PICES Press, Vol. 17, No. 2, July 2009

Major Outcomes from the 2009 PICES Annual Meeting: A Note from the Chairman (pdf, 0.1 Mb) The FUTURE is Here (pdf, 0.1 Mb) PICES Harmful Algal Bloom International Seafood Safety Project (pdf, 0.3 Mb) PICES at the 2009 GLOBEC Open Science Meeting (pdf, 0.4 Mb) Modeling Ecosystems and Ocean Processes Workshop (pdf, 0.1 Mb) Krill Biology and Ecology Workshop (pdf, 0.1 Mb) Polar and Sub-Polar Marine Ecosystems Workshop (pdf, 0.4 Mb) Biogeochemistry of the Oceans in a Changing Climate Workshop (pdf, 0.1 Mb) Continuous Plankton Recorder Surveys of the Global Oceans (pdf, 0.4 Mb) Plankton Phenology Workshop (pdf, 0.2 Mb) Workshop on “Climate Impact on Ecosystem Dynamics of Marginal Seas” (pdf, 0.1 Mb) Erratum (pdf, 0.4 Mb) The State of the Western North Pacific in the Second Half of 2008 (pdf, 0.2 Mb) State of the Northeast Pacific into early 2009 (pdf, 0.1 Mb) Current Status of the Bering Sea Ecosystem (pdf, 0.1 Mb) 2009 Salmon Forecasting Forum (pdf, 0.3 Mb) The Third Argo Science Workshop: “The Future of Argo” (pdf, 0.1 Mb) 2009 ESSAS Annual Science Meeting (pdf, 0.1 Mb) A Visit Fit for an Emperor and Empress of Japan (pdf, 0.9 Mb)

PICES Press, Vol. 16, No. 1, January 2008

◾PICES Science in 2007 (pdf, 0.1 Mb) ◾2007 Wooster Award (pdf, 0.1 Mb) ◾FUTURE - A milestone reached but our task is not done (pdf, < 0.1 Mb) ◾International symposium on "Reproductive and Recruitment Processes of Exploited Marine Fish Stocks" (pdf, 0.1 Mb) ◾Recent results of the micronekton sampling inter-calibration experiment (pdf, 0.1 Mb) ◾2007 PICES workshop on "Measuring and monitoring primary productivity in the North Pacific" (pdf, 0.1 Mb) ◾2007 Harmful Algal Bloom Section annual workshop events (pdf, 0.1 Mb) ◾A global approach for recovery and sustainability of marine resources in Large Marine Ecosystems (pdf, 0.3 Mb) ◾Highlights of the PICES Sixteenth Annual Meeting (pdf, 0.4 Mb) ◾Ocean acidification of the North Pacific Ocean (pdf, 0.3 Mb) ◾Workshop on NE Pacific Coastal Ecosystems (2008 Call for Salmon Survival Forecasts) (pdf, 0.1 Mb) ◾The state of the western North Pacific in the first half of 2007 (pdf, 0.4 Mb) ◾PICES Calendar (pdf, 0.4 Mb) ◾The Bering Sea: Current status and recent events (pdf, 0.3 Mb) ◾PICES Interns (pdf, 0.3 Mb) ◾Recent trends in waters of the subarctic NE Pacific (pdf, 0.3 Mb) ◾Election results at PICES (pdf, 0.2 Mb) ◾A new PICES award for monitoring and data management activities (pdf, < 0.1 Mb)

Osmotic stress does not trigger brevetoxin production in the dinoflagellate Karenia brevis

With the global proliferation of toxic Harmful Algal Bloom (HAB) species, there is a need to identify the environmental and biological factors that regulate toxin production. One such species, Karenia brevis, forms nearly annual blooms that threaten coastal regions throughout the Gulf of Mexico. This dinoflagellate produces brevetoxins, potent neurotoxins that cause neurotoxic shellfish poisoning and respiratory illness in humans, as well as massive fish kills. A recent publication reported that a rapid decrease in salinity increased cellular toxin quotas in K. brevis and hypothesized that brevetoxins serve a role in osmoregulation. This finding implied that salinity shifts could significantly alter the toxic impacts of blooms. We repeated the original experiments separately in three different laboratories and found no evidence for increased brevetoxin production in response to low-salinity stress in any of the eight K. brevis strains we tested, including three used in the original study. Thus, we find no support for an osmoregulatory function of brevetoxins. The original publication also stated that there was no known cellular function for brevetoxins. However, there is increasing evidence that brevetoxins promote survival of the dinoflagellates by deterring grazing by zooplankton. Whether they have other as yet unidentified cellular functions is currently unknown.

