Trace Metals in Selected Benthic Invertebrates from Belgian Coastal Waters (1981–1996)     

M Guns  P Van Hoeyweghen  W Vyncke  H Hillewaert 《Marine pollution bulletin》1999,38(12):746-1193

Mercury, cadmium, lead, copper, zinc and chromium were assessed in brown shrimp (Crangon crangon), swimming crab (Liocarcinus holsatus), hermit crab (Pagurus bernhardus), starfish (Asterias rubens) and cut trough shell (Spisula subtruncata) from ten sampling stations off the Belgian coast, including three dredge spoils disposal sites. Calculations of time trends indicated that on the whole concentrations of trace metals had significantly decreased since 1981, also on dredged material dumping sites. Starfish and hermit crab were found to be the most promising benthic indicator species for metal contamination. Globally, the location of the sites, including the dredge spoils disposal zones, showed to be of little influence on the concentrations of trace metals.  相似文献   

浙江省近岸海域底栖生物生态研究   总被引：5，自引：1，他引：5  

胡颢琰  唐静亮  李秋里  黄备  陈逸华  毛宏跃  张立 《海洋学研究》2006,24(3):76-89

对2003年4~5月在浙江省近岸海域底栖生物调查中获得的126种底栖生物的种类组成、生物量及栖息密度的分布和群落结构进行了叙述和讨论。结果表明:底栖生物种类组成以甲壳动物及软体动物占优势,两者占生物总种数的51.6%;浙江近岸海域底栖生物总平均生物量为18.74 g/m2;总平均栖息密度为89.1个/m2。按生态特征划分,调查海域的底栖生物可分成7个群落。分析调查海域各测站群落结构指数可以看出,浙江近岸海域70%测站呈现出生物多样性指数低及种类分布不均匀等特点。  相似文献   

Increased benthic grazing: An alternative explanation for low phytoplankton biomass in northern San Francisco Bay during the 1976–1977 drought     

Frederic H. Nichols 《Estuarine, Coastal and Shelf Science》1985,21(3):379-388

Among the consequences of extremely low river flow into northern San Francisco Bay during a two-year drought were (1) a gradual increase in salinity, (2) an unusual decline in chlorophyll a concentration, and (3) the upstream migration of estuarine benthic invertebrates to the normally brackish area of the bay. Total abundance in the benthos at a shallow monitoring site increased from a normal 2000 to greater than 20 000 individuals m^?2 during the summer of 1977, presumably in response to the increased salinity. Estimated filtration rates derived from equations in the literature for one of the species, the suspended-feeding bivalve Mya arenaria ranged from 1 to 4 m³ m^?2 day^?1 during 1977 depending on abundance and mean size on sampling dates. Because water depth at this site is less than 2 m, Mya could have filtered all of the particles (including diatoms) from the water column on the order of once per day. Several other immigrant species undoubtedly contributed to the removal of particles from the near-bottom water as well. Increased benthic grazing, therefore, could have accounted for the anomalously low phytoplankton biomass observed during the drought. These results suggest that during periods of prolonged low river flow and increased salinity benthic food webs could become more important than planktonic food webs in the upper part of the estuary.  相似文献   

Mayfly communities in a prealpine stream system of Switzerland     

Daniel Hefti  Ivan Tomka 《Aquatic Sciences - Research Across Boundaries》1991,53(1):20-38

The mayfly fauna of twelve localities belonging to a calcareous stream system of the Swiss Prealps was investigated during the last three years. The stream system was divided into three distinct topographical sections, each characterized by specific thermic and geomorphologic components. Thirty-five mayfly species, that belonged to different faunistic groups according to their respective longitudinal distribution, were found. A coefficient of interspecific association was determined for every pair of species. Non-parametric indices of diversity, as well as a parametric analysis, were calculated for the three stations investigated quantitatively. The faunistic classification of the twelve stations reflected the main topographical organization of the stream system.  相似文献   

