厦门近岸海域大型底栖动物次级生产力

于2013年5月和11月在厦门近岸海域设置67个站位进行大型底栖动物定量调查,运用Brey(1990)经验公式对该海域的次级生产力进行估算。结果表明:该海域大型底栖动物年均总次级生产力P和P/B值分别为4.6±10.1 g AFDW·m-2·a-1和1.0±0.4a-1,软体动物和多毛类为该海域P值的主要贡献类群,秋季的P值略高于春季,同安湾的P值明显高于大嶝海域、九龙江口、厦门外海域和围头湾。相关性分析显示,该海域次级生产力与沉积物有机质含量以及水体底温呈显著相关,底质类型以及采砂、航道清淤、环境污染等人类活动干扰也是影响次级生产力分布的主要因素。     

Resistance to copper ions and antibiotics in marine heterotrophic bacteria in the coastal waters of Vietnam

Copper and antibiotic resistance was experimentally studied for the first time in marine heterotrophic bacteria that were isolated from microfoulings of copper and copper-alloy test plates in coastal waters of Vietnam. Resistance to copper ions and to at least one of the antibiotics tested was detected in 78.7% of the isolates. A total of 28 models of antibiotic resistance were found in the bacteria. All strains isolated from the foulings of the copper plates were resistant to seven or more antimicrobials. The microfouling communities of copper and copper-alloy plates were dominated by Bacillus spp. and Staphylococcus spp. Copper and antibiotic resistance was statistically independent of the taxon of the tested bacteria.     

Trophic interactions among heterotrophic microplankton,nanoplankton, and bacteria in Lake Constance

A considerable portion of the pelagic energy flow in Lake Constance (FRG) is channelled through a highly dynamic microbial food web. In-situ experiments using the lake water dilution technique according to Landry & Hasset (1982) revealed that grazing by heterotrophic nanoflagellates (HNF) smaller than 10 µm is the major loss factor of bacterial production. An average flagellate ingests 10 to 100 bacteria per hour. Nano- and micro-ciliates have been identified as the main predators of HNF. If no other food is used between 3 and 40 HNF are consumed per ciliate and hour. Other protozoans and small metazoans such as rotifers are of minor importance in controlling HNF population dynamics.Clearance rates varied between 0.2 and 122.8 nl HNF^–1 h^–1 and between 0.2 and 53.6 µl ciliate^–1 h^–1, respectively.Ingestion and clearance rates measured for HNF and ciliates are in good agreement with results obtained by other investigators from different aquatic environments and from laboratory cultures. Both the abundance of all three major microheterotrophic categories — bacteria, HNF, and ciliates — and the grazing pressure within the microbial loop show pronounced seasonal variations.     

Abundance and biomass of heterotrophic microorganisms in Lake Tanganyika

1. This study focused on heterotrophic microorganisms in the two main basins (north and south) of Lake Tanganyika during dry and wet seasons in 2002. Bacteria (81% cocci) were abundant (2.28–5.30 × 10⁶ cells mL^?1). During the dry season, in the south basin, bacterial biomass reached a maximum of 2.27 g C m^?2 and phytoplankton biomass was 3.75 g C m^?2 (integrated over a water column of 100 m). 2. Protozoan abundance was constituted of 99% of heterotrophic nanoflagellates (HNF). Communities of flagellates and bacteria consisted of very small but numerous cells. Flagellates were often the main planktonic compartment, with a biomass of 3.42–4.43 g C m^?2. Flagellate biomass was in the same range and often higher than the total autotrophic biomass (1.60–4.72 g C m^?2). 3. Total autotrophic carbon was partly sustained by the endosymbiotic zoochlorellae Strombidium. These ciliates were present only in the euphotic zone and usually contributed most of the biomass of ciliates. 4. Total heterotrophic ciliate biomass ranged between 0.35 and 0.44 g C m^?2. In 2002, heterotrophic microorganisms consisting of bacteria, flagellates and ciliates represented a large fraction of plankton. These results support the hypothesis that the microbial food web contributes to the high productivity of Lake Tanganyika. 5. As the sole source of carbon in the pelagic zone of this large lake is phytoplankton production, planktonic heterotrophs ultimately depend on autochthonous organic carbon, most probably dissolved organic carbon (DOC) from algal excretion.     

