海洋微型浮游动物对浮游植物和初级生产力的摄食压力

综述了国际上研究微型浮游动物对浮游植物和初级生产力摄食的方法,并重点介绍了稀释法的理论和在实践中遇到的问题。各种方法的微型浮游动物对浮游植物和初级生产力摄食压力的估计表明,微型浮游动物在海洋生态系统中的扮演重要角色。     

Vertical relationships between chlorophyll, production and copepods in the eastern tropical Pacific

Data consisting of high resolution profiles of in situ chlorophyll,copepods and primary production have been measured with a towedBatfish and profiling pumping system at two sites named ‘BIOSTAT’(9°45'N, 93°45'W) and ‘DOME’ (7°19'N,83°25'W) sites during March 1981. Primary production profileswere generated from Batfish profiles using a chlorophyll/lightmodel and incubated pump samples, the latter with high verticalresolution of 3–5 m. The BIOSTAT site had a subsurfacechlorophyll maximum situated at {small tilde}50 m, and a productionmaximum at a depth of 40 m Copepods had a mean depth centroidcorresponding to the production maximum although their distributionwas more uniformly dispersed from 0 to 40 m. The latter observationindicated that copepods occurred at depths of high productionpotential and low biomass rather than high total productionand high biomass as found at 40 m depth. The DOME site had amixed surface layer of chlorophyll (0–20 m) while copepodswere located at the base of the chlorophyll layer and primaryproduction maximum located at the surface (0–10 m). Theareal daily production measured at the BIOSTAT and DOME siteswere 0.27 and 0.80 mg C m^–2day^–1 respectively.     

Relations between tocopherol, chlorophyll and lipid peroxides contents in shoots of Ni-treated wheat

The influence of 50 and 100 microM Ni on chlorophyll and tocopherol contents, as well as lipid peroxidation was studied in the shoots of wheat plants. Chlorophyll content in the shoots decreased in response to Ni application. Ni stress led to an enhancement of lipid peroxides content, accompanied by a substantial increase in tocopherol concentration in the wheat shoots.     

Tintinnids and other microzooplankton -- seasonal distributions and relationships to resources and hydrography in a Maine estuary

Species composition and abundance of tintinnids and other microzooplanktonwere studied in the Damariscotta River estuary, Maine, USA duringthe period March 1981 to May 1982. Peak tintinnid abundancesoccurred during spring and summer and exceeded 7 x 10³ I^–1.Spearman rank correlation coefficients indicated that temperature,nanoplankton chlorophyll and phaeopigments passing a 20 µnfilter were important factors correlating with total tintinniddensity. Species composition of tintinnids changed seasonallyand was similar in the spring of both years. Non-loricate ciliateswere also most abundant in the spring, reaching peak densitiesof 4.5 x 10⁴ I^–1 in April 1982. Rotifers were most commonupestuary in the spring. Present address: Department of Zoology, University of Georgia,Athens, GA 30602, USA     

Temporal-spatial variations of chlorophyll a and primary production in Meiliang Bay, Lake Taihu, China from 1995 to 2003

There are few long-term data sets on primary production in alake, which can be used to validate the output from a productionmodel. To address this need, we determined the temporal–spatialvariations of chlorophyll a (Chl a) and primary production (PP_eu),based on the vertically generalized production model (VGPM)by using 742 samplings at seven sites in Meiliang Bay in LakeTaihu from 1995 to 2003. An empirical model estimating primaryproduction (PP_in) was used to validate VGPM PP_eu and the dominantfactors controlling PP were determined. Markedly higher Chla and PP_eu values were recorded in Meiliang Bay in 1996 and1997 than in other years and a marked decrease in Chl a andPP_eu was found between 2001 and 2003. Peaks of Chl a typicallyappeared in summer (June–August) and minima occurred inwinter (January). The highest daily mean PP_eu usually occurredin summer (June); the exception was at site 1, where peak dailymean PP_eu occurred in spring (April). The lowest daily meanPP_eu was recorded in winter (January). In Meiliang Bay, 43.0%of annual PP occurred in only 3 months, from June to August.The relative difference of maximum and minimum PP_eu was markedlylarger than the corresponding difference in Chl a. Levels ofboth Chl a and PP_eu were markedly decreased from the inner tothe outer areas of Meiliang Bay; the highest annual integratedPP_eu was found at site 1, close to the inflow of the River Liangxiand this level was 1.85 and 2.14 times higher than at sites3 and 6, respectively, that were located in outer Meiliang Bay.The estimated daily mean PP_eu variation closely matched withthat of the Chl a concentration, implying that Chl a concentrationcan account for the considerable variation of PP. The annualintegrated PP_eu of the euphotic zone in Meiliang Bay rangedfrom 3.44 x 10⁴ tC year^-1 to 8.59 x 10⁴ tC year^-1 with an overallmean of 5.65 x 10⁴ tC year^-1. A significant positive linearrelationship was found between VGPM PP_eu and empirical modelPP_in [PP_in = 0.826 (±0.015)PP_eu + 272.0 (±25.0),r² = 0.80, n = 742, P < 0.0001]. By considering the effectof water temperature, photosynthetically active radiation andphotoperiod on PP, the VGPM- generated PP_eu more accuratelycaptured monthly variations than did the empirical model thatonly included Chl a concentration.     

