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1.
In order to examine the accumulation pattern of organotin compounds (OTs) accompanying the migration pattern in diadromous fish, tributyltin (TBT) and triphenyltin (TPT) compounds and their derivatives were determined in the liver, muscle, gill, and ovary tissues of both sea-run and freshwater-resident masu salmon, which are of the same species, Oncorhynchus masou. Their migratory histories were estimated using strontium (Sr) and calcium (Ca) analysis in the otolith. A significant difference in the mean Sr:Ca ratio from the core to the edge of the otolith was found between sea-run and freshwater-resident masu salmon. The TBT concentration in the liver was significantly higher than that in the other tissues in both sea-run and freshwater-resident fishes. In sea-run masu salmon, the TBT concentrations in all tissues except for the ovary were significantly higher than in those of freshwater-resident individuals. In the sea-run type, the percentage of TBT was higher than that of the freshwater-resident type. The TPT concentration in the liver of the sea-run type was also significantly higher than that in the other tissues, while that in the gill of the freshwater-resident type was significantly higher than that in the other tissues except for the ovary. The TPT concentrations found in the liver and muscle of the sea-run type were significantly higher than those in the freshwater-resident type, whereas the values of the gill in the sea-run type were significantly lower than those in the freshwater-resident fish examined. The percentage of TPT in the sea-run type was higher than that of the freshwater-resident type. These results suggest that the sea-run O. masou has a higher ecological risk of TBT and TPT exposure than the freshwater-residents during their life history. 相似文献
2.
The apparent use of marine and freshwater habitats by European eel Anguilla anguilla was examined by analyzing the strontium (Sr) and calcium (Ca) concentrations in otoliths of the eels collected from Irish coastal and fresh waters. The age and growth of eels were also examined using their otolith annuli. The sizes and ages of the female eels were greater than those of the males. The somatic growth rates ranged from 15 to 62 mm/year, which is typical for Ireland and other European countries. Analyses of Sr:Ca ratios along a life history transect in each otolith showed peaks (maximum more than 25 × 10−3) between the core and elver mark corresponding to the period of their leptocephalus and early glass eel stages in the ocean. Outside the elver mark, the Sr:Ca ratios indicated that eels had remained in different habitats that included freshwater (average Sr:Ca ratios, 0.98–1.78 × 10−3) and areas with relatively high salinities (average Sr:Ca ratios, 6.73–8.89 × 10−3). Some individuals showed clear evidence of shifts from sea to fresh waters. These findings suggest that Irish eels have the same behavioral plasticity regarding whether or not to enter freshwater or remain in marine environments as has been recently documented in this species and several other temperate anguillid species. However, patterns of habitat use in Irish waters were somewhat different than those previously reported for other habitats. 相似文献
3.
To examine the accumulation pattern of organotin compounds (OTs) in relation to the migration of diadromous fish, tributyltin (TBT) and triphenyltin (TPT) compounds and their derivatives were determined in the muscle tissue of both sea-run (anadromous) and freshwater-resident (nonanadromous) types of the white-spotted charr Salvelinus leucomaenis. There were generally no significant correlations between the TBT and TPT accumulation and various biological characteristics such as the total length (TL), body weight (BW), age and sex in S. leucomaenis. It is noteworthy that the TBT and TPT concentrations in sea-run white-spotted charr were significantly higher than in freshwater-resident individuals, although they are intraspecies. These results suggest that the sea-run S. leucomaenis has a higher ecological risk of TBT and TPT exposure than the freshwater-residents during their life history. 相似文献
4.