Abundance and distribution of nanoplankton in the epipelagic subtropical/tropical open Atlantic Ocean

The objective of this research was to quantify the abundanceand distribution of nanoplanktonic particles available to frequentlyoccurring juvenile and adult planktonic copepods in the epipelagialof the open subtropical and tropical ocean. We chose locationsoff Puerto Rico and off the Bahamas to achieve our purpose.The hydrography for all stations revealed a thin upper mixedlayer, a thermocline with varying temperature decreases, salinitiesapproaching and surpassing 37     

Abundance and productivity of protozoa in chalk streams

The distribution and abundance of protozoa in two chalk streams were studied. Particular attention was given to the ciliates and amoebae associated with the dominant submerged macrophyte, Ranunculus penicillatus . Highest numbers of protozoa occurred in habitats in the stream where the current velocity was reduced. Mean standing crops of ciliates, flagellates and amoebae were 32.5, 2.9 and 2.0 mg dry wt m⁻² of stream bed respectively. Estimates of production and respiration rates by field populations of ciliates and amoebae were made for one type of habitat within the streams. The results are compared with published data on the productivity of protozoa in other habitats and of other invertebrates within the chalk stream ecosystem. The limitations of such productivity estimates are discussed.     

Autotrophic and heterotrophic nanoplankton in the diet of the estuarine copepods Eurytemora affinis and Acartia bifilosa

The ingestion of autotrophic and heterotrophic nanoplanktonby two estuarine copepods, Eurytenora affinis and Acarith bifilosa,was measured in various environmental conditions using the incubationmethod and epifluorescence microscopy. Egg production of thespecies was also deter mined in order to estimate their carbonrequirements. Assuming a gross efficiency of egg productionof 0.3, nanoplanktonic carbon ingested always met the carbonrequirements suggesting that, most of the time, other carbonsources could be unnecessaly. Nanoplankton ingestion by A.bifilosa(from 128 to 1693 cells ind.^–1 h^–1) was dominatedby autotrophic forms (60–97%) and was seriously affectedby high (>100 mg l^–1 suspended particulate matter (SPM)concentrations. Nanoplankton ingestion by E.affinis (from 300to 1049 cells ind^–1 h^–1) was relatively stable incomparison, but this latter species seemed to switch its grazingpressure from autotrophic to heterotrophic forms when SPM concentrationsincreased. Thus, two copepod species, living in the same estuary,presented two different feeding behaviours, probably to maximizeenergy input per unit of energy expenditure. Such differencescould contribute to the spatial and seasonal segregation ofthese species which is usually observed.      

Photo- and heterotrophic pico- and nanoplankton in the Mississippi River plume: distribution and grazing activity

The abundance of pico- and nanophytoplankton, bacteria and heterotrophicnanoflagellates, and grazing rates on phototrophic pico- andnanoplankton and bacterioplankton were assessed along a salinitygradient (0.2–34.4) in the Mississippi River plume inMay 2000. Grazing rates were established by serial dilutionexperiments, and analysis by flow cytometry allowed differentiationof grazing rates for different phytoplankton subpopulations(eukaryotes, Synechococcus spp., Prochlorococcus spp.). Grazingrates on phytoplankton tended to increase along the salinitygradient and often approached or exceeded 1 day^-1. Phytoplanktonnet growth rates (growth – grazing) were mostly negative,except for positive values for eukaryotic nanoplankton in thelow-salinity, high-chlorophyll region. Grazing pressure on bacteriawas moderate (     

Phytoplankton productivity in turbid waters

Many of the freshwater areas in the world are turbid, due tosuspended inorganic particles. The euphotic depth of the shallowturbid impoundment, Wuras Dam, varies between 0.3–1.3m. This results in a compressed production profile where accuratemeasurements become difficult. Tubes of various lengths havebeen used and usually render higher rates, when compared todiscrete bottle incubations. A tube the depth of the euphoticzone confines the phytoplankton in the light and the rates measuredrepresent the maximal possible under the prevailing conditions.Longer tubes include an aphotic portion and give an idea ofthe magnitude of respiration losses. The depth of the mixinglayer appears to be especially important in turbid systems asthe time spent in the dark, relative to the light is of greatimportance and may be the most important regulating factor insuch waters. ^*This paper is the result of a study made at the Group for AquaticPrimary Productivity (GAP), Second International Workshop heldat the National Oceanographic Institute, Haifa, Israel in April–May1984.     

Tick infestations of birds in coastal Georgia and Alabama

Mist-netted birds were examined for ticks on Jekyll Island, Glynn Co., Georgia (32 bird species) in 1996-1998, and at Fort Morgan, Baldwin Co., Alabama (36 species) in 1998 during fall migration. Sixty-two (14.7%) of 423 birds from Jekyll Island and 22 (13.3%) of 165 birds from Fort Morgan were infested with ticks. The mean number of ticks per infested bird was 2.0 on Jekyll Island and 6.3 at Fort Morgan. Ten species of birds were infested with ticks on Jekyl1 Island where 87% of all ticks were recovered from 3 species: the common yellowthroat (Geothlypis trichas), gray catbird (Dumetella carolinensis), and northern waterthrush (Seiurus noveboracensis). Eight species of birds were infested with ticks at Fort Morgan where 83% of all ticks were recovered from 3 species: the brown thrasher (Toxostoma rufum), swamp sparrow (Melospiza georgiana), and common yellowthroat. Six species of ticks (Amblyomma americanum, Amblyomma maculatum, Haemaphysalis leporispalustris, Ixodes brunneus, Ixodes minor, and Ixodes scapularis) were recovered from the Georgia birds, whereas 3 species (A. maculatum, H. leporispalustris, and Ixodes dentatus) were recovered from the Alabama birds. Attempts to isolate Borrelia burgdorferi sensu stricto, the etiologic agent of Lyme borreliosis, from Ixodes spp. ticks recovered from birds were unsuccessful.     

