The distribution of bacterioplankton and mesozooplankton biomass in the White and Barents Seas coastal water

The total population density and the biomass of bacterioplankton, mesozooplankton, and phosphate-accumulating bacteria (PAB) were estimated during the 2000-2001 summer-autumn seasons in the coastal waters of the White and Barents Seas, which are subjects to the action of tidal and sea currents, the inflow of riverine waters, and anthropogenic impact. In the shallow estuarine waters with salinities of 6.5-32@1000 near the Chernaya, Pesha, and Pechora River mouths, the population of PAB fluctuated from 0.1 to 9.1 million cells/ml (0-36% of the total bacterial population). In pelagic seawaters, which are low in phosphates (12-50 micrograms/l) and are characterized by an increased iron/phosphorus ratio (2.0-3.6), bacterioplankton amounted to 0.1-1.6 million cells/ml and was mainly represented by small organisms with a volume of 0.08-0.15 micron 3, commonly lacking intracellular polyphosphates. In the pelagic zone of the Barents Sea, the biomass of mesozooplankton (Bz) was comparable with that of bacterioplankton (Bb = 39-175 mg/m3), the Bb/Bz ratio being 1.4-4.6. Off the Varandeiskii, Pechora, and Kolguyev oil terminals, Bb increased to 155-300 mg/m3 and the Bb/Bz ratio rose to 1.4 to 50.3 (with an average value of 20.9), presumably due to the severe anthropogenic impact on these waters. In this case, the dense population of bacterioplankton (0.9-7.6 million cells/ml) was mainly represented by large cells (0.12-0.76 micron 3 in volume), most of which (3-43% of the total bacterioplankton population) contained polyphosphates. The chemical composition of these waters was characterized by an elevated content of the total phosphorus (65-128 micrograms/l) and by a low iron/phosphorus ratio (0.9-1.2).     

桂西北喀斯特峰丛洼地表层土壤养分时空分异特征

本文运用传统统计方法研究了典型喀斯特峰丛洼地4个植被演替阶段(草地、灌木林、次生林、原生林)表层(0—15 cm)土壤养分的空间分异特征,并分析其成因。结果表明：(1)不同植被演替阶段土壤养分（有机碳、全氮、碳氮比、全磷、全钾、碱解氮、速效磷、速效钾）及pH值有明显差异（P<0.05）;除全钾外,其他养分含量均随植被正向演替而增加。(2)地貌部位对养分含量的影响不尽一致：各植被演替阶段的磷、钾及原生林的碳氮均符合养分的“洼积效应”,只有受人为干扰较强的草地、灌木林、次生林的碳氮养分存在随坡位升高而增加的现象。通过本研究得知,植被演替对养分积累具有积极作用;磷素（速效磷3.55—11.41 mg/kg）、钾素（速效钾64.05—105.75 mg/kg）是该区域的养分限制性因子;该区域养分的“倒置现象”并不普遍存在。     

Nitrogen limitation of phytoplankton in a Spanish karst lake with a deep chlorophyll maximum: a nutrient enrichment bioassay approach

An in vitro nutrient addition bioassay was performed to testthe relative inorganic nitrogen (N) and phosphorus (P) limitationof phytoplankton in a Spanish karst lake (El Tejo) during thelast part of the stratification period, when nutrient limitationis most pronounced. Nutrient deficiency was tested in samplesfrom three different layers of the lake: the epilimnion, metalimnionand oxic hypolimnion. Nitrogen additions, either without orcombined with P, increased phytoplankton growth in all threestrata, compared with controls or P treatments. This showedthat N was the nutrient limiting phytoplankton growth in latesummer–early fall. Since both hypolimnetic diffusion andgroundwater fluxes of N-rich waters into the lake are much reducedduring summer, N becomes the limiting nutrient as stratificationadvances. We suggest that in this Mediterranean area with lowatmospheric deposition of anthropogenic N and in lakes relativelyfree of surface run-off, nutrient supply by atmospheric depositionmight be a key factor in controlling nutrient deficiency forphytoplankton growth.     

Bioassays with Stigeoclonium Kütz. (Chlorophyceae) to identify nitrogen and phosphorus limitations

Eleven strains of the filamentous algae genus Stigeoclonium Kütz. (Chlorophyceae) were tested as bioassay organisms to identify nitrogen and phosphorus limitations to growth in a variety of waters. The assay results were related to the nutrient status of the waters during the year. Optimal growth was obtained at an inorganic phosphorus concentration of 0.65 mg P 1^?1 and an inorganic nitrogen concentration of 3.75 mg N 1^?1. The algal growth potentials were generally higher in November and February than in August. In summer, nitrogen became important as a limiting nutrient. When ratios of inorganic nitrogen to inorganic phosphorus (N/P) were above 6.2, phosphorus was primarily limiting and at lower N/P ratios nitrogen became the important limiting factor. Stigeoclonium proved to be a suitable bioassay organism to identify nutrient limitation in freshwaters.     

Rice (Oryza sativa) as a Remediation Tool for Nutrient Runoff

Hypereutrophication of U.S. surface waters is one of the leading causes of impairment for water quality. With nutrient criteria development and total maximum daily load (TMDL) issues looming for regulators, agricultural research is focusing on practices aimed at decreasing nutrient contributions to receiving aquatic ecosystems. This study examined the use of rice (Oryza sativa) for luxury uptake of nitrogen and phosphorus components associated with agricultural storm runoff. Mesocosms (379 L) planted with rice were exposed to two concentrations (5 and 10 mg/L) of nitrate, ammonia, and orthophosphorus. Results from these mesocosms were compared to unvegetated controls (also amended with 5 or 10 mg/L nitrate, ammonia, and orthophosphorus) to determine efficiency of rice in remediating nutrient runoff. Statistically significant differences in ammonia and nitrate retention of vegetated mesocosms amended with 5 mg/L versus vegetated mesocosms amended with 10 mg/L were noted after the first exposure. Although rice is a nutrient-dependent aquatic plant, this study suggests that more efficient mitigation is possible at lower inflow concentrations as opposed to higher inflow concentrations.     

Rainwater: Nutrient additions to a hypereutrophic lake

Rainwater was collected near culturally eutrophic Lake Sallie, Minnesota. Rain pH was low, but sulphuric acid did not appear to be the causative agent. Nitrogen varied greatly in single rainfalls. Ammonia was normally more concentrated than nitrate; both fell in sufficient quantitites to enrich surface waters. Atmospheric N loading may stimulate algal production. Rainwater phosphorus was normally less than 40 µg/l and insignificant in contrast to cultural influences. Calculations of rainfall nutrient contributions are given.     

磷素营养对降香黄檀幼苗生长及叶片养分状况的影响

设置0、15、30、60、100、150 mg P·株^-1等6个磷素处理开展降香黄檀幼苗盆栽试验,测定各处理幼苗的生长、生物量、叶片养分含量等指标,采用临界浓度法确定降香黄檀幼苗的适宜施磷量,从而探讨不同磷素水平对降香黄檀幼苗生长和叶片养分状况的影响,揭示其磷素需求规律以及适宜的磷供应范围。结果显示磷肥能促进幼苗生长和生物量的积累,而且随施磷量的增加,各指标呈现先升高后降低的趋势,最高值出现在60 mg P·株^-1处理,其苗高、地径、叶面积、生物量分别为对照的3.07、2.35、49.21和24.25倍。施磷显著降低幼苗叶片氮、钾含量,提高磷、镁含量,其中30、60、100 mg P·株^-13个处理间叶片磷含量差异不显著,约为对照的1.65倍。根据幼苗生物量与叶片磷含量、氮钾含量比、磷钾含量比的抛物线关系,确定叶片最适磷含量范围为1.35~2.32 g·kg^-1,由此推断降香黄檀幼苗最适宜的施磷量为60~100 mg P·株^-1。     

Cell-to-cell pollution reduction effectiveness of subsurface domestic treatment wetlands

Quarterly water quality data from 1998 to 2003 for eight single-family domestic systems serving 2-7 people in Ohio, USA, were studied to determine the cell-to-cell and system wide pathogen reduction efficiency and effectiveness of these systems in meeting compliance standards. Two-cell domestic wastewater treatment systems displayed significant variability in their cell-to-cell performance that directly impacted the overall ability of systems to meet effluent compliance standards. Fecal coliform was effectively reduced (approximately 99%) in these systems while two-thirds of the input biochemical oxygen demand was mitigated in each of the cells of these systems. Fecal coliform and biochemical oxygen demand were typically reduced below 2000 counts per 100 ml and 15 mg/l (respectively) before discharge to surface waters. Total suspended solids were reduced by approximately 80% overall with cell one retaining the majority of the solids (approximately 70%). These systems discharged more than 18 mg/l of suspended solids in less than 5% of the samples thus displaying a very high compliance rate. Ammonia and total phosphorus were less effectively treated (approximately 30-40% reductions in each cell) and exceeded standards (1.5 mg/l) more frequently. Analyses based on the number of occupants indicated that the two-cell design used here was most effective for smaller occupancy systems. More study is required to determine the value of this design for large occupancy systems. In the future, wetlands should be evaluated based on the total loads delivered to the watershed rather than by effluent concentrations.     