National Centers for Coastal Ocean Science (NCCOS) research highlights in the Chesapeake Bay

The Chesapeake Bay is the largest estuary in the United States. It is a unique and valuable national treasure because of its ecological, recreational, economic and cultural benefits. The problems facing the Bay are well known and extensively documented, and are largely related to human uses of the watershed and resources within the Bay. Over the past several decades as the origins of the Chesapeake’s problems became clear, citizens groups and Federal, State, and local governments have entered into agreements and worked together to restore the Bay’s productivity and ecological health. In May 2010, President Barack Obama signed Executive Order number 13508 that tasked a team of Federal agencies to develop a way forward in the protection and restoration of the Chesapeake watershed. Success of both State and Federal efforts will depend on having relevant, sound information regarding the ecology and function of the system as the basis of management and decision making. In response to the executive order, the National Oceanic and Atmospheric Administration’s National Centers for Coastal Ocean Science (NCCOS) has compiled an overview of its research in Chesapeake Bay watershed. NCCOS has a long history of Chesapeake Bay research, investigating the causes and consequences of changes throughout the watershed’s ecosystems. This document presents a cross section of research results that have advanced the understanding of the structure and function of the Chesapeake and enabled the accurate and timely prediction of events with the potential to impact both human communities and ecosystems. There are three main focus areas: changes in land use patterns in the watershed and the related impacts on contaminant and pathogen distribution and concentrations; nutrient inputs and algal bloom events; and habitat use and life history patterns of species in the watershed. Land use changes in the Chesapeake Bay watershed have dramatically changed how the system functions. A comparison of several subsystems within the Bay drainages has shown that water quality is directly related to land use and how the land use affects ecosystem health of the rivers and streams that enter the Chesapeake Bay. Across the Chesapeake as a whole, the rivers that drain developed areas, such as the Potomac and James rivers, tend to have much more highly contaminated sediments than does the mainstem of the Bay itself. In addition to what might be considered traditional contaminants, such as hydrocarbons, new contaminants are appearing in measurable amounts. At fourteen sites studied in the Bay, thirteen different pharmaceuticals were detected. The impact of pharmaceuticals on organisms and the people who eat them is still unknown. The effects of water borne infections on people and marine life are known, however, and the exposure to certain bacteria is a significant health risk. A model is now available that predicts the likelihood of occurrence of a strain of bacteria known as Vibrio vulnificus throughout Bay waters.

Brevetoxin in two planktivorous fishes after exposure to Karenia brevis: implications for food-web transfer to bottlenose dolphins

Brevetoxin uptake was analyzed in 2 common planktivorous fish that are likely foodweb vectors for dolphin mortality events associated with brevetoxin-producing red tides. Fish were exposed to brevetoxin-producing Karenia brevis for 10 h under conditions previously reported to produce optimal uptake of toxin in blood after oral exposure. Striped mullet Mugil cephalus were exposed to a low dose of brevetoxin, and uptake and depuration by specific organs were evaluated over a 2 mo period. Atlantic menhaden Brevoortia tyrannus specimens were used to characterize a higher brevetoxin dose uptake into whole body components and evaluate depuration over 1 mo. We found a high uptake of toxin by menhaden, with a body to water ratio of 57 after a 10 h exposure and a slow elimination with a half life (t1/2) of 24 d. Elimination occurred rapidly from the intestine (t1/2 < 1 wk) and muscle (t1/2 ≈ 1 wk) compartments and redistributed to liver which continued to accumulate body stores of toxin for 4 wk. The accumulation and elimination characteristics of the vectoring capacity of these 2 fish species are interpreted in relation to data from the Florida Panhandle dolphin mortality event of 2004. We show that due to slow elimination rate of brevetoxin in planktivorous fish, brevetoxin-related dolphin mortality events may occur without evidence of a concurrent harmful algal bloom event.

