Amphipod-supported food web: Themisto gaudichaudii, a key food resource for fishes in the southern Patagonian Shelf     

Luciano N. Padovani  María Delia Viñas  Felisa SánchezHermes Mianzan 《Journal of Sea Research》2012,67(1):85-90

The trophic role of the hyperiid amphipod Themisto gaudichaudii in the southern Patagonian shelf food web was assessed from the analysis of stomach contents of the local fish assemblage. A total of 461 trawl samples were collected during seven seasonal cruises. A total of 17 out of 38 fish species were found to ingest T. gaudichaudii. This amphipod was a main prey item in five of these species, showing high values of alimentary index: Seriolella porosa (99.9%), Macruronus magellanicus (68.8%), Micromesistius australis (59.1%), Patagonotothen ramsayi (48.6%), and Merluccius hubbsi (10.9%). The contribution of T. gaudichaudii, in weight, to their summer diet was 60%, on average. This contribution was minimal in winter and maximal in summer. Fisheries studies have indicated that these five species, mainly M. magellanicus, account for almost 85% of the fish biomass in the area. Although the remaining 15% did not feed heavily on T. gaudichaudii, they are known to prey on the main hyperiid predators. Our study shows that T. gaudichaudii contributes greatly, both directly and indirectly, to supporting the fish community. We thus proposed that T. gaudichaudii plays a key role as a “wasp-waist” species in the sub-Antarctic region, similar to that of krill in Antarctic waters, channeling the energy flow and enabling a short and efficient food chain.  相似文献   

Polycyclic Aromatic Hydrocarbons in the Food Web of Coastal Wetlands: Distribution,Sources and Potential Toxicity          下载免费PDF全文

Yu Zhang  Baoshan Cui  Qijun Zhang  Xinhui Liu 《洁净——土壤、空气、水》2015,43(6):881-891

  相似文献   

Identification of coastal water quality by statistical analysis methods in Daya Bay, South China Sea   总被引：3，自引：0，他引：3  

Mei-Lin Wu  You-Shao Wang  Cui-Ci Sun  Haili Wang  Jian-Ping Yin 《Marine pollution bulletin》2010,60(6):852-5195

In this paper, cluster analysis (CA), principal component analysis (PCA) and the fuzzy logic approach were employed to evaluate the trophic status of water quality for 12 monitoring stations in Daya Bay in 2003. CA grouped the four seasons into four groups (winter, spring, summer and autumn) and the sampling sites into two groups (cluster DA: S1, S2, S4-S7, S9 and S12 and cluster DB: S3, S8, S10 and S11). PCA identified the temporal and spatial characteristics of trophic status in Daya Bay. Cluster DB, with higher concentrations of TP and DIN, is located in the western and northern parts of Daya Bay. Cluster DA, with the low Secchi, is located in the southern and eastern parts of Daya Bay. The fuzzy logic approach revealed more information about the temporal and spatial patterns of the trophic status of water quality. Chlorophyll a, TP and Secchi may be major factors for deteriorating water quality.  相似文献   

Fatty acid profiles of benthic environment associated with artificial reefs in subtropical Hong Kong     

Siu Gin Cheung  Paul K.S. Shin 《Marine pollution bulletin》2010,60(2):303-308

Artificial reefs can enhance habitat heterogeneity, especially in seabed degraded by bottom-dredging and trawling. However, the trophodynamics of such reef systems are not well understood. This study provided baseline data on trophic relationships in the benthic environment associated with artificial reefs in late spring and mid summer of subtropical Hong Kong, using fatty acid profiles as an indicator. Data from sediments collected at the reef base, materials from sediment traps deployed on top and bottom of the reefs, total particulate matter from the water column and oyster tissues from reef surface were subjected to principal component analysis. Results showed variations of fatty acid profiles in the total particulate matter, upper sediment trap and oyster tissue samples collected in the two samplings, indicating seasonal, trophodynamic changes within the reef system. The wastes produced by fish aggregating at the reefs can also contribute a source of biodeposits to the nearby benthic environment.  相似文献   

Assessment of the ecological status of transitional waters in Sicily (Italy): First characterisation and classification according to a multiparametric approach     

Gabriella Caruso  M. Leonardi  F. Decembrini  E. Crisafi  A. Bergamasco 《Marine pollution bulletin》2010,60(10):1682-1690

