Minimum Quota Research Articles

Import of Biofuels into and the Marketing of Biofuels in the European Union: an Analysis of the Current Law on Customs, Energy Taxes and Biofuel Quotas

Currently, there is an ongoing discussion about the pros and cons of biofuels. However, it is an inalienable fact that it is not realistic to reduce greenhouse gases in the transport sector using current fuels. Therefore, biofuels have to be promoted. In order to increase the use of biofuels it is first important to produce more biofuels at both the national and the European level. Secondly, however, imports of biofuels from countries outside the European Union have to increase. This article analyses the implications of importing these products into the European Union from the perspective of customs and energy tax law as well as the so-called biofuel quota.Under current European customs law there is no single classification for biofuels. Depending on their chemical make-up, biofuels are treated as chemical or agricultural products. While bioethanol is classified as alcohol, the classification of vegetable oil depends on its intended use. The classification of biodiesel differs depending on whether it is pure biodiesel or not. Once a biofuel is within the European Union, it may be regarded as an energy product. This is the case when the product is suitable for use and is used as a fuel. In this case, the biofuel may be subject to energy tax. Some European Member States grant tax relief but others, eg, in a recent move, Germany, only grant tax relief for unmixed products. The increase of the minimum level of biofuel that is put into circulation on the internal market is a target set out by the European Union. To achieve this aim, the German and other governments introduced biofuel quotas. Companies have to guarantee a particular minimum biofuel quota each calendar year. This quota may be satisfied by placing pure biodiesel on the market or by mixing it into mineral fuels. Furthermore, companies may trade in quotas. In the future, certain sustainability requirements will play an important role.

Competition patterns among phytoplankton functional groups: How useful are the complex mathematical models?

Simple models have significant contribution to the development of ecological theory. However, these minimalistic modeling approaches usually focus on a small subset of the causes of a phenomenon and neglect important aspects of system dynamics. In this study, we use a complex aquatic biogeochemical model to examine competition patterns and structural shifts in the phytoplankton community under nutrient enrichment conditions. Our model simulates multiple elemental cycles (org. C, N, P, Si, O), multiple functional phytoplankton (diatoms, green algae and cyanobacteria) and zooplankton (copepods and cladocerans) groups. It also takes into account recent advances in stoichiometric nutrient recycling theory, and the zooplankton grazing term is reformulated to include algal food quality effects on zooplankton assimilation efficiency. The model provided a realistic platform to examine the functional properties (e.g., kinetics, growth strategies, intracellular storage capacity) and the abiotic conditions (temperature, nutrient loading) under which the different phytoplankton groups can dominate or can be competitively excluded in oligo, meso and eutrophic environments. Based on the results of our analysis, the intergroup variability in the minimum cell quota and maximum transport rate at the cell surface for phosphorus along with the group-specific metabolic losses can shape the structure of plankton communities. We also use classification tree analysis to elucidate aspects (e.g., relative differences in the functional group properties, critical values of the abiotic conditions, levels of the other plankton community residents) of the complex interplay among physical, chemical and biological factors that drive epilimnetic plankton dynamics. Finally, our study highlights the importance of improving the mathematical representation of phytoplankton adaptive strategies for resources procurement (e.g., regulation of transport kinetics, effects of transport kinetics on the kinetics of assimilation, relationship between assimilation and growth) to effectively link variability at the organismal level with ecosystem-scale patterns.

The importance of the form of the quota curve and control of non-limiting nutrient transport in phytoplankton models

The description of phytoplankton growth and nutrient acquisition plays a pivotal role in affecting the performance of plankton ecosystem models. A comparison was made between the behaviour of multi-nutrient phytoplankton models with alternative descriptions of the relationships between the nutrient:C quota and growth rate (μ) and for the control of the transport of the non-limiting nutrient. Using Droop kinetics (i.e. employing a hyperbolic curve form fixed by the ratio of maximum: minimum quotas), or conversely a linear quota-μ relationship, gave models that could display behaviour in strong disagreement with that of the optimal model when operated in a dynamic scenario. The appropriate description of the control of the transport of the non-limiting nutrient is also important; in particular, a fixed algal N:P should not be assumed. Behaviour was most likely to be aberrant when P was limiting; behaviour under nutrient limitation when the N:P nutrient supply ratio accorded with Redfield expectations (16:1 mole) was least aberrant. Deviations of model output from expected behaviour would affect the simulation of the dynamics of phytoplankton growth, nutrient cycling, competition and have serious repercussions in models in which the stoichiometric quality of the phytoplankton prey affects zooplankton activity. It is important that the behaviour of phytoplankton behaviour accords with that of the groups they purport to represent. However, we currently lack the data upon which to parameterize such models.

Phosphorus acquisition by Chlamydomonas acidophila under autotrophic and osmo-mixotrophic growth conditions

Chlamydomonas acidophila Negoro is a green algal species abundant in acidic waters where inorganic phosphorus (P(i)) and carbon (CO(2)) are considered the most important growth-limiting nutrients for the phytoplankton. This paper describes the P(i) uptake and growth kinetics under varying carbon supply by cultivating the alga autotrophically, with and without CO(2) aeration, and osmo-mixotrophically with glucose under low P(i) conditions at pH 2.7. The low minimum cellular phosphorus quota (Q(0); ranging from 0.6 to 1.1 mmol P mol(-1) C) suggested P(i)-limiting conditions under all different modes of carbon supply, and was lowest under CO(2)-aerated conditions. The threshold P(i) concentration for growth did not vary from zero, suggesting no detectable metabolic costs. Maximum P(i)-uptake rates (V(max)) were a better indication of P(i) limitation when compared with the affinity constant for P(i) uptake (K(m)), as V(max) was only high under P(i)-limited conditions whereas K(m) was low under both P(i)-limited and P(i)-replete conditions. Osmo-mixotrophic growth conditions did not result in decreased extracellular phosphatase activity, but often resulted in physiological characteristics comparable with CO(2)-aerated cells, suggesting intracellular CO(2) production by glucose respiration. In addition, at low CO(2) and in autotrophic conditions, C. acidophila had a higher Q(0), lower dissolved organic carbon concentration, lower maximum P(i)-uptake rates, and lower phosphatase activity, suggesting that growth was co-limited by CO(2) and P(i). Furthermore, cells may respond physiologically to both nutrient limitations simultaneously.

Low potassium and inorganic carbon concentrations influence a possible phosphorus limitation in Chlamydomonas acidophila (Chlorophyceae)

Chlamydomonas acidophila, a dominant phytoplankton species in the very acidic Lake 111 (pH 2.7) situated in Germany, faces low concentrations of inorganic phosphorus (Pi), inorganic carbon (Ci) and potassium (K+) in its environment, which may lead to a complex colimitation by these nutrients. We performed laboratory and field investigations to test for Pi limitation and its dependence on Ci and K+ concentrations. The minimum cell quota for phosphorus (Q0) and phosphatase enzyme activity were similar to those for neutrophilic algae, despite the low pH and high concentrations of iron and aluminium, indicating no extra metabolic costs or inhibition of enzymes by the extreme environment. The threshold concentration of soluble reactive phosphorus for growth (SRPt), the algal C:P ratio and the alkaline phosphatase enzyme activity all suggested a moderate Pi limitation of C. acidophila in Lake 111. SRPt and Q0 were higher at low CO2 and K+ concentrations in culture, showing a relationship between Ci and Pi acquisition. Furthermore, SRPt and Q0 were higher under K+/Pi-colimiting conditions than under Pi-limiting conditions alone, suggesting that K+ concentrations influence Pi limitation in C. acidophila as well. Our results show that a limitation by one macronutrient requires consideration of the availability of the others as their uptake mechanisms depend on each other. Notwithstanding these interactions, Ci or K+ concentrations had no clear influence on the Pi limitation of C. acidophila in Lake 111.

Nitrogen and phosphorus utilization in the cyanobacterium Microcystis aeruginosa isolated from Laguna de Bay, Philippines