A supply network configuration perspective on international supply chain development

Purpose - The purpose of this paper is to explore the impact of configuration on supply network capability. It was believed that a configuration perspective might provide new insights on the capability and performance of supply networks, a gap in the literature, and provide a basis for the development of tools to aid their analysis and design. Design/methodology/ approach - The methodology involved the development of a configuration definition and mapping approach extending established strategic and firm level constructs to the network operational level. The resulting tools were tested and refined in a series of case studies across a range of sectors and value chain models. Supply network capability assessments, from the perspective of the focal firm, were then compared with their configuration profiles. Findings - The configuration mapping tools were found to give new insights into the structure of supply networks and allow comparisons to be made across sectors and business models through the use of consistent and quantitative methods and common presentation. They provide the foundations for linking configuration to capability and performance, and contribute to supply network design and development by highlighting the intrinsic capabilities associated with different configurations. Research limitations/implications - Although multiple case networks have been investigated, the configuration exemplars remain suggestive models. The research suggests that a re-evaluation of operational process excellence models is needed, where the link between process maturity and performance may require a configuration context. Practical implications - Advantages of particular configurations have been identified with implications for supply network development and industrial policy. Originality/value - The paper seeks to develop established strategic management configuration concepts to the analysis and design of supply networks by providing a robust operational definition of supply network configuration and novel tools for their mapping and assessment. © Emerald Group Publishing Limited.

Phylogenetic studies of pantherine cats (Felidae) based on multiple genes, with novel application of nuclear beta-fibrinogen intron 7 to carnivores

The pantherine lineage of the cat family Felidae (order: Carnivora) includes five big cats of genus Panthera and a great many midsized cats known worldwide. Presumably because of their recent and rapid radiation, the evolutionary relationship among pantherines remains ambiguous. We provide an independent assessment of the evolutionary history of pantherine lineage using two complete mitochondrial (mt) genes (ND2 and ND4) and the nuclear beta-fibrmogen intron 7 gene, whose utility in carnivoran phylogeny was first explored. The available four mt (ND5, cytb, 12S, and 16SrRNA) and two nuclear (IRBP and TTR) sequence loci were also combined to reconstruct phylogeny of 14 closely related cat species. Our analyses of combined mt data (six genes; approximate to 3750 bp) and combined mt and nuclear data (nine genes; approximate to 6500 bp) obtained identical tree topologies, which were well-resolved and strongly supported for almost all nodes. Monophyly of Panthera genus in pantherine lineage was confirmed and interspecific affinities within this genus revealed a novel branching pattern, with P. tigris diverging first in Panthera genus, followed by P. onca, P. leo, and last two sister species P. pardus and P. uncia. In addition, close association of Neofelis nebulosa to Panthera, the phylogenetic redefinition of Otocolobus manil within the domestic cat group, and the relatedness of Acinonyx jubatus and Puma concolor were all important findings in the resulting phylogenies. The potential utilities of nine different genes for phylogenetic resolution of closely related pantherine species were also evaluated, with special interest in that of the novel nuclear beta-fibrinogen intron 7. (c) 2005 Elsevier Inc. All rights reserved.

Spring Diatom Blooming Phases in a Representative Eutrophic Bay of the Three-Gorges Reservoir, China

We investigated dynamics of the phytoplankton community and abiotic factors in Xiangxi Bay of the Three-Gorge Reservoir, China, by daily sampling, a specific site during a spring algal bloom (February 23-April 28, 2005). Among the 76 taxa observed, Asterionella formosa and Cyclotella spp. were the dominants, accounting for 47.2% and 29.9% of the total abundance, respectively. We determined the five distinct developing phases of the bloom by analyzing the dissimilarity of physicochemical parameters. Simultaneously, six phytoplankton community groups were distinguished by TWINSPAN classifications. The pattern for algal community succession was similar to that for the bloom phase shift, and the structural complexity of communities significantly decreased over time. Water temperature and silicate were the main factors that related to the development of the bloom and the shifts of the phytoplankton community.

