Variations of organotin bioaccumulation in the Salmo trutta and Anguilla japonica collected from freshwater and seawater habitats: A re-interpretation from biomonitoring point of view.

This paper reviewed two important published papers on variation in organotin compounds (OTs) accumulation in relation to the life history in Anguilla japonica and Salmo trutta. The data cited from the two papers were re-interpretated from biomonitoring point of view. An overall discussion of the tributyltin (TBT) and triphenyltin (TPT) contamination based on the sampling sites was presented. In general, S.trutta with higher OT levels inhabiting the sea habitat, namely Hakodate Bay, had higher bioavailability of OTs than the Hekirichi River and Kunebetsu River. Similarly, the eels A. japonica with higher OTs collected in the marine habitat at Miyako Bay and its adjacent waters, also had higher levels of TBT than those collected from the Mabuchi River, Hei River and Tsugaruishi River. This indicated that Hakodate Bay and Miyako Bay had higher contamination by OTs than freshwater sampling sites. Since Hakodate Bay and Miyako Bay are characterized by many marinas and shipping activities, this review paper based on the two papers agreed with the fact that higher anthropogenic activities would always be reflected in the higher bioaccumulation of OTs of the two biomonitors

Life history-related organotin body burden in the catadromous eels Anguilla marmorata and A. bicolor pacifica in Vietnam.

In order to understand the ecological risks caused by organotin compounds (OTs) in diadromous fish migrating between sea and freshwater, tributyltin (TBT) and triphenyltin (TPT) compounds, and their breakdown products, were determined in the catadromous eels Anguilla marmorata and A. bicolor pacifica, collected in Vietnam waters. Ontogenic changes in otolith strontium (Sr) and calcium (Ca) concentrations were examined along life history transects in order to determine habitat use in the eel. There were generally no significant correlations between TBT and TPT accumulation and various biological characteristics such as total length (TL) and body weight (BW). In A. bicolor pacifica, TBT and the total butyltin (BT) concentrations of yellow-stage eels (immature eels) were significantly higher than those in silver-stage eels (mature eels). This suggests that yellow-stage eels have a higher risk of contamination by TBT than silver-stage individuals. Positive linear relationships were found between Sr:Ca ratios, total BTs and total phenyltins. These results suggest that the ecological risk of OTs in these eels increases with increasing sea residence period. Thus, migratory history and maturation stage are the most important factor for OT accumulation in catadromous eels

Notes on the occurrence of the tropical eel Anguilla bicolor bicolor in Peninsular Malaysia, Malaysia

Previous studies indicated that a tropical freshwater eel Anguilla bicolor bicolor occurs in Africa, India, Sri Lanka, Bangladesh, Myanmar, Indonesia and Australia, but an intensive survey has indicated an extended distribution range for the species into Peninsular Malaysia. Thus, A. b. bicolor is a native subspecies of Malaysia

Age at maturation of a tropical eel Anguilla bicolor bicolor in Peninsular Malaysia, Malaysia.

Anguillid eel species are widely distributed throughout the world. The eels have catadromous life history, migrate between freshwater growth habitats and offshore spawning areas. Fifteen species of Anguilla have been reported worldwide, ten of which occur in tropical regions (Ege 1939). Of the latter, seven species/subspecies occur in the western Pacific around Indonesia and Malaysia, i.e. A. celebesensis, A. interioris, A. nebulosa nebulosa, A. marmorata, A. borneensis, A. bicolor bicolor and A. bicolor pacifica (Ege, 1939; Castle & Williamson, 1974; Arai et al., 1999). The tropical species is thought to be more closely related to the ancestral (primitive) form than their temperate counterparts. Studying the distribution and life history of tropical eels may provide some clues to understanding the nature of primitive forms in anguillid eels and how the distribution of the genus became established. The recent decline of glass eel (juvenile) catches in East Asia has caused serious problems in eel aquaculture in Japan and Taiwan. Eighteen percent of the eel consumed in Japan is produced in the country (23, 211 tons, aquaculture; and 817 tons, wild in 1999), and the remainder is imported from China, Taiwan, and Malaysia (Kato & Kobayashi, 2003). Therefore, the tropical eels are considered to be a major target species for the eel trading recently. However, little attention has been given to natural populations and the resource management of eel in Malaysia. Therefore, the objective of this study was to gain the biological information of a tropical eel Anguilla bicolor bicolor collected in the Peninsular Malaysia. In the present study, we found maturing stage of the eel in Malaysian waters. There is no information available regarding the maturation in the tropical eel species. We reported the first eel biology study in Malaysia. A total of 10 specimens were collected by local fishermen mainly in Kurau River in Bukit Merah and Penang River in Peneng Island of the northwestern peninsular (4°59'-5°23 N, 100°12-100°40'E) during November 2008 and August 2010. The eels were collected by angling and bamboo trap at night. The total length (TL), predorsal length (PDL), preanal length (PAL) (Fig. 1), body weight (BW) and gonad weight were measured. The gonad and body weights were measured to determine the gonado somatic index (GSI) of each eel

