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1.
中国近海藻毒素及有毒微藻产毒原因种调查研究进展   总被引:2,自引:0,他引:2  
麻痹性贝类毒素在我国近海污染问题已十分突出,基本呈现逐年加剧的趋势。20世纪90年代,南海麻痹性贝类毒素污染较重; 21世纪初,北黄海麻痹性贝类毒素污染较重;近几年,渤海和福建近海麻痹性贝类毒素污染较重;可产生麻痹性贝类毒素的微藻有亚历山大藻和裸甲藻等。采用小鼠生物法检测我国近海腹泻性贝类毒素超标率32%左右,采用液相色谱/质谱法检测,仅有3起超标的研究报道;现行小鼠生物法检测腹泻性贝类毒素假阳性问题十分突出,应尽快废除;腹泻性贝类毒素均是脂溶性的,脂溶性海洋生物毒素在我国近海常年可检出,偶有虾夷扇贝毒素和鳍藻毒素超标现象。可产生脂溶性毒素微藻有鳍藻和原甲藻及网状原角藻等。失忆性贝类毒素在我国近海常有检出,但无超标现象;产毒微藻有拟菱形藻等。西加鱼毒素在我国南海污染较重,但毒素标准物质的匮乏,限制了西加鱼毒素的调查研究;至今尚未确定产生西加鱼毒素的微藻。酶联免疫吸附法和液相色谱串联质谱法相结合已成为藻毒素快速准确检测成熟的技术,逐渐代替小鼠生物法和液相色谱法。  相似文献   

2.
我国近海有毒藻和藻毒素问题的研究现状与展望   总被引:2,自引:0,他引:2  
于仁成  罗璇 《海洋科学集刊》2016,51(51):155-166
海洋中的一部分微藻能够产生藻毒素,导致鱼、贝类等养殖动物染毒或死亡,甚至危及人类健康和海洋生态安全。近20年来,随着对有害藻华(Harmful algal bloom, HAB)问题关注程度的不断提高和研究手段的快速发展,对我国近海有毒藻和藻毒素的认识也在不断深入。本文针对常见的几类藻毒素,从贝类中藻毒素污染状况、毒素来源、有毒藻藻华状况等角度,对我国当前相关研究工作进展进行了综述。大量研究表明,麻痹性贝毒毒素(paralytic shellfish toxins, PSTs)和腹泻性贝毒毒素(diarrhetic shellfish toxins, DSTs)在我国近海最为常见,其中,麻痹性贝毒主要由有毒亚历山大藻(Alexandrium spp.)产生,产毒藻种常见于南海海湾、福建沿海、长江口邻近海域、海州湾、北黄海和秦皇岛近海等,中毒事件也时有发生。常见的大田软海绵酸、扇贝毒素等腹泻性贝毒毒素多由鳍藻(Dinophysis spp.)产生,我国近海贝类沾染藻毒素的现象也非常常见。近年来,随着高效液相色谱和质谱技术的发展,在我国近海发现了越来越多的有毒藻和藻毒素。在对文献进行综合分析的基础上,简单探讨了有毒藻与藻毒素对海产品食品安全的影响及风险,以及未来研究发展方向。  相似文献   

3.
Chronological variation in otolith chemistry can be used to reconstruct migration histories of fish. The use of otolith chemistry to study migration, however, requires knowledge of relationships between the chemical properties of the water and elemental incorporation into otoliths, and how water chemistry varies in space and time. We explored the potential for otolith chemistry of snapper, Pagrus auratus, to provide information on movement history between a large semi-enclosed bay, Port Phillip, and coastal waters in south-eastern Australia. Comparisons of water chemistry across two years demonstrated that ambient barium (Ba) levels in Port Phillip Bay were approximately double those in coastal waters (11 μg L−1 versus 6 μg L−1). Ba levels in otolith margins of wild juvenile snapper were highly positively correlated with ambient levels across 17 sampling locations, and levels in otolith margins of adult snapper collected from Port Phillip Bay were approximately double those of snapper collected in coastal waters. Mean partition coefficients for Ba (DBa) were similar for juvenile (0.43) and adult (0.46) otoliths, suggesting that otolith Ba incorporation relative to ambient levels was similar across life-stages. Low Ba variation across otoliths from adult snapper maintained in tanks for three years indicated that annual temperature and/or growth cycles did not strongly influence otolith Ba variation. We concluded that chronological Ba variation in snapper otoliths would be a reliable proxy for life-history exposure to variable ambient Ba. We used water chemistry data and Ba levels across otoliths of ocean resident snapper to estimate otolith Ba levels indicative of residence in Port Phillip Bay (>10 μg g−1) or coastal waters (<6 μg g−1). Peaks in Ba exceeding 10 μg g−1 were common across otoliths of snapper collected in Port Phillip Bay and a nearby coastal region. The location of strong Ba peaks within otoliths was consistent with residence in Port Phillip Bay during the spring/summer when snapper move into the Bay from coastal waters to spawn. Our results for snapper support the use of otolith Ba as a proxy for ambient levels throughout the life-history, however, confident interpretation of migration history from otolith Ba chronologies will most likely require matching time series of ambient Ba in the water bodies of interest.  相似文献   