Allelopathic effects of phenolic compounds present in submerged macrophytes on Microcystis aeruginosa

In laboratory studies, the allelopathic effects of 3 (Hydrocharitaceae family) submerged macrophytes (Elodea nuttallii (Planch) St. John, Hydrilla verticillata (L.f.) Royle and Vallisneria spiralis L.) were investigated on two strains of Microcystis aeruginosa. Both aqueous methanol extracts and exudates of three macrophytes inhibited the growth of both strains of Microcystis aeruginosa, After 3-days culture, E nuttallii, H. verticillata and V. spiralis excreted 0.8, 0.3 and 1.0% of total phenolic compounds (TPC), respectively, into the surrounding water. After removing phenolic compounds by polyvinylpolypyrrolidone (PVPP)), the plant exudates showed very weak activity. The inhibitory rates of exudates of E. nuttallii, H. verticillata and V. spiralis, against non-toxic M. aeruginosa were decreased by 35.7, 43.4 and 59.1% respectively. Thus 3 submerged macrophytes released the phenolic compounds into the surrounding water, to inhibit the growth of M. aeruginosa. This information may help us in understanding the mechanism of allelopathy in aquatic ecosystems and to control the algal bloom in eutrophic water bodies.

Distribution of phytoplankton in the Three-Gorge Reservoir during rainy and dry seasons

After damming of the Yangtze River, in order to explore the impacts of the Three-Gorge Dam (TGD) on the aquatic ecosystem, phytoplankton composition, abundance and biomass spatial distribution were studied in the Three-Gorge Reservoir (TGR), and the closest upstream anabranch Xiangxi River, which is 38 kin away from the Three-Gorge Dam (TGD) during August (rainy season) 2004 and April (dry season) 2005. In surveys, 6 transects (2 downstream and 4 cross-stream) and 25 stations have been investigated and 314 samples were collected from the surface to the river bed with water samplers. In TGR, 63 taxa and 60 taxa were identified in the rainy and dry seasons, respectively. In the Xiangxi River, 39 taxa were observed in the rainy and dry seasons. Algal blooms occurred in the Xiangxi River and at the influx region of the Yangtze and Xiangxi in both seasons, but had not occurred prior to damming. In the rainy season, the dominant species was Chroomonas acuta with 1.84 x 10(7) cells l(-1), and in the dry season the dominant species were Asterionella formosa and Cryptomonas ovata with 1.34 x 10(7) cells l(-1) and 1.79 x 10(6) cells(.)l(-1), respectively. In the main channel of TGR, there were no significant correlations between phytoplankton abundance and the concentrations of the main soluble nutrients. In the Xiangxi River, significant negative correlations were observed between phytoplankton abundance and nitrate (Spearman, p < 0.01, n=21), phosphate (Spearman, p < 0.05, n=21) and silicate (Spearman, p < 0.01, n=21) in the rainy season, and similar correlations were also observed with nitrate (Spearman, p < 0.05, n=28) and silicate (Speannan, p < 0.01, n=28), but not with phosphate in the dry season. Since the damming of the Yangtze River, eutrophication in the anabranch within the backwater has occurred and become severe, and the frequency of algal bloom within TGR and anabranches is expected to increase. (c) 2006 Elsevier B.V. All rights reserved.

The temporal and spatial distribution, composition and abundance of Protozoa in Chaohu Lake, China: Relationship with eutrophication

Systematic investigations into the temporal and spatial distribution, composition and abundance of protozoa in two regions with different trophic levels in Chaohu Lake, a large, shallow and highly eutrophic freshwater lake in China, were conducted during 2002-2003. A total of 114 species of protozoa, including phytomastigophorans, zoomastigophorans, amoebae and ciliates, were identified from 120 polyurethane foam unit (PFU) samples exposed at four stations and from various types of natural substrates. Of the 114 taxa, 36 core species were found on PFU substrates and 23 of these were found on natural ones. Protozoan abundance and chemical physical parameters at nine sampling stations, four in the western lake and five in the eastern part, indicate trophic gradient changes along the lake. Seasonal variations in the species composition of major groups at littoral PFU sampling stations illustrate the effect of a severe algal bloom on the protozoan community structure. Temporal and spatial distributions of individual abundance as functions of water temperature and trophic status were revealed. This study demonstrates again that the PFU artificial substrate method samples protozoan communities more effectively than routine natural substrate methods. (c) 2005 Elsevier GmbH. All rights reserved.

