Changes of Allozymes (GOT, EST and ME) of Perna viridis Subjected to Zinc Stress: A Laboratory Study

It had been documented through electrophoretic studies that allozyme polymorphisms of bivalve populations are affected by heavy metal stress. In the present laboratory study, by using P. viridis as a test organism, the results indicated that changes in the enzymes GOT, EST and ME were due to Zn stress which are complemented by reductions of filtration rate and condition index. However, it is not yet known for sure whether the enzymes GOT, EST and ME are inducing behavioural and other changes in P. viridis. This is because of the possible subtle interactions could occur between different environmental stresses

Biomonitoring of heavy metals in the west coastal waters of Peninsular Malaysia using the green-lipped mussel perna viridis: Present status and what next?

This paper aims to review the papers published using Perna viridis as a biomonitoring agent of heavy metals in this region and particularly from Malaysia and to discuss the existing knowledge. Further research which will enhance our understanding and increase our knowledge on heavy metal ecotoxicology in Malaysia by using P. viridis is also suggested. This can be part of Mussel Watch monitoring program in this region. The work in establishing P. viridis for the biomonitoring of heavy metals, which is fundamentally based on the recommended criteria for a good biomonitoring agent, can be applied in other mollusks species

Byssus of the green-lipped mussel Perna viridis (Linnaeus) as a biomonitoring material for Zn

Recently, Yap et al. (2003) suggested that the byssus of the green-lipped mussel Perna viridis can be a biomonitoring material for Zn although further validation is required. In this work, we did a simple correlation study between Zn concentrations in the byssus (and soft tissue) and in different geochemical fractions of the sediment. A significant (P<0.01) Pearson’s correlation coefficient (R=0.84) between the Zn concentrations in the byssus and soft tissue indicated that the Zn level in the byssus is highly correlated to its level in the soft tissue and that the byssus could act as an excretion route for Zn. Higher R-values were found between the byssus–easily or freely, leachable and exchangeable, byssus–acid-reducible, byssus–oxidizable-organic and byssus–nonresistant fractions of the sediment, and the byssus–Zn concentration in the total sediment when compared to those found between the soft tissue and the same geochemical fractions. This indicated that the byssus was more reflective of Zn contamination in the field environment than the soft tissue. Therefore, the data further support the use of the byssus as a biomonitoring material for Zn as was originally suggested by Yap et al

Heavy metal (Cd, Cu, Pb and Zn) concentrations in the green-lipped mussel Perna viridis (Linnaeus) collected from some wild and aquacultural sites in the west coast of Peninsular Malaysia

The green-lipped mussel Perna viridis (L.), collected from nine (four wild and five aquacultural) sites between 1999 and 2001, off the west coast of Peninsular Malaysia, were analysed for cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn). The concentrations (μg/g dry weight) of these heavy metals ranged from 0.68 to 1.25 for Cd, 7.76 to 20.1 for Cu, 2.51 to 8.76 for Pb and 75.1 to 129 for Zn. These levels should result in no acute toxicities of the metals since they are lower than the permissible limits for human consumption. In addition, these metal concentrations are also considered to be low when compared with regional data using P. viridis as a biomonitoring agent. © 2003 Elsevier Ltd. All rights reserved

Mercury concentrations in the different soft tissues and byssus of Perna viridis (L.) collected from the west coast of Peninsular Malaysia.

Green-lipped mussel Perna viridis collected between 1999-2000 from 7 geographical sites from the west coast of Peninsular Malaysia were dissected into mantle, foot, gill, crystalline style, muscle, gonad and byssus. All the 6 different soft tissues and byssus were analyzed for elemental Hg by using a Hg Analyzer Model MA-1S. When compared to food safety guidelines, the concentrations of Hg in all the different soft tissues of mussels were below typical public health recommended limits. Therefore, the consumption of P. viridis from the west coast of Peninsular Malaysia is not a health hazard as far as contamination by Hg is concerned. It was also found that tissue distributions of Hg is similar to Cd, Cu, Pb, Zn although their concentrations are different from metal to another and from one tissue to another. It is recommended that future studies are much needed to monitor the metal contamination in the coastal waters potentially receiving anthropogenic inputs of heavy metals

Cadmium, Copper, Lead and Zinc Levels in the green-lipped Mussel Perna viridis (L.) from the West Coast of Peninsular Malaysia: Safe as Food?

