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《Marine environmental research》2011,71(5):368-373
Monitoring effects of contaminants at lower levels of biological organisation (e.g. biochemical and cellular) allows for mechanistic evaluation of effects of contaminant exposure through laboratory exposures. However, higher level organism effects (e.g. physiological and behavioural) are deemed more ecologically-relevant. In the present study, cellular (cell viability and immune function), physiological (cardiac activity) and behavioural (foraging behaviour) responses were evaluated in field-collected shore crabs Carcinus maenas from three estuaries [a ‘relatively’ (polycyclic aromatic hydrocarbon) PAH-contaminated site (Plym Estuary) and two ‘comparatively clean’ field sites (Avon and Yealm Estuaries)] and compared with responses of crabs exposed in the laboratory to a model organic contaminant (PAH) pyrene (200 μg l−1 for 28 days). The hypothesis that behavioural indicators may be more sensitive than other more traditional methods was tested. No significant impacts were observed at the cellular or physiological level in Plym-collected crabs (the ‘relatively’ contaminated site), but foraging behaviour was significantly altered (increased prey handling time) compared to individuals collected from the ‘relatively’ uncontaminated sites (Avon and Yealm). When given a cockle as a prey item, both Plym-collected and laboratory-exposed crabs took longer to handle and break into cockle shells. Therefore, ecologically-relevant behavioural observations may serve as valuableindicators of environmental quality. 相似文献
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Wenbin Zhu Kaner Lu Zhanhui Lu Qian Dai Zhenghua Li Yongdong Zhou Siqi Huang Haichen Zhu Guocheng Cui 《海洋学报(英文版)》2021,40(6):67-74
This study attempted to compare the performance of local polynomial interpolation,inverse distance weighted interpolation,and ordinary kriging in studying distribution patterns of swimming crabs.Cross-validation was used to select the optimum method to get distribution results,and kriging was used for making spatial variability analysis.Data were collected from 87 sampling stations in November of 2015(autumn) and February(winter),May(spring) and August(summer) of 2016.Results indicate that swimming crabs widely distributed in autumn and summer:in the summer,they were more spatially independent,and resources in each sampling station varied a lot;in the winter and spring,the abundance of crabs was much lower,but the individual crab size was bigger,and they showed the patchy and more concentrative distribution pattern,which means they were more spatially dependent.Distribution patterns were in accordance with ecological migration features of swimming crabs,which were affected by the changing marine environment.This study could infer that it is applicable to study crab fishery or even other crustacean species using geostatistical analysis.It not only helps practitioners have a better understanding of how swimming crabs migrate from season to season,but also assists researchers in carrying out a more comprehensive assessment of the fishery.Therefore,it may facilitate advancing the implementation in the pilot quota management program of swimming crabs in northern Zhejiang fishing grounds. 相似文献
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Estuarine environmental assessment by sub-individual responses is important in order to understand contaminant effects and to find suitable estuarine biomonitor species. Our study aimed to analyze oxidative stress responses, including glutathione-S-transferase (GST) activity, total antioxidant capacity (ACAP) and lipid peroxidation levels (TBARS) in estuarine crabs Hemigrapsus crenulatus from a high anthropogenically-impacted estuary (Lenga) compared to low and non-polluted estuaries (Tubul and Raqui), in a seasonal scale (winter–summer), tissue specific (hepatopancreas