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1.
Diel changes in the frequency of dividing cells (FDC) of freshwaterpicocyanobacteria populations from a mesotrophic lake correlatedwith the day-night light cycle and did not appear to be underendogenous control. The highest FDC values (2427%) wereobtained between noon and early afternoon. In late summer, whenpicocyanobacterial abundance was at a seasonal high (13105cells ml1), doubling times estimated from dilution experimentswere 相似文献
2.
Growth and grazing rates of Protoperidinium hirobis Abe, a thecate heterotrophic dinoflagellate 总被引:1,自引:0,他引:1
Growth and feeding rates of a laboratory-reared small thecateheterotrophic dinoflagellate, Protoperidinium hirobis Abè,grown on the diatom Leptocylindrus danicus, were measured inbatch cultures. Ingestion rates were determined directly bythe enumeration of empty diatom frustules produced by dinoflagellatefeeding. Both growth and feeding rates saturated at diatom concentrationsof {small tilde} 104 cells ml1, and reached maximum valuesof 1.7 divisions day1 and 23 diatoms grazer1 day1,respectively. This rate of cell division is notably high comparedto photosynthetic dinoflagellates, which seldom grow fasterthan 1 division day1. A maximal clearance rate of 0.5µl h1 was measured. Mean cell size varied proportionallywith food abundance, with food-saturated cells having doublethe mean volume of food-depleted cells. Tuning of cell divisionand grazing rate patterns were also examined; while mitosisoccurred chiefly during the dark period, no diel variationsin feeding rate were detected. These rates represent the firstdirect growth and ingestion measurements to be made for a thecateheterotrophic dinoflagellate. They serve to underscore one functionthese dinoflagellates perform within the microzooplanktonicfood web: that of transforming large diatoms into particlesmore easily ingested by microzooplankters. 相似文献
3.
Production of Penilia avirostris in Kingston Harbour, Jamaica 总被引:2,自引:0,他引:2
The cladoceran Penilia avirostris is one of the more abundantand widespread members of the crustacean zooplankton in nearshoretropical and subtropical waters. Its abundance, biomass, fecundity,development rate and production were estimated in Kingston Harbour,Jamaica, during an 18 month period. Mean annual abundance ofPenilia was 1821 m3, while biomass (excluding eggs/embryos)was 2.87 mg ash-free dry-weight (AFDW) m3 (43.1 mg AFDWm2), accounting for 13% of the copepod community biomass.Fecundity increased with body size. There was no clear seasonalpattern of abundance, size or fecundity, nor were physical orbiological variables correlated to these variations. Developmenttime averaged 20.5 h for juveniles and 41.4 h for adult femalesduring incubations; there was no clear evidence of a diel patternto molting. Growth rate appeared to be exponential, with correspondingsomatic growth rates, averaging 0.27 day1 for juveniles,and 0.34 day1 for somatic plus reproductive growth inadult females. Annual production was estimated as 173 kJ m2year1, 相似文献
4.
The population abundances and rates of biomass production ofheterotrophic nanoplankton (HNAN) in Georgia coastal waterswere evaluated by epifluorescence microscopy. HNAN populations(mostly non-pigmented microflagellates <10 µm in diameter)ranged from 0.3 x 103 cells ml1 in shelf waters 15 kmoffshore to 6.3 x 103 cells ml1 in waters 0.25 km fromthe coast. There was a strong correlation (r = 0.83) betweenHNAN and free bacterioplankton population abundances, but noapparent relation (r = 0.38) between HNAN and phototrophic nanopLankton(PNAN) abundances. HNAN biomass production in estuarine andnearshore shelf waters, as estimated from increases in HNANpopulations during laboratory incubations of natural water samples,ranged from 0.10 to 0.79 mg C m3 h3, with populationgeneration times of 9.7 to 26.5 h. There was a significant linearrelation (r = 0.95) between HNAN biomass and HNAN productivity.We calculated that HNAN may graze at least 30% to 50% of dailybacterioplankton production in Georgia coastal waters. 相似文献
5.