Abundance and distribution of Legionellaceae in Puerto Rican waters

Waters in marine and freshwater areas of Puerto Rico were analyzed for the presence of Legionella spp. by direct fluorescent antibody assay with guinea pig confirmation. Several species, including L. bozemanii, L. dumoffii, L. gormanii, L. longbeachae, L. micdadei, and L. pneumophila, were widely distributed among all sites. Legionellaceae, including L. pneumophila, were found in high densities in water collected in the rain forest from epiphytes in trees 30 ft. (about 9.25 m) above the ground. Both interspecific and intersite variations were significant. L. pneumophila was the most abundant species at all sites, with average densities of 10(4) cells ml-1, very close to the range which is potentially pathogenic for humans. Densities of L. pneumophila were highest in sewage-contaminated coastal waters. These are the highest densities of Legionella spp. ever reported for marine habitats. Densities of L. pneumophila were positively correlated with concentrations of sulfates, phosphates, and pH. A survey of 88 fatal atypical pneumonia cases at a Puerto Rico hospital showed that 15% of the patients had L. pneumophila infections. This study establishes L. pneumophila as a relatively common cause of atypical pneumonia in Puerto Rico and suggests natural aquatic habitats as possible sources or reservoirs of pathogenic Legionella spp. in the tropics.     

Abundance, species composition of microzooplankton from the coastal waters of Port Blair, South Andaman Island

ABSTRACT: BACKGROUND: Microzooplankton consisting of protists and metazoa <200 mum. It displays unique feeding mechanisms and behaviours that allow them to graze cells up to five times their own volume. They can grow at rates which equal or exceed prey growth and can serve as a viable food source for metazoans. Moreover, they are individually inconspicuous, their recognition as significant consumers of oceanic primary production. The microzooplankton can be the dominant consumers of phytoplankton production in both oligo- and eutrophic regions of the ocean and are capable of consuming >100% of primary production. RESULTS: The microzooplankton of the South Andaman Sea were investigated during September 2011 to January 2012. A total of 44 species belong to 19 genera were recorded in this study. Tintinnids made larger contribution to the total abundance (34%) followed in order by dinoflagellates (24%), ciliates (20%) and copepod nauplii (18%). Foraminifera were numerically less (4%). Tintinnids were represented by 20 species belong to 13 genera, Heterotrophic dinoflagellates were represented by 17 species belong to 3 genera and Ciliates comprised 5 species belong to 3 genera. Eutintinus tineus, Tintinnopsis cylindrical, T. incertum, Protoperidinium divergens, Lomaniella oviformes, Strombidium minimum were the most prevalent microzooplankton. Standing stock of tintinnids ranged from 30--80 cells.L-1 and showed a reverse distribution with the distribution of chlorophyll a relatively higher species diversity and equitability was found in polluted harbour areas. CONCLUSIONS: The change of environmental variability affects the species composition and abundance of microzooplankton varied spatially and temporarily. The observations clearly demonstrated that the harbor area differed considerably from other area in terms of species present and phytoplankton biomass. Further, the phytoplankton abundance is showed to be strongly influenced by tintinnid with respect to the relationship of prey--predator. Consequently, further investigation on microzooplankton grazing would shed light on food web dynamics.     

Use of coastal waters as condenser coolant in electric power plants: Impact on phytoplankton and primary productivity

(1) Studies on phytoplankton entrained in cooling system of a power plant revealed a reduction in biomass and gross primary productivity (GPP) at outfall, compared to intake.     

成都地区天然水域中异养微藻的分离及其特性研究

采用添加不同浓度和种类抑菌剂的平板进行多次平板划线分离和三角瓶培养,从成都地区四川大学望江及江安校区附近水域中分离得到了一株可在无光照条件下异养生长的微藻,经初步鉴定为小球藻并编号为Chlorella SCU-01.在此基础上初步研究了该藻株在不同葡萄糖起始浓度下的异养生长及色素合成特性.     