Chlorophyll budget in a productive tropical pond: algal production,sedimentation, and grazing by microzooplankton and rotifers

Chlorophyll a and pheopigment standing stocks and fluxes were used during a two weeks colonization experiment in a productive tropical pond (Layo, Côte d'Ivoire) in order to establish a chlorophyll budget. The experiment started from an azoïc state (the pond was dried, limed and progressively filled with ground water). Algal production was the only input to the phytoplanktonic system, while grazing and algal sedimentation were the main outputs. Chlorophyll a reflected the algal biomass, and degradation pigments were considered as an index of grazing by zooplankton (here, protozoans and rotifers). An estimation of the input through the algal growth rate was performed for the two main biological events observed during the study. The first algal bloom, with a large picoplankton participation, was mainly regulated by microzooplankton (increase of the peak) and rotifers (decrease of the peak). The second bloom (exclusively nanoplankton) was regulated by rotifers (increase) and by sedimentation of living cells (decrease). This last process was related to a sudden exhaustion of ammonia in the water column. Because of the time-lag between algal proliferation and zooplanktonic bloom, the phytoplanktonic biomass was able to be adjusted according to the availability of nutrients. This self-regulation took the form of sinking of active algal cells, resulting in a transient reduction of the food available for rotifers. This process had drastic consequences in these shallow waters, since a major part of the phytoplankton produced was removed from the pelagic system. For an optimal exploitation of the natural resources of an aquaculture pond, a study of the equilibrium nutrients-phytoplankton-zooplankton would provide a basis for artificial intervention, with a view to limit the impact of this mode of natural regulation.     

The contribution of the deep chlorophyll maximum to primary production in a seasonally stratified shelf sea, the North Sea

Results from extensive cruises in the years 2000 and 2001 throughout distinct ecohydrodynamic regions of the central and southern North Sea are presented and used to generate estimates of gross primary production and new production. An undulating CTD fitted with a fluorometer was towed over a distance of 12,000 kms. Fluorescence data were used to determine the chlorophyll distribution and derive estimates of phytoplankton biomass. These results were combined with estimates of primary production (new and regenerated) from experiments from one cruise in order to estimate gross production for a greater geographical extent. Results from repeat inter-annual transects showed that the strength of the thermocline and the associated deep chlorophyll maximum were variable. However, when the primary production was integrated over the 15–40 m depth, the variability between years was low. While the depth and strength of the deep chlorophyll maximum varied across the region, a deep chlorophyll maximum (DCM) is a consistent and widespread feature of this region at around 30 m depth. In 2001 the calculated average primary production rate in summer for the whole area surveyed was 0.91 g C m^?2 day^?1. This daily production equates to ~130 g C m^?2 for the summer stratified period. In the offshore stratified regions around the Dogger Bank and Eastern Central North Sea primary production of 64 g C m^?2 associated with the deep chlorophyll maximum (15–40 m) accounted for 60 % of total primary production during the summer stratified period (after the spring bloom). Approximately 66 % of new production in these areas occurred in the DCM. This study shows the extent of the DCM in the North Sea and demonstrates its importance in sustaining primary production after the spring bloom.     