Development of rRNA and rDNA-targeted probes for fluorescence in situ hybridization to detect Heterosigma akashiwo (Raphidophyceae)

Heterosigma akashiwo (Hada) is a fragile, fish-killing alga. Efforts to understand and prevent blooms due to this harmful species to mitigate the impact on aquaculture require the development of methods for rapid and precise identification and quantification, so that adequate warning of a harmful algal bloom may be given. Here, we report the development and application of rRNA and rDNA-targeted oligonucleotide probes for fluorescence in situ hybridization (FISH) to aid in the detection and enumeration of H. akashiwo. The designed probes were species specific, showing no cross-reactivity with four common HAB causative species: Prorocentrum micans Ehrenberg, P. minimum (Pavillard) Schiller, Alexandrium tarmarense (Lebour) Balech, and Skeletonema costatum (Greville) Cleve, or with four other microalgae, including Gymnodinium sp. Stein, Platy-monas cordiformis (Karter) Korsch, Skeletonema sp.1 Greville and Skeletonema sp.2. The rRNA-targeted probe hybridized to cytoplasmic rRNA, showing strong green fluorescence throughout the whole cell, while cells labeled by rDNA-targeted probe exhibited exclusively fluorescent nucleus. The detection protocols were optimized and could be completed within an hour. For rRNA and rDNA probes, about a corresponding 80% and 70% of targeted cells could be identified and quantified during the whole growth circle, despite the inapparent variability in the average probe reactivity. The established FISH was proved promising for specific, rapid, precise, and quantitative detection of H. akashiwo. (C) 2008 Elsevier B.V. All rights reserved.

Morphological and phylogenetic analysis of a Gymnodinium-like species from the Chinese Coast

A Gymnodinium-like species was studied with light microscopy (LM) and scanning electron microscopy (SEM). Also, the internal transcribed spacers (containing 5.8S rDNA) and large ribosomal subunit DNA (D1-D2) sequences were obtained by PCR amplification, and then sequenced to explore the relationships within our isolate, Gymnodinium and other Gymnodinium-like species, including Karenia, Gyrodinium, Karlodinium and Symbiodinium. The LM observation showed that the species was characterized by moving in a levorotatory direction, visible hypocone, epicone and transverse groove, all of which are typical for Gymnodinium. In addition, two flagella could be found under SEM. The phylogenetic analysis revealed that the isolate grouped with Symbiodium, rather than other relevant dinoflagellates. All results showed our isolate belongs to Symbiodium. The strain was isolated from a red tide water sample, denoting that Symbiodium may be causative species for algal bloom.

