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1.
Aquatic fungi growing on dead fragments of submerged plants   总被引：1，自引：0，他引：1  
The authors investigated the dead fragments of 22 species of submerged plants in the water from three limnological and trophical different water bodies (spring, river and pond). A total of 184 species of aquatic fungi, including 119 zoosporic and 65 conidial species were found on the fragments investigated plants. The most common fungus species were Aphanomyces laevis, Saprolegnia litoralis, Pythium rostratum (zoosporic fungi) and Acrodictys elaeidicola, Anguillospora longissima, Angulospora aquatica, Lemonniera aquatica, Mirandina corticola, Tetracladium marchalianum, Tetracladium maxiliformis, Trinacrium subtile (conidial fungi).

Most fungus species were observed on the specimens of Elodea canadensis (33 fungus species), Hippuris vulgaris f. submersa (33), Myriophyllum spicatum (34) and Potamogeton crispus (33), fewest on Ceratophyllum demersum (24), Fontinalis dalicarlica and Potamogeton nitens (each 25).

The most fungi were growing in the water from River Supraśl (107), the fewest in the water from Pond Dojlidy (99). Some aquatic fungus species were observed in the water of only one of the three water bodies – in Pond Dojlidy (30), in Spring Jaroszówka (32) and in the River Supraśl (39) species. Seventy-five species growing only on fragments of single submerged plants. A number of zoosporic and conidial species (22 and four, respectively) appeared new to Polish waters. Out of these 119 zoosporic species, some are known as parasites or necrotrophs of fish.  相似文献   


2.
This study investigated the subcellular distribution of Cu, Zn, Cd and Ag in liver of mallard (Anas platyrhynchos), spot-billed duck (A. poecilorhyncha) and great cormorant (Phalacrocorax carbo) to better understand metal fractionation and dynamics in avian liver. Most of the total Cu, Zn, Cd and Ag were present in hepatocytosol, and their concentrations increased with total hepatic levels in all the three avian species. Copper, Zn and Cd in hepatocytosol were present mostly in metallothionein fractions (MTs), and Cu and Cd contents in this fraction were positively correlated with hepatocytosol levels in all the species. Silver was observed mostly in both high-molecular weight and MT fractions in hepatocytosol in mallard and great cormorant, whereas it was present in both low-molecular weight and MT fractions in spot-billed duck, suggesting that distribution of Ag in the hepatocytosol was species-specific. The elution profile of metals in MT fractions revealed six metallic peaks in mallard and spot-billed duck, and three peaks in great cormorant, implying the presence of multiple MT isoforms in the liver of these avian species. The present study demonstrated that MTs are closely associated with metal regulation, especially Cu and Cd, in these three aquatic birds.  相似文献   

3.
The authors investigated aquatic fungi growing on the carapaces of 29 species of dead crustaceans (13 species of Copepoda, 13 species of Cladocera and 3 species of Ostracoda) in the water from six limnological and trophical different water bodies (two springs, one river, one lake and two ponds). All of these waterbodies are strongly loaded. 146 species of aquatic fungi were found on the carapaces: 40 Chytridiomycetes, 1 Hyphochytriomycete and 105 Oomycetes. The most common fungus species were Karlingia chitinophila, Myzocytium microsporum, Myzocytium zoophthorum, Pythium acanthicum, Pythium butleri and Pythium myriotylum. Most zoosporic fungus species were observed on the specimens of Daphnia pulex (50 fungus species), Daphnia magna (48) and Cyclocypris laevis (44), fewest on Cyclops fuscus and Cyclops vicinus (each 10).The most fungi were growing in the water from River Supraśl (86), the fewest in the water from Pond Fosa (53). Cluster analysis of the investigated parameters carried out in water bodies during the experiment on zoosporic fungus species has revealed that in the water from springs and Pond Fosa the number of fungus species is closely associated with the concentration of sulphates, in water from River Supraśl and Lake Komosa with calcium and in the water from Pond Dojlidy with chlorides. Out of these 146 species, 21 are known as parasites or necrotrophs of fish. Some dead specimens of crustacean species are a new substrate for some fungus species.  相似文献   

