities of Phalaris arundinacea L. (reed canary grass)

“…Translocation factors for all trace elements analyzed in P. arundinacea were below unity (Table 3) confirming high root retention capacity for the elements and low intensity of their transfer to other plant organs (Eid et al, 2012). These results were in agreement with several studies according to which trace metal concentrations in belowground organs of different plant species are generally higher than in aboveground tissues (Bonanno, 2011;Shuping et al, 2011). The bioaccumulation of metals in belowground tissues is a strategy that plants use to restrict the distribution of metals to aboveground organs to avoid damage of their photosynthetic tissues (Deng et al, 2004).…”

Occurrence and probabilistic risk assessment of PAHs in water and sediment samples of the Diep River, South Africa

“…The Diep River, an important freshwater ecosystem (utilised for irrigation and recreation) in the Western Cape province of South Africa, had been reported to be negatively impacted as a result of anthropogenic activities (Jackson et al, 2009;Shuping et al, 2011;Daso et al, 2016). To investigate the source inputs of the 16 US EPA priority PAHs and present the associated probable risk, with the levels at which they were detected in the freshwater system of the Diep River, three sites were selected.…”

Geochemical assessment of sediment in Cape Town harbour, South Africa

“…Sediments and water have been used globally to assess the pollution levels in aquatic ecosystems [4][5][6]. Similar studies have been carried out in South Africa [7][8][9][10][11][12]. Sediment particles are made up of materials derived from rock, soil and anthropogenic sources.…”