东海大规模赤潮对微型浮游动物群落结构影响的研究

本文从赤潮发生前的现场模拟实验、赤潮发生时的现场培养实验和赤潮发生过程中的现场调查等方面，较为系统地研究了东海大规模赤潮对微型浮游动物群落结构的影响。 2005年长江口及邻近海区赤潮发生前，赤潮973MC2005－03航次在本海区进行了综合调查，期间分别于4月27日、5月4日和5月8日，在zzf1、zc18a和ra5三个站位利用现场船基培养的方法，研究了添加到赤潮密度106 cells L-1的东海原甲藻（Prorocentrum donghaiense）对微型浮游动物群落结构的影响。结果发现，赤潮密度的东海原甲藻对小型无壳纤毛虫的种群数量影响较大，而对中大型砂壳纤毛虫的影响较小，从而使得微型浮游动物群落有向中大型砂壳纤毛虫演替的趋势。在zzf1站位，小型无壳纤毛虫占绝对优势，添加东海原甲藻72 h后，优势种由管游虫（Cyrtostrombidium sp.）演替为另一种小型无壳纤毛虫急游虫4（Strombidium sp.4）；在以中型砂壳纤毛虫百乐拟铃虫（Tintinnospsis beroidea）为优势种的zc18a站位，仍然是以此为优势种，但其在群落中的优势度更加明显；ra5站位也是以小型无壳纤毛虫为主，添加东海原甲藻72 h后，其群落结构由急游虫2（Strombidium sp.2）向中大型砂壳纤毛虫纤毛虫百乐拟铃虫和亚速岛网纹虫（Favella azorica）演替。不同站位微型浮游动物群落结构变化的差异与其本身的群落结构组成有一定关系，也与浮游植物的群落组成有关。zzf1和ra5站位实验组中微型浮游动物的总丰度和总生物量都低于对照组，而zc18a站位变化不明显，这是由于前两个站位实验组中的优势种管游虫（zzf1站位）和急游虫2（ra5站位）的丰度和生物量迅速下降，而zc18a站位实验组的优势种百乐拟铃虫的丰度和生物量比较稳定造成的。 2005年长江口及邻近海区赤潮发生时，赤潮973 MC2005－04航次在本海区进行了综合调查，期间分别于5月26日、5月28日、5月28日和5月29日，在xzm1、srb、sra1和hb8a四个站位利用现场培养的方法，研究了东海大规模赤潮对微型浮游动物群落结构的影响。结果发现，东海大规模赤潮对微型浮游动物群落结构的影响与赤潮藻的密度密切相关：xzm1、srb和sra1站位是赤潮区，两种赤潮藻的总密度分别为，1.3×106 cells L-1、1.8×106 cells L-1和5.6×106 cells L-1，而hb8a站位位于非赤潮区，两种赤潮藻的总密度仅为5×105 cells L-1；实验进行72 h后，在以大型砂壳纤毛虫网纹虫和筒壳虫（Tintinnidium sp.）为主的xzm1、srb和sra1站位，仍然是以这些大型砂壳纤毛虫为主，且其在群落中的百分比显著增大，尤其在赤潮藻密度最高的的sra1站位，这种演替趋势表现的最明显；而在以小型无壳纤毛虫急游虫2为主的hb8a站位，微型浮游动物群落向中型砂壳纤毛虫真丁丁虫（Eutintinnus sp.）演替。培养过程中微型浮游动物总丰度的变化以及总生物量的变化都与赤潮藻的密度密切相关：赤潮藻密度较低的xzm1站位和srb站位变化不大；赤潮藻密度较高的sra1站位则快速下降；而非赤潮区的hb8a站位呈快速上升的趋势。以上结果进一步表明东海大规模赤潮能使微型浮游动物群落向中大型砂壳纤毛虫演替。 在2006年4月18日－5月30日，赤潮973项目MC2006航次在长江口及其邻近海区围绕东海原甲藻和米氏凯伦藻赤潮进行了综合调查。为了研究该过程中微型浮游动物群落结构的变化，我们在南北5个断面共计21个站位进行了取样，样品涉及赤潮发生前期、发生期和消退期。本次调查共发现纤毛虫66种，其中砂壳纤毛虫有8属37种，寡毛类无壳纤毛虫25种，另外还有前口类3属4种。在赤潮发生前之前，小型无壳纤毛虫的丰度普遍较高，平均值为1574 ind L-1，而中大型砂壳纤毛虫的丰度普遍偏低，平均值仅为14 ind L-1；赤潮发生以后，在大多数站位小型无壳纤毛虫的丰度出现不同程度的下降，平均值降为171 ind L-1，而中大型砂壳纤毛虫的丰度出现一定程度的上升，平均值增至216 ind L-1。赤潮消退时，小型无壳纤毛虫丰度的平均值降为109 ind L-1，而中大型砂壳纤毛虫的丰度继续增长，变为401 ind L-1。不同微型浮游动物百分比的统计结果也表明：微型浮游动物群落由小型无壳纤毛虫向中大型砂壳纤毛虫演替的趋势：小型无壳纤毛虫在群落中百分比的平均值由赤潮发生前的62 %变为赤潮发生时的32 %，至赤潮消退时又降为15 %；而中大型砂壳纤毛虫百分比的平均值从赤潮发生前的10 %变为赤潮发生时的24 %，至赤潮消退时增至50 %。典型站位za3、za5、zb7和zb9的结果再次表明了赤潮发生过程中微型浮游动物群落由小型无壳纤毛虫向中大型砂壳纤毛虫演替的趋势。 由以上赤潮发生前的现场模拟实验、赤潮发生时的现场培养实验和赤潮发生过程中的现场调查的结果均可见，东海大规模赤潮可以改变微型浮游动物的群落结构，呈现由小型无壳纤毛虫向中大型砂壳纤毛虫演替的趋势，进而有可能影响中大型浮游动物等摄食者的种群数量和群落结构，最终可能会影响整个海洋生态系统的结构和功能。

Relationships between nitrogen and phosphorus forms and ratios and the development of dinoflagellate blooms in the East China Sea

During late spring and early summer of 2005, large-scale (> 15 000 km(2)), mixed dinoflagellate blooms developed along the the coast of the East China Sea. Karenia mikimotoi was the dominant harmful algal bloom species in the first stage of the bloom (late May) and was succeeded by Prorocentrum donghaiense approximately 2 wk later. Samples were collected from different stations along both north-south and west-east transects, from the Changjiang River estuary to the south Zhejiang coast, during 3 cruises of the Chinese Ecology and Oceanography of Harmful Algal Blooms Program, before and during the bloom progression. