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1.
During the summers of 2005 and 2006, experiments designed to understand the properties of densely concentrated, thin layers of plankton and the processes governing their dynamics were conducted in Monterey Bay, California, USA. Our goal was to elucidate the role that species-specific properties of phytoplankton play in thin layer dynamics. Using adaptive sampling, we collected water samples from inside and outside bio-optical features of the water column. Characterization of the phytoplankton was compiled from live and preserved samples, and analyzed within a framework of physical, optical, chemical and acoustical data. In both years, Monterey Bay was home to an extraordinarily diverse assemblage of phytoplankton and other protists. Bioluminescent dinoflagellates, and Harmful Algal Bloom (HAB) taxa were common. In 2005, community assemblages were widespread, thus advection of water through the experimental mooring array did not result in floristic changes. In 2006 phytoplankton were very patchy in horizontal distribution, and advection of water through the array was at times accompanied by dramatic shifts in community composition. Individual taxa often exhibited disparate patterns of vertical distribution, with some found throughout the water column, whereas others were restricted to narrow depth intervals. Thin layers were observed in both years. In 2005, the dinoflagellate Akashiwo sanguinea formed intense thin layers near the pycnocline at night, and migrated to near surface waters at dawn. In 2006, layer composition was more complex, and related to the water mass present at the time of sampling. Optically detected thin layers of phytoplankton can be studied from the perspective of the impact their high biomass has on both ecological processes, and ocean optics. But thin layers can also be studied from the species-specific perspective of each organism, its role within the thin layer habitat, and the impact that life within a thin layer has on its life history and ecology. Several low-abundance taxa appeared to be restricted to narrow depth intervals in the water column, and constitute species-specific thin layers with the potential to have a large ecological impact even if their biomass is too low to dominate an optically defined thin layer. Concentration into thin layers may also facilitate obligatory relationships between taxa, such as the hypothesized interrelationships between cryptomonads, Myrionecta rubra, and Dinophysis spp., all of which were observed in this system. Complexity of vertical structure in Monterey Bay rivals that already demonstrated in topographically constrained, stratified systems, and presents challenges to our theoretical framework of phytoplankton ecology.  相似文献   

2.
Thin layers are fine-scale structures with high concentrations of organisms or particles occurring over very small vertical scales (a few meters or less), but with large horizontal scales, often extending for many kilometers. Because of their small vertical scales, thin layers are traditionally under sampled, but when proper measurement techniques are used, thin layers have been found to be ubiquitous in stratified oceans. A multi-investigator, interdisciplinary study of thin layers was sponsored by the US Office of Naval Research under a research initiative termed: Layered Organization in the Coastal Ocean (LOCO). The goal of this program was to understand the properties of coastal thin layers and the interacting physical, chemical, biological and optical processes responsible for their formation, maintenance and dissipation. As part of this program, fine-scale vertical profiles (cm resolution) of biological, physical and chemical properties were made hourly over periods spanning 1–3 weeks during three summers in Monterey Bay, California USA. The vertical profiles were made using arrays of moored autonomous profilers. In total, these profilers made ~2000 individual vertical profiles and provided a unique view of phytoplankton thin layer spatial-temporal dynamics. The autonomous profiler data were supplemented with high-resolution ship-based profiling and discrete water sampling for identifications of organisms.Persistent phytoplankton thin layers were observed during each year in Monterey Bay; however, each year had very different biological and physical dynamics. During 2002, thin layers were dominated by the non-motile and potentially toxic diatom genus Pseudo-nitzschia; during 2005, thin layers were dominated by the highly motile dinoflagellate species Akashiwo sanguinea; and during 2006, a more complex phytoplankton assemblage was present, but thin layers of the toxic dinoflagellate species Alexandrium catenella frequently occurred. The variability in the vertical location of thin layers in 2002 was primarily controlled by physics, while behavior, e.g. diurnal vertical migration patterns and daytime near-surface aggregations, primarily controlled the location of thin layers in 2005 and 2006. In 2002, phytoplankton thin layers were present in the water column 87% of the time, in 2005, 56% of the time and in 2006, 21% of the time. The median integrated chlorophyll concentration within the thin layers was found to be approximately 47% of the total water column chlorophyll in 2002, 41% in 2005 and 33% in 2006. Additional results in this study describe the mechanisms driving the spatial-temporal dynamics of these phytoplankton thin layers with special emphasis on diel patterns and the specific relationships that thin layers have to biological and physical processes and water column optics.  相似文献   