4.
This study was aimed at determining multielemental concentration and its intracellular distribution in selected tissues of cormorant and waterfowl species. Non-essential elements such as Hg, Tl, Cd, Pb and V in tissues were generally consistent with those in ingested items, indicating the significance of food sources of non-essential metal accumulation in great cormorants and mallards. Great cormorants and four waterfowl species examined reflected natural background levels of toxic metals such as Cd, Hg and Pb as well as some essential elements, indicating no specific metal exposure from local sources. Most of Cu, Zn, Se, Rb, Ag, Cd, Cs, and Hg contents were present in the hepatocytosolic fraction, whereas a large percentage of V and Mo were present in insoluble fraction in great cormorant, mallard, and spot-billed duck. The major role of these subcelluar fractions in elemental regulation accounts for the high percentage contribution of each cellular fraction to the total metal contents. Cadmium and Cu are chiefly sequestered through binding to metallothioneins (MTs) of hepatocytosolic fraction in these three avian species. Both MTs and high-molecular-weight substance (HMWS) for Zn and low-molecular-weight substance (LMWS) for Rb were also involved in their sequestration in cytosolic fractions. Relatively different species-specific cytosolic substances were responsible for varying degrees of Ag, Mn, and Co accumulation. It is worth noting that these intracellular metal levels in birds are closely regulated by metal-associated cellular constituents. Therefore, risk assessment studies of metal accumulation in such wild birds should take intracellular metal distribution and specific cellular constituents into account.  相似文献   

5.
Seasonal Occurrence of Species of Saprolegniales and Leptomitales in Lake Aue and the River Fulda in Kassel (Hesse) with Special Consideration of Fish Pathogenic Species In this study, we examined the occurrence of species of aquatic Oomycetes of Saprolegniales und Leptomitales in Lake Aue and the river Fulda in Kassel (Hesse, Germany) with special consideration of fish pathogenic species. We monthly collected water samples of both water bodies from July 2003 to June 2004. The baiting method was used to gain an insight into the specific seasonal occurrence of aquatic Oomycetes. Some species show a seasonal periodicity. Nine of 11 species of Saprolegniales isolated from the two water bodies, and Leptomitus lacteus (Roth) C. Agardh, one of the two species of Leptomitales, were already documented on fish according to references. Additionally, 7 of 10 species could according to references already be detected on fish species present in the two water bodies. Simultaneous measurements of limnological‐chemical parameters were done during the sampling of water for the isolation of aquatic Oomycetes. The results of some measurements, concerning the river Fulda, were additionally compared with the predetermined guideline values and limit values of water bodies of fish of the “Cyprinid region”.  相似文献   

6.
Studies on the biodiversity and population dynamics of freshwater planktonic Gastrotricha have been carried out in conjunction with a physical–chemical analysis of the water in the Yaounde Municipal Lake (Cameroon, Central Africa) over a 14 months period (November 1996–December 1997). The results obtained allow to consider the Yaounde Municipal Lake as an eutrophic lake. It harbours eight species of Gastrotricha belonging to four genera (Chaetonotus, Dasydytes, Neogossea and Polymerurus) of the order Chaetonotida. This community was characterized by high abundances of populations, and was dominated by the genus Neogossea and Chaetonotusreaching up to 2000 ind. L−1. Polymerurus was mostly abundant at the almost anoxic bottom layers. The highest abundances were found mostly during the rainy season, when there is an important sedimentation process of organic matter, and were influenced by several different environmental factors such as dissolved oxygen, temperature and pH of the water.

Finally this community which may play an important role in the water bodies, is a potential water quality indicator.  相似文献   


7.
In this paper, the distribution of Cladocera species in the different sampling sites: the main channel/old river bed, parapotamal type side arms and plesiopotamal side arms, is described. The structure of cladoceran assemblages in the by-passed Danube section and in the adjacent floodplain water bodies has changed since the Gabčíkovo hydropower plant was put into operation. Great changes have been observed in the previous parapotamal side arm situated between river km 1840 and 1820, artificially fed with water from the head-race canal. The dominance of tychoplanktonic (benthic and phytophilous) species has increased, while the typical euplanktonic species have disappeared. Three characteristic groups of cladoceran assemblages were recorded when a different type of habitat was taken into consideration. Euplanktonic cladocerans prevailed on all sampling sites before damming. In periods after damming, littoral species, and later also a euplanktonic forms, dominated on the main channel sampling sites. In parapotamal and plesiopotamal side arms with rich littoral macrovegetation during periods after damming, phytophilous cladoceran species were the ones with the highest occurrence. The samplings from the first time period were rather homogenous. The samplings from the second and third period were more similar when considering the sample site than regarding the time period. In total, 64 cladoceran species were recorded in the course of 13 years (from 1991 to 2004). The increase in number of Cladocera species from 1991 to 2004 was significant. Chydorus sphaericus was found to be the most widely distributed species in the study area. The finding of Disparalona hamata is the first faunistic record from the central part of the Danubian watersheds.  相似文献   