European eel (Anguilla anguilla) recruitment is declining dramatically since the 1980s. Causes for this decline are explained by a combination of environmental changes basically affecting oceanic larval stages and a variety of anthropogenic impacts during the continental phase. Today, evidence is growing that poor silver eel quality has a major impact on reproductive success, implying that habitat quality plays a key role in stock decline. Since eels are frequently moving through a variety of different habitats during their life cycle, a better understanding of the implications of individual diadromous behaviour and habitat choice on spawner quality are crucial for management considerations for a stock recovery. The present study tested whether individual migratory behaviour and habitat choice of European eels affect spawner quality. Therefore, the migratory behaviour of 287 European eels from marine, brackish and freshwater stations in the North Sea, the Baltic Sea and from Northern German inland waters was examined by otolith strontium/calcium analysis. All individuals were classified either as freshwater residents, coastal residents, downstream shifters, upstream shifters or interhabitat shifters. As indicators for eel quality, muscle fat content, infection with the introduced swimbladder nematode Anguillicoloides crassus and body length at onset of spawning migration were assessed. Results indicate that individuals that exclusively inhabited freshwaters had significantly lower muscle fat contents and were more seriously infected with A. crassus than eels that never entered freshwaters. Since high fat contents are considered as prerequisites for a successful transoceanic spawning migration and high A. crassus loads have a negative impact on condition, this study outlines the importance of brackish waters as eel habitats in temperate latitudes. Furthermore, it questions the net benefit of stocking programs for the European eel population, since they include the translocation of eels from coastal waters into freshwaters. 相似文献
5.
In order to understand the metal concentrations in Japanese eel Anguilla japonica, nine elements were analyzed in the livers of different migratory types of eels collected from Tokushima region (south Japan). Migratory types were defined by examining the Sr:Ca ratio in otoliths. The results showed that there were significant differences in V, Cr, Cd, and Pb concentrations among the migratory types. Mature-sea-eels show a higher risk of metal accumulation than other migratory types of eels, and the concentrations of Mn, Cu, and Zn in mature eels were significantly higher than those in immature eels. The study suggests that the eel liver is a valuable bioindicator for trace metals; however, when using the eel as a bioindicator to reveal the pollutants in aquatic systems, life history analysis should be carried out for accurate interpretation of the results. 相似文献
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Habitat use of the tapertail anchovy(Coilia mystus Linnaeus, 1758) from the Oujiang River Estuary and the Zhujiang(Pearl) River Estuary was studied by examining the environmental signatures of Sr and Ca in otoliths using electron probe microanalysis. Individuals from the Oujiang River had higher and varied Sr:Ca ratios(expressed as(Sr:Ca)×1 000, 3.83–13.0 average) in the otolith core regions, suggesting that they were born in brackish or sea waters, and that a freshwater habitat might not be necessary for egg hatching and larval growth.While, individuals from the Zhujiang River had lower Sr:Ca ratios(0.39–2.51 average) in the core regions,suggesting a freshwater origin. After hatching, anchovies from the Zhujiang River migrate downstream to the river estuary close to brackish water. Our results demonstrated varied habitat use for spawning during stages of early life history between the two populations, and suggested that such variations are promoting diversity of life history strategies of this species. 相似文献
8.
长江口水域四种鱼类的耳石微化学研究 总被引：2，自引：0，他引：2
利用X-射线电子探针微区技术(electron probe microanalysis, EPMA),对长江口不同水域中捕获的焦氏舌鳎、皮氏叫姑鱼、鮸鱼和光泽黄颡鱼耳石中的Sr含量进行耳石微化学研究,结果发现,焦氏舌鳎是典型的海水鱼类,不仅Sr:Ca比(按惯例标准化为Sr:Ca×10~3)的移动平均值高(7),而且Sr含量面分析图亦呈现为对应高盐度海水的黄色或红色图谱。虽然皮氏叫姑鱼和鮸鱼从出生直至被捕Sr:Ca比的移动平均值都在3—7间波动,总体上属河口半咸水栖息鱼类,但从Sr含量面分析图来看,皮氏叫姑鱼生活史履历更为复杂,可包括淡水(对应蓝色图谱)和半咸水生境(对应绿色图谱);而鮸鱼仅在长江口较高盐度半咸水或海水生境中活动,未见进入过淡水的履历。光泽黄颡鱼表现出仅利用淡水生境的履历,其Sr:Ca比的移动平均值仅在1.5—3间窄幅波动,整个生活史均在淡水区域里活动,表现为长江口典型的淡水栖息鱼类。本研究从新的角度提供了较为客观、直观和最新的信息,用以较为准确地重建和掌握长江口这些不同鱼类的生境利用特征。 相似文献
9.