Spatial patterns of chlorophyll, primary production, macrozooplankton biomass, and physical structure in the central North Pacific Ocean

The relation between the large-scale horizontal patterns ofbiological properties (primary production and the standing stocksof phytoplankton and macrozooplankton) and physical structurein the North Pacific central gyre is described based upon samplingon a north-south section in August 1980 (expedition FIONA).Primary production in the central North Pacific is nutrientlimited and the large-scale patterns in the measured biologicalproperties appear to be determined by physical processes whichaffect the vertical flux of new nutrients from deeper waterto the euphotic zone. The observed biological patterns can thusbe used to infer horizontal variations in physical processeswhich affect the rate of nutrient supply to the euphotic zone.A mesoscale eddy in the southern part of the section decreasedthe local level of primary production by pushing density andnutrient surfaces to deeper depths. In addition, there was alarge-scale, south-to-north decrease within the central gyrein chlorophyll, primary production and macrozooplankton biomass.This biological gradient was not related in any simple way tothe horizontal distribution of light penetration or the depthsof the nutricline or chlorophyll maximum layer. The hypothesisthat horizontal patterns of nutrient input and production weredetermined by vertical Fickian diffusion and, thus, should bepositively correlated with the vertical nutrient gradient andnegatively correlated with the vertical density gradient, wastested. This simple model however was not supported, suggestingthat either some other process drives the large-scale patternsof vertical nutrient input to the euphotic zone, or that k₂(the vertical eddy diffusivity) is uncorrelated with the meanvertical density gradient. There was some support for a previoushypothesis that enhanced mixing is associated with the densityvariance maximum, and that the relation of the depth of thevariance maximum to the depth of the top of the nutricline mayaffect the large-scale biological patterns.     

Environmental variables affecting small-scale distributions of five rotifer species in Lancaster Lake,Michigan

The small-scale distributions of the rotifers Polyarthra vulgaris, Synchaeta stylata, Conochilus unicornis, Hexarthra mira, and Asplanchna priodonta were investigated in Lancaster Lake, Cheboygan County, Michigan, July 21, 1974. Measurements were taken for 13 depths (at 1-m intervals) and at 4 times of the day (1:00 AM, 7:00 AM, 1:00 PM, and 7:00 PM). In addition, the abundances of 6 crustacean, 2 planktonic dipteran, and 10 algal species, as well as temperature, light, oxygen, chlorophyll a, alkalinity, pH and free carbon dioxide were measured. Whereas abiotic factors appeared to control large scale occupation of the lake, and excluded most species from the deeper portions of the hypolimnion, small-scale distributional variation of the rotifers depended upon biotic interactions, particularly with the crustacean zooplankton.     

Phytoplankton primary production,chlorophyll and species composition,organic carbon and turbidity in the Marsdiep in 1990, compared with foregoing years

Annual primary production in 1990 in the Marsdiep amounted to about 250 g C.m^–2, which is lower than during the mid 1980s, but still higher than the about 150 g C.m^–2a^–1 measured during the 1960s and early 1970s. The annual curve shows a clear spring peak and a broad but lower summer peak. Chloropyll-a showed a similar annual curve, the maximum of 35 mg.m^–3 during the spring peak, as well as the annual average of 6 mg.m^–3 were lower than during the late 1970s and the 1980s. Organic carbon values for 1990 were similar to those observed in 1978 to 1984. Turbidity (at high tide) at our sampling station did not change over the period 1973 to 1990. The high winter temperature of 1989/90 did not influence the timing of the phytoplankton spring bloom. The diatom spring peak is better related to light. With more light in spring and clearer water, the peak occurs earlier. The trend of an increase of the period of occurrence ofPhaeocystis continued.Phaeocystis colonies and single cells were present almost the year round, however, the maximum cell numbers ofPhaeocystis (80,000 ml^–1) was relatively low. Newly formed colonies on spines of diatoms (Chaetoceros sp.,Bacteriastrum hyalinum) were observed in autumn. Its life-cycle remains enigmatic.Rhizosolenia indica, a warm water species, was observed for the first time in net-plankton samples, it occurred from September to December 1990.     