Contamination profiles of antifouling biocides in selected coastal regions of Malaysia

The concentrations of butyltins (BTs) in sediment from Peninsular Malaysia along the Strait of Malacca and their spatial distribution are discussed. The concentrations of BTs were high in the southern part of Peninsular Malaysia where there is a lot of ship traffic, because trade is prosperous. The concentrations of monobutyltin (MBT), dibutyltin (DBT), and tributyltin (TBT) in sediment from the coastal waters of Peninsular Malaysia were in the range 4.1-242 microg/kg dry weight (dw), 1.1-186 microg/kg dw, and 0.7-228 microg/kg dw, respectively. A higher percentage of TBT was observed in the area where TBT concentrations were high. The concentrations of monophenyltin (MPT), diphenyltin (DPT), and triphenyltin (TPT) were in the range <0.1-121 microg/kg dw, 0.4-27 microg/kg dw, and 0.1-34 microg/kg dw in sediment from Peninsular Malaysia, respectively. MPT was the dominant phenyltin species. MBT, DBT, and TBT in green mussel (Perna viridis) samples were detected in the range 41-102 microg/kg, 3-5 microg/kg, and 8-32 microg/kg, respectively. A tolerable average residue level (TARL) was estimated at 20.4 microg/kg from a tolerable daily intake (TDI) of 0.25 microg TBTO/kg body weight/day. The maximum value of TBT detected in green mussel samples was the value near the TARL. TPTs were not detected in green mussel samples. The concentrations of Diuron and Irgarol 1051 in sediment from Peninsular Malaysia were in the range <0.1-5 microg/kg dw and <0.1-14 microg/kg dw, respectively. High concentrations of these compounds were observed in locations where the concentrations of TBT were high. Sea Nine 211, Dichlofluanid, and Pyrithiones were not detected in sediment. The concentrations of antifouling biocides in Melaka and the Strait of Johor were investigated in detail. BTs were found in similar concentrations among all sampling sites from Melaka, indicating that BT contamination spread off the coast. However, Sea Nine 211, Diuron, and Irgarol 1051 in the sediment from Melaka were high at the mouth of the river. BT concentrations at the Strait of Johor were higher than those in Peninsular Malaysia and Melaka and were high at the narrowest locations with poor flushing of water. The concentrations of antifouling biocides were compared among Malaysia, Thailand, and Vietnam. A higher concentration and wide variations of TBT and TPT in sediment from Malaysia were observed among these countries. The Irgarol 1051 concentrations in sediment from Malaysia were higher than those in Thailand and Vietnam

Elemental composition in otoliths of surfperch, Ditrema temmincki

The elemental composition of the otolith was examined in both male and female surfperch, Ditrema temmincki. The determined concentrations of 22 elements were the same regardless of the fish\u27s sex. K, Mg, and Na which are major elements in seawater, accumulations from seawater to otolith of those elements were quite smaller than other minor elements. This suggests that elemental discrimination might occur during the movement from blood plasma to endolymph after the branchial uptake from ambient water

Biological effects of low concentrations of tributyltin on the caprellid amphipod Caprella danilevskii

In order to examine the biological effects of tributyltin (TBT), experiments involving the exposure of 5 levels of TBT concentrations (0, 10, 100, 1000 and 10000 ngl^) were conducted on the caprellid amphipod Caprella danilevskii, both over a generation after hatching (50 days) and embryonic stage (5 days). In TBT exposure after hatching, marked delays in growth and molting during the early developmental stage and mature stage were found in both 100 and 1000ng TBTCll^ concentrations in spite of the sex. All specimens died in 10000 ng TBTCll^ within 4 days after hatching. Inhibition of maturation and reproduction such as delaying in the achievement of maturity and a decrease in the number of juveniles hatched was apparent in 10 and 100ng TBTCll^ concentrations. Furthermore, brood loss, and failure in egg formation and hatching were observed as the TBT concentration became higher. No significant changes in sex ratio were seen in response to TBT exposure after hatching. A drastic decrease in survival rate was observed at 10ng TBTCll^ which corresponds to the mean level in coastal waters. In embryonic exposure, although the female proportion was 36% of the total in the control, its proportion increased up to 80% at 100 and 1000ngl^ in the hatched juvenile. All specimens died in 10000 ngTBTCll^ within 5 days after spawning due to the acute toxic concentration for the species. No significant differences were observed to occur in the sex ratio in response to the exposure after hatching (50 days) in a previous study. Sex disturbance might therefore be induced during the embryonic stage in the caprellid. Reproductive inhibitions such as brood loss and oogenesis inhibition occurred even at 10-100 ng TBTCll^ exposures in the short-term period in both parental females and their offspring females. The embryo survival rate in the offspring decreased drastically as the TBT concentrations increased, with the decrease being observed at TBT concentrations as low as 10ngl^ during 5 days. In parental females, the survival rate also decreased at more than 100ng TBTC ll^, despite transfer into the no TBT-added seawater after 5 days. Therefore, our data suggest that nanogram concentrations TBT exposure, both short- and long-term, in the coastal environment might critically damage the life history characters of caprellids, and may influence populations of C. danilevskii in the coastal ecosystem