Green-lipped mussels, Perna viridis, were collected between 2002-2004, from 10 locations on the west coast of Peninsular Malaysia. The samples were analysed for cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn). The metal concentrations (mg/g dry weight) ranged from 0.11 to 5.55 for Cd, 3.49 to 31.1 for Cu, 1.16 to 18.62 for Pb and 60.51 to 119.5 for Zn. From the public health point of view, these metal concentrations were below the maximum permissible levels set by the Malaysian Food Regulations (1985) and were also below the levels regarded as harmful according to the median international standards for metals in mollusks compiled lJy the FAO of the United Nations. Non-carcinogenic hazard indices of the metals in the mussels in this present study showed that the consumption of the mussels was not risky and any risk is dependent on the amount of mussels consumed and the sites they were collected from

A baseline study on mercury concentrations in the surface sediments of the Straits of Malacca collected during four sampling cruises conducted between 1998-200

Total elemental mercury (Hg) levels in the surface sediments along the Straits of Malacca were analysed by using a Hg Analyzer Model MA-1S. Based on four sampling cruises conducted between 1998- 2000, the Hg levels in more than 95% of the sampling sites were lower than 100 μg/kg dry weight while the Hg range was between 9.86-202 μg/kg dry weight with the northern part of the Strait recorded higher concentration of Hg when compared to central and southern parts. In comparison to other regional results and established sediment quality guidelines for Hg, Hg contamination in the Straits is not serious but regular monitoring of this hazardous element is necessary

The identification of point sources in a river receiving industrial metal effluents at the Serdang industrial area, Selangor.

Surface sediments from three sampling sites, namely Kuyoh River Industrial Area, Kuyoh River Residential Area and Sri Serdang Lake at the Sri Serdang Area were collected and determined for the concentrations of Cu and Zn. The mean total Cu concentrations in the sediment of the three sites were 347.64, 32.04 and 21.71 nig dry weight, respectively, while those for Zn were 219.75, 140.64 and 85.10 p,g/g dry weight, respectively. The geochemical distributions of the 'non-resistant' (non-lithogenous) and the 'resistant' fractions for Cu in the three sites were 99.6% and 0.4% for the Kuyoh River Industrial Area, 99.19% and 0.81% for the Kuyoh River Residential Area while for the Sri Serdang Lake they were 97.74% and 2.26%, respectively. For Zn, the geochemical distributions of the 'non-resistant' and the 'resistant' fractions in the three sites were 61.2% and 38.3% for the Kuyoh River Industrial Area, 56.2% and 43.8% for the Kuyoh River Residential Area while for the Sri Serdang Lake they were 52.65 % and 47.35%, respectively. These results showed that the site at the Kuyoh River Industrial Area had the highest concentrations of Cu and Zn. These levels greatly exceeded the natural background levels and so this was considered to be seriously polluted. The topography of the Kuyoh River shows that the sampling site at the Kuyoh River Residential Area is located after the Sri Serdang Lake while the sampling site at the Kuyoh River Industrial Area is located on another branch of Kuyoh River but it is located right after a metal factory which later joins the branch running through the Kuyoh River Residential Area at the downstream. The exact location of the point source and the river flow are two major factors contributing to the elevated levels of Cu and Zn at a particular sampling site. The elevation of the Cu and Zn levels suggest that the regulations on untreated effluents should be strictly implemented by the local authorities in order to remedy the situation

Effect of body size on heavy metal contents and concentrations in green-lipped mussel Perna viridis (Linnaeus) from Malaysian coastal waters

The concentrations of cadmium, copper, zinc and lead, in the total soft tissues of green-lipped mussel Perna viridis of a wide range of sizes (2-11 cm), were determined from a population at Pasir Panjang. The metal contents (μg per individual) and concentrations (μg per g) of cadmium, lead, copper and zinc were studied in P. viridis to find the relationships with body sizes. Smaller and younger mussels showed higher concentrations (μg per g) of Cd, Pb and Zn than the larger and older ones. The results of the present study showed that the plotting of the metal content, against dry body flesh weight on a double logarithmic basis, gave good positive straight lines; this observation is in agreement with Boyden’s formula(1977). This indicated that P. viridis showed a different physiological strategy for each metal being studied, which is related to age

TOA-based indoor localization and tracking with inaccurate floor plan map via MRMSC-PHD filter

This paper proposes a novel indoor localization scheme to jointly track a mobile device (MD) and update an inaccurate floor plan map using the time-of-arrival measured at multiple reference devices (RDs). By modeling the floor plan map as a collection of map features, the map and MD position can be jointly estimated via a multi-RD single-cluster probability hypothesis density (MSC-PHD) filter. Conventional MSC-PHD filters assume that each map feature generates at most one measurement for each RD. If single reflections of the detected signal are considered as measurements generated by map features, then higher-order reflections, which also carry information on the MD and map features, must be treated as clutter. The proposed scheme incorporates multiple reflections by treating them as virtual single reflections reflected from inaccurate map features and traces them to the corresponding virtual RDs (VRDs), referred to as a multi-reflection-incorporating MSC-PHD (MRMSC-PHD) filter. The complexity of using multiple reflection paths arises from the inaccuracy of the VRD location due to inaccuracy in the map features. Numerical results show that these multiple reflection paths can be modeled statistically as a Gaussian distribution. A computationally tractable implementation combining a new greedy partitioning scheme and a particle-Gaussian mixture filter is presented. A novel mapping error metric is then proposed to evaluate the estimated map's accuracy for plane surfaces. Simulation and experimental results show that our proposed MRMSC-PHD filter outperforms the existing MSC-PHD filters by up to 95% in terms of average localization and by up to 90% in terms of mapping accuracy