3.
During the 2005 Layered Organization in the Coastal Ocean (LOCO) field program in Monterey Bay, California, we integrated intensive water column surveys by an autonomous underwater vehicle (AUV) with satellite and mooring data to examine the spatiotemporal scales and processes of phytoplankton thin-layer development. Surveying inner to outer shelf waters repeatedly between August 18 and September 6, the AUV acquired 6841 profiles. By the criteria: [(1) thickness ≤3 m at the full-width half-maximum, (2) peak chlorophyll at least twice the local background concentrations, and (3) a corresponding peak in optical backscattering], thin layers were detected in 3978 (58%) of the profiles. Average layer thickness was 1.4 m, and average intensity was 13.5 μg l?1 above (3.2x) background. Thin layers were observed at depths between 2.6 and 17.6 m, and their depths showed diurnal vertical migration of the layer phytoplankton populations. Horizontal scales of thin-layer patches ranged from <100 m to>10,000 m. A thin-layer index (TLI), computed from layer frequency, intensity and thinness, was highest in mid-shelf waters, coincident with a frontal zone between bay waters and an intrusion of low-salinity offshore waters. Satellite observations showed locally enhanced chlorophyll concentrations along the front, and in situ observations indicated that phytoplankton may have been affected by locally enhanced nutrient supply in the front and concentration of motile populations in a convergence zone. Minimum TLI was furthest offshore, in the area most affected by the intrusion of offshore, low-chlorophyll waters. Average thin-layer intensity doubled during August 25–29, in parallel with warming at the surface and cooling within and below the thermocline. During this apparent bloom of thin-layer populations, density oscillations in the diurnal frequency band increased by an order of magnitude at the shelfbreak and in near-bottom waters of the inner shelf, indicating the role of internal tidal pumping from Monterey Canyon onto the shelf. This nutrient transport process was mapped by the AUV. Peak TLI was observed on August 29 during a nighttime survey, when phytoplankton were concentrated in the nutricline. Empirical orthogonal function decomposition of the thin-layer particle size distribution data from this survey showed that throughout the inner to outer shelf survey domain, the layers were dominated by phytoplankton having a cross-section of ～50 μm. This is consistent with the size of abundant Akashiwo sanguinea cells observed microscopically in water samples. During a subsequent and stronger intrusion of low-salinity offshore waters, spatially-averaged vertical density stratification decreased by > 50%, and phytoplankton thin layers disappeared almost completely from the AUV survey domain.  相似文献   

4.
Thin phytoplankton layers are common features in the coastal environment; however sampling these fine-scale optical features across broad horizontal scales remains a challenge. To investigate the horizontal spatial structure of thin phytoplankton layers, we performed an overnight survey in northern Monterey Bay, CA, USA using a SeaSciences Acrobat towed-vehicle. Physical and optical measurements were collected between the surface and near-bottom-depths along four parallel, across-shore transects. Three coherent chlorophyll features were observed: (1) a broad, sub-surface patch at the offshore end, (2) a near-surface patch at the nearshore end, and (3) a deep patch located between the nearshore and offshore patches. The offshore and nearshore patch were separated by a change in seafloor slope and a region of compressed, shoaling isopycnals. Both the offshore and nearshore features were located at the pycnocline, had similar optical properties, and were co-located with a low-salinity intrusion. The deep chlorophyll patch had associated physical and optical properties that were distinct from the patches at the pycnocline. The results from this study further underscore the heterogeneous horizontal spatial structure of thin layers and also add to the growing evidence suggesting that low-salinity intrusions may be strongly linked to the formation of thin phytoplankton layers over the northern shelf of Monterey Bay.  相似文献   