and gills) and sex related responses. Results showed that hepatopancreas in male crabs better reflected inter-estuary differences. Morpho-condition traits as Cephalothorax hepatopancreas index (CHI) could be used as an indicator of physiological status of estuarine crabs. Discriminant analysis also showed that GST and TBARS levels in summer are more suitable endpoints for establishing differences between polluted and non-polluted sites. These results suggest the importance of seasonality, target tissue, sex and physiological status of brachyuran crabs for estuarine biomonitoring assessment. 相似文献
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Distributions and seasonal variability of dissolved organic nitrogen in two estuaries in SW England 总被引：4，自引：0，他引：4
Nitrogen loadings to coastal waters have increased over the last century, resulting in deterioration in water quality. In this study we investigated the distributions and seasonality of dissolved organic nitrogen (DON), and its relationship to total dissolved nitrogen (TDN), for two anthropogenically influenced estuarine systems in southwest England. Concentrations of DON in both estuaries were generally < 80 μM. DON showed non-conservative distributions, resulting from external and internal inputs and in situ reactivity. DON contributed 38 ± 22% (range 4–79%, Yealm) and 36 ± 17% (range 4–84%, Plym) to the TDN pool, with lower values generally observed in the fresher samples relative to the more saline samples. DON was a larger fraction of the TDN pool during the summer and autumn relative to winter and spring, indicating the influence of bacterioplankton release on nitrogen cycling in the estuaries. Ammonification and nitrification were observed in the estuaries, processes which were reproduced in incubation experiments using bioreactors. The bioreactor experiments showed that 12% h− 1 of the DON flux from the River Plym may be available to bacteria, indicating significant removal of DON during the residence time of the water in the estuary (a few days). The bioavailable nature of the DON means that this N fraction significantly adds to the eutrophication burden of the receiving coastal waters, and therefore cannot be ignored in environmental assessments. 相似文献
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以深圳沿岸海域为研究区,以MODIS/AQUA卫星遥感产品为数据源,结合实测浮标数据修正了VGPM中叶绿素a含量的估算进而分析深圳沿岸海域净初级生产力的时空分布规律.研究表明:(1)深圳沿岸海域2014年2、5、8、10月的净初级生产力在空间分布上从近海向外逐渐降低,初级生产力整体呈现出"西高东低"的局面,且未有明显的季节性波动.(2)4个海区的叶绿素a含量均表现为夏季最高秋冬季次之,但各海区主要影响因素不同,珠江口主要受季风造成的浮游植物种类与细胞密度的季节变化影响,大亚湾主要受营养盐限制,大鹏湾的主导因素为湾内余流的季节变化,深圳湾的叶绿素a含量主要与浮游植物细胞密度的季节变化有关.(3)珠江口的初级生产力春夏季高于秋冬季;大鹏湾的初级生产力夏季最高,且季节变化趋势与叶绿素a表现一致;深圳湾的初级生产力夏季最高,且季节变化趋势与海表温度表现一致;大亚湾的初级生产力波动明显,夏冬季海洋初级生产力数值总体高于春秋季. 相似文献
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Mohammad Mokhtari Ahmad SavariHamid Rezai Preeta KochanianAmir Bitaab 《Estuarine, Coastal and Shelf Science》2008
Fiddler crabs are known as the most conspicuous bioturbating animals in mangrove forest, which by their burrowing activities promote nutrient cycling in ecosystems. Mangroves, crabs and bacteria are connected in the form of positive feedback loop, whereby an increase in the activity of any participant will tend to increase the activity of all others as well. Population structure, growth, mortality, recruitment, biomass and production of fiddler crabs as dominant species of deposit-feeder crabs have been investigated from May 2005 to March 2006 in the Sirik mangrove estuary in the eastern part of Strait of Hormuz. Ten 1 m2 squares of the substrate were randomly sampled during low tide. There was a significant change in organic content in the sampling area during study period. The sex ratio was significantly deviated from 1:1 ratio in large sizes, where males were dominated year around. Fiddler crabs showed seasonal growth pattern during a year, which the maximum growth was observed during autumn and early summer and ceased during winter by