Pantoja Silvio; Gonzalez Humberto; Bernal Patricio A. 《Journal of plankton research》1989,11(3):599-604
Bacterial biomass (BB, acridine orange) and bacterial secondaryproduction (BSP, [3H]thymidine incubations) were measured forthe first time in Concepción Bay (37°35'S, 73°01'W).BB ranged from 1.8x106 to 22.5x106 cells ml1 (the lattervalue observed near to an industrial effluent), BSP from 0.27x106to 2.5x106 cell ml1 day1 and heterotrophic turnoverrates between 0.15 and 1.0 doublings day1. 相似文献
6.
We describe zooplankton community structure and copepod eggproduction in the vicinity of the coastal boundary zone of theGreat Barrier Reef lagoon, Australia. The abundance and eggproduction rate of constituents of the zooplankton assemblagecharacteristic of the coastal zone rapidly increase subsequentto events such as flooding and upwelling. Our sampling spannedtwo summer monsoonal seasons, the first of which (1990-91) wasvery wet. The second monsoonal season (1991-92) was very dryand was characterized by intrusive upwelling events from theCoral Sea. Chlorophyll a concentrations did not rise in thewet year, probably because of light limitation, but did riseas a result of upwelling. Terrestrial run-off in the wet yearhad a greater apparent effect on zooplankton abundance patternsthan did upwelling in the dry year, except where coastal trappingallowed sufficient time for increases in zooplankton abundanceto occur. Egg production rates by the copepods Acrocalanus gibberand Acrocalanus gracilis showed haphazard spatial differences.Nitrogen-specific egg production ranged between 0.03 and 0.21day1 for A.gibber, and between 0.13 and 0.41 day1for A.gracilis. The egg production rate by A.gibber was foodlimited for most of the year and showed a poor correlation withtemperature.
3Present address: Department of Biological Sciences, FloridaTech, 150 W University Boulevard, Melbourne, FL 32901, USA 相似文献
7.
Biomass, feeding and production of Noctiluca scintillans in the Seto Inland Sea, Japan 总被引:1,自引:0,他引:1
The abundance and biomass of the large heterotrophic dinoflagellateNoctiluca scintillans, together with the changes in its potentialprey items, were monitored in the Seto Inland Sea, Japan, duringsummer 1997 (17 July-11 August). Growth and grazing rates ofNscintillans fed natural plankton populations were also measuredeight and seven times, respectively, during the survey period.The abundance and biomass of N scintillans averaged over thewater column (19 m) were in the range 1345 cells 11(temporalaverage = 93 cell11) and 0.149.6 µg C l1(temporalaverage = 13.8 µg C l1; three times higher thanthat of calanoid copepods during the same period). Noctilucascintillans populations followed the changes in phytoplankton:N.scintillans biomass was increasing during the period of diatomblooms and was at a plateau or decreasing during periods oflow chlorophyll a. The growth rates of N.scintillans (µ)were also consistent with the wax and wane of the N.scintillanspopulation: N.scintillans showed highest growth rates duringdiatom blooms. A simple relationship between µ and chlorophylla concentration was established, and the production of N.scintillanswas estimated using this relationship and the measured biomass.The estimated production averaged over the water column wasin the range >0.15.2 µg C l1 day1(temporalaverage = 1.4 µg C l1 day1; 64% of the productionof calanoid copepods during the same period). Diatom clearancerates by N.scintillans were in the range 0.100.35 mlcell1 day1, and the phytoplankton population clearanceby N.scintillans was >12% day1. Thus, although thefeeding pressure of N.scintillans on phytoplankton standingstock was low, N.scintillans was an important member of themesozooplank-ton in terms of biomass and production in the SetoInland Sea during summer. 相似文献
8.
The in situ predation rate of the siphonophore Sphaeronectesgracilis was estimated from gut content analysis of hand-collectedsiphonophores and from laboratory data on digestion rates ofprey organisms. At daytime prey densities of 0.25 copepods 11,S. gracilis was estimated to consume 8.1 15.4 prey day1siphonophore1. From data on abundances of siphonophoresand copepods, S. gracilis was estimated to consume 24%of the copepods daily. In laboratory experiments, ingestionrates averaged 13.8 prey day1 siphonophore1 atprey densities of 5 copepods 11 and 36.9 at 20 copeods11. This was equivalent to a specific ingestion rate(for both carbon and nitrogen) of 17% day1 and45% day1, respectively, while specific ingestion in situwas only 2% day1. Ammonium excretion averaged 0.095 µg-atsiphonophore1 day1 at 5 prey 11, and 0.162at 20 prey 11. The specific respiration (carbon) andspecific excretion (nitrogen as ammonium) were calculated tobe 3% day1 at the lower experimental food level, and5% day1 at the higher food level.