5.
Most existing studies on the algal communities of acid lakes are based on environments that have been caused by anthropogenic disturbances. Such lakes have a different origin compared to the natural acidic lakes and could be expected to differ also in the mechanisms controlling phytoplankton and trophic status. Planktonic community in Lake Caviahue is somewhat diverse in spite of the low pH of the water. Algae have a distinctive vertical distribution: the values of phytoplankton biomass remain constant throughout the water column and at times were highest in the upper end of the hypolimnion, forming a maximum or a layer of chlorophyll a at depth. The goal of this work was to investigate the factors influencing the seasonal and vertical distribution of phytoplankton. The lake was sampled between the years 2004 and 2006. Physical, chemical and biological parameters at different depths throughout the water column were determined. The interrelationships between environmental variables at different sampling dates were analyzed using an integration of multivariate matrices, multiple factor analysis, to analyze any joint partnerships in the samples. We found that phytoplankton biomass is dominated by Keratococcus rhaphidioides. With regard to zooplankton, we found a single species of rotifers (Philodina sp.). The two arms of the lake and the depths have different behaviours showing differences in the arms' conductivity, dissolved oxygen and pH. The more superficial layers were characterized by high values of phytoplankton and zooplankton biomass, organic and inorganic carbon, dissolved oxygen and pH. The deeper layers showed high values of chlorophyll a, ammonium and phosphorus (dissolved and particulate). From the multivariate analysis the relationships of the each algal species with pH, as a possible indicator of the degree of “acidophilia”, could be extracted.  相似文献   

6.
太湖梅梁湾春季浮游植物初级生产力   总被引：3，自引：3，他引：0  
用黑白瓶测氧法对梅梁湾春季浮游植物初级生产力的变化特征进行研究,探讨了初级生产力的日变化、垂直变化、区域分布、浮游植物现存量与初级生产力的关系以及不同曝光时间对P-I曲线的影响.结果表明,梅梁湾浮游植物初级生产力存在明显的日变化,最大值出现在10:00-14:00;初级生产力在梅梁湾分布呈现为从湾内向湾口逐渐递减的趋势;除表层水受光抑制影响使其生产力相对较低外,初级生产力随水深的增加而降低;初级生产力与叶绿素a存在显著的正相关,用水柱层平均叶绿素a浓度来估算初级生产力比用表层叶绿素a浓度来估算要更为精确;短的曝光时间往往带来高的初级生产力和同化系数.  相似文献   

7.
The small-scale distribution of zooplankton in the euphotic zone has aroused much interest in recent years, particularly with regard to which features of the water column structure might be causing or strongly affecting such distributions. At a station on the continental shelf off Mauretania pump sampling techniques were used to investigate the relation between the vertical distribution of various zooplankton taxa and the physical, chemical, and biological structure of the water column (water depth 60 m). Attention was focused on the very precise patterns of zooplankton distribution in the region of the pycnocline and its associated massive chlorophyll a and phytoplankton biomass maximum. The possible trophic relations of these taxa were considered with respect to the difficulties inherent in drawing meaningful conclusions about the ways in which resource or space might be partitioned, particularly when such trophic relations probably were indirect.  相似文献   

8.
We present the results of multiparametric observations designed to follow the phytoplankton dynamics and interrelated physical, chemical and biological processes in the Gulf of Finland (Baltic Sea). Data were acquired by an autonomous moored water column profiler, an acoustic Doppler current profiler, a flow-through system installed aboard a ferry and by profiling and discrete water sampling aboard research vessels in July and August 2009. The main aim of the study was to investigate the processes responsible for the formation and maintenance of sub-surface maxima of phytoplankton biomass. We suggest that the environmental conditions caused by the prevailing atmospheric and oceanographic forcing (wind; vertical stratification; basin-wide, mesoscale and sub-mesoscale processes) are preferred by certain species/taxonomic groups and explain the migration patterns of phytoplankton. Nocturnal downward migration of phytoplankton with a swimming speed up to 1.6 m h−1 occurred when the community was dominated by the dinoflagellate Heterocapsa triquetra. The observed splitting of the population into two vertically separated biomass maxima suggests that the H. triquetra cells, which reached the sub-surface layers with high nutrient concentrations, experienced bi-diurnal or asynchronous (when swimming upwards) vertical migration. The most intense sub-surface biomass maxima, on some occasions with the biomass much higher than that in the surface layer, were detected in connection to the sub-mesoscale intrusions below the depth of the strongest vertical density gradient.  相似文献   