Recovery and diversity of heterotrophic bacteria from chlorinated drinking waters

Heterotrophic bacteria were enumerated from the Seattle drinking water catchment basins and distribution system. The highest bacterial recoveries were obtained by using a very dilute medium containing 0.01% peptone as the primary carbon source. Other factors favoring high recovery were the use of incubation temperatures close to that of the habitat and an extended incubation (28 days or longer provided the highest counts). Total bacterial counts were determined by using acridine orange staining. With one exception, all acridine orange counts in chlorinated samples were lower than those in prechlorinated reservoir water, indicating that chlorination often reduces the number of acridine orange-detectable bacteria. Source waters had higher diversity index values than did samples examined following chlorination and storage in reservoirs. Shannon index values based upon colony morphology were in excess of 4.0 for prechlorinated source waters, whereas the values for final chlorinated tap waters were lower than 2.9. It is not known whether the reduction in diversity was due solely to chlorination or in part to other factors in the water treatment and distribution system. Based upon the results of this investigation, we provide a list of recommendations for changes in the procedures used for the enumeration of heterotrophic bacteria from drinking waters.     

Planktonic viruses,heterotrophic bacteria,and nanoflagellates in fresh and coastal marine waters of the Kara Sea Basin (the Arctic)

In August–September 2009, the concentration of dissolved organic matter and quantitative distribution of virioplankton, bacterioplankton, and heterotrophic nanoflagellates were studied in the coastal waters of the Kara Sea, the fresh waters of the islands and the coasts of the sea, and the estuaries of the Ob’ and Yenisei rivers. A high positive correlation was observed between the abundances of viruses and bacteria. The frequency of visibly infected bacteria in marine waters ranged from 0.6 to 4.3% (an average of 1.6%); in the fresh waters of islands and coastline and in estuaries, it ranged from 0.3 to 3.9% (an average of 1.5%) and from 0.5 to 1.6% (an average of 1.1%) respectively. In most surveyed water bodies, the role of viruses in bacterioplankton mortality was considerably higher than that of heterotrophic flagellates.     

Nitrogen uptake by heterotrophic bacteria and phytoplankton in Arctic surface waters

We estimated rates of heterotrophic bacterial and phytoplanktonuptake of nitrate, ammonium, and urea using ¹⁵N-labelled nitrogenand specific metabolic inhibitors of prokaryote and eukaryotenitrogen metabolism in the surface waters of the North Water(northern Baffin Bay) during autumn that were characterizedby the absence of cyanobacteria (comprising prochlorophytes).The percentage of nitrate + ammonium uptake by heterotrophicbacteria ranged between 44 and 78% of the measured total uptakeand was the highest when the phytoplankton biomass was relativelylow (<2 µg Chlorophyll a L^–1). Phytoplanktonaccounted for a larger fraction (e.g., 58–95%) of ureauptake than heterotrophic bacteria. When our results are combinedwith those from previous studies carried out in diverse temperateand polar areas, it appears that heterotrophic bacteria accountfor 25% (14–40%; median and interquartile range) of thetotal nitrate uptake in surface waters with chlorophyll biomass<2 µg L^–1. Estimates of new production computedfrom phytoplankton carbon uptake and f-ratios may be stronglyoverestimated in regions where nitrate uptake by heterotrophicbacteria is high and the biomass of phytoplankton is low.     

Abundance and diversity of microfungi in three coastal beaches of Mexico

The abundance and diversity of species of microfungi was investigated on the beaches of Delfines, Km 24 Veracruz-Alvarado Highway, and El Coco, located on the coasts of the Caribbean Sea, Gulf of Mexico, and the Pacific Ocean, respectively. On each beach a sample composed of sand, subtidal wood or washed-up detritus with moist sand was collected. The samples were analyzed by three different methods, resulting in a total of 1,160 occurrences that fluctuated between 340 and 441 occurrences/sample. The number of species/sample fluctuated between 20 and 32. A total of 52 species was found, of which 12 were marine, and 40 nomarine, of terrestrial origin, and of these 15 were ascomycetes, 34 were hyphomycetes, 2 were blastomycetes and one was a coelomycete. The abundance distribution showed few species with high or low values, with the greates proportion having intermediate values. In order to compare species diversity among the samples frequency curves were utilized, based on the number of species expected from samples taken at random; the results showed that the beach at El Coco was richest in species.     

Summer bacterio- and zooplankton in coastal waters of Svalbard

The distribution of bacterio- and zooplankton was studied in West Spitsbergen (Svalbard) coastal waters in August 2009. The bacterial abundance and biomass varied from 110 to 3360 × 10³ cells/ml and from 0.66 to 44.93 mg C/m³, respectively. These values were the highest in the surface water layers and decreased with depth. The greatest abundance of bacteria (5099 individuals/m3) was found in the freshened and warm water layer in Isfjorden. The highest biomass of zooplankton (182.41 mg C/m³) was registered in the zone of interaction of coastal and transformed Atlantic waters in the archipelago inner shelf. The spatial variations of abundance and biomass of the planktonic communities were related to the thermohaline characteristics of the water masses and, probably, to microalgal blooms.