1Contribution from the Catalina Marine Science Center No. 66.
2Present address: Dept. of Biology, University of Victoria,Victoria, B.C., Canada V8W 2Y2. 相似文献
9.
We measured in situ grazing rates of the mixotrophic dinoflagellateGyrodinium galatheanum (Braarud) Taylor 1995 on populationsof phycoerythrin-containing cryptophytes in Chesapeake Bay.Rates were estimated from instantaneous food vacuole contents,in situ temperatures, cryptophyte abundances and experimentallydetermined digestion rates. Laboratory digestion experimentsshowed that specific digestion rate constants increased sigmoidallywith temperature, but were unrelated to the initial food vacuolecontent when it was <0.46 cryptophytes dinoflagellate1.These results allowed us to establish an empirical model toestimate in situ ingestion of cryptophyte prey by G. galatheanum.The estimated rates ranged from 0 to 0.26 cryptophytes dinoflagellate1day1, corresponding to daily ingestion of 012.29pg carbon, 02.48 pg nitrogen and 00.34 pg phosphorusdinoflagellate1. Estimated daily consumption of cryptophytebiomass by G. galatheanum was equivalent to 012% of bodycarbon, 013% of body nitrogen and 021% of bodyphosphorus. Estimated in situ clearance rates for cryptophytesranged from 0 to 0.27 µl dinoflagellate1 day1,representing daily removal of 04% of the cryptophytestanding stock. Although G. galatheanum may increase its growthrate through phagotrophy, it appears to have little grazingimpact on cryptophyte prey populations. 相似文献
10.
Mixotrophic nanoplankton in oligotrophic surface waters of the Sargasso Sea may employ phagotrophy to obtain major nutrients 总被引:4,自引:0,他引:4
The vertical distribution and abundance of mixotrophic nanoplanktonwas examined during two cruises to the Sargasso Sea south ofBermuda. Fluorescently labeled bacteria and cyanobacteria wereused as tracers of ingestion in experiments designed to determineabundances of mixotrophic nanoplankton. Phagotrophic nanoplanktonic(220 µm) algae ranged from undetectable to >100ml1, and were more abundant near the surface (up to 140ml1) than in the deeper euphotic zone. On two occasions,50% of the phototrophic nanoplankton in surface waters wereobserved with ingested fluorescent tracers. The contributionof mixotrophic algae to the total phototrophic nanoplanktonassemblage in the deep chlorophyll maximum, however, did notexceed 0.5%. It is possible that mixotrophic algae were moreabundant in the deep chlorophyll maximum, but were not phagotrophicallyactive. Two 4 day experimental incubations were subsequentlycarried out to examine the adaptive significance of phagotrophicbehavior for algae in surface waters of the Sargasso Sea. Greatermixotrophic nanoplankton abundances were observed in treatmentsthat received no nutrient inputs and were limited by the availabilityof inorganic nutrients during the experiments. A decrease inthe abundance of mixotrophic algae or a decrease in their phagotrophicactivity occurred with nutrient enrichment. Based on the experimentalresults, we suggest that phagotrophy was a mechanism by whichthese algae supplemented nutrient acquisition during periodsof low dissolved nutrient concentrations. Higher abundancesof mixotrophic nanoplankton observed in the upper 50 m of theSargasso Sea may have been due to the generally low nutrientconcentrations in these waters. 相似文献
11.
Seasonal dynamics in the abundance of Micromonas pusilla (Prasinophyceae) and its viruses in the Gulf of Naples (Mediterranean Sea) 总被引:2,自引:0,他引:2
To assess the role of viruses in the bloom dynamics of Micromonaspusilla in the Gulf of Naples (Mediterranean Sea), variationsof host and virus abundance were followed over one annual cycleand in late winterspring of three consecutive years.Micromonas pusilla was recorded from autumn to spring, withpeak values up to 6.6 x 103 cells ml1, but was undetectablein summer. Free M.pusilla viruses were detectable in all seasons,with concentrations from 0.02 viruses ml1 to 1.9 x 103viruses ml1, exceeding host abundances only in one case.We found a great intraspecific variability in host susceptibilityto viruses present in natural samples, with viral titres rangingover one or two orders of magnitude for the same samples incubatedon different M.pusilla strains. Over the winterspringperiods, a highly dynamic situation was evident, with wide fluctuationsfor both host and virus abundances from one week to another.In some cases, peak host concentrations were accompanied byan increase in viral numbers, whereas in other cases the respectivefluctuations were uncoupled. Although fluctuations of M.pusillaabundance could be influenced by viral infection, there wasno evidence that viruses were able to terminate host blooms.The summer decline of M.pusilla populations did not appear tobe related to the impact of viral infection. 相似文献
12.
