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21.
Samples collected in the Irminger Basin during the Marine Productivity Programme (2001–2004) were used to study Calanus finmarchicus vertical distribution and histological changes of its mid-gut epithelium in relation to overwintering strategy. Previous
studies have shown that cell composition of the glandular part of the mid-gut, size and abundance of B cells responsible for
digestive enzyme secretion and thickness of the epithelium could be good indicators of individual physiological state. We
used C. finmarchicus abundance, vertical distribution, lipid sac volume and mid-gut epithelium histological composition of individuals collected
in contrasting hydrographic areas of the Irminger Basin and sampled at different seasons to understand C. finmarchicus life cycle in the Irminger Basin. Lipid sac volumes were significantly different between the seasons but neither between
the hydographic areas nor the various depths of the water column. B cells concentrations and thickness of the epithelium have
allowed us to distinguish a non-diapausing surface population (350 m) in the East Greenland Current while individuals at depth
(1,250 m) were overwintering. This result is correlated by a bimodal vertical distribution of the CV in this biozone. In the
other hydrographic areas, all CV were dormant, although surface individuals were not analysed in the Southern Irminger Current. 相似文献
22.
M. J. Briand Y. Letourneur X. Bonnet E. Wafo T. Fauvel F. Brischoux G. Guillou P. Bustamante 《Environmental science and pollution research international》2014,21(6):4576-4591
New Caledonia is one of the main hot spots of biodiversity on the planet. Large amounts of contaminants are discharged into the lagoon as a result of increasing anthropogenic activities such as intense mining, urbanization, and industrialization. Concentrations of 14 trace elements and 26 persistent organic pollutants (POPs: PCBs and pesticides) were measured in the muscles of two anguilliform fish species, over a coast to barrier reef gradient in two lagoon areas differently exposed to anthropic disturbances. This study emphasizes the high trace element contamination status of anguilliform fish and also highlights slight but perceptible organic pollution. The contamination extends throughout the lagoon, from coast to barrier reef, even in areas remote from emission points. High levels of trace elements, especially those linked to mining activities (i.e., Co, Cr, Fe, Mn, and Ni), were detected in coastal sites. Furthermore, the large dispersion of most POPs throughout the entire lagoon poses the question of their potential toxicity on marine organisms from numerous habitats. Our results underline the need for long-term monitoring of various contaminants over large spatial and time scales. 相似文献
23.
S. Grellier J. L. Janeau W. Thothong A. Boonsaner M. P. Bonnet C. Lagane P. Seyler 《Environmental monitoring and assessment》2013,185(7):5523-5536
Trace metal elements (TME) can be real threats for living organisms. However, few studies dealt with TME in reservoirs in rural areas where farming practises could induce negative effects. Mae Thang reservoir (northern Thailand) has been studied for 3 years to understand the seasonal behaviour of dissolved TME: Fe, Mn, Cd, Al, Pb, V, Cr, Co, Ni, Cu, Zn, Mo, U and As and associated physicochemical parameters. In situ measurements of these parameters were done during the dry and the wet seasons as well as water samples along the water column for further analyses and TME determination by inductively coupled plasma-mass spectrometry (ICP-MS). In the dry season, the water column was characterized by a strong stratification and anoxic conditions in the hypolimnion. High rain and water input from the watershed during the wet season induced mixing of the water. All TME, except Ni, Co and Cr were less concentrated in the wet season indicating a dilution effect by water input. There was thus no important dissolved pollution coming from the watershed. The anoxic conditions in the dry season enhanced the reduction of Fe and Mn and the desorption processes. Depth, and thus oxic–anoxic conditions were the main drivers of TME in the dry season, while in the wet season, dissolution processes from parent rocks of watershed were favoured. The average concentrations of TME in the reservoir were in the limit of the international and Thai standards. Only localized values in the bottom of the reservoir for Fe and Mn were higher than the limits. 相似文献
24.
A procedure based on a biological treatment of whey was tested as part of research on waste treatment at the scale of small cheesemaking units. We studied the potential biodegradation of whey by a protozoan ciliate, Tetrahymena pyriformis, and evaluated the functional, microbiological and physiological disturbances caused by crude whey and the biodegraded whey in laboratory-scale pilots mimicking a natural lagoon treatment. The results show that T. pyriformis can strongly reduce the pollutant load of whey. In the lagoon pilots serving as example of receptor media, crude whey gradually but completely arrested operation, whereas with the biodegraded whey adverse effects were only temporary, and normal operation versus a control was gradually recovered in a few days. 相似文献
25.
Jean-Pierre Bigot Abdellah Touil Patrick Bonnet Jean-Marc Lacme 《Journal of Loss Prevention in the Process Industries》2005,18(4-6):433-442
Droplet size distribution inside water flashing jets and corresponding rain-out fraction were measured. Mass distribution showed that a few droplets are ‘large’ (d>150 μm) and count for more than 85% of the liquid mass in the jet because of their large individual mass. This could be due to incomplete thermal fragmentation. It could explain the rain-out falling near the orifice or pipe exit. 相似文献
26.
Despite intensive sampling efforts in coral reefs, densities and species richness of anguilliform fishes (eels) are difficult
to quantify because these fishes evade classical sampling methods such as underwater visual census and rotenone poisoning.
An alternative method revealed that in New Caledonia, eels are far more abundant and diverse than previously suspected. We
analysed the stomach contents of two species of sea snakes that feed on eels (Laticauda laticaudata and L. saintgironsi). This technique is feasible because the snakes return to land to digest their prey, and (since they swallow their prey whole)
undigested food items are identifiable. The snakes’ diet consisted almost entirely (99.6%) of eels and included 14 species
previously unrecorded from the area. Very large populations of snakes occur in the study area (e.g. at least 1,500 individuals
on a small coral islet). The snakes capture approximately 36,000 eels (972 kg) per year, suggesting that eels and snakes play
key roles in the functioning of this reef ecosystem. 相似文献