9.
Turbulence measurements in fine-scale phytoplankton layers (∼1 to ∼10 m) in the Gulf of Aqaba (Red Sea) were used to evaluate mechanisms of layer formation, maintenance, and breakdown. Simultaneous profiles of chlorophyll a (Chl a) fluorescence and temperature microstructure were measured in the upper 40 m of a 430 m water column over a 16-d period, using a Self Contained Autonomous MicroProfiler (SCAMP). Layers of concentrated phytoplankton were identified in 95 of the 456 profiles. The layers were situated in density stratified regions between 15 and 38 m depth and were characterized by intensities of 0.1 to 0.35 μg Chl a L−1 (as much as two times background concentrations) and an average thickness of 10 m. We show that turbulent mixing and isopycnal displacements associated with internal waves modulated the thickness of the layers. Variations in mixing rates within layers were connected to the vertical structure of the stratified turbulence and the stage of layer development. The breakdown of a persistent phytoplankton layer was tied to strong turbulent mixing at the base of the surface mixed layer, which encroached on the layer from above. Hydrographic observations and scaling analysis suggest that the layers most likely formed in horizontal intrusions from the adjacent coastal region. The cross-shore propagation of phytoplankton-rich intrusions may have important implications for the trophic state of offshore planktonic communities.  相似文献   

10.
The degree of layered organization of planktonic organisms in coastal systems impacts trophic interactions, the vertical availability of nutrients, and many biological rate processes. While there is reasonable characterization of the vertical structure of these phenomena, the extent and horizontal length scale of variation has rarely been addressed. Here we extend the examination of the vertical scale in the first paper of the series to the horizontal scale with combined shipboard acoustic measurements and bio-optic measurements taken on an autonomous underwater vehicle. Measurements were made in Monterey Bay, CA from 2002 to 2008 for the bio-optical parameters and during 2006 for acoustic scattering measurements. The combined data set was used to evaluate the horizontal decorrelation length scales of the bio-optical and acoustic scattering layers themselves. Because biological layers are often decoupled from the physical structure of the water column, assessment of the variance within identified layers was appropriate. This differs from other studies in that physical parameters were not used as a basis for the layer definition. There was a significant diel pattern to the decorrelation length scale for acoustic layers with the more abundant nighttime layers showing less horizontal variability despite their smaller horizontal extent. A significant decrease in the decorrelation length scale was found in bio-optical parameters over six years of study, coinciding with a documented shift in the plankton community. Results highlight the importance of considering plankton behavior and time of day with respect to scale when studying layers, and the challenges of sampling these phenomena.  相似文献   

11.
In many coastal plain estuaries light attenuation by suspended sediments confines the photic zone to a small fraction of the water column, such that light limitation is a major control on phytoplankon production and turnover rate. For a variety of estuarine systems (e.g. San Francisco Bay, Puget Sound, Delaware Bay, Hudson River plume), photic-zone productivity can be estimated as a function of phytoplankton biomass times mean irradiance of the photic zone. Net water column productivity also varies with light availability, and in San Francisco Bay net productivity is zero (estimated respiratory loss of phytoplankton balances photosynthesis) when the ratio of photic depth (Zp) to mixed depth (Zm) is less than about 0.2. Thus whenever Zp: Zm < 0.2, the water column is a sink for phytoplankton production.Much of the spatial and temporal variability of phytoplankton biomass or productivity in estuaries is explained by variations in the ratio of photic depth to mixed depth. For example, phytoplankton blooms often coincide with stratification events that reduce the depth of the surface mixed layer (increase Zp: Zm). Shallow estuarine embayments (high Zp: Zm) are often characterized by high phytoplankton biomass relative to adjacent channels (low Zp: Zm). Many estuaries have longitudinal gradients in productivity that mirror the distribution of suspended sediments: productivity is low near the riverine source of sediments (low Zp: Zm) and increases toward the estuary mouth where turbidity decreases. Some of these generalizations are qualitative in nature, and detailed understanding of the interaction between turbidity and estuarine phytoplankton dynamics requires improved understanding of vertical mixing rates and phytoplankton respiration.  相似文献   

12.
2010年7月对亚热带特大型水库——新安江水库湖泊区水体的垂向物理、化学参数以及浮游植物群落进行了观测研究,并应用Water-PAM对水体浮游植物垂向光合作用参数进行了测定.研究结果表明:夏季该水库湖泊区在水下10～20 m处形成明显的温跃层,垂向pH值、溶解氧及浊度的变化同叶绿素a浓度呈现高度一致;夏季浮游植物群落以硅藻占绝对优势,水体表层以梅尼小环藻(Cyclotella meneghiniana)为主,表层以下其它各层均以巴豆叶脆杆藻(Fragilaria cro-tonensis)为绝对优势种,垂向分布表现为5～10 m区间为浮游植物高密度区域,温跃层以下浮游植物密度显著下降,水温分层可能是决定浮游植物垂向分布的重要因素之一.浮游植物最大光合效率从表层向下层逐步降低,实际光合效率最大值出现在垂向10 m区域.  相似文献   

