Evaluation of the Res-ponses of a Wetland, Tropical Earthworm to Heavy Metal Contaminated Soil

Abstract

In view of the global importance of wetlands in providing food and income for millions of people through agricultural activities, efforts should be geared toward identifying appropriate biomonitoring organisms for them. This study investigated the mortality and burrowing responses of Libyodrilus violaceus earthworm to heavy metals in the laboratory. The worms were subjected to heavy metal spiked soil in graded concentrations following the procedure recommended by the Organization for Economic Cooperation and Development for a period of 14 days. Zn had the highest significant mean lethal effect (6.35±4.04) on this species, followed by the mixtures of Zn, Cd (5.90±5.05); Zn, Pb, Cd (5.40±4.5); Zn, Pb (5.05±4.37), in that order. The median lethal concentration (LC 50) values for zinc (Zn), lead (Pb), and cadmium (Cd) obtained from the study stood at 520.06, 1551.55, and 706.66 mg/kg soil respectively. The species also showed inhibited burrowing responses to these metals in individual and combined concentrations. It is concluded that L. violaceus should be a candidate for consideration in assessing the health of wetland soils.

Ecological risk evaluation of spent engine oil pollution using earthworm and microbial bioassays

“…The burrowing and survival responses of the exposed earthworms to soil contamination at various concentrations were evaluated using the protocol outlined by the Organization for Economic Co-operation and Development (OECD, 2008), as reported by Dada et al (2016) with minor modifications. The time (T) taken for all worms or the last worm to burrow in each concentration level was recorded.…”

“…Mortality was assessed at 7th and 14th days of exposure (Dada et al, 2016). After 14 days in the laboratory, the soil, along with the worms in each container, was poured into a plastic tray and spread out thinly film to count live worms (OECD, 2006).…”

Effects of Container Types and Soil Organic Matter Proportions on the Culture of a Tropical Earthworm (Libyodrilus violaceus Beddard, 1891)

“…The collection was limited to a particular area to reduce variability [18]. The species was identified as in [7].…”

“…Earthworms have been successfully introduced into reclaimed soils to restore soil fertility [3]. Earthworms have been identified as good biomonitoring agents [4,5,6,7]. They can be used to clean up contaminants [2].…”

Negative Effect of Phosphogypsum Over Physiological Activity of Earthworm Eisenia Fetida

“…Phosphogypsum generation in India is about 11 million tons per annum and primarily consists of calcium sulphate dihydrate with small amounts of silica, usually as quartz and un-reacted phosphate rock, radioactive material (like radium, uranium) and heavy metals namely arsenic, cadmium, chromium, mercury, nickel, lead and zinc (HAZWAMS/2012-2013). There was very considerable volume of work and research regarding the positive roles of earthworms in agroecosystems, environmental monitoring and sustainability (Dada et al, 2013) but the concern here is to evaluate the influence of phosphogypsum over various physiological parameters of Eisenia fetida under laboratory conditions. Lee et al (2009) determined the effect of alkalized phosphogypsum on soil chemical and biological properties.…”