8.
Sediment and biota samples were collected from Msimbazi and Kizinga rivers and from the coastal marine environment of Dar es Salaam during both dry and wet seasons. The samples were analyzed for various organochlorine pesticide residues using GC-ECD and GC-MS. Dieldrin, p,p′-DDT, p,p′-DDE, p,p′-DDD, o,p′-DDT and γ-HCH were detected at significantly greater concentrations above the method detection limits. Recoveries of pesticide residues ranged 86.5–120% in sediments and 62–102% in biota. The average concentrations of total DDT in sediments for the two seasons were almost the same. Biota samples showed significant difference in levels of residues depending on mode of feeding and age of analyzed biota. p,p′-DDT to total DDT ratios in all matrices indicated recent use of DDT. The levels of residues in sediments suggest possible adverse effects to humans consuming biota that are directly exposed to the sediments. This effect, which is associated with bio-concentration of residues in the tissues of edible aquatic biota, should not affect wildlife. In spite of concern on the adverse effect to humans posed by pesticide residues in sediments, edible biota from the examined water bodies were found to be safe for human consumption.  相似文献   

9.
Four seal species (Phoca caspica, Phoca sibirica, Phoca hispida and Phoca largha) and one whale (Orcinus orca) from Russia and Japan were examined to determine the body distribution, bioaccumulation and contamination status of tris(4-chlorophenyl) methane (TCPMe) and tris(4-chlorophenyl) methanol (TCPMOH). Lipid normalized concentrations of TCPMe and TCPMOH were comparable in various organs and tissues, implying that their body distribution is followed to the lipid-dependent accumulation, similar to that for other organochlorines. The highest body burden of these compounds was found in the blubber. Bioaccumulation potential of TCPMe and TCPMOH was high and comparable to PCBs and DDTs. Relatively higher concentrations of TCPMe and TCPMOH were observed in Caspian seal than in other seal species examined. TCPMOH concentration in killer whale was the highest of the marine mammals examined. Another peak detected had similar mass spectrum to TCPMOH, however, at a different retention time, suggesting the presence of an isomer of TCPMOH.  相似文献   

10.
A field study evaluated Spartina alterniflora sensitivity to oiling and to in situ burning of applied crude oil. Experimental plots (2.4 m × 2.4 m × 0.6 m) were constructed in the salt marsh for control, oiling (natural clean-up) and oiling/burning treatments. South Louisiana Crude was applied to oiling and oiling/burning treatment plots at 2 l m−2 and the burn conducted. S. alterniflora responses (height, live stem density, carbon fixation and biomass) were measured for 50 weeks after the August burn. Oiling and oiling/burning had short-term detrimental effects on the salt marsh. One year after the late summer burn, S. alterniflora responses measured in the oiled and oiled/burned plots were not significantly different compared to control values. Results suggest that, under our experimental conditions, intervention may not be required for marsh recovery. However, if spill conditions require a rapid response to control contaminant spread or protect other sensitive resources, burning may be a clean-up operation to consider.  相似文献   

11.
Image analysis of historical aerial photographs was used to examine the effects of the Amoco Cadiz oil spill and resulting clean-up on marsh ecology. Two heavily oiled marsh systems were compared. The marsh which received no clean-up recovered to its prior condition. The marshes in the system cleaned by sediment removal were extensively altered as a result of changes in intertidal height of the sediment surface.  相似文献   

12.
The barge Florida spilled No. 2 fuel oil into Buzzards Bay, Massachusetts on 29 September 1969. Sediments from five of the original stations were sampled in August 1989 and analysed for fuel oil hydrocarbons. Two subtidal and one intertidal marsh station showed no evidence of fuel oil. One subtidal mud core had traces of biodegraded fuel oil at 10–15 cm. One marsh core contained 10−6 g g−1 dry wt of weathered and biodegraded fuel oil aromatic hydrocarbons and cycloalkanes at 5–10 cm with lesser concentrations at 0–5 and 10–15 cm. Although present in trace concentrations, these hydrocarbons appear to be slightly inducing cytochrome P4501A in marsh fish (Fundulus heteroclitus).  相似文献   