low temperature. Growth parameters were estimated by Appeldoorn's method and fitted with seasonalized von Bertalanffy growth models. The Kimura likelihood ratio test revealed significant differences in the overall growth curves between males and females, originated from the differences in k and L∞ between sexes. Males were found to exhibit higher growth rate and larger size than females, this could be attributed to the higher investment of energy for reproduction in females. Reproduction was restricted to spring and early summer, while recruitment occurs at the end of summer. Total annual production of males and females was 37.90 and 10.05 g dry weight/10 m2 respectively and major production took place during early summer. Because of impact of temperature on the activity of fiddler crabs in subtropical regions, density of crabs has significant positive correlation with temperature (P < 0.01), while growth rate shows significant negative correlation with organic matter of sediment (P < 0.05). In conclusion these crabs showed lower mortality and production rate with the seasonal growth and recruitment in comparison with tropical species. 相似文献
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The tissue concentrations and contents of calcium, copper and zinc were determined at different stages in the moult cycle of the shore crab Carcinus maenas. The crabs were dissected into the following tissues: the midgut gland, the gill, the ‘rest tissue’ (the latter defined as the left over tissue, i.e. muscles and exoskeleton), and the haemolymph, and analysed as such. One group of crabs was maintained in clean seawater. In these crabs, calcium was lost from haemolymph during premoult and apparently stored in the midgut gland. At ecdysis approximately 90% of the whole body calcium content was lost with the exuviae while the haemolymph calcium content doubled. During early postmoult calcium stored in the midgut gland was used in combination with calcium absorbed from the surrounding seawater for a rapid calcification of the new exoskeleton. Both the copper and zinc concentrations declined in the ‘rest tissue’ compartment during premoult. At ecdysis the haemolymph copper and zinc contents increased 35 and 86%, respectively, from premoult to the newly moult stage. At the same time, however, the copper and zinc haemolymph concentrations decreased. During postmoult, copper (25%) and zinc (45%) were lost from haemolymph and mainly excreted but a minor fraction (5–10%) was stored in the midgut gland.A second group of crabs was maintained in copper-contaminated seawater (0.1 mgl−1) during ecdysis and postmoult. Following exposure of the animals to raised ambient levels of copper, the calcium and zinc contents of the midgut gland were reduced while the copper contents of the midgut gland and most other tissues were increased in comparison to crabs held in clean seawater. 相似文献
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This study measured aspects of the physiology of juvenile [(<35mm carapace width (CW)] and adult (>60mm CW) Carcinus maenas to test the hypothesis that these different life-history stages exhibit different sensitivities to environmental contamination. Newly-collected juveniles had significantly (P<0.05) lower immunocompetence (phagocytosis and cellular integrity), lower metabolic energy (haemolymph glucose) and increased scope for growth compared with adults. Seven day exposure to a sub-lethal concentration (200microgL(-1)) of pyrene significantly (P<0.01) reduced immunocompetence, elevated basal heart rate and decreased respiration (at rest) for juveniles but had no overall impact on adult crab physiology. Results confirm that physiological differences exist between juvenile and adult shore crabs, and cause juveniles to be more susceptible to the effects of pyrene exposure than adults. Such differences in sensitivity to contamination between life-cycle stages of the same species have to be taken into account during the risk assessment process. 相似文献