4.
Many fish species rely on estuarine nursery habitats as they transition to adult life stages. Quantifying nursery value, however, requires identification of the life stages (often small and short-lived) that utilise nursery habitats, and survey methods that provide comparable estimates across habitats. We focused our surveys on post-settlement snapper (Chrysophrys auratus) using video camera deployments across habitats within a northeastern New Zealand harbour. Post-settlement snapper abundance was higher among structured habitat types relative to bare sediments, with the type of structured habitat not influential. The exception appeared to be for reef habitat (although sampling was limited). Reef sites were structurally complex, but largely inhabited by older life stages (snapper and other fish species). Overall, nursery value for snapper appears to be connected to structure, rather than structure type. This result emphasises the importance of a broadened scope to coastal fishery management, one that incorporates not just fish extraction, but also habitat maintenance or restoration.  相似文献   

5.
Estuarine and sheltered coastal habitats that contain physical structure are potentially important nurseries for juvenile fish. Many of these structured habitats, however, are potentially vulnerable to stressors such as elevated turbidity. Quantifying the benefits that structured habitats provide to juvenile fish may therefore be an important step in the management process. We investigated the value of structured habitat for juvenile fishes in northeastern New Zealand, using artificial seagrass units (ASUs) with varying blade density. ASUs were predominantly settled by juvenile snapper (Pagrus auratus) and spotty (Notolabrus celidotus). The density of both snapper and spotty was greatest on ASUs with the highest blade density. For snapper, a gradient in abundance was present (with higher abundance closer to the harbour mouth), suggesting either a gradient in the supply of recruits or a potential recruitment shadow effect. The size distribution of juvenile snapper (12–70 mm fork length) was very similar on both sampling trips, despite the 2‐month interim period, suggesting an ontogenetic habitat shift dependent on size. The condition of juvenile snapper from ASUs with the highest blade density was also greater than the other ASU treatments. Overall, these results provide new empirical evidence that habitats with physical structure within shallow estuarine systems are important to early stage juvenile fishes such as snapper, and indicate that the location‐specific context of that habitat is also likely important.  相似文献   

6.
Snapper (Chrysophrys auratus) is an important coastal fish species in New Zealand for a variety of reasons, but the large amount of research conducted on snapper has not been reviewed. Here, we review life history information and potential threats for snapper in New Zealand. We present information on snapper life history, defining stages (eggs and larvae, juvenile and adult), and assess potential threats and knowledge gaps. Overall we identify six key points: 1. post-settlement snapper are highly associated with certain estuarine habitats that are under threat from land-based stressors. This may serve as a bottleneck for snapper populations; 2. the largest knowledge gaps relate to the eggs and larvae. Additional knowledge may help to anticipate the effects of climate change, which will likely have the greatest influence on these early life stages; 3. ocean acidification, from land-based sources and from climate change, may be an important threat to larval snapper; 4. a greater understanding of population connectivity would improve certainty around the sustainability of fishery exploitation; 5. the collateral effects of fishing are likely to be relevant to fishery productivity, ecosystem integrity and enduser value; 6. our understanding of the interrelationships between snapper and other ecosystem components is still deficient.  相似文献   

7.
采用高效液相色谱-串联质谱方法对我国近海贝类中腹泻性贝毒成分进行研究,结果发现采自北黄海大连附近海域的海湾扇贝和虾夷扇贝含有25~41μg/kg的虾夷扇贝毒素(yessotoxin,YTX),在虾夷扇贝体内还含有37.2μg/kg的45-OH-YTX,并在5种贝中发现微量的Homo-YTX毒素组分,这是首次报道在我国贝中检出此类毒素。虾夷扇贝毒素YTXs是一类含有2个磺酰基的脂溶性多环聚醚类化合物,对小鼠的腹腔注射急性致死毒性很高,毒理作用机制尚不清楚。本研究的结果说明我国贝类体内生物毒素成分复杂,亟需进行毒素成分结构、来源生物、生态毒理效应、分布规律及安全限定标准的研究。  相似文献   