13.
The water level of marsh wetlands is a dominant force controlling the wetland ecosystem function, especially for aquatic habitat. For different species, water level requirements vary in time and space, and therefore ensuring suitable water levels in different periods is crucial for the maintenance of biodiversity in marsh wetlands. Based on hydrodynamic modelling and habitat suitability assessment, we determined suitable dynamic water levels considering aquatic habitat service at different periods in marsh wetlands. The two-dimensional hydrodynamic model was used to simulate the temporal and spatial variation of water level. The habitat suitability for target species at various water levels was evaluated to obtain the fitting curves between Weighted Usable Area (WUA) and water levels. And then suitable water levels throughout the year were proposed according to the fitting curves. Using the Zhalong Wetland (located in northeastern China) as a case study, we confirmed that the proposed MIKE 21 model can successfully be used to simulate the water level process in the wetland. Suitable water levels were identified as being from 143.9–144.2 m for April to May, 144.1–144.3 m for June to September, and 144.3–144.4 m for October to November (before the freezing season). Furthermore, proposed water diversion schemes have been identified which can effectively sustain the proposed dynamic water levels. This study is expected to provide appropriate guidance for the determination of environmental flows and water management strategies in marsh wetlands.  相似文献   

14.
Isolation and characterization of Aeromonas species were undertaken in the Ebrié lagoon (Abidjan, Côte d’Ivoire) over a one year period. Overall 63% of 501 water samples were identified as positive for Aeromonas spp. A. sobria, A. hydrophila and A. caviae represent respectively 49.20%, 20.63% and 30.15% of the positive samples. Thirty nine of the positive samples were recovered from surface water samples; while 24 bottom water samples were positive for Aeromonas. Aeromonas species are most frequently (82.53) present in the Ebrié lagoon urban area during the rainy and flood seasons when the salinity is low and below 10‰. A lower isolation frequency is noticed during the dry season when water salinity is over 10‰. Finally, a higher isolation frequency occurred in samples with highest counts of Escherichia coli.  相似文献   

15.
Biodiversity and Ecology of Species of Aquatic Oomycetes in the Aue Lake and the River Fulda in Kassel (Hessen) In this study, we record diversity and ecology of aquatic Oomycetes in the Aue Lake and the river Fulda in Kassel (Hesse, Germany). We monthly collected water samples of both water bodies from July 2003 to June 2004. The baiting method was used to gain an insight into the occurrence of aquatic Oomycetes. A total of 14 species of aquatic Oomycetes belonging to the orders Saprolegniales, Leptomitales and Olpidiopsidales could be isolated of both water bodies. Numerous saprophytic isolates of Rhizophydium Schenk (Chytridiomycetes), Rhizophydium carpophilum (Zopf) Fischer, parasitic on Oomycetes, and additionally one species of Plasmodiophoromycetes, Woronina polycystis Cornu could be isolated. Many isolates of Saprolegniales attributable to the genera Achlya Nees, Dictyuchus Leitgeb, Saprolegnia Nees and Pythium Pringsheim (Pythiales), which could only be identified on generic level, could be isolated as well. The species were examined and discussed with respect to their occurrence in the stagnant water Aue Lake and/or in the running water of the river Fulda. Half of the isolated species only occurred in one of the water bodies. In this study the occurrence of Achlya proliferoides Coker could be documented for Germany for the first time. The trophic status of the Aue Lake and of the classification of water quality of the river Fulda were determined by limnological‐chemical parameters obtained by simultaneous investigations of both water bodies.  相似文献   

16.
Raul Primicerio   《Limnologica》2000,30(4):301-310
Zooplankton vertical distribution was studied in Lake Takvatn (69°07′ N) by discrete sampling of the water column during the open water season. Attention was focused on predation risk and competition to understand when, where and to what degree a given species should aggregate along the water column. Temperature profiles and phytoplankton abundance and composition were recorded to assess degree of heterogeneity and food availability in the pelagic zone. Vertical segregation was evident during thermal stratification. Rotifers partitioned the water column, with species less susceptible to predation (e.g. Conochilus unicornis) in the epilimnion, where they overlapped with the predators Asplanchna priodonta and Polyphemus pediculus, and species more vulnerable to these predators (e.g. Keratella cochlearis) in the hypolimnion. Cladocerans remained in the epilimnion, in a year when predation by fish was limited. The copepodites of Eudiaptomus graciloides and Cyclops scutifer maintained different depths staying respectively near surface and in the meta-hypolimnion. A broader distribution with increasing density was evident among rotifers and C. scutifer nauplii. Density-dependent habitat selection behaviour is considered as a mechanism explaining the observed distribution of predators and competing prey and promoting species coexistence.  相似文献   