三湖连江水库水化学特征

总结了1987年4月至1989年10月三湖连江水库水化学特征,季节变化及其年际变动,结果表明:该水库水质清澈,透明度平均为313cm,pH值平均为7.8,水呈中性,溶解氧丰富平均为8.81mg/L;矿化度平均为121.82mg/L,水型属重碳酸盐类,钙组Ⅱ型水(CⅡCa);水中主要营养元素氮含量高,总氮平均为1.38mg/L,磷含量低,总磷平均为0.022mg/L,氮和磷比为62.7:1,表明磷是水体生物生产力的主要限制性营养元素。多数理化组分周年中出现明显的季节变化,和在平面分布上差异显着,多数理化组分年际变化不明显。       

The effect of aquatic plant chemistry and morphology on feeding selectivity by the crayfish, Orconectes virilis

SUMMARY. 1. Feeding preference trials conducted with male and female crayfish ( Orconectes virilis ) showed that out of ten submersed aquatic plant species, Chara sp. and Lemna trisulca were the preferred food sources, followed by Myriophyllum exalbescens or Utricularia vulgaris .
2. Analysis of plant fibre, alkaloid, total phosphorus, total and available nitrogen, and organic content showed that crayfish feeding preferences were not related ( P >0.5) to plant fibre or alkaloid content but were negatively correlated ( P <0.05) with plant nutrient content such that species of low nutritional value ( Chara and Lemna ) were consistently preferred.
3. Despite this preference for low nutrient food, daily intake rates by crayfish for phosphorus, nitrogen and organic matter were greatest when feeding on Lemna or Chara due to the large quantity consumed.
4. We suggest that feeding preferences of O. virilis are not determined by plant chemistry but, rather, relate to ease of handling small, short, bottom-dwelling plants such as Chara and Lemna as compared with large erect, roseate or floating-leaved forms. Because crayfish are selective herbivores, their introduction into waters where they do not naturally occur could have a dramatic effect on both the species composition and biomass of submersed plants.     

Responses of periphyton to artificial nutrient enrichment in freshwater kettle ponds of Cape Cod National Seashore

Nutrient enrichment bioassays, in conjunction with sampling and analysis of surface water chemistry, were conducted in freshwater lakes (kettle ponds) of Cape Cod National Seashore (Massachusetts, USA) to ascertain the importance of nitrogen (N) and phosphorus (P) in regulating the growth of periphyton. Arrays of nutrient diffusing substrata (NDS) were suspended 0.5 m below the water surface in a total of 12 ponds in July and August 2005. Algal biomass developing on each NDS after ~3 weeks of exposure in each month was assessed by quantifying chlorophyll a + phaeophyton pigments. In both July and August, strong responses to N + P and N enrichments were observed in the majority of ponds, while P had no stimulatory effect. These responses correspond well with low atomic ratios (1–18) of dissolved inorganic nitrogen (DIN) to total phosphorus (TP) in ambient surface waters. The results suggest that conditions in the kettle ponds develop whereby nitrogen is the primary limiting nutrient to periphyton growth. While this may be a seasonal phenomenon, it has implications for nutrient management in individual ponds and within the larger watershed.     

长兴县合溪水库集雨区苗木地不同施肥管理模式对径流磷素流失的影响

为保护主要饮用水源合溪水库水质,长兴县将合溪水库集雨区农业种植结构向苗木种植方式调整,但缺乏优化施肥管理模式。针对该问题,选取集雨区典型苗木种植地进行径流小区定位试验,设置了撒施(对照)、地膜覆盖、秸秆覆盖、区外设置植草缓冲带、条施、穴施6个处理,研究不同施肥管理模式下苗木地径流磷素流失特征,筛选最优施肥管理模式,实现最大化的削减农田磷素流失。结果表明:不同施肥管理模式下,苗木地地表径流年总磷素径流流失通量大小顺序为:撒施(对照)地膜覆盖条施穴施区外植草缓冲带秸秆覆盖,撒施(对照)、地膜覆盖、条施、穴施、区外设置植草缓冲带和秸秆覆盖六种施肥管理模式下的年总磷素径流流失通量分别为:9.60、9.14、5.49、4.44、2.48、1.37 kg hm-2a-1,说明穴施、区外设置植草缓冲带和秸秆覆盖是较佳的施肥管理模式,若将其优化组合将显著消减合溪水库集雨区苗木地径流磷素流失及其对合溪水库水质的潜在影响。此外,不同施肥管理模式下,苗木地径流水样磷素流失的首要形态均为颗粒态磷,其次为溶解态磷,其中,撒施(对照)、地膜覆盖、秸秆覆盖、区外植草缓冲带、条施和穴施小区径流年均流失的颗粒态磷占流失总磷的比例分别是66.09%、70.69%、67.97%、71.63%、68.11%和67.87%。     