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随着全球海平面的上升及极端气象的频发,全球海滩总体呈现出一定的退化现象,海滩保护成为海岸带生态修复的焦点问题之一。我国华南地区岬湾型海滩分布广泛,以深圳市大鹏湾官湖海滩为代表,基于2020—2021年实测海滩剖面高程数据,分析岬湾型海滩季节性变化特征。研究表明,官湖海滩剖面坡度夏秋缓冬春陡,夏秋侵蚀冬春淤积;海滩沉积物粒径季节性变化不明显。海滩剖面形态受风浪、平均潮位的季节性变化控制,以夏秋季为例,平均潮位逐渐升高,南向波浪强度较大,在二者的共同作用下,海滩后滨侵蚀明显,泥沙离岸输运,并在前滨淤积。补沙方案宜在夏秋季进行,且重点区域为官湖海滩东侧与观海湾海滩,防御方案应主要削弱南向波浪。 相似文献
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Ana C. F. Silva Maryam Shapouri Rui Cereja Awantha Dissanayake Catarina Vinagre 《Marine Ecology》2017,38(1)
Crabs are important predators of inter‐tidal ecosystems, controlling the abundance and distribution of their prey populations. Often the same crab species occupies several habitats and, although their effects on prey have been quantified across habitats, crabs’ dietary and morphological responses to differing environmental influences have been overlooked. Here, we used the crabs Eriphia verrucosa and Pachygrapsus marmoratus as model species to examine differences in claw morphometry – size and wear – and diet between rocky shore and heterogeneous sand flat habitats. We predicted that, intra‐specifically, crabs from rocky shores would consume more hard‐shelled prey owing to their high availability and consequently, would display chelipeds with the following claw characteristics: a higher degree of claw damage, stronger musculature (higher propel height) and increased mechanical advantage (defined as the ratio of input lever length to output lever length) than crabs in the heterogeneous sand flat habitats. Sampling was performed in heterogeneous sand flat habitats and rocky shores of the Central Portuguese coast. For each crab species, carapace width, diet composition and several claw morphometric measures were recorded, revealing significant intra‐specific differences (using multivariate analysis) between shore types. We found that E. verrucosa and P. marmoratus consumed more hard prey on rocky shore than on sand flat habitats, which resulted in rocky shore crabs having more accentuated dentition wear and larger musculature than their sand flat habitat counterparts. We suggest that the strong response of crab claw morphometry to environmentally induced diet variations is an important mechanism in the successful adaptation of crab species to inhabit differing habitats. A major implication is that the impact of the same species on prey may vary largely with habitat type as a result of predation efficiency varying with claw condition. 相似文献
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锯缘青蟹秋苗土池越冬的试验研究 总被引：4，自引：0，他引：4
本文报道１９９３和１９９４年秋季作者培育的部分锯缘青蟹仔蟹苗土池越冬试验。结果表明人工培育的青蟹苗在闽南地区的自然条件下,可以在室外土池完全越科,成活率可达６０－８０％,水温是影响青蟹生命活动的主要因素;由于越冬期间青蟹营养积累不足,导致难以顺利地完成越冬后的第一次生长蜕壳,造成大量死亡,这是影响青蟹越冬存活率的主要因素之一;越科后期病死青蟹肝胰组织进行涂片处理,发现６只受检蟹中２只肝胰组织中有日 相似文献
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Peter L. Horn 《新西兰海洋与淡水研究杂志》2013,47(3-4):253-261
Various morphological and physiological features of Sypharochiton pelliserpentis (Quoy & Gaimard, 1835) were examined in relation to the different physico‐chemical characteristics experienced at 4 sites on Kaikoura Peninsula and 2 sites in the Avon‐Heathcote Estuary. Body water content of chitons from high‐shore exposed and estuarine rocky sites was significantly greater (P<0.005) and desiccation rates were significantly less (P<0.05) than those of chitons from low‐shore marine sites and an estuarine mudflat. The percentage of body water loss causing death was greatest for high‐shore marine chitons and least for estuarine chitons. Estuarine chitons had relatively more gill tissue than marine individuals. Body shape appeared to be correlated with intensity of wave action, and narrow animals were found in more wave‐exposed areas. Variations in radula length showed no clear‐cut trends among localities. 相似文献