8.
A bottom trawl survey was used to determine the position of a nursery ground for snapper, Chrysophrys auratus, in the North Taranaki Bight, New Zealand, and so indicate what area should be protected from potentially harmful fishing techniques. A nursery ground for trevally, Caranx georgianus, was also identified. The growth rate of snapper from the North Taranaki Bight is shown to be much faster than Hauraki Gulf and East Cape stocks, but quite similar to Tasman Bay fish. The onset of sexual maturity appears to be related to fish size rather than age, with about 80% of snapper being mature at a fork length of 25 cm. Recruitment success varies greatly between years, and successful recruitment may be related to warm spring temperatures.  相似文献   

9.
The food of the snapper, Chrysophrys auratus (Forster), in the Hauraki Gulf was investigated by an occurrence method. The diet was extremely varied and depended on the size of the fish and the food available to it. Variation in feeding occurred during the day, but there was no difference in diet at different times of the year or between male and female snapper.

No evidence was found for the existence of two races of snapper in the Hauraki Gulf. Changes of colouration and behaviour among snapper schooling in the summer appeared merely to be associated with spawning activity.  相似文献   

10.
Management of fish populations is often focused on the exploitation of adult fish. Maintaining the habitat requirements of all life stages may also be an important consideration. We investigated the value of structured habitat to juvenile fishes within a northeastern New Zealand harbour using artificial seagrass units (ASUs). Specifically, we deployed ASUs across treatments with high vs. low habitat manipulations. We hypothesised that if the abundance of recruiting juvenile fishes was greater on the high habitat availability treatments this would suggest that the availability of habitat was limiting juvenile fish abundance. Our analyses were focused on the four most abundant fishes that settled on our ASUs: snapper (Pagrus auratus); spotty (Notolabrus celidotus); trevally (Pseudocaranx dentex); and an assemblage of pipefish species. For snapper, spotty and pipefish, abundance was greater on the high habitat availability treatments. This result would be unlikely to occur if the availability of juvenile fishes was limiting, suggesting that juvenile fish abundance is more likely to be limited by habitat. In terms of spatial gradients, spotty abundance and size increased with distance into the harbour. The spatial gradient present for spotty indicates the importance of placing the habitat dependency of juvenile fish into a landscape context. Overall, these results demonstrate that maintaining structured habitats may be an important consideration for some valuable inshore fish populations in northeastern New Zealand.  相似文献   

11.
In this study, the development of the technique APCI+ LC/MS/MS allowed the detection of phenanthrene, pyrene and metabolites of alkyl homologs in fish bile (in situ) and in urine of crabs. Laboratory experiments were carried out exposing crabs from an unpolluted mangrove (Barra de Guaratiba) to phenanthrene, and to the alkylated homologs 1-methyl phenanthrene and 2,6,9-trimethyl phenanthrene. Urine samples were collected at 0, 24, 48, 72, and 96 h. Fishes were captured from strategic sites from Guanabara Bay. Hydroxylated metabolites of phenanthrene, epoxides, orthoquinone and glucoside conjugates were identified in both samples. The method APCI+ LC/MS/MS showed to be effective in a preliminary assessment of phenanthrene metabolite formation, although the low concentrations of 1-methyl phenanthene and 2,6,9-trimethyl phenanthrene did not allow a systematic evaluation of data. The method, however, proved to be excellent tool for studies of PAHs metabolites due to the high selectivity, sensitivity and separation attained.  相似文献   

12.
Increases in the density of exploited species on unfished reefs logically implies that some individuals are at least temporarily resident, or show fidelity to a particular area. We tagged snapper (Pagrus auratus (Bloch & Schneider 1801)) in the Leigh Marine Reserve, New Zealand using visible implant fluorescent elastomer tags, recoverable by diver visual sightings without the need to recapture the fish. Batch tagging of snapper (n = 907) was done during an angling survey in June and December 1996, and individually coded tags were implanted by divers (n = 117) in January 1999. Snapper tagged during both programmes were recovered on irregular intervals from 1997 to 2000. There were 71 recoveries of batch tags within 500 m of their tagging sites, and these recoveries were still being made >3 years after tagging: Of individually coded fish, 49 (42%) were seen, sometimes repeatedly over several months, close to their respective tagging sites. These observations included snapper as small as 23 cm fork length, contradicting the commonly held impression that only large snapper take up long‐term residency on reefs. This preliminary evidence suggests that some snapper exhibit site fidelity to areas only a few hundred metres wide, and in the absence of fishing may occupy the same area for years.  相似文献   