饥饿胁迫对麦长管蚜有翅成蚜能量物质含量的影响

【目的】分析饥饿胁迫下麦长管蚜Sitobion avenae(Fabricius)的能量物质含量变化,以期从生理生化角度为蚜虫饥饿胁迫下的能量适应机制提供依据。【方法】以取食小麦苗的麦长管蚜为对照,测定饥饿胁迫下麦长管蚜有翅成蚜的鲜重、干重、含水量、可溶性糖、糖原、总脂和可溶性蛋白质含量变化,通过这些不同生化物质含量之间的相关关系,分析饥饿胁迫下麦长管蚜的能量代谢特点。【结果】麦长管蚜饥饿组鲜重和干重均低于羽化后同一时间取食个体,前者范围分别为5.30~8.73和1.67~3.10 mg/20头,后者分别为7.93~8.73和2.53~3.10 mg/20头;饥饿组和取食组含水量范围分别为63.16%~71.76%和63.25%~67.32%,除羽化后1 d外,饥饿组含水量均高于羽化后同一时间取食个体;饥饿组可溶性糖、糖原、总脂和可溶性蛋白质的含量分别在6.60~11.21,0.35~10.81,18.28~30.42和12.77~33.44μg/mg鲜重之间,均低于羽化后同一时间取食个体(分别为7.53~11.21,3.66~10.81,27.53~33.63和21.54~34.43μg/mg鲜重)。饥饿3 d恢复取食后1 d,鲜重、干重、含水量和糖原含量均增加,而可溶性糖、总脂和可溶性蛋白质的含量均降低。相关分析表明,饥饿组可溶性糖与糖原、总脂或者可溶性蛋白质的含量以及可溶性蛋白质与糖原或者总脂的含量存在正相关关系。【结论】饥饿胁迫下麦长管蚜的代谢变化与其糖原、总脂和可溶性蛋白质含量降低有密切关系,通过能量物质的综合利用来适应短期饥饿胁迫。     

Evaluation of mercury level in waters, bottom sediments and soils in selected rural areas

The studies carried out aimed at evaluation of the mercury level in waters, bottom sediments and soils in selected rural areas, during the season of mercury biocides application and after their withdrawal from agricultural use. Generally, in the period between 1976-1980 the mercury level in 1268 environmental samples has been examined. Shallow dug wells of bad technical state and wrong location particularly exposed to contamination, have been selected for the studies. Mercury level has been determined after mineralization with concentrated acids by means of flameless method of atomic absorption spectrophotometry. The results have been compared with standards for mercury level in drinking waters (1 microgram/l) and in surface waters (5 micrograms/l), with the Warren-Devault criterion for soils (0.25 mg/kg) and with the value 1 mg/kg adopted as maximum natural mercury level in bottom sediments. The results have also been the subject to statistical analysis by means of the Tsao-Fei method and t-test. Mercury level in well waters, surface waters, bottom sediments and soils varied according to the region and the year of study and were respectively: 0.08-26.00 micrograms/l; 0.00-25.20 micrograms/l; 0.02-91.91 mg/kg; 0.01-24.94 mg/kg. Mercury levels of several dozen micrograms/l (waters) and several dozen mg/kg (bottom sediments and soils) have been recorded only in a few cases. A statistically significant decrease of mercury level in the environment of the regions investigated coincided with mercury biocides withdrawal from agricultural practice in our country.     

辽西北沙地苹果-大豆间作对土壤养分和微生物量分布的影响

为了解辽西北沙地果农间作系统中土壤养分及微生物量分布特征,选取研究区具有代表性的苹果(Malus pumila)-大豆(Glycine max)间作系统为研究对象,对间作系统0～60 cm 土层、0～300 cm水平距离范围内的土壤养分和微生物量进行了测定,并与大豆单作、苹果单作进行对比.结果表明:辽西北沙地苹果与大豆...     

