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

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

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

Environmental history of Japanese eel, Anguilla japonica collected in Miyako Bay, northeastern Japan

The environmental history in combination with age of the Japanese eel, Anguilla japonica, collected in Miyako Bay along the Sanriku Coast of Japan, was examined using the otolith microstructure and analysis of strontium (Sr) and calcium (Ca) concentrations with wavelength dispersive X-ray spectrometry by an electron microprobe. The line analysis of Sr : Ca ratios along the life history transect of each otolith showed a peak (ca 12-17×10^) between the core and elver mark, which corresponded to the period of their leptocephalus and early glass eel stages in the ocean. The mean Sr : Ca ratios from the elver mark to the otolith edge indicated that there were eels with several general categories of migratory history, that included sea eels that never entered freshwater (average Sr : Ca ratios, >6.0×10^) and others that had entered freshwater for brief periods, but returned to the estuary or bay. This evidence of the occurrence of sea eels indicates that Japanese eels in this northern area do not necessarily migrate into freshwater rivers during recruitment as glass eels at the beginning of their growth phase, and even those that do enter freshwater may later return to the marine environment

Effects of tributyltin on the chlorophyll contents of marine microalga Tetraselmis tetrathele, Nannochloropsis oculata and Dunaliella sp

Three species of marine microalga Tetraselmis tetrathele, Nannochloropsis oculata and Dunaliella sp., the important phyto-plankton in many hatcheries, were used in an acute toxicity test of TBT with emphasis on the chlorophyll a and b contents. After a very short exposure time of three concentrations of TBT, 0.1, 0.5 and 1μgl^, the three species of algae showed different responses. The chlorophyll a and b contents of T. tetrathele in all treatments were higher than those in controls, even be doubled in 1μgl^ of TBT. N. oculata and Dunaliella had a slightly higher chlorophyll a and b contents in the lowest TBT concentration tested (0.1μgl^) than those in control, but as the TBT concentration increased their chlorophyll contents decreased. Three levels of TBT tested are within the range of the no observable effect concentration (NOEC) for T. tetrathele, while the lowest observable effect concentrations (LOEC) for N. oculata and Dunaliella are between 0.1 to 0.5μgl^. Among the three species, N. oculata has a highest sensitivity towards TBT

Effects of triphenyltin exposure on the red alga Eucheuma denticulatum

Toxic effects of triphenyltin (TPT) on the marine alga Eucheuma denticulatum obtained from Nain Island, North Sulawesi, Indonesia have been examined in laboratory condition. The algal samples were first acclimated in laboratory prepared seawater for three days. The algae were then divided into 12 culture chambers for treatments with different concentrations of TPT between 5-30 μgl^ with 5μgl^ interval, and in another container for control. After two-week experimentation, some samples of algae were obtained from each chamber for histopathological examination. The aniline blue stained tissue of alga E. denticulatum showed that at all TPT concentration tested, the cortex had morphological changes, even almost disappeared at higher concentration (>20μgl^). The medullary cells of alga exposed to 5-15μgl^ have been decreasing in size compared to those in control. Cell walls of some medullary cells have damaged at 20μgl^ and totally lysed in all cells of alga exposed to 25 and 30μgl^. The pattern of zonatedly dividing tetrasporangium had not occurred anymore in alga exposed to TPT even at the lowest tested concentration (5μgl^) and had totally damaged in higher concentrations, such as that of 20μgl^. The tetraspores in tetrasporangium seem to be fused or shrinkage, no more dividing process occurred as in control. Therefore, reproductive cells of alga is more sensitive than somatic cells, indicating that no further development of alga will occur in aquatic environment contaminated even with unlethal TPT levels

Organotin Levels in Coastal Areas in Vietnam

The present status of levels of butyltin (BT) and phenyltin (PT) compounds in clam and sediment in Vietnam are overviewed. The levels of TBT in clams and sediments were within limits reported from other countries. Further, the TBT level in clams was lower than the tolerable average residue level (TARL) estimated based on tolerable daily intake (TDI). Trace amounts of PTs were also found in both clam and sediment samples. Of total BTs, TBT was the dominant species in clams from almost sites reported. The ratios of TBT in sediment tended to be higher among BT compounds. In spatial distribution, TPT showed a pattern similar to TBT, suggesting the use of TPT as an antifouling paint

Ecotoxicological risk of organotin compounds on zooplankton community

Organotin compounds are bioavailable to zooplankton through direct cellular interaction or feeding mechanisms and therefore could be biomagnified to higher trophic levels. Among organotin species, tributyltin (TBT) shows the longest persistence in the lower trophic levels, and is accumulated in zooplankton up to 150,000 times that in ambient water. Higher ability of zooplankton to accumulate butyltins could be associated with their feeding behaviour as filter feeders. Some zooplankton such as rotifers can accumulate 5 and 2 folds that of alga and mysids, respectively. Generally, meroplankton such as veliger larvae of the mussel (Mytilus edulis) and lobster larvae (Homarus americanus) are more sensitive than the adults. Threshold concentration (i.e. the concentration at which toxicity starts) for acute toxicity in certain copepods is below 0.3mgl(-1) TBTO. Chronic toxicity levels are in the range of one-thousandth to one-tenth part per billion, and generally the No Observed Effects Concentration (NOEC) for zooplankton is 1ngl(-1). The most worrisome are chronic effects on reproduction that could decrease marine-species populations. Long term monitoring programs, including those on zooplankton, for the assessment of the effectiveness of global ban is obviously necessary.Proceedings of the Horiba International Conference "New Direction of Ocean Research in the Western Pacific" : Past, Present and Future of UNESCO/IOC/WESTPAC Activity for 50 years and the JSPS Project "Coastal Marine Science"Section I: Research Articles/Pollutio

Organotin Levels in Coastal Areas in Vietnam

The present status of levels of butyltin (BT) and phenyltin (PT) compounds in clam and sediment in Vietnam are overviewed. The levels of TBT in clams and sediments were within limits reported from other countries. Further, the TBT level in clams was lower than the tolerable average residue level (TARL) estimated based on tolerable daily intake (TDI). Trace amounts of PTs were also found in both clam and sediment samples. Of total BTs, TBT was the dominant species in clams from almost sites reported. The ratios of TBT in sediment tended to be higher among BT compounds. In spatial distribution, TPT showed a pattern similar to TBT, suggesting the use of TPT as an antifouling paint