Phytoplankton supports fisheries and aquaculture production. Its vital role as food for aquatic animals, like mollusks, shrimp, and fish cannot be overemphasized. Because of its contribution as a food source for fish, the growth kinetics of Microcystis aeruginosa, a dominant cyanobacterium in the lake, was studied. The regular occurrence of M. aeruginosa is experienced during the months of May to July or from September to November in Laguna de Bay, the largest freshwater lake in the Philippines. M. aeruginosa was collected from Laguna de Bay, isolated, and established in axenic conditions. Data on the growth kinetic parameters for nitrate-nitrogen and phosphate-phosphorus utilization by M. aeruginosa gave the following values: half-saturation constant (K s ), 0.530 mg N. L−1 and 0.024 mg P. L−1 respectively; maximum growth rate (μ max ), 0.671. d−1 and 0.668. d−1 respectively; maximum cell yield, 6.5 and 6.54 log, cells. ml−1 respectively; nutrient level for saturated growth yield, 8.71 mg N. L−1 and 0.22 mg P. L−1 respectively; and minimum cell quota (Q 0 ), 2.82 pg N. cell−1 and 0.064 pg P. cell−1 respectively. The low K s value and high maximum growth rate (μ max ) for phosphorus by M. aeruginosa would suggest a high efficiency of phosphorus utilization. On the other hand, the high K s value for nitrogen indicated a low rate of uptake for this nutrient.

Nutrition and growth kinetics in nitrogen- and phosphorus-limited cultures of the novel red tide flagellate Chattonella ovata (Raphidophyceae)

In the summer of 2004, a harmful bloom caused by Chattonella ovata (Raphidophyceae) occurred over almost the entire area of the Seto Inland Sea and caused fishery damages. This incident was the first record of a bloom and damage to the fisheries caused by this species in Japanese waters. In order to elucidate the mechanism of the bloom outbreak, we examined the nutrition and the growth kinetics in nitrogen (N)- and phosphorus (P)-limited semi-continuous cultures of this species. Inorganic N compounds, such as nitrate, nitrite, and ammonium, were found to be good nitrogen sources for the growth of C. ovata, while organic nitrogen (urea and uric acid) was not utilized. This species was capable of using ATP, ADP and inorganic phosphorus compounds, but did not utilize phosphate monoesters as a sole P source. Under both N-limited and P-limited steady state conditions, the growth rate as a function of cell nitrogen and phosphorus quota, respectively, followed the Droop equation. Kinetic parameters μ m (maximum growth rate) and k q (minimum cell quota) obtained for N- and P-limited cultures were 0.79 day −1 and 5.5 pmol N cell −1 and 0.86 day −1 and 0.48 pmol P cell −1, respectively. The minimum cell quotas were 23–30% lower than those of C. antiqua. The nutrient availability and kinetic parameters of C. ovata are compared with other harmful algae and the ecological implications of these characteristics discussed.

여수해만산 유독 와편모조류 Gymnodinium catenotum (Graham)의 용존태 무기인에 대한 성장 및 흡수

We investigated the growth and phosphate uptake of a toxic dinoflagellate, Gymnodinium catenatum, isolated from Yeosuhae Bay, South Korea. A short-term phosphate uptake experiment revealed that its maximum uptake and the half-saturation constant were 1.39 pmol/cell/hr and <TEX>$2.65{\mu}M$</TEX>, respectively. In a semicontinuous culture, the maximum specific growth rate and minimum phosphorus cell quota of G. catenatum were 0.39/day and 1.27 pmol/cell, respectively. Thus, G. catenatum is a poor competitor in terms of inorganic nutrient use and is unlikely to form blooms in Yeosuhae Bay.

Policies to Reduce Rent Seeking in Controlled Markets

We analyze the effects of various policies to reduce rent seeking in the controlled market in which buyers have heterogeneous valuation regarding the coveted good. The good is allocated according to the buyer-specific signal (‘test score’), which is determined by the quantity of wasteful ‘rent seeking’ exerted by the buyer. We consider three common forms of market control: minimum qualification score, quota, and price ceiling. The potential buyers with higher valuations are more likely to receive the good in equilibrium, while they exert more rent-seeking efforts. Marginally relaxing market control does not necessarily decrease the aggregated amount of rent-seeking activities, and the effectiveness of policy measures usually depends on the current degree of competitiveness in the market.