圈养大熊猫食谱组成与营养成分分析

为了探讨圈养大熊猫主食竹食谱组成及主要影响因素,并为圈养单位提供科学合理的食物营养配比和饲养管理建议。本研究通过对成都大熊猫繁育研究基地１０ 只成年大熊猫４ 年（２００９. ０３ －２０１３.０２）的饲养数据,３只成年大熊猫１ 年（２０１２. ０７ －２０１３. ０６）的觅食行为观察数据,以及投饲的３ 种竹笋和５ 种主食竹常规养分和总黄酮含量的统计分析。结果发现,基地圈养大熊猫偏好竹笋,喜食巴山木竹叶、白夹竹茎和苦竹茎,随机采食箬竹叶和刺竹茎;基地大熊猫根据投饲竹种类和季节的变化,形成了较为稳定的食谱组成;对投饲竹各部位成分比较分析发现,投饲竹养分含量的变化呈现出一定的规律性：其中粗蛋白、粗脂肪、蛋白质和能量比都以竹叶最高,竹枝次之,竹茎最低;干物质和粗纤维的含量则以竹茎最高,竹枝次之,竹叶最少;竹茎和竹枝呈现钙少磷多的现象,而竹叶则是钙多磷少;各投饲竹不同部位总黄酮含量以叶中最高,枝中其次,茎中最低。研究结果表明,圈养大熊猫主食竹食谱的选择遵循能量和营养学的规律,选择适口性强、营养价值高的食物假说。     

太平湖水库水质的理化特征

总结了1985年11月至1986年7月太平湖水库水质的理化特性,结果表明:太平湖水库水质良好,透明度高平均为321cm;pH值平均为7.4;水中溶解氧丰富;总离子量较低;水质属重碳酸盐类钙组Ⅰ型水(CⅠCa).水中主要生物营养元素氮含量较高,总氮平均为1.49mg/L,磷含量较低,总磷平均为0.012mg/L.氮、磷比为124.2:1,表明磷是该水体生物生产力的限制性营养元素。水中多数理化组分有明显的季节变化,多数理化组分在平面和垂直分布上也有差异,但差异不显着。       

Sources and bioavailability of phosphorus fractions in freshwaters: a British perspective

This paper seeks a perspective on the forms of phosphorus which promote aquatic eutrophication, with the particular quest of establishing their sources. A short background traces the development of understanding of nutrient enrichment and the suppositions about the relative contributions of agriculture, sewage and detergent residues. Most aquatic systems, and their primary producers, are naturally deficient in biologically-available phosphorus. Aquatic plants have evolved very efficient phosphorus uptake mechanisms. The biomass responses to an increase in the supply of phosphorus are stoichiometrically predictable. The most bioavailable forms of phosphorus are in solution, as orthophosphate ions, or are readily soluble or elutable from loose combinations. Ready bioavailability coincides well with what is measurable as molybdate-reactive (MRP) or soluble-reactive phosphorus (SRP). Most other forms, including phosphates of the alkaline earth metals, aluminium and iron are scarcely available at all. Orthophosphate ions sorbed to metal oxides and hydroxides are normally not biologically available either, except through weak dissociation ('desorption'). The production of alkaline phosphatase provides organisms with an additional mechanism for accelerating the sequestration of phosphate from organic compounds. Bioavailable phosphate is liberated when redox- or alkali-sensitive metal hydroxides dissolve but these processes are minor contributors to the biological responses to nutrient enrichment. Most of the familiar eutrophication is attributable to the widespread application of secondary sewage treatment methods to the wastes emanating from a burgeoning and increasingly urbanised human population. The use of polyphosphate-based detergents, now in decline, has contributed to the problem. In aquatic systems, the additional phosphorus raises the biological supportive capacity, sometimes to the capacity of the next limiting factor (carbon, light, hydraulic retention or of another nutrient). At high orthophosphate loadings, the straight stoichiometric yield relationship between biomass yield and phosphorus a vailability is lost. Movements of phosphorus and its recycling within aquatic systems do not prevent the slow gravitation of phosphorus to the bottom substrata. The phosphorus retentivity of sediments depends upon their chemical composition. While oxide-hydroxide binding capacity in the surface sediments persists, they act as a sink for phosphorus and a control on further cycling. Iron-rich and clay-rich sediments perform best in these conditions; calcareous sediments least so. Eutrophication may lead to the exhaustion of sediment P-binding capacity. Non-sorbed phosphate is readily recyclable if primary producers have access to it. Recycling is most rapid in shallow waters (where sediment disturbance, by flow, by wind action and through bioturbation, is frequent and least in deep ventilated sediments. The contributions of phosphorus from catchments are assessed. The slow rate of weathering of (mostly apatitic) minerals, the role of chemical binding in soils and the incorporation and retentivity bv forested terrestrial ecosystems each contribute to the minimisation of phosphorus leakage to drainage waters. Palaeolimnological and experimental evidence confirms that clearance of land and ploughing its surface weakens the phosphorus retentivity of catchments. The phosphorus transferred from arable land to drainage remains dominated by sorbed fractions which are scarcely bioavailable. Some forms of intensive market gardening or concentrated stock rearing may mobilise phosphates to drainage but it is deduced that drainage from agricultural land is not commonly a major source of readily bioavailable phosphorus in water. Careful budgeting of the phosphates in run-off from over-fertilised soils may nevertheless show that a proportionately small loss of bioavailable phosphorus can still be highly significant in promoting aquatic plant production. The bioavailable-phosphorus (BAP) load achieving the OECD threshold of lake eutrophy (35 mg P m(-3)) is calculated to be equivalent to a terrestrial loss rate of approximately 17.5 kg BAP km(-2) year(-1)), or only 1-2% of a typical fertiliser application. The output is shown to be comparable with the P yield from secondary treatment of the sewage produced by a resident population of 30-44 persons km(-2). With tertiary treatment, the equivalence is with approximately 200 persons km(-2).     