13.
The New Zealand snapper Chrysophrys auratus is the object of a major fishery and contributes approximately 30% of the annual landed weight of fin‐fish. Samples of 65 fish from 7 localities on the New Zealand coast were analysed for mercury. Though there is an increase in mercury concentration with size of fish, the larger, older individuals with relatively high mercury levels contribute only a small proportion to the landed catch. Therefore, in establishing the average concentration of mercury in fish, due weight should be accorded to the differences in size composition of the catch. On this basis the average levels of mercury in snapper offered for human consumption are of the order of 0.25 ppm. As this is only half the “permissible safe level” of most other countries where fish consumption is much higher, the risk to the New Zealand consumer is negligible.  相似文献   

14.
In this paper we describe results of a study designed to test the hypothesis that coastal regions with weak subtidal flow (i.e., coastal null zones) may serve as retention areas for estuarine larval forms. Our investigation assessed the distribution of 3 taxa of crab larvae (Callinectes sapidus, Uca spp., and Hexapanopeus angustifrons) within a 200-km2 region encompassing the mouth of Delaware Bay (ca. 39° N, 75° W). Previous studies had shown that larvae of C. sapidus and Uca spp. are exported to the coastal ocean, while larvae of H. angustifrons are retained within the estuary. In the present investigation, we conducted simultaneous plankton tows at 3 stations during peak spawning season. Samples were collected from a depth of 1 m every 30 min throughout a complete tidal cycle. One station was located 15 km within the bay and was subjected to strong flow at tidal frequency. A second station was located within a southward-flowing coastal current near the southern terminus of the bay at Cape Henlopen. A final station was located in a coastal area of weak subtidal flow near Cape May at the northern terminus of the bay. Results provide a unique synoptic view of larval distributions in 3 distinct hydrographic regimes in the mouth of a major estuary. The coastal-current station was characterized by low concentrations of newly hatched C. sapidus and Uca zoeae, while the null-zone station had high densities of both early and advanced larval stages of these two taxa. In contrast, the station located within the bay had few C. sapidus or Uca zoeae and was dominated by both early and advanced stages of the mud crab H. angustifrons. These data provide clear evidence for the retention of exported larval forms in a coastal null zone associated with the circulation of a large estuary and thus are consistent with our hypothesis.  相似文献   

15.
Feeding was examined in 1,194 snapper, Chrysophrys auratus (Forster), from Hauraki Gulf and north‐west Bay of Plenty. Occurrence and points (bulk) methods of food analysis were used in this study. By occurrence and bulk, crustaceans, polychaetes, echinoderms, molluscs, and teleosts formed the main snapper food groups, with crustaceans being the most important. Size of snapper, bottom type, depth, time of day and geographical regions affected the occurrence and importance of food items, while sex of fish probably did not.  相似文献   

16.
ABSTRACT

The wreck of the MV Rena in October 2011 discharged large quantities of potentially toxic materials in the coastal marine environment of the Bay of Plenty, New Zealand. We evaluated sublethal effects of the water soluble fractions of physically and chemically dispersed heavy fuel oil (HFO) and the water soluble fraction of cryolite on the haematology of subadult or adult snapper (Chrysophrys auratus), spotted wrasse (Notolabrus celidotus) and red rock lobster (Jasus edwardsii). Small but transient effects occurred, the most significant of which were changes in circulating immune cell populations in fish and lobster that recovered by the conclusion of a 96-h exposure period. No post-exposure effects were observed during a 10-day recovery in toxicant-free seawater. Corexit 9500 oil dispersant increased polycyclic aromatic hydrocarbon (PAH) uptake from HFO in fish and lobster by around two-fold and four-fold, respectively, and caused a larger change in immune cell abundance in snapper than exposure to HFO alone. While depuration of PAHs was more rapid in fish than lobster, significantly elevated PAH levels were still evident after 10 days of depuration.  相似文献   