Relative importance of phosphorus,invasive mussels and climate for patterns in chlorophyll a and primary production in Lakes Michigan and Huron

相似文献   

Optical fractionation of chlorophyll and primary production for coastal waters of the Southern Ocean

Our objective was to quantify the potential variability in remotely sensed chlorophyll a (Chl a) and primary productivity in coastal waters of the Southern Ocean. From data collected throughout the springs/summers of 1991–1994, we calculated the proportion of water column Chl a and primary productivity within the upper optical attenuation length (K ⁻¹ _par) and the satellite-weighted depth. The temporal variability was resolved every 2–3 days and was observed to be greater within years than between years. Three-year averages (n=223) revealed that 10.2 ± 3.6% of total Chl a and 14.8 ± 6.5% of production occurred within satellite-weighted depth in predominantly Case I waters. The average values were twice as high within K ⁻¹ _par, 24.1 ± 8% of total Chl a and 34 ± 9% of production respectively. Masked in these long-term averages are very large changes occurring on short time scales of seasonal blooms. We observed that the patterns of Chl a vertical distribution within blooms are also subject to taxonomic influence and dependent upon the physiological state of the phytoplankton. Highest proportions of water column Chl a in the first optical depth were measured during the rapid onset of surface cryptophyte blooms each year, i.e. 50% within K ⁻¹ _par and 30% above the satellite-weighted depth. Lowest fractions, 6% and 2% of biomass within K ⁻¹ _par and satellite-weighted depth respectively, were associated with peak bloom conditions independent of taxonomy. Our analyses suggest that satellite-dependent models of Chl a and subsequent chlorophyll-dependent primary production will be challenging to develop for the near-shore Southern Ocean, especially given the potentially high natural variability in the vertical distribution of Chl a driven by physical forcing, the photoadaptive abilities of polar phytoplankton, and taxonomic influences. Accepted: 27 August 1999     

Seasonal and interannual variability of chlorophyll a and primary production in the Equatorial Atlantic: in situ and remote sensing observations

The seasonal variability of phytoplankton in the EquatorialAtlantic was analysed using Sea-viewing Wide Field-of-view Sensor(SeaWiFS)-derived chlorophyll a (Chl a) concentration data from1998 to 2001, together with in situ Chl a and primary productiondata obtained during seven cruises carried out between 1995and 2000. Monthly averaged SeaWiFS Chl a distributions werein agreement with previous observations in the Equatorial Atlantic,showing marked differences between 10° W in the EasternTropical Atlantic (ETRA) and 25° W in the Western TropicalAtlantic (WTRA) provinces (Longhurst et al. 1995. J. PlanktonRes., 17, 1245–1271). The seasonal cycle of SeaWiFS-derivedChl a concentration calculated for 0–10° S, 0–20°W (ETRA) is consistent with in situ Chl a measurements, withvalues ranging from 0.16 mg m^–3, from February to April,to 0.52 mg m^–3 in August. Lower variability was observedin 10° N–10° S, 20–30° W (WTRA) whereminimum and maximum concentrations occurred in April (0.15 mgm^–3) and in August (0.24 mg m^–3), respectively.A significant empirical relationship between depth-integratedprimary production and in situ measured sea surface Chl a wasfound for ETRA, allowing us to estimate the seasonal cycle ofdepth-integrated primary production from SeaWiFS-derived Chla. As for Chl a, this model was verified in a small area ofthe Eastern Equatorial Atlantic (0–10° S, 0–20°W), although in this instance it was not completely able todescribe the magnitude and temporal variability of in situ primaryproduction measurements. The annual euphotic depth-integratedprimary production rate estimated for ETRA by our empiricalmodel was 1.4 Gt C year^–1, which represents 16% of theopen ocean primary production estimated for the whole AtlanticOcean.     

Modelling the contribution of deep chlorophyll maxima to annual primary production in the North Sea

Seasonally stratified areas in temperate shelf seas are usually characterized by a strong spring bloom, followed by limited production within the surface mixed layer as nutrients are depleted in the post-bloom period. The bottom mixed layer remains nutrient-rich, due to regeneration processes. When the thermocline is within the euphotic zone, primary production at thermocline depth is possible as organisms can access nutrients from the bottom layer. Ship-based observations indicate that production within these deep chlorophyll maxima (DCM) can form a substantial part of the annual production, but this process is not captured by satellite observations. The spatial and temporal behaviour of DCM-related production is therefore less well known. To study the extent of DCM occurrence we applied a fully three dimensional, hydro-biogeochemical model to the North Sea. The simulation was used to quantify sub-surface production in space and time to determine the importance of production within the DCM layer with respect to annual and spring bloom primary production in the North Sea. The results showed that locally, in thermally stratified areas in the North Sea, up to 30% of annual net primary production occurred below 15 m depth. In a 21-year average, sub-surface production contributed 10% to the total annual net primary production in the entire North Sea. These values should be interpreted as lower estimates, as the model was unable to represent observed hot-spots of very high chlorophyll a concentrations at depth. The importance of DCM-related production may increase under future climate scenarios when the length of the stratified period may increase.     