Levels of non-essential (Cd, Pb and Hg) elements in muscle tissues of Anguilla bicolor bicolor, McClelland 1844 from Kedah and Anguilla bengalensis bengalensis, Gray 1831 from Perak and human consumption risks

A study on heavy metals accumulation and human health risk assessment in the consumption of two tropical freshwater eel species (Anguilla bengalensis bengalensis) from the Sungai Perak at Kuala Kangsar, Perak and (Anguilla bicolor bicolor) from the Air Hitam irrigation canal, Kampung Kuala Sanglang, Kedah was carried out. Specimens were examined and analyzed for Pb and Cd concentrations using ICP-MS while the total Hg concentration was measured using a direct mercury analyzer (MA-3000). The range for the total concentrations (μg/g wet wt.) in Anguilla bicolor bicolor were 0.01-0.4 (Cd), 0.03-0.77 (Pb) and 0.36-0.94 (Hg) while for Anguilla bengalensis bengalensis, they were 0.76-1.23 (Cd), 0.01-0.10 (Pb) and 0.27-1.5 (Hg). Anguilla bengalensis bengalensis (Sungai Perak) showed a significant strong relationship between Hg/Pb (r = .771, P < 0.05) and Anguilla bicolor bicolor (Air Hitam irrigation canal) with Cd/Pb (r = -.895, P < 0.05) in muscle tissues and the results indicated Hg and Pb were introduced from point and non-point sources, therefore it is of concern. Interspatial comparison with the findings of previous local and international studies showed both species of freshwater eels accumulated Hg to high levels, exceeding the safe limits stipulated in the Malaysian Food Act of 1984, Food Regulations (1985) and USEPA (1997). However, the Target Hazard Quotient (THQ) and Hazard Index (HI) indicated that both freshwater eels from the studied sites are safe to consume as there is no risk posed from consumption based on the health risk assessment results as Pb, Cd and Hg concentrations were under the permissible limits of nutrient intake

An assessment of selected trace elements in intertidal surface sediments collected from the Peninsular Malaysia

Concentrations of 11 trace elements (V, Cr, Co, Ni, Cu, Zn, As, Ag, Cd, Pb, and U) were determined in the intertidal surface sediments of Peninsular Malaysia. The average trace element concentrations are ranked as follows: Zn>V>As>Cr>Pb>Cu>Ni>Co>U>g>Cd. Interim Sediment Quality Guidelines (ISQGs) employed in present study are the Australia and New Zealand joint guideline (ANZECC/ARMCANZ), and the Hong Kong authorities. From the pooled data, none of these trace elements have the average concentration above the ISQG-high values. However, As and Ag average concentrations were over the ISQG-low values. Some elements were found to have the average concentration above the ISQG-high and/or ISQG-low in certain locations, including Kampung Pasir Putih (JPP), Lumut Port (ALP), Kuala Perai (PKP), Port Dickson (NPD), and others. The lowest and highest concentrations in a specific sampling location and maritime area varied among the elements, variations that were greatly affected by natural and anthropogenic activities in a given area. For each trace element, there were various levels of concentration among the sampling locations and maritime areas. These patterns indicated pollutant sources of an element for each area perhaps derived from nearby areas and did not widely distributed to other locations. It is necessary for Malaysia to develop an ISQG for effective quick screening and evaluation of the coastal environment of Peninsular Malaysia

Johor Strait as a hotspot for trace elements contamination in Peninsular Malaysia

Present study was conducted to evaluate current status of trace elements contamination in the surface sediments of the Johor Strait. Iron (2.54 ± 1.24%) was found as the highest occurring element, followed by those of zinc (210.45 ± 115.4 μg/g), copper (57.84 ± 45.54 μg/g), chromium (55.50 ± 31.24 μg/g), lead (52.52 ± 28.41 μg/g), vanadium (47.76 ± 25.76 μg/g), arsenic (27.30 ± 17.11 μg/g), nickel (18.31 ± 11.77 μg/g), cobalt (5.13 ± 3.12 μg/g), uranium (4.72 ± 2.52 μg/g), and cadmium (0.30 ± 0.30 μg/g), respectively. Bioavailability of cobalt, nickel, copper, zinc, arsenic and cadmium were higher than 50% of total concentration. Vanadium, copper, zinc, arsenic and cadmium were found significantly different between the eastern and western part of the strait (p < 0.05). Combining with other factors, Johor Strait is suitable as a hotspot for trace elements contamination related studies