13.
抚仙湖浮游甲壳动物群落结构与空间分布   总被引：4，自引：3，他引：1  
云南抚仙湖是我国典型的高原深水湖泊,为揭示湖中浮游甲壳动物对生态系统变化的响应,研究了其群落结构与空间分布特征.2005年6-7月在抚仙湖共采集浮游甲壳动物8种,平均密度为27.6ind./L,优势类群为桡足类.桡足类优势种为舌状叶镖水蚤(Phyllodiaptomus tunguidus Shen et Tai),枝角类优势种为角突网纹涵(Ceriodaphnia cornuta Sars)和象鼻溞(Bosmina sp.).浮游甲壳动物主要分布在0-30m水层,密度随水深增加而下降;0-10m水层,枝角类和无节幼体占优势,大于10m水层,桡足类占优势.浮游甲壳动物密度南区大于北区(P<0.01),而沿岸区与湖心区之间、沉水植物区与非沉水植物区之间无显著性差异(P>0.05).相关分析表明:浮游甲壳动物密度的垂直分布与藻类密度和水体理化凼子相关关系显著,而水平分布与藻类密度和水体理化因子相关关系不显著.与20世纪80年代相比,抚仙湖浮游甲壳动物优势种发生了演替,西南荡镖水蚤(Neutrodiaptomus mariadviagae mariadviagae (Brohm))消失,被舌状叶镖水蚤代替,可能与太湖新银鱼(Neosalanx taihuensi Chen)引入有关;浮游甲壳动物密度表现出增加趋势,但仍处于较低水平,与水体营养水平的提高及太湖新银鱼的捕食压力有关.  相似文献   

14.
Under biogenic load and at high abundance of ichthyofauna (the concentration of total phosphorus Ptot = 0.20 mg P/l, mineral phosphorus Pmin = 0.13 mg P/l, and at the ratio N: P = 4: 1 in early summer), zooplankton reduced phytoplankton biomass during summer and autumn and determined high water transparency, reaching >50% of the depth of the water body. It was found that, with a passage of ichthyofauna to artificial food, the trophic press of plankton-eating fish on zooplankton decreases. Under such conditions, with the biomass ratio of plant-eating zooplankton to edible phytoplankton between 0.4 and 7.9, zooplankton can reduce phytoplankton biomass within a day. The major portion (up to 100%) in phytoplankton biomass reduction was due to large-size filterers-phytophages Daphnia longispina and verticators Asplanchna priodonta helvetica.  相似文献   

15.
Experimental studies were carried out in a water body near Moscow and in a flow-through system in the territory of fertilized agricultural fields. It is shown that under high biogenic load, at the concentrations Ptot = 0.14 mg P/l, Pmin = 0.07 mg P/l, and the ratio N: P = 7.9: 1, in early summer, and in the absence of plankton-eating fish, zooplankton was regulating phytoplankton development and contributed to the preservation of high water transparency. At the biomass ratio of plant-eating zooplankton to eatable phytoplankton from 0.6 to 42.2, zooplankton can reduce the eatable part of phytoplankton within a day. The main consumers of the eatable fraction of phytoplankton biomass were large-size filterers Daphnia longispina.  相似文献   

16.
Residual, or tidally averaged, circulation in fjords is generally assumed to be density driven and two layered. This circulation consists of a thin surface layer of outflow and a thick bottom layer of sluggish inflow. However, development of different vertical structures in residual circulation in fjords can arise from wind, remote, and tidal forcing that may modify the two-layer circulation. Particularly, theoretical results of tidal residual flows in homogeneous semienclosed basins indicate that their vertical structure is determined by the dynamical depth of the system. This dynamical depth can be considered as the ratio between the water column depth and the depth of frictional influence in an oscillatory flow (inverse of Stokes number). When the frictional depth occupies the entire water column, the tidal residual flow is one layered as in shallow basins. But when the frictional depth is only a small portion of the water column (>6 times smaller), the tidal residual is three layered. In relatively deep fjords (say deeper than 100 m), where frictional depths typically occupy a small portion of the water column, the tidal residual flow is expected to be three layered. Ample observational evidence presented here shows a three-layered exchange flow structure in fjords. On the basis of observational and theoretical evidence, it is proposed that the water exchange structure in deep fjords (more than six frictional layers deep, or inverse Stokes number >6) is tidally driven and is three layered. The tidally driven three-layer structure of residual flows could be regarded in some cases as the fundamental structure. However, this structure will only be observed sporadically as it will be masked by wind forcing, remote forcing from the ocean, and freshwater pulses.  相似文献   

