Different element/Ca ratios in the otolith of cultured sea bass in Malaysia and relationship to salinity

The otoliths of cultured sea bass (Lates calcarifer) were sampled from 24 locations in Malaysian coastal waters in order to analyse the ratio values of Sr/Ca, Mg/Ca, Ba/Ca and Zn/Ca. Then the ratio values were discriminated to reconstruct a reliable marker for the migration of wild sea bass. Cultured sea bass was collected from cages and ponds along Malaysian coastal areas from March 2007 to May 2009 with ambient water salinity from oligohaline (0.1 psu) to euhaline (30-35 psu). The study found that the ratios of Mg/Ca and Zn/Ca in cultured sea bass otoliths were not influenced by the variation in water salinity. However, contradictory pattern value ratios of Ba/Ca in sea bass otoliths were found for the thalassic series. The oligohaline waters were shown to have the highest Ba/Ca ratio with the exception of Sr/Ca ratios in saline waters. This indicates that the concentration of the Sr element is slightly dominant in the otolith whereas the content of Ba was significant with salinity values. The Partition Coefficient (DMe) value also supports the proposition that the Ba element is a good tracer for salinity fluctuations in the otolith as shown by the sea bass migration track along the salinity gradient according to thalassic series

Pemendapan sedimen dan proses 210Pb di Lembangan Melayu dan Selat Melaka

Sebanyak dua teras sedimen diperoleh dari Lembangan Melayu dan Selat Melaka bagi mengenal pasti pemendapan sedimen serta proses 210Pb di Lembangan Melayu dan Selat Melaka. Di kawasan kajian, purata aktiviti 210Pb adalah sebanyak 111.47 ± 15.01 Bq/kg dan 126.38 ± 16.8 Bq/kg di stesen M17 dan M43 dengan perbezaan antara stesen adalah sebanyak 10%. Kedua-dua stesen menerima input yang berlainan melalui saluran air ke arah kawasan persampelan, menyebabkan peningkatan kandungan 210Pb di dalam sedimen. Proses hidrologi yang dikawal melalui perbezaan temporal turut mempengaruhi proses fizikal dan secara tidak langsung, mempengaruhi proses sedimentasi. Proses hidrologi melalui perbezaan temporal yang mempengaruhi proses fizikal dan kemudiannya mempengaruhi kadar proses pemendapan. Memandangkan sistem monsun mempengaruhi daya kitaran hidrologi, mekanisme timbal-balik kesan saiz butiran terhadap 210Pb telah berubah berikutan pengaruh arus monsun bersama dengan lempung sebagai pembawa utama yang menonjol untuk teras sedimen, sekali gus mempunyai kesan serta-merta pada pemendapan sedimen. Di samping itu, inventori dan fluks Lembangan Melayu dan Selat Melaka menunjukkan kesan monsun juga menyumbang kepada perubahan inventori dan fluks 210Pb di Lembangan Melayu dan Selat Melaka apabila daya kitaran hidrologi mengubah keupayaan kesan penggarutan 210Pb di sekitar perantaraan sedimen dan air laut

Natural Polonium-210 in Bivalve Species in Peninsular Malaysia Waters as Recent Pollution Indicator

Po-210 is an alpha rays emitter in U-238 decay series and a natural radionuclide found in the ocean, and bivalve is the best biological indicator compared to the other organisms because of their feeding methods that are filter-feeding and suspension-feeding. They are able to accumulate toxic substances from marine environment in their tissue and researches were conducted in edible tissues of Meretrix meretrix, Perna virid, Glauconome virens, Anadara granosa, Anadara ovalis, Pholas orientalis, Donax sp., Polymesoda bengalensis, Phapia undulata, and Tellina virgate. Result showed Po-210 activity distributions were ranging from 2.61 ± 1.50 to 517.46 ± 56.64 Bq/kg. The lowest value of Po-210 activity recorded in Anadara granosa and the highest value recorded in Donax sp. Small-sized of bivalve species contained higher Po-210 activity than the larger one. Higher Po-210 contents in bivalve obtained from the west coast of Peninsular Malaysia might be closely related to anthropogenic factors from the coastline. This study also found that Donax sp. is able to be a good indicator of environmental pollutants as it accumulates Po-210 in higher concentrations than other bivalve species. Donax sp. can be found in several parts of Malaysia and available in large quantities but it appears to be seasonal. While for seafood safety monitoring, Anadara granosa is capable of becoming a good benchmark for seafood security as it found in most parts of Malaysia. It is not seasonal and a kind of Malaysian favorite seafood