Episodic Events: Their Relevance to Ecology and Evolution     

Ferdinando  Boero 《Marine Ecology》1996,17(1-3):237-250

Abstract. An episodic event can be one of the many "episodes" forming a normal flow of related events. But it can also be an "incident" interrupting a trend and initiating a new one. Appreciation of contrasting meanings of apparently identical categories of phenomena is familiar to evolutionary biologists who, for instance, envisage evolution as the result of both gradual and punctuated events. Seasonal plankton blooms (both normal and noxious), species outbreaks, mass mortalities, and human predation are taken as examples of "episodes" that can influence and/or modify what we perceive as "normality". Recruitment is another example of an episodic event heavily conditioning both community structure and function, as recently highlighted by the so-called supply-side ecology. The reductionistic study of ecology. more linked to thermodynamics than to history, allowed the formulation of general ecological laws which, however, stem from the laws of thermodynamics. The totalizing value of such laws blurs appreciation of heterogeneity and change, so that many ecologists tend to be rather conservative, using a concept like "conservation" as an absolute paradigm to follow and to consider "change" as an a priori negative phenomenon. Episodes can have a "conservative" or "innovative" meaning, and are the driving force of the history of life. Their importance is recognized mainly when dealing with the history of organisms (evolutionary biology), whereas the assemblages of organisms ( i.e ., communities) are too often described and interpreted in an ahistorical context or in a too narrow time frame. Recognition of the importance of history in ecology (evolutionary ecology) can lead to a better understanding of environmental dynamics, albeit restricting the supposed predictive strength of ecology, a science timely integrating the reductionistic-thermodynamic approach with the holistic-historical one.  相似文献   

Variability and stability in benthos: twenty-two years of monitoring off Northumberland     

Frid  C. L. J.; Buchanan  J. B.; Garwood  P. R. 《ICES Journal of Marine Science》1996,53(6):978-980

  相似文献   

Effects on benthic scavengers of discards and damaged benthos produced by the beam-trawl fishery in the southern North Sea   总被引：2，自引：2，他引：2  

Groenewold  Stefan; Fonds  Mark 《ICES Journal of Marine Science》2000,57(5):1395-1406

  相似文献   

Long-term changes in the benthic communities on North Sea fishing grounds   总被引：1，自引：2，他引：1  

Frid  C. L. J; Harwood  K. G.; Hall  S. J.; Hall  J. A. 《ICES Journal of Marine Science》2000,57(5):1303-1309

  相似文献   

Spatial and temporal trends in the benthos and sediments in relation to sewage sludge disposal off the northeast coast of England     

Rees  H. L.; Rowlatt  S. M.; Lambert  M. A.; Lees  R. G.; Limpenny  D. S. 《ICES Journal of Marine Science》1992,49(1):55-64

  相似文献   

Paleoecological Relations of Foraminifera in a Desert-Enclosed Sea -The Gulf of Aqaba (Elat), Red Sea     

E. Halicz  Z. Reiss 《Marine Ecology》1981,2(1):15-34

Abstract. Planktonic and benthonic foraminifera live in the desert-enclosed, hypersaline and oligotrophic Gulf of Aqaba and northernmost Red Sea near the edge of their ecological tolerance. Marked changes in foraminiferal abundance patterns in the past, resulting from hydrological shifts related to global climatic fluctuations, facilitate a high-resolution ecostratigraphic subdivision of deep-sea records covering the last 150,000 years. Of particular significance are the foraminiferal plankton/benthos ratios, the presence/absence pattern of such species as Globigerinoides sacculifer , as well as the frequency variation of Globigerina bulloules-falconensis, Buliminacea, Miiiolacea and various "rotaliform" species. Paleoceanographic interpretation of the shifts in assemblage composition and of stable oxygen isotope data obtained on planktonic foraminifera and pteropods indicates that during glacial intervals - because of global cooling, lowered sea-level and reduced water exchange at the straits of Bab-el-Mandeb - the temperature of the upper waters fell by about 4–6 ^oC (to 15–17 ^oC), salinity rose by about 10%o to more than 50%₀ while residence time of the water became longer and the input/output ratio of nutrients became higher. As a consequence, fertility of the photic zone was higher, the organic content of the sediments increased and oxygen levels in the deep basin became reduced. Thus, sea level-oscillations and strait-dynamics played a major role in the foraminiferal paleoecology of the Red Sea.  相似文献