城市化背景下白洋淀入湖营养盐负荷模拟研究

过量的营养盐输入导致白洋淀富营养化程度较高。雄安新区建设伴随着快速城镇化进程,将可能进一步增加入湖营养盐负荷。为摸清新区建设背景下白洋淀入湖营养盐负荷的变化趋势及削减量,基于入湖营养盐负荷模型计算了历史不同时期（1995-2015年）白洋淀入湖营养盐盐负荷,预测了土地利用、农业管理和污水处理系统变化下入湖营养盐负荷的变化趋势。结果表明,白洋淀历史时期入湖总氮和总磷年平均负荷分别为2018 t和313 t,主要来源分别是耕地和畜禽粪便排放。就土地利用变化而言,以2010年为基准,2050年白洋淀入湖总氮和总磷负荷在建设用地快速增长（RAP）情景下增长率最高,分别增长了56%和60%,主要原因在于城镇人口增加,从而增加了畜禽需求量和生活污水排放。就农业管理而言,削减化肥使用有利于降低入湖总氮负荷,控制畜禽粪便排放更有利于入湖总磷负荷的降低。2050年,生活污水将成为白洋淀入湖营养盐的重要来源,因此,在制定未来社会经济发展路径时,应重点提高农村地区生活污水收集率和处理效率。PCLake模型对不同入湖负荷下湖泊营养状态演变的模拟发现,削减入湖总磷负荷是白洋淀水质恢复的关键。白洋淀水质达到III类和IV类标准时,入湖总磷负荷阈值分别为2.1和2.6 mg P m^-2 d^-1。在建设用地快速增长情景下,若使白洋淀水质达到III类标准,入湖总磷负荷应减少131 t。     

An optical-density-based feedback feeding method for ammonium concentration control in Spirulina platensis cultivation

Cultivation of Spirulina platensis using ammonium salts or wastewater containing ammonium as alternative nitrogen sources is considered as a commercial way to reduce the production cost. In this research, by analyzing the relationship between biomass production and ammonium- N consumption in the fed-batch culture of Spirulina platensis using ammonium bicarbonate as a nitrogen nutrient source, an online adaptive control strategy based on optical density (OD) measurements for controlling ammonium feeding was presented. The ammonium concentration was successfully controlled between the cell growth inhibitory and limiting concentrations using this OD-based feedback feeding method. As a result, the maximum biomass concentration (2.98 g/l), productivity (0.237 g/l·d), nitrogen-to-cell conversion factor (7.32 gX/gN), and contents of protein (64.1%) and chlorophyll (13.4 mg/g) obtained by using the OD-based feedback feeding method were higher than those using the constant and variable feeding methods. The OD-based feedback feeding method could be recognized as an applicable way to control ammonium feeding and a benefit for Spirulina platensis cultivations.