Chemical characterization of atmospheric transported polycyclic aromatic hydrocarbons in Peninsular Malaysia: a quarter century view

Atmosphere has long been known as free way for the transport of particle reactive chemicals far distances. Polycyclic aromatic hydrocarbons (PAHs) are priority pollutants in the environment where anthropogenic sources such as petroleum are studied. Chemical characterization of deposited PAH in Peninsular Malaysia showed that compounds resulting from combustion contribute more to atmospherically transported compounds than do un-combusted materials, which usually follow the lateral transport, local oil discharge and in-situ natural production. The composition and characterization of PAH demonstrated a higher abundance of parent compounds than of alkyl substitutes. These include pyrene, benzo(e)pyrene, benzo(a)pyrene and benzo(k)fluorenthene. Parent compounds represent a higher proportion of combusted organic materials as well as of petroleum that transfers via atmospheric movement rather than laterally via, for example, rivers and run-off discharges. Diagnostic chemical ratios of chemical compounds such as phenantherene to antheracene and fluorenthene to pyrene showed that combusted materials are dominant that are transferred by atmosphere movement, either over short or long distances, in the studied area

Vertical Profiles of Natural Uranium Isotopes in Sediment Cores from Kota Kinabalu and Labuan Ports, Malaysia

Sediment cores were collected from Kota Kinabalu and Labuan ports to determine the distribution of natural uranium isotopes, calcium (Ca), aluminium (Al) and total organic matter (TOM). A strong statistical correlation value between 234U/238U and Ca contents were shown at Kota Kinabalu (r2 = 0.811), and Labuan (r2 = 0.833) ports. Good statistical correlation r2 > 0.8 was also obtained between uranium isotopes and TOM at Kota Kinabalu port. Most activity ratio values of 234U/238U found in sediment cores from Kota Kinabalu port were more than 1.0; the major input of uranium at Kota Kinabalu port may be related to the sorptive process of authigenic uranium that occurs in the water column. In this case, the mobile U(VI) was reduced to immobile U(IV) by organic matter and scavenged to the sediment with co-precipitation of organic matter and calcium carbonate. On the other hand, a low activity ratio of 234U/238U (≤ 1) from Labuan was of detrital origin and also showed positive statistical correlation between calcium and aluminium

Assessment Activity of 210Po and 210Pb in the Edible Tissues of Cultured Seabass (Lates calcarifer)at Peninsular Malaysia

Analysis levels of 210Po and 210Pb were determined in the edible tissue of sea bass (Lates calcarifer) from 14 cages in the west and east coast Peninsular of Malaysia. The concentrations level in fish were found varies from 1.35 ± 0.22 to 6.20 ± 0.99 Bq/kg dry weight210Po and 3.30 ± 2.69 to 51.71 ± 19.26 Bq/kg dry weight 210Pb. The level of this radionuclide was much related to the anthropogenic activities at the sampling locations neighbouring area, differences in metabolisms of fish and food intake pattern for each cage. Then the calculated daily intake value due to fish consumption was to be 7.69 mBq/d/person210Po and 35.90 mBq/d/person210Pb, which lower than those reported in others countries. In addition, the collective doses of210Po and210Pb were estimated to be 0.001mSv/year and 0.009 mSv/year, respectively. This suggests that the dose received by Malaysian due to consumption of fish is rather small, and did not deteriorate human’s health and safe for consumption