Trophodynamics of the plankton community at Dogger Bank: predatory impact by larval fish 总被引:2,自引:1,他引:1
The trophodynamics of a coastal plankton community were studied,focusing on fish larvae and their copepod prey. The major objectiveswere to describe distributional overlap and evaluate the predatoryimpact by larval fish. The study was carried out across DoggerBank in the North Sea, August-September 1991. Sampling transectscrossed tidal fronts off the Bank and plankton at all trophiclevels showed peak abundance within frontal zones. Also Verticallythere was a significant overlap in distributional patterns ofthe plankton. Seven species of fish larvae were abundant, ofthese sprat (Sprattus sprattus) dominated. The abundance ofone group of fish larvae peaked in the shallow water close tothe Bank, whereas other species, including sprat, were foundin deeper water. Prey preference and predation pressure of fishlarvae were assessed using information on prey sizes and growthrates of larvae and the copepod prey. We estimated larval removalof preferred prey sizes to 34% day1, counterbalancedby a 37% day1' replenishment from copepod productionand growth. Additional predation pressure on copepods by aninvertebrate predator was estimated to 13%day1.In conclusion, the dynamics of fish larvae and other zooplankterswere closely linked. At peak abundances of fish larvae (>35mg dry weight m2), the accumulated predation on specificsize ranges of copepods, exerted by larvae and other predators,could exceed the ability of copepod replenishment and intra-/interspecificcompetition among predators might take place. 相似文献
13.
Autotrophic picoplankton in southern Lake Baikal: abundance, growth and grazing mortality during summer 总被引:5,自引:0,他引:5
Nagata Toshi; Takai Kenji; Kawanobe Kyoko; Kim Dong-Sup; Nakazato Ryoji; Guselnikova Nina; Bondarenko Nina; Mologawaya Oliga; Kostrnova Tatyana; Drucker Valentine; Satoh Yasuhiro; Watanabe Yasunori 《Journal of plankton research》1994,16(8):945-959
Autotrophic picoplankton were highly abundant during the thermalstratification period in late July in the pelagic area (waterdepth 5001300 m) of southern Lake Baikal; maximum numberswere 2 x 106 cells ml1 in the euphotic zone ({small tilde}15m). Unicellular cyanobacteria generally dominated the picoplanktoncommunity, although unidentified picoplankton that fluorescedred under blue excitation were also abundant (maximum numbers4 x 105 cells ml1) and contributed up to {small tilde}40%of the total autotrophic picoplankton on occasions. Carbon andnitrogen biomasses of autotrophic picoplankton estimated byconversion from biovolumes were 1484 µg C l1and 3.621 µg N l1. These were comparableto or exceeded the biomass of heterotrophic bacteria. Autotropicpicoplankton and bacteria accounted for as much as 33% of paniculateorganic carbon and 81% of nitrogen in the euphotic zone. Measurementsof the photosynthetic uptake of [l4C]bicarbonate and the growthof picoplankton in diluted or size-fractionated waters revealedthat 80% of total primary production was due to picoplankton,and that much of this production was consumed by grazers inthe <20 µ.m cell-size category. These results suggestthat picoplankton-protozoan trophic coupling is important inthe pelagic food web and biogeochemical cycling of Lake Baikalduring summer. 相似文献
14.