A inclusão de pessoas com necessidades especiais no trabalho: a visão de empresas e de instituições educacionais especiais na cidade de Curitiba

A inclusão é um processo pelo qual a sociedade se adapta para permitir a participação das pessoas em todos os seus setores, inclusive daquelas pessoas com necessidades especiais (PNE's), e estas, por sua vez, se preparam para assumir seus papéis na sociedade. O acesso de PNE's ao mercado de trabalho é um dos aspectos do processo de inclusão, importante por proporcionar às pessoas condições para a satisfação de suas necessidades básicas, a valorização de si mesmas e o desenvolvimento de suas potencialidades. O objetivo dessa pesquisa foi levantar, junto a empresas com mais de 100 funcionários e a instituições que atendem jovens e adultos com necessidades especiais, quais as práticas que vêm sendo adotadas para inclusão de PNE's no mercado de trabalho e as eventuais dificuldades encontradas nesse processo. Foram realizadas entrevistas com 30 empresas e 10 instituições educacionais, todas na cidade de Curitiba (PR). Os resultados indicaram que as empresas não cumprem a Lei de Cotas, que regulamenta a contratação de PNE's. As empresas afirmam que o maior empecilho para isso é a baixa escolarização das PNE's e sua baixa qualificação profissional. As instituições educacionais criticam os processos adotados pelas empresas na contratação de PNE's, mas poucas oferecem escolarização para seus alunos, concentrando-se, em sua maioria, no desenvolvimento de habilidades básicas para o trabalho ou em capacitação profissional eventualmente diferente daquela exigida pelo mercado de trabalho. São discutidas, também, as contradições encontradas entre legislação, práticas educacionais e mercado de trabalho, no que diz respeito à inclusão.

Promoting renewable energies under the CDM: combining national quotas in Europe and the CDM

Abstract In the context of combating climate change, renewable energies are considered to play an important role. As these energies are currently not fully competitive compared with conventional power generation technologies, (minimum) quotas have been proposed as one means of overcoming this problem. However, when implementing any instruments at the national level, one should bear in mind that the efficiency of most types of renewable energies is dependent on the location. Thus, leaving the national perspective and investing abroad may result in improved efficiency. Against this background, the integration of the CDM into the European renewable energy policy is proposed.

Growth and uptake kinetics for nitrate, ammonium and phosphate by the toxic dinoflagellate Gymnodinium catenatum isolated from Hiroshima Bay, Japan

: Growth and uptake kinetics for nitrate, ammonium and phosphate by Gymnodinium catenatum isolated from Hiroshima Bay were experimentally investigated. Maximum uptake rate (ρmax) and half saturation constant (Ks), which were obtained by short-term uptake experiments, were 6.48 pmol/cell per h and 7.60 µM for nitrate, 3.37 pmol/cell per h and 33.6 µM for ammonium, and 1.42 pmol/cell per h and 3.40 µM for phosphate, respectively. Specific maximum growth rate (µ′m) and minimum cell quota (Q0), which were obtained by semicontinuous growth experiments, were 0.36/day and 31.3 pmol/cell for the N-limited conditions, respectively. The µ′m and QP0 for P-limited conditions were 0.37/day and 1.83 pmol/cell, respectively. These results indicate that G. catenatum is a poor competitor in terms of utilization of inorganic nutrients and is unlikely to form blooms in Hiroshima Bay where phosphate is chronically depleted unless the growth is supported by organic species (i.e. dissolved organic phosphorus) of the nutrients.

Effects of salinity and nutrient conditions on growth and haemolytic activity of Fibrocapsa japonica (Raphidophyceae)

The influence of salinity and a number of nitrogen (N) and phosphorus (P) levels on growth and haemolytic activity of the harmful algal bloom (HAB) species Fibrocapsa japonica were studied simultaneously. The F. japonica strain studied had a euryhaline growth profile with an optimum growth rate at 26 psu. Measurements of the minimum cell quota of N and P revealed an optimum N:P ratio of 24.5 and a relatively high requirement of nutrients (q0N = 7.1 pmol cell -1 ; q0P = 0.29 pmol cell -1 ). These characteristics fit the habitat of this species, among which is the P-controlled eutrophied Dutch coastal waters. Salinity had a significant effect on the growth rate of F. japonica and on its haemolytic activity, even on the basis of equal cell volume. The highest haemolytic activity was found at 16 psu, the lowest salinity condition tested. The EC50 values that were expressed on a per cell basis revealed that F. japonica had a high haemolytic activity when compared with other HAB species. Under N limitation, cells of F. japonica were less haemolytic than cells not limited for N, but this could be caused by a slight decrease in cell volume only. Remarkably, cells not limited for N appeared to form aggregates, which in combination with the elevated levels of haemolytic compounds per cell may result in obstruction of gills, causing fish kills during F. japonica blooms. So, despite the absence of brevetoxin in our strain of F. japonica, this strain may be lethal to fish due to its haemolytic activity.