17.
Determining the nursery habitat of fishes that have moved from estuarine nursery habitats is difficult. The elemental fingerprints of otoliths of three species of sparids were determined to investigate their utility as a natural tag of the nursery habitat. Juvenile Pagrus auratus (snapper), Rhabdosargus sarba (tarwhine) and Acanthopagrus australis (bream) were collected from two sites in each of 15, six and three estuaries, respectively, and their otoliths analysed by solution-based inductively coupled plasma-mass spectrometry. Significant differences in otolith chemistry were found for all three species of juveniles collected from different estuaries. The same patterns among estuaries were not seen for all species, although it was not possible to sample the same sites within an estuary for all species. For bream, significant differences in otolith chemistry were found among all three estuaries, whereas for tarwhine the six estuaries were separated into three groups. For snapper, a number of estuaries could be separated, but there was some overlap for other estuaries. All three species were collected from the same site within one estuary and their otoliths analysed. Significant differences were found among species, but the implication of this finding remains unclear as the three species show differences in microhabitat use and may also differ in age. Because the elemental fingerprints of juveniles vary among estuaries or groups of estuaries, the nursery or recruitment estuary of adult fish could now be determined by analysing the juvenile region of adult otoliths. Thus, connectivity between estuaries and open coastal populations could be determined. Such information will have major implications for fisheries management because it will provide information on the distance that fish have moved from their recruitment estuary and the number of estuaries that contribute to each adult population.  相似文献   

18.
浙江近岸海域贝类中重金属和贝毒污染状况研究   总被引:4,自引:0,他引:4  
在浙江近岸海域采集了青蛤(Cyclina sinensis)、毛蚶(Scapharca subcrenata)、厚壳贻贝(Mytilus coruscus)、缢蛏(Sinonovacula constricta)、泥螺(Bullacta exarata)、菲律宾蛤仔(Ruditapes philippi-narum)、文蛤(Meretrix meretrix)、僧帽牡蛎(Ostrea cucullata)和栉孔扇贝(Chlamys farreri)共9种贝类计29份样品,检测其中重金属汞、砷、铜、铅、锌、镉以及麻痹性贝毒和腹泻性贝毒.结果表明,瑞安毛蚶、瑞安栉孔扇贝中有麻痹性贝类毒素检出,嵊泗文蛤、毛蚶和乐清牡蛎中存在重金属超标的情况;牡蛎对汞、铜、锌、镉有较强的富集能力.  相似文献   

19.
Feeding relationships between two predatory demersal fishes, tarakihi Cheilo‐dactylus macroplerus (Bloch & Schneider) and snapper Chrysophrys auratus (Bloch & Schneider), in relation to the benthos were examined at six sampling areas in the western Bay of Plenty during October to December 1969 and April to June 1970.

Food selectivity was determined. The results showed that both fish species positively selected many of the same food categories. The average Food Similarity Index based on volume data was 18.9% and the average number of food categories shared was approximately 60% of the total number of food categories consumed.

The feeding relationships between tarakihi and snapper and the benthos varied with both sampling area and sampling period. Competition for food is probably minimal, since both fish species eat a wide range of foods and feed at different times.  相似文献   

20.
We hypothesized that temporal variation in fish species composition and community structure in a low complexity habitat in the Pueblo Viejo Lagoon, Mexico, is influenced by diel light/dark cycles and tidal stage, and by seasonal changes in salinity and temperature. We collected a total of 17,661 individuals during 2‐h interval sampling over six bi‐monthly 24‐h sampling cycles representing 53 species, of which 11 (~20%) were previously unknown in the system. Diel variation indicated that significantly higher numbers of individuals and species were caught at night, whereas diversity and evenness were higher during the day. Species richness was significantly higher in July and January, whereas diversity and evenness peaked around May; both were correlated with temperature. Diel variation in species composition was influenced primarily by the light/dark cycle. Cluster analyses of each diel cycle separated fish assemblages from midday samples from those of nocturnal samples, separated by an extended wide transition period as fish moved at dawn and during the late afternoon/dusk. Significant shifts (as determined by MANOVA) in assemblage structure occurred between months. Canonical correspondence analysis showed that temperature and day/night effects were the most important environmental variables structuring the fish community. This constrained ordination also defined species with specific habitat preferences as follows: (i) diurnal, warm temperature species (mainly planktivores) (Brevoortia gunteri, Cetengraulis edentulus, Diapterus auratus, and Membras martinica); (ii) nocturnal, warm temperature species (mainly predators) (Citharichthys spilopterus, Cathorops melanopus, and Bairdiella spp.); and (iii) low temperature, diurnal species (Brevoortia patronus and Mugil curema) or those with twilight and nocturnal distributions (Anchoa mitchilli, the most numerically abundant species). Our results indicate that diel and seasonal changes in fish community structure were mainly related to day/night cycles and temperature regimes.  相似文献   

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