Inventory and flux of ^<210>Po and ^<210>Pb in the water column of southern South China Sea and Malacca Straits

Activities of ^Po and ^Pb were determined in dissolved (0.45μm) fractions in water column from two different sampling locations as southern South China Sea (southern SCS) and Malacca Straits. Results obtained from analyzed samples showed that the activity of both nuclides in total phase (dissolved+particulate) is highly found in the Malacca Straits, while the opposite situations were shows by the calculated inventory and flux of ^Po and ^Pb. Calculated inventories and fluxes of ^Po and ^Pb in the water column at southern SCS and Malacca Straits were affected by the northeast and southwest monsoons, respectively with hundred times higher than the northern South China Sea

Geochronology of 210Pb in sediments of Sepang Besar River, Malaysia

Geochronological studies to determine pattern and rate of sediment deposition is still lacking in Malaysia. The aim of this study is to investigate geochronological pattern of 210Pb in core sediments of the Sepang Besar River. Sediment cores were collected from rivermouth, middle course and upper course of the river. Sediment cores were cut at 2 cm interval for each layer, treated with established method and analyzed by beta spectrometry. Results showed the activities of 210Pb along Sepang Besar River varied at a wide range. Significantly lower 210Pb activity was found at the rivermouth as compared to middle and upper courses of Sepang Besar River. This could be due to the geology of the watershed and chemical weathering conditions around the area

Natural Radioistopes of Polonium and Lead in the Edible Muscle of Cultured Seabass (Lates calcarifer)

Activity levels of 210Po and 210Pb were determined in the edible tissue of seabass (Lates calcarifer) from 23 cages located in the west, south and east coasts of Peninsular Malaysia. The concentration levels of 210Po and 210Pb in fish varied from 5.10 ± 0.36 Bq/kg to 15.53 ± 5.40 Bq/kg dry weight and 7.09 ± 0.54 Bq/kg to 21.72 ± 2.64 Bq/kg dry weight, respectively. The highest concentrations of 210Po and 210Pb were found at Stations S3 and S23 due to rapid development at the upper stream. In addition, the ratio between 210Po and 210Pb shows a distinction between stations of each sampling location. The 210Po/210Pb activity ratio at the Tebrau Strait was higher than the unity value (1.04) compared to the west and east coasts of Peninsular Malaysia. Most of the samples contain slightly lower 210Po/210Pb activity ratios which are related to the high input of lead from watersheds in neighboring areas

Detection of plasmids in heavy metal resistance bacteria isolated from the Persian Gulf and enclosed industrial areas

Several heavy metal resistant bacterial strains were isolated from sediment and water samples collected from the Persian Gulf and enclosed industrial areas. All the isolated bacteria were identified by 16S rRNA gene sequencing. Isolated bacteria were tested for the presence of plasmids using the modified alkaline lysate method. The method was effective for identification and characterization of plasmids of different sizes without the use of highly toxic chemicals. The study revealed that the frequency of the occurrence of plasmids in heavy metal resistant bacteria was more than that in the common bacteria. The study also demonstrated that about 66% of isolated bacteria carried large (38-62kb) and/or small sized (4- >2 kb) plasmids. The highest plasmid incidence (84.6%) was detected from industrial wastewater bacteria. A slightly higher incidence of plasmids occurred in bacteria isolated from marine sediments (55.5%) compared to that of the marine water (53.8%). The findings suggested that plasmids are highly ubiquitous and predominant in most heavy metal resistant bacteria. Removal of lead and cadmium from solution by some of these bacteria was very efficient, approximately 120 mg/g dry weightas high as 90%. The isolates tested, presented distinct uptake capacities and the best results were obtained for Delftia tsuruhatensis and Pseudomonas AU3411 respectively