After the Revolution: Gender and Democracy in El Salvador, Nicaragua, and Guatemala

After the Revolution: Gender and Democracy in El Salvador, Nicaragua, and Guatemala

Nutrition and growth kinetics in nitrogen- or phosphorus-limited cultures of the ‘novel red tide’ dinoflagellate Heterocapsa circularisquama (Dinophyceae)

Heterocapsa circularisquama is a dinoflagellate that has only recently been recorded as producing red tides; it causes severe damage to Japanese shellfish aquaculture by killing bivalves. In order to elucidate the mechanism of red tide outbreaks, the nutrition and growth kinetics of H. circularisquama were examined in nitrogen (N)– or phosphorus (P)–limited semicontinuous culture. Inorganic N compounds, such as nitrate, nitrite, and ammonium, were found to be good nitrogen sources for the growth, whereas organic nitrogen (urea and uric acid) was not utilized. Heterocapsa circuiarisquama could successfully use a wide variety of inorganic and organic phosphorus compounds of different molecular structures as the sole P source. Under N-limited steady-state conditions, the dilution rate (= growth rate) as a function of cell nitrogen quota followed the Droop equation. Under P-limited steady state culture too, the dilution rate as a function of cell P quota followed the Droop equation. Kinetic parameters Dm, (the maximum dilution rate) and Kq (minimum cell quota) were 0.9 d−1 and 1.1 pmol N cell−1 for N-limited cultures and 1.1 d−1 and 89.4 fmol P cell−1 for P-limited cultures. The nutrient availability and kinetic parameters of H. circularisquama are compared with other red-tide organisms and the ecological implications of these characteristics are discussed.

Effects of temperature, and availability of nitrogen and phosphorus on the abundance of Anabaena and Microcystis in Lake Biwa, Japan: an experimental approach

Under optimal nutrient conditions, both Microcystis sp. and Anabaena sp. isolated from Lake Biwa grew optimally at 28–32°C but differed in maximal growth rates, phosphate uptake kinetics, maximal phosphorus quotas, and growth responses to nitrogen and phosphorus limitation. The maximal growth rates of Microcystis and Anabaena were 1.6 and 1.25 divisions day−1, respectively. With phosphate and nitrate in the growth-limiting range, the growth of Microcystis was optimal at an N : P ratio of 100 : 1 (by weight) and declined at lower (nitrogen limitation) and higher (phosphorus limitation) ratios. In contrast, Anabaena growth rates did not change at N : P ratios from 1000 : 1 to 10 : 1. Starting with cells containing the maximal phosphorus quota, Microcystis growth in minus-phosphorus medium ceased in 7–9 days, compared with 12–13 days for Anabaena. The phosphate turnover time in cultures starved to their minimum cell quotas was 7.9 min for Microcystis and 0.6 min for Anabaena. Microcystis had a higher K s (0.12 μg P l−1 10−6 cells) and lower V max (9.63 μg P l−1 h−1 10−6 cells), than Anabaena (K s 0.02 μg P l−1 h−1 10−6 cells; V max 46.25 63 μg P l−1 h−1 10−6 cells), suggesting that Microcystis would not be able to grow well in phosphorus-limited waters. We conclude that in spite of the higher growth rate under ideal conditions, Microcystis does not usually bloom in the North Basin because of low availability of phosphorus and nitrogen. Although Anabaena has an efficient phosphorus-uptake system, its main strategy for growth in low-phosphorus environments may depend on storage of phosphorus during periods of abundant phosphorus supply, which are rare in the North Basin.

Cellular microcystin content in N-limited Microcystis aeruginosa can be predicted from growth rate.