17.
The coastal water bodies that separate from White Sea water area due to Kandalaksha coast rise are examined. The hydrological and hydrochemical characteristics of these water bodies are found to notably differ from these in the bays and straits connected with them. Extreme values of water temperature and salinity were recorded. High concentrations of oxygen (>20 mg/l) were recorded in the near-surface water layers and high concentrations of hydrogen sulfide (>90 mg/l) in bottom waters. The species composition of phyto- and zooplankton was found to be poor. The characteristics of enzymatic destruction in subsurface waters of lakes are an order of magnitude greater than those in White Sea open areas.  相似文献   

18.
The chemical effects of chronic petroleum input into a shallow water marsh were examined by measuring hydrocarbon levels and dissolved organic carbon content of sediments associated with two active oil fields in south Louisiana. Annual levels of total organic carbon in the surface waters of the oil fields were higher by 1 mg C/l. in the salt marsh and 5 mg C/l. in the fresh marsh than the respective controlsites. Average dissolved organic carbon concentrations in the interstitial waters of cores taken within the oil field environments were 105% higher than the control in the salt marsh and 43% higher than the control in the fresh marsh. Significantly lower ratios of C17 to pristane occurred in both oil field sediments; however, average odd-even predominance values were not indicative of petroleum contaminated sediments. The results indicate that microbial processes are responsible for dissolution of petroleum into dissolved organic carbon and that dissolved organic carbon concentrations may be a more significant measure of chronic petroleum input than hydrocarbon distribution.  相似文献   

19.
The aim of the study was to evaluate pattern of the aquatic macrophyte species distribution along the Danube fluvial corridor in Slovakia, and to identify the impact of environmental abiotic parameters on macrophyte species diversity. Field sampling was performed in the period 1999–2005 from the boat. Aquatic habitats were divided into 365 survey unit (SU). The survey of aquatic macrophytes and abiotic parameters followed the European standard approach EN 144184 2003. The plant mass estimate (PME – a semi-quantitative estimation of the amount of individual species in a SU, which takes into account three-dimensional development of plant stands) was estimated according to a five-point-scale in each SU; environmental pattern, were assessed over six abiotic parameters (river km, bank type, sediment type, flow velocity class, land-use type, and heavily man-modified water bodies). Altogether, four hydrologic connectivity types of aquatic habitats were distinguished: the Danube River, Open Arms, Separated Arms, and Seepage Water-bodies.

In total, 54 aquatic macrophytes were recorded for the whole data set of the Danube fluvial corridor. The PME data of true aquatic macrophytes and the length of SUs created a basis for numerical derivates, relative plant mass (RPM), mean mass indices (MMT, MMO) and the distribution ratio (d).

The results correspond with comparable studies on this topic: the highest macrophytes species diversity occurred in Separated Arms. On the contrary, macrophytes had the lowest richness in the Danube River main channel, although their diversity was slightly higher in heavily man-modified water bodies (such as the hydropower plant's reservoir and the abandoned main channel of the so-called Old Danube). Our results suggest that the lateral connectivity types of the river water bodies, primarily characterised by different hydrologic dynamics and human impact expressed as land-use types are responsible for the variability of aquatic macrophyte assemblages along the Danube corridor in Slovakia.  相似文献   


20.
Sea level rise (SLR) is threatening coastal marshes, leading to large-scale marsh loss in several micro-tidal systems. Early recognition of marsh vulnerability to SLR is critical in these systems to aid managers to take appropriate restoration or mitigation measures. However, it is not clear if current marsh vulnerability indicators correctly assess long-term stability of the marsh system. In this study, two indicators of marsh stress were studied: (i) the skewness of the marsh elevation distribution, and (ii) the abundance of codominant species in mixtures. We combined high-precision elevation measurements (GPS), LiDAR imagery, vegetation surveys and water level measurements to study these indicators in an organogenic micro-tidal system (Blackwater River, Maryland, USA), where large-scale historical conversion from marshes to shallow ponds resulted in a gradient of increasing marsh loss. The two indicators reveal increasingly stressed marshes along the marsh loss gradient, but suggest that the field site with the most marsh loss seems to experience less stress. For the latter site, previous research indicates that wind waves generated on interior marsh ponds contribute to lateral erosion of surrounding marsh edges and hence marsh loss. The eroded marsh sediment might temporarily provide the remaining marshes with the necessary sediment to keep up with relative SLR. However, this is only a short-term alleviation, as lateral marsh edge erosion and sediment export lead to severe marsh loss in the long term. Our findings indicate that marsh elevation skewness and the abundance of codominant species in mixtures can be used to supplement existing marsh stress indicators, but that additional indices such as fetch length and the sediment budget should be included to account for lateral marsh erosion and sediment export and to correctly assess long-term stability of micro-tidal marshes. © 2020 John Wiley & Sons, Ltd.  相似文献   

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