Sukyung Kang Suam Kim Kevin Telmer David Welch Youn-Ho Lee 《Ocean Science Journal》2014,49(3):201-210
Chum salmon (Oncorhynchus keta) in the North Pacific Ocean are anadromous fish, and spend most of their life in the sea until spawning in natal streams. To identify the stock and habitat characteristics of chum salmon, the composition of chemical elements (Ca, Mn, Sr, Zn, and Ba) in otolith was examined using laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). Two main types of analytical work have been carried out; discrete spot analysis and line scan analysis of otolith sections. Salmon otoliths were obtained from the eastern (Canada and USA) and western (Japan and Korea) North Pacific during 1997–1999 spawning seasons. Spot analysis of otolith cores demonstrated significant differences in the element concentration among countries (p = 0.003). Line scanning from the core to the margin showed that Sr concentrations were elevated at the core of the otoliths, decreased during the freshwater stage, increased suddenly at a certain point, and oscillated periodically towards the margin matching with year-ring. The elevated Sr concentration at the core may reflect the maternal contribution to the egg, and the oscillations toward the margin may reflect salinity gradients between onshore/offshore or north/south migrations. The Zn profiles also oscillated and corresponded to the annual ring of the otolith. However, the profiles of Sr and Zn oscillated oppositely after salmon migrated to saline water and the Zn uptake declined toward the rim of the otolith while Sr uptake increased. 相似文献
10.
For many years, estuarine science has been the ‘poor relation’ in aquatic research - freshwater scientists ignored estuaries as they tended to get confused by salt and tides, and marine scientists were more preoccupied by large open systems. Estuaries were merely regarded by each group as either river mouths or sea inlets respectively. For the past four decades, however, estuaries (and other transitional waters) have been regarded as being ecosystems in their own right. Although often not termed as such, this has led to paradigms being generated to summarise estuarine structure and functioning and which relate to both the natural science and management of these systems. This paper defines, details and affirms these paradigms that can be grouped into those covering firstly the science (definitions, scales, linkages, productivity, tolerances and variability) and secondly the management (pressures, valuation, health and services) of estuaries. The more ‘science’ orientated paradigms incorporate the development and types of ecotones, the nature of stressed and variable systems (with specific reference to resilience and redundancy), the relationship between generalists and specialists produced by environmental tolerance, the relevance of scale in relation to functioning and connectivity, the sources of production and degree of productivity, the biodiversity-ecosystem functioning and the stress-subsidy debates. The more ‘management’ targeted paradigms include the development and effects of exogenic unmanaged pressures and endogenic managed pressures, the perception of health and the ability to manage estuaries (related to internal and external influences), and the influence of all of these on the production of ecosystem services and societal benefits. 相似文献
11.
The estuarine tapertail anchovy(Coilia nasus) is a high-value commercial fish. Estimating the spawning site or hatchery origin and habitat is essential for its conservation. This study aimed to determine the habitat use and life history characteristics of C. nasus from the Changjiang River Estuary. We investigated the environmental signatures of strontium(Sr) and calcium(Ca) in the otoliths of the collected specimens using electron probe microanalysis; additionally, we examined their gonadal mat... 相似文献
12.
为了探讨浙江沿海贝类体内有机锡的存在形态及分布特征,采用戊基化格氏衍生GC-FPD方法测定了沿海六县(市)采集的双壳贝类体内3种丁基锡和3种苯基锡化合物含量,并采用风险系数法进行了健康风险评价。研究表明,苯基锡是贝类体内有机锡的主要污染物,含量范围为nd~203.6 ng·g-1(干重),以二苯基锡为主。丁基锡总含量范围为nd~8.2 ng·g-1(干重),以三丁基锡为主。贝类中贻贝对有机锡的富集能力较强。不同区域贝类体内的有机锡主要来源于海运船舶的防污涂料。健康风险评价结果表明,浙江沿海贝类对食用人群的健康是安全的。 相似文献
13.