Cell quotas of microcystin (Q(MCYST); femtomoles of MCYST per cell), protein, and chlorophyll a (Chl a), cell dry weight, and cell volume were measured over a range of growth rates in N-limited chemostat cultures of the toxic cyanobacterium Microcystis aeruginosa MASH 01-A19. There was a positive linear relationship between Q(MCYST) and specific growth rate (mu), from which we propose a generalized model that enables Q(MCYST) at any nutrient-limited growth rate to be predicted based on a single batch culture experiment. The model predicts Q(MCYST) from mu, mu(max) (maximum specific growth rate), Q(MCYSTmax) (maximum cell quota), and Q(MCYSTmin) (minimum cell quota). Under the conditions examined in this study, we predict a Q(MCYSTmax) of 0.129 fmol cell(-1) at mu(max) and a Q(MCYSTmin) of 0.050 fmol cell(-1) at mu = 0. Net MCYST production rate (R(MCYST)) asymptotes to zero at mu = 0 and reaches a maximum of 0.155 fmol cell(-1) day(-1) at mu(max). MCYST/dry weight ratio (milligrams per gram [dry weight]) increased linearly with mu, whereas the MCYST/protein ratio reached a maximum at intermediate mu. In contrast, the MCYST/Chl a ratio remained constant. Cell volume correlated negatively with mu, leading to an increase in intracellular MCYST concentration at high mu. Taken together, our results show that fast-growing cells of N-limited M. aeruginosa are smaller, are of lower mass, and have a higher intracellular MCYST quota and concentration than slow-growing cells. The data also highlight the importance of determining cell MCYST quotas, as potentially confusing interpretations can arise from determining MCYST content as a ratio to other cell components.

Modelling Si-N-limited growth of diatoms

A mechanistic model for silicon (Si) physiology is developed, interfaced with a model of nitrogen IN) physiology, which is capable of simulating the major documented facets of Si-N physiology in diatoms. The model contains a cell cycle component that is involved in regulating the timing ol the synthesis of valves, girdles and setae. In addition to reproducing the timing of diatom cell division within a light- dark cycle, the model simulates the following features seen in real diatoms. Synthesis of valves only occurs during G 2 interphase and M, while the girdles and (if appropriate) setae are synthesized during G 1 Si stress alone results in a loss of setae, followed by a thinning of the valves in successive generations until a minimum Si cell quota is attained. After this point, the duration of G 2 increases and growth is Si limited. Concurrently, the carbon (C) cell quota increases, offering the capability to simulate the documented increase in sinking rates with Si stress. N stress alone results in an increase in the duration of G 1 and G 2 interphases, and high Si cell quotas, From this complex model which must be run for arrays of subpopulations to simulate non-synchronous growth, a simpler model is developed. This is capable of reproducing similar growth dynamics, although with no reference to component parts of the frustule. When allied to a photoacclimative submodel, a prediction of the model is that diatoms starved of Si will release increased amounts of dissolved organic C because cell growth is halted more rapidly than the photosystems can be degraded.

Effect of nitrogen and phosphorus on the growth of a red tide dinoflagellateScrippsiella trochoidea (Stein) Loeblich III

Scrippsiella trochoidea (Stein) Loeblich III was grown in a nitrogen-or phosphorus-limited batch culture system in laboratory. Growth rates and cellular Chl-a were measured as functions of nitrate and phosphate concentrations. Growth rates were hyperbolic with both nitrate and phosphate concentration and fit the Monod equation. The minimum cell quota of nitrogen and phosphorus and then the optimum N∶P ratio ofS. trochoidea were estimated in this study. Measurement of phosphate concentration in Jiaozhou Bay suggest that phosphorus is the limiting factor ofS. trochoidea growth.

Growth and phosphate uptake kinetics of the toxic dinoflagellate Alexandrium tamarense from Hiroshima Bay in the Seto Inland Sea, Japan

SUMMARY Shellfish poisoning by the toxic dinoflagellate Alexandrium tamarense (Lebour) Balech occurred for the first time in Hiroshima Bay, Japan, in 1992. Oyster culture in the bay produces as much as 60% of the total production in Japan, and it suffered severe damage. In the present study, we experimentally investigated the growth rate and phosphate uptake kinetics of A. tamarense, Hiroshima Bay strain. A short-term phosphate uptake experiment revealed that the maximum uptake rate was 1.4 pmol P cell-1 per h and the half-saturation constant was 2.6 umol L-1. In semicontin-uous culture, the maximum specific growth rate and the minimum phosphorus cell quota were 0.54 day-1 and 0.56 pmol P cell-1, respectively. These uptake rates suggest that A. tamarense is a poor phosphorus competitor compared with other species. However, the large phosphorus storage capacity (Qpmax/qo= 36), the surge phosphorus uptake ability (Vs/Vi= 4.1) and the low growth rate would be advantageous for surviving brief periods of phosphorus limitation which frequently occur in Hiroshima Bay.