Airborne remote sensing of chlorophyll distributions in Mono Lake, California

As part of a long-term investigation of seasonal and interannual variations of plankton in Mono Lake (California), we developed a methodology using airborne imaging spectrometry to synoptically measure chlorophyll concentrations. Images of Mono Lake were acquired with NASA's Airborne Visible and Infrared Imaging Spectrometer (AVIRIS) and were atmospherically corrected by applying a version of the radiative transfer model MODTRAN. Using a predictive equation for calculation of chlorophyll based on a band ratio of remote sensing reflectances (R _{{ rs}}; R _{{ rs}} 490 nm/R _{{ rs}} 550 nm), spatial distributions of chlorophyll throughout the lake were determined; broad east to west gradients in chlorophyll and gyres are evident.     

Sound production and endothermy in the horse botfly, Gasterophilus intestinalis

ABSTRACT. Adult Gasterophilus intestinalis (De Geer) frequently produce a 'buzzing' sound while stationary. This buzzing was always associated with heat production in the fly's thorax, although sometimes heat production occurred without audible buzzing. Thoracic temperature (Tth) could be elevated by as much as 12°C. As buzzing continued, the Tth rose, the pitch of the buzzing sound increased, the frequency being directly proportion to Tth. Periods of buzzing were usually, but not always, terminated by attempted flight. Often, flies showed long episodes of cycling, when periods of continuous buzzing were interspersed with periods of rest. Such cycling maintained Tth above ambient temperature for long periods. During sustained tethered flight, flies were able to maintain Tth at high, steady values for long periods. Heat loss from the thorax is restricted by a dense covering of hair, and also by active control over heat transfer between thorax and abdomen.     

Sound production by a recoiling system in the pempheridae and terapontidae

Sound‐producing mechanisms in fishes are extraordinarily diversified. We report here original mechanisms of three species from two families: the pempherid Pempheris oualensis, and the terapontids Terapon jarbua and Pelates quadrilineatus. All sonic mechanisms are built on the same structures. The rostral part of the swimbladder is connected to a pair of large sonic muscles from the head whereas the posterior part is fused with bony widenings of vertebral bodies. Two bladder regions are separated by a stretchable fenestra that allows forward extension of the anterior bladder during muscle contraction. A recoiling apparatus runs between the inner face of the anterior swimbladder and a vertebral body expansion. The elastic nature of the recoiling apparatus supports its role in helping the swimbladder to recover its initial position during sonic muscle relaxation. This system should aid fast contraction (between 100 and 250Hz) of sonic muscles. There are many differences between species in terms of the swimbladder and its attachments to the vertebral column, muscle origins, and morphology of the recoiling apparatus. The recoiling apparatus found in the phylogenetically‐related families (Glaucosomatidae, Pempheridae, Terapontidae) could indicate a new character within the Percomorpharia. J. Morphol. 277:717–724, 2016. © 2016 Wiley Periodicals, Inc.     

Relationship between chlorophyll concentration and the energy reaction between protochlorophyll and chlorophyll in mixed associations

In the paper results are presented of investigation of protochlorophyll (PChl) and chlorophyll (Chl) mixed associations and of interaction between them within the polymer molecular complex, which forms in mixture of water-dioxane (1 : 4). The initial PChl concentration in all solutions was constant (CPChl = 1 . 10(-5) m/l), and Chl concentration varied from 1.10(-8) m/l up to 2.10(-5) m/l. It is shown that with the rise of Chl proportion in the mixed aggregate the rearrangement of both donor (PChl) and acceptor (Chl) components of complex takes place. The luminescence quenching of PChl and the sensitization of Chl emission in mixed pigment associates were investigated of different Chl levels and the evaluation of efficiency of intracomplex electronic excitation energy transfer, determined from quenching and sensibilization, was performed. Similar dependence of energy transfer effectiveness on Chl concentration, determined by the two above-mentioned methods shows that the excitation migration in an associate takes place without losses. An analysis of results permits to conclude that a small trapping efficiency of PChl excitation by the acceptor part of the complex may be connected with the existence of the prerelaxation reverse energy transfer from Chl to PChl in mixed pigment associates. On the basis of the obtained data a mechanism of energy transfer from protochlorophyllide to chlorophyllide in etiolated leaves and homogenates is discussed.