The purpose of this study was to examine the role of the cysteine-rich protein metallothionein (MT) in the detoxification and metabolism of metals in livers of eels Anguilla anguilla from the Thames Estuary, and to assess the value of MT measurements in environmental monitoring. Hepatic MT levels and associated metal concentrations were determined in A. anguilla collected on three occasions during 1998 at sites along the tidal Thames (from freshwater to the sea) and also from a reference site (Tamar Estuary) in southwest England. MT was present at basal levels of 2 mg g(-1) dry weight (dw), predominantly in association with the essential metals Cu and Zn. MT concentrations were variable within each eel 'population' but were generally highest (up to 11 mg g(-1) in individual eels) at the more contaminated upper- and mid-estuarine sites in the Thames (e.g. Brentford and Kew). Lowest MT levels were those in eels from Blythe Sands at the mouth of the estuary. Season, sex, reproductive status and salinity may have influenced MT levels to some extent, although metals were the most significant factor. Hepatic MT concentrations were highly correlated with associated metal burdens (Zn, Cu, Ag and Cd),--notably reflecting Cu and Ag enrichment in the upper- and mid-estuary. With the exception of Zn, metals in the supernatant fraction of eel livers were primarily associated with MT. Proportions of Cu, Ag and Cd bound to MT increased as a function of accumulated metal burdens, with no indication of saturation. Thus, despite causing induction of MT, excess bioavailable Cu, Ag and Cd appear to be successfully detoxified in eels over the range of environmental contamination encountered along the Thames Estuary. Paradoxically, it may be argued from conventional doctrine that the presence of raised levels of MT, at upstream sites, constitutes a response to contamination and, by definition, signals that the fish are affected by metals; however, obvious signs of deleterious effects were not detected. Superficially, from liver MT data, it would seem that eel populations have become biochemically adapted to metal contamination. The approach tested here has proved viable in helping to interpret trends in bioavailability and the toxicological significance of accumulated metal burdens in Thames eels. A. anguilla is a common inhabitant of estuarine and fresh waters throughout Europe, and related species occur world wide. Therefore, determination of hepatic MT (and associated metals) in eels could be useful for monitoring responses to metal exposure and environmental quality on a much broader basis. Ideally these determinations should be performed in tandem with other sublethal-effects measurements to maximise information. 相似文献
14.
Tributyltin (TBT) has been widely employed in marine anti-fouling paints as a biocide, although it represents a serious risk, particularly in estuarine and coastal water/sediment ecosystems. In this study, the embryotoxic effects of TBT and its degradation products, dibutyltin (DBT) and monobutyltin (MBT), were analyzed during the development of the sea urchin Paracentrotus lividus from post-fertilization to the pluteus stage, to better clarify ecotoxicological impact. The embryotoxicity of butyltins is concentration-dependent and increases proportionally with number of butyl groups. Significant growth reduction was observed at TBT concentrations as low as 0.01 microgram l-1; 1 microgram l-1 was the maximum concentration allowing embryos to reach the pluteus stage at 48 h post-fertilization. Development was blocked at the morula or blastula stage with higher TBT concentrations. DBT and MBT are less toxic: slowed development and a decrease in pluteus size occurred at 10 micrograms l-1 DBT and 0.5 mg l-1 MBT. Effects on both skeletal deposition and blocked embryonic development are suggested to be due to the interference of organotin compounds with intracellular calcium homeostasis. 相似文献
15.
Imposex was measured in the rock shell, Thais clavigera, from the coast of the Korean peninsula. Frequency of imposex was 0% at two reference sites, but at 47 out of 61 sites, frequency of imposex was recorded as 100%. The degree of imposex was relatively high at the sites near a harbor and a shipyard. Tributyltin (TBT) and triphenyltin (TPT) concentrations in T. clavigera ranged from 5 to 508 ng/g and from 3 to 2460 ng/g, respectively. A significant positive relationship was found between degree of imposex and organotin concentration, whereas a significant negative relationship was obtained between female-to-male sex ratio and the degree of imposex. During a field transplantation of T. clavigera from a pristine area to a port, TBT and TPT were accumulated in T. clavigera, and imposex was induced. T. clavigera shows considerable potential as a bioindicator species of the adverse effects of TBT and TPT contamination. 相似文献
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It is generally believed that size grading in a fish farm improves the total biomass output, because it will minimise the stress imposed by larger individuals over small individuals, resulting in higher feed intake and growth rate. The objective of this study was to evaluate the effect of size grading on individual growth performance of yellow New Zealand shortfin eel (Anguilla australis). A 109 day trial was conducted in a recirculation aquaculture system (RAS) with 103 eels of similar initial weight (101 ± 12 g). All eels were individually marked by PIT (passive integrated transponder) tags. On day 42, eels were graded to establish the following groups: only small eels (S-graded ≤ 135 g), only large eels (L-graded > 135 g), and small and large eels together (S-ungraded and L-ungraded). The large eels showed better specific growth rate (SGR), feed intake (FI) and feed conversion ratio (FCR) than the small eels. Nevertheless, no significant differences were found either between L-graded and L-ungraded or between S-graded and S-ungraded. The age of eels was not significantly different between groups. These findings suggest that the individual growth rate performance of the eels is not primarily a consequence of social interaction among tank-mates. 相似文献
18.