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The determination of costs and benefits experienced by crustaceans as a result of occupation by their symbionts has received increased attention from marine ecologists. However, the interactions between some important species and their associates remain unclear. We examined the distribution of amphipods in the genus Ischyrocerus on the red king crab Paralithodes camtschaticus, a commercially important species, in two areas of the Barents Sea. Ischyrocerus commensalis was found on 30.5% of crabs in Dalnezelenetskaya Bay (DZB) with the mean number per crab being 55.1, in Dolgaya Bay (DLB) these rates were 28.6% with 19.3 specimens per crab. Sympatric species Ischyrocerus anguipes was found on 13.5% of crabs in DZB with a mean of 7.3 individuals per host, in DLB it had much lower occurrence (1.3% and 1.5 specimens per host). There were no significant differences between proportions of male and female crabs infested by amphipods in both areas examined. Prevalence of amphipods was similar among years examined except for I. commensalis on small crabs (carapace length CL <90 mm) and I. anguipes on large crabs (CL >90 mm) in DZB. We found that I. commensalis and I. anguipes are not egg predators of P. camtschaticus in the Barents Sea, at least in summer. High numbers of I. commensalis occur in crab gills, and both mean intensity of the amphipods and their empty tubes increased with crab size. In the gills, I. commensalis predominated in the section nearest the mouth parts. Possible negative impacts for the hosts due to gills infestation are discussed. In contrast, I. anguipes were predominately found on the carapace and limbs of crabs and appears to be a less specific symbiont of P. camtschaticus. Both amphipod species seem to be commensals, however possible negative impacts for the host could not be excluded. 相似文献
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2009—2011年东海陆架海域网采浮游植物群落的季节变化 总被引：3，自引：0，他引：3
根据2009年7、8月(夏季)、12月到翌年1月(冬季)、2010年11月(秋季)和2011年4、5月(春季)共4个航次在东海陆架区进行的现场多学科综合调查,报道了4个季节在整个东海海域的浮游植物的空间分布及群落结构特征,并探讨了影响其分布格局的环境因子效应。结果表明,东海浮游植物群落主要由硅藻、甲藻组成。共检出浮游植物5门88属299种(含未定种)。调查区夏季细胞丰度达最高,平均为(8 659.572±28 937.27)cell/L,其次是秋、冬季,春季最低,分别为(4 413.726±12 534.573)cell/L、(421.773±647.532)cell/L和(218.479±265.897)cell/L。硅藻细胞丰度在夏、秋、冬3个季节占总平均丰度的95%以上,甲藻细胞丰度在春季最高,占总浮游植物细胞丰度的69%。调查海区浮游植物丰度高值区主要集中在长江口海域,并向外海呈递减趋势。不同群落间存在季节更替和演替现象。物种丰富度自春夏秋冬逐渐升高。香农指数(Shannon-Wiener index)和均匀度指数(Pielou index)分布较为一致,物种丰富度指数(Margalef index)呈现时空分布差异。Pearson相关分析结果表明:不同季节的物种间更迭与海区特定的物理化学参数显著相关。 相似文献
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东海浮游翼足类(Pteropods)数量分布的研究 总被引：10，自引：1，他引：10
根据1997～2000年东海海域23°30'～33°00'N,118°30'～128°00'E的4个季节海洋调查资料,运用定量、定性方法,探讨了东海浮游翼足类总丰度的平面分布、季节变化及变化的动力学机制.结果表明,东海翼足类总丰度和出现频率有明显的季节变化,均为秋季最高,夏季次之,春季最低;总丰度在各个季节基本上呈东海南部高于北部、外海高于近海的分布趋势;春季的尖笔帽螺(Creseis acicula)、夏季的锥笔帽螺(Creseis virgula)、秋季的蝴蝶螺(Desmopterus papilio)和冬季的马蹄螔螺(Limacina trochiformis)是导致总丰度季节变化的最主要的种类;冬、春和夏3个季节丰度变化及4季总丰度的变化同表层或10m层水温有非常显著的线性相关关系,与底层温度及盐度的相关关系不显著.夏季翼足类高丰度区位于台湾暖流与黑潮暖流的分支处;从夏季到秋季,翼足类随着台湾暖流向北扩展,并在与长江冲淡水,闽浙沿岸水团,黄海水团等交汇处形成高丰度(大于500×10-2个/m3)和较高丰度(250×10-2～500×10-2个/m3)分布区.水温和海流是影响东海翼足类总丰度分布的主要环境因素. 相似文献
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南海海面高度季节变化的数值模拟 总被引：8，自引：1，他引：8
比较POM模式模拟与观测(TOPEX/Poseidon高度计资料)的南海海面高度(SSH)的季节变化在空间分布上的一致性和差异.结果表明:本文使用的POM模式能较好地模拟南海SSH的季节变化;冬季与夏季,春季与秋季南海海面异常场形式完全相反,冬季Ekman输运造成在西海岸的堆积要比夏季在东海岸堆积更明显,而吕宋冷涡中心附近和吕宋海峡海面季节变化振幅最大;除春季以外,在南海绝大部分海域,海面高度的季节变化主要受风力的控制,南海海面热量通量对SSH的季节变化贡献约为20%,风应力对SSH的季节变化的贡献约为80%. 相似文献
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为了揭示长江口外海域海流的特征及其季节和垂向变化规律,于2006年8月1日-2007年7月31日在长江口外海域（平均水深约46.0m）利用大型浮标进行了1年的分层海流流速流向观测。结果表明：（1）该海域海流为顺时针方向的旋转流,在垂向上流向较一致,季节变化不显著。（2）长江口外海域水平流速总体较大,夏季表层最大流速为128.5cm/s,冬季最大表层流速为105.5cm/s;垂线平均流速相近（差异<8.0 cm/s）,夏季流速最大为47.0cm/s,冬季为40.8cm/s。小潮的平均流速为26.5cm/s,大潮平均流速为小潮的2倍。（3）剖面各层流速垂向差异明显,最大流速出现在表层（春季和冬季）或次表层（夏季和秋季）,最小流速均出现在底层;各层的最大平均流速为57.9cm/s,出现在夏季的18m层。（4）垂线平均余流为7.5~11.3 cm/s,春季最强冬季最弱;春季和冬季各层余流均为东向,夏季和秋季基本为东北向或北向。（5）观测海域海流受长江冲淡水、台湾暖流、季风、潮汐等动力作用的共同制约。 相似文献