A 1-year cycle of observations was performed in four Sicilian transitional water systems (Oliveri-Tindari, Cape Peloro, Vendicari and Marsala) to characterise their ecological status. A panel of variables among which trophic and microbial (enzyme activities, abundance of hetetrophic bacteria and of bacterial pollution indicators) parameters, were selected. Particulate organic carbon (POC) and nitrogen (PON) and chlorophyll-a (Chl-a) contents defined the trophic state, while microbial hydrolysis rates and abundance gave insights on microbial community efficiency in organic matter transformation and on allochthonous inputs. To classify the trophic state of examined waters, the synthetic trophic state index (TRIX) was calculated.Microbial hydrolysis rates correlated positively with POC and Chl-a, which increased along the eutrophication gradient. The significant relationships among TRIX, trophic and microbial parameters suggested the use of leucine aminopeptidase, alkaline phosphatase and POC as suitable parameters to implement the Water Framework Directive when assessing the ecological status of transitional water systems.  相似文献   

The relative importance of physicochemical factors and crustacean zooplankton as determinants of rotifer density and species distribution in lakes adjacent to the Yangtze River, China   总被引：2，自引：0，他引：2  

Songbo Wang  Ping Xie  Hong Geng 《Limnologica》2010,40(1):1-7

The planktonic community of freshwater Rotifera in 27 subtropical lakes was studied to assess the relative importance of physicochemical factors and crustacean zooplankton as determinants of rotifer density and species distribution. Factor analysis and multiple linear regressions showed that 21.9% and 29.9% of the variance in rotifer density was explained by physicochemical factors and crustaceans, respectively. Larger rotifer density was possible in shallower lakes with higher concentration of inorganic nitrogen and less herbivorous crustaceans such as Sinocalanus dorrii and Daphnia. Redundancy analysis showed that the variances of rotifer species distribution explained by crustaceans and physicochemical factors were 26.9% and 31.0%, respectively. Further analysis demonstrated that the variances explained by pure crustaceans and pure physicochemical factors were 12.5% and 16.6%, respectively. However, these two percentages were not statistically different. Rotifer species distribution was strongly associated with Chl a and Moina micrura. Their coexistence with crustaceans seemed to be determined by their defense against potential predators and competitors.  相似文献   

2010年中国非开挖行业调查     

颜纯文 《岩土钻凿工程》2011,(2):1-3,10

本文分析了中国地质学会非开挖技术专业委员会对2010年我国非开挖行业的调查和统计,主要是水平定向钻机的销售情况和非开挖管道修复与更换方法在管道工程施工中的应用情况,最后总结了2010年我国非开挖行业发展的几个特点。  相似文献   

存储过程在天气预警短信监控系统中的应用   总被引：1，自引：0，他引：1       下载免费PDF全文

潘静  卢娟  张凯 《气象与环境学报》2008,24(1):48-51

为保障天气预警短信接收覆盖面,对预警短信用户短信状态报告的接收情况进行监控,应用存储过程方法设计了状态报告查询模块,实现了预警短信监控系统中短信状态报告的查询、解析功能。利用存储过程设计的查询模块可有效地降低网络负载,平均查询速度提高30%,并能够调取不同的数据结果为后续预警短信操作提供依据。  相似文献   

Sampling strategies to evaluate the status of offshore soft sediment assemblages     

Rogers SI  Somerfield PJ  Schratzberger M  Warwick R  Maxwell TA  Ellis JR 《Marine pollution bulletin》2008,56(5):880-894

  相似文献   

Difference of mercury bioaccumulation in red mullets from the north-western Mediterranean and Black seas   总被引：1，自引：0，他引：1  

M. Harmelin-Vivien  D. Cossa  D. B?naru  C. Mellon-Duval 《Marine pollution bulletin》2009,58(5):679-321

The relationships between total mercury (Hg) concentration and stable nitrogen isotope ratio (δ¹⁵N) were evaluated in Mullus barbatus barbatus and M. surmuletus from the Mediterranean Sea and M. barbatus ponticus from the Black Sea. Mercury concentration in fish muscle was six times higher in the two Mediterranean species than in the Black Sea one for similar sized animals. A positive correlation between Hg concentration and δ¹⁵N occurred in all species. Increase in Hg concentration with δ¹⁵N was high and similar in the two Mediterranean fishes and much lower in the Black Sea species. Since this was neither related to trophic level difference between species nor to methylmercury (MeHg) concentration differences between the north-western Mediterranean and the Black Sea waters, we suggested that the higher primary production of the Black Sea induced a dilution of MeHg concentration at the base of the food webs.  相似文献