利用电子显微探针元素分析技术(EPMA)对黄海南部野生银鲳和鮸鱼的耳石进行了锶和钙沉积特征的初步分析。定量线分析结果表明,两种鱼类耳石的Sr/Ca之间存在显著的种间差异。银鲳耳石Sr/Ca比,在耳石核心及相邻处为低值区(5.86±0.92);3段Sr/Ca高值区分别为近核心部(7.88±1.28)、第1龄处(9.44±1.82)及耳石边缘(7.91±1.38);揭示银鲳孵化和早期发育应需要盐度适中的生境,当龄鱼在后期的生长中需洄游经过两段高盐生境(其中之一在第1龄时)。鮸鱼耳石Sr/Ca比波动表现为耳石核心处(7.72±0.97)高于其余部分,反映了鮸鱼孵化及初期发育阶段可能生活在高盐度生境,而当龄鱼随后阶段的生长和发育过程则会洄游至盐度有所降低的生境中进行。 相似文献
19.
Rita P. Vasconcelos Patrick Reis-Santos Susanne Tanner Anabela Maia Christopher Latkoczy Detlef Günther Maria José Costa Henrique Cabral 《Estuarine, Coastal and Shelf Science》2008
Connectivity is a critical property of marine populations, particularly for species with segregated juvenile and adult habitats. Knowledge of this link is fundamental in understanding population structure and dynamics. Young adults of commercially important fish species Solea solea, Solea senegalensis, Platichthys flesus, Diplodus vulgaris and Dicentrarchus labrax were sampled off the Portuguese coast in order to establish preliminary evidence of estuarine nursery origins through otolith elemental fingerprints. Concentrations of Li, Na, Mg, K, Mn, Cu, Zn, Sr, Ba and Pb in the otolith section corresponding to juvenile's nursery life period were determined through laser ablation inductively coupled plasma mass spectrometry. Element: Ca ratios in coastal fish differed significantly amongst collection areas, except for Platichthys flesus, and were compared with the elemental fingerprints previously defined for age 0 juveniles in the main estuarine nurseries of the Portuguese coast. Identification of nursery estuaries was achieved for four of the species. Assigned nursery origins varied amongst species and differences in the spatial scale of fish dispersal were also found. Diplodus vulgaris was not reliably assigned to any of the defined nurseries. Overall, results give evidence of the applicability of estuarine habitat tags in future assessments of estuarine nursery role. Research developments on the links between juvenile and adult habitats should contribute for the integrated management and conservation of nurseries and coastal stocks. 相似文献
20.
Lake Manapouri in the South Island of New Zealand has a significant hydroelectric generation facility, which potentially has a negative impact on the successful emigration of longfin eels (Anguilla dieffenbachii) from the upper Waiau catchment. Consequently, a trap-and-transfer programme has been implemented to allow silver (migratory) eels access to the sea. The present study analysed data on the timing of captures and numbers of silver eels over four seasons, including the influence of possible migration cues. Silver eels were captured over an extended season of seven months (November–May), with peak numbers during December and January. Flow at the lake outflow was found to have a weak relationship with the number of eels caught, as did lake level, but moon phase and rainfall had no significant effect. These results highlight the variability in silver longfin eel behaviour both in terms of timing and response to potential environmental cues. 相似文献