17.
The Bohai Sea is a semi-enclosed inland sea with case-2 waters near the coast. A comprehensive set of optical data was collected during three cruises in June, August, and September 2005 in the Bohai Sea. The vertical profile measurements, such as chlorophyll concentration, water turbidity, downwelling irradiance, and diffuse attenuation coefficient, showed that the Bohai Sea was vertically stratified with a relative clear upper layer superimposed on a turbid lower layer. The upper layer was found to correspond to the euphotic zone and the deep chlorophyll maximum (DCM) occurs at the base of this layer. By tuning a semi-analytical model (24 and 25) for the Bohai Sea, we developed a method to derive water inherent optical properties and the depth of DCM from above-surface measurements. Assuming a ‘fake’ bottom in the stratified water, this new method retrieves the ‘fake’ bottom depth, which is highly correlated with the DCM depth. The average relative error between derived and measured values is 33.9% for phytoplankton absorption at 440 nm, 25.6% for colored detrital matter (detritus plus gelbstoff) absorption at 440 nm, and 24.2% for the DCM depth. This modified method can retrieve water inherent optical properties and monitor the depth of DCM in the Bohai Sea, and the method is also applicable to other stratified waters.  相似文献   

18.
Limnological characteristics of Lake Burdur in Lake District in south‐western Turkey are presented. It is a deep, tectonic (estimated max. depth 100 m), athalassic, highly alkaline, and saline lake. A set of physical and chemical variables was monitored, phyto‐ and zooplankton was sampled from surface layer of the lake during 1997. Physico‐chemical variables indicated that the lake is hyposaline and composed of some hydrochemically different water layers formed by groundwater sources located on the bottom of the lake. The phytoplankton composition of Lake Burdur consisted of Cyanophyta, Chlorophyta, Bacillariophyta, Dinophyta, and Chrysophyta. The abundance and number of species of Chlorophyta and Cyanophyta were higher than the other taxa. The zooplankton composition of the Lake consisted of Rhizopoda, Rotifera, and Crustacea. Number of species of Rotifera was higher than the other taxa. The diversities of the phyto‐ and zooplankton were calculated according to the Shannon‐Weaver diversity index. The diversity of each group was found to be low in the lake.  相似文献   

19.
Neustonic microplastic and zooplankton abundance was determined in the North Western Mediterranean Sea during a summer cruise between July 9th and August 6th 2010, with a break between July 22 th and 25th due to a strong wind event. Ninety percent of the 40 stations contained microplastic particles (size 0.3-5mm) of various compositions: e.g., filaments, polystyrene, thin plastic films. An average concentration of 0.116 particles/m(2) was observed. The highest abundances (>0.36 particles/m(2)) were observed in shelf stations. The neustonic plastic particles concentrations were 5 times higher before than after the strong wind event which increased the mixing and the vertical repartition of plastic particles in the upper layers of the water column. The values rise in the same order of magnitude than in the North Pacific Gyre. The average ratio between microplastics and mesozooplankton weights was 0.5 for the whole survey and might induce a potential confusion for zooplankton feeders.  相似文献   

20.
太湖梅梁湾冬末春初浮游动物时空变化及其环境意义   总被引：20，自引：8，他引：12  
根据１９９８年２－３月完全原庆湖梅梁湾地区水环境综合调查,对有关浮游动物时空情况进行了分析,这次调查共设７个点,湾口上的Ｊ２,Ｊ４与湾内的Ｊ６,Ｊ７均是分５层采样,共分无风,小风和大风３次天气过程,每次过程采集２到３次样品与记录。结果显示,太湖梅梁湾地区浮游生物中枝角类和桡足类的生物量与水温变化关系密切,水温越高,生物量越高,温度相同时,其生物量与透明度呈正比。  相似文献   

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