Density and distribution of bacterioplankton and planktonic ciliates in the Bering Sea and North Pacific 总被引:3,自引:0,他引:3
The total number of planktonic bacteria in the upper mixed layerof the Bering Sea during the late spring-early summer periodranged between 1 and {small tilde}4 x 106 ml1 (biomass1040mg C m3). In the northern Pacific, along 47526N,the corresponding characteristics of the bacterioplankton densityin the upper mixed water layer were: total number 12x 106 cells ml1 and biomass 1546mg C m3Below the thermocline at 50100 m, the density of bacterioplanktonrapidly decreased. At 300 m depth, it stabilized at 0.10.2x 106 cells ml1. The integrated biomass of bacterioplanktonin the open Bering Sea ranged between 1.2 and 3.6 g C m2(wet biomass 618 g m2) Its production per dayvaried from 2 to 23 mg C m3 days1 in the upper0100 m. The numerical abundance of planktonic ciliatesin this layer was estimated to be from 3 to l0 x 103 cells l1,and in the northern Pacific from 0.4 to 4.5 x 103 l2.Their populations were dominated by naked forms of Strombidium,Strombilidium and Tontonia. In some shelf areas, up to 40% ofthe total ciliate population was represented by the symbioticciliate Mesodinium rubrum. The data on the integrated biomassof basic groups of planktonic microheterotrophs are also presented,and their importance in the trophic relationships in pelagiccommunities of subarctic seas is discussed. 相似文献
15.
The vertical distribution and abundance of microbial assemblagesand the grazing of nanoheterotrophs upon prokaryotes in oxicand suboxic waters were examined in two coastal upwelling areasoff northern Chile where a shallow Oxygen Minimum Zone (OMZ)is characteristic. Prokaryotic prey included bacterioplanktonand cyanobacteria (Synechococcus); both displayed a bimodaldistribution, with abundance maxima above and within the upperOMZ. Flagellates numerically dominated the nanoplankton andwere mostly concentrated in the oxic layer. Mean ingestion ratesof cyanobacteria by nanoflagellates (vacuole content method)ranged from 0.2 to 1.1 cells flagellate1 h1 andmean consumption rates (34160 cells mL1 h1)were four times higher in the oxic layer. With the selectiveinhibitors technique, specific grazing rates on bacteria werelow (<0.1 h1) and consumption did not control bacterialproduction in the surface layer but did so in the suboxic layer(accounting for >100% of bacterial production). With thesame method, the specific grazing rate on cyanobacteria rangedbetween zero and 0.23 h1 with no clear differences betweenoxygen conditions; prey growth and production were always higherthan the grazing pressure (accounting for <17% of cyanobacterialproduction). The impact of grazing by nanoheterotrophs in regulatingthe production of prokaryotes in oxic and suboxic waters inthis region is discussed. 相似文献
16.
Growth and ingestion rates of larval fish populations in the coastal waters of Israel 总被引:1,自引:0,他引:1
Clupeoid larvae were collected on eight cruises between February1984 and February 1985 in the coastal waters of Israel. Fromanalysis of daily growth increments of otoliths, growth ratesof the abundant clupeoids, Engraulis encrasicolus, Sardina pilchardusand Sardinella aurita were found to be 0.55 mm day1,0.67 mm day1 and 0.60 mm day1, respectively, duringthe first month after hatching. Ingestion rates were estimatedusing an equation from the literature relating ingestion andgrowth of larval fish. Ingestion calculated for populationsof fish larvae in pelagic waters ranged from 0 to >23 mgC m2 day1 with maximum rates observed in April.Annual ingestion by larval fish at a pelagic station near Haifawas calculated to be 2.2 g C m2 year1, 1020%of annual primary production estimated from 14C uptake. 相似文献
17.
Fonda Umani S.; Beran A.; Parlato S.; Virgilio D.; Zollet T.; De Olazabal A.; Lazzarini B.; Cabrini M. 《Journal of plankton research》2004,26(5):545-561
The first bloom of Noctiluca scintillans in theNorthern Adriatic Sea was recorded in 1977. The organism causedseveral red tides in the whole basin during the late 1970s,a period characterized by increasing nutrient loads. Duringthe 1980s and early 1990s, there was no red tide,but the species was an almost constant summer presence, associatedwith high temperatures. Noctiluca scintillans was almost completelyabsent from 1994 until May 1997, concurrent with a general planktondecrease. From summer 1997, N. scintillans was recorded againin the whole basin, although there was no other signal of increasingeutrophication. In contrast to all previous observations, duringwinter 20022003, N. scintillans was continuously sampledin the Gulf of Trieste. We estimated experimentally growth andgrazing rates of the dinoflagellate at 910°C in cultureand consuming the natural assemblage. Noctiluca scintillanswas able to reproduce actively at low temperatures, showingsimilar growth rates in both experiments (k = 0.2 day1).The values found were close to those reported in the literaturefor higher temperatures. The natural diet was mainly composedof phytoplankton (ingestion = 0.008 µg C Noctiluca 1day1), microzooplankton (ingestion = 0.008 µg CNoctiluca 1 day1) and bacteria (ingestion = 0.005µg C Noctiluca 1 day1) with an average carboncontent of 0.138 ± 0.020 µg C Noctiluca cell1. 相似文献
18.
Copepod abundance in the western Irish Sea: relationship to physical regime, phytoplankton production and standing stock 总被引:1,自引:0,他引:1
Gowen R.J.; McCullough G.; Dickey-Collas M.; Kleppel G.S. 《Journal of plankton research》1998,20(2):315-330
The distinct patterns of stratification in the North Channeland stratified region of the western Irish Sea influence theseasonal abundance of phytoplankton. The 34 month productionseason in the stratified region was characterized by productionand biomass peaks in the spring (up to 2378 mg C m2 day1and 178.4 mg chlorophyll m2) and autumn (up to 1280 mgC m2 day1 and 101.9 mg chlorophyll m2).Phytoplankton in the North Channel exhibited a short, late productionseason with a single summer (June/July) peak in production (4483mg Cm2 day1) and biomass (160.6 mg chlorophyllm2). These differences have little influence on copepoddynamics. Both regions supported recurrent annual cycles ofcopepod abundance with similar seasonal maxima (182.8241.8103ind. m2) and dominant species (Pseudocalanus elongatusand Acartia clausi). Specific rates of population increase inthe spring were 0.071 and 0.048 day1 for the North Channel andstratified region, respectively. Increased copepod abundancein the stratified region coincided with the spring bloom, andwas significantly correlated with chlorophyll standing stock.Increased copepod abundance preceded the summer production peakin the North Channel. This increase was not correlated withchlorophyll standing crop, suggesting that a food resource otherthan phytoplankton may be responsible for the onset of copepodproduction prior to the spring bloom. Hetero-trophic microplanktonas an alternative food source, and advection of copepods fromthe stratified region, are proposed as possible explanationsfor copepod abundance increasing in advance of the summer peakin primary production. 相似文献
19.
Halsband-Lenk C.; Nival S.; Carlotti F.; Hirche H.-J. 《Journal of plankton research》2001,23(6):597-609
Reproduction of the dominant copepods Centropages typicus andTemora stylifera was studied at a permanent station in the LigurianSea (north-western Mediterranean). Seasonal patterns of eggproduction, clutch size, egg size and female prosome lengthwere followed from January 1998 to December 1999. Female carboncontent and weight-specific egg production were compared inautumn 1998 and spring 1999. Reproductive patterns of C. typicusand T. stylifera were very similar, indicating that reproductionwas affected by the same environmental factors. Reproductiveactivity was highest in autumn in both species and years. Asecond peak of egg production was observed in early summer,which was less intense in 1999 after a bloom of salps. Egg productionrates reached maximal values of 33.5 and 33.3 eggs female1day1 and annual means of 10.8 and 11.7 eggs female1day1 in Centropages and Temora, respectively. Maximalweight-specific egg production was 0.21 day1 in bothspecies in November 1998, when female carbon contents were 6.7(C. typicus) and 12.0 µg (T. stylifera). No statisticalrelationship between egg production and food availability ortemperature was detected. Reproductive activity did not reflectthe seasonal abundance patterns, with C. typicus dominatingin spring and T. stylifera in autumn. 相似文献
20.
The impact of grazing by natural assemblages of microzooplanktonwas estimated in an upwelling area (Concepción, Chile)during the non-upwelling season in 2003 and 2004. Seawater dilutionexperiments using chlorophyll a (Chl a) as a tracer were usedto estimate daily rates of phytoplankton growth and microzooplanktongrazing. Initial Chl a concentrations ranged from 0.4 to 1.4mg Chl a m3 and phytoplankton prey biomass and abundancewere numerically dominated by components <20 µm. Phytoplanktongrowth and microzooplankton grazing rates were 0.190.25day1 and 0.260.52 day 1, respectively.These results suggest that microzooplankton exert a significantremoval of primary production (>100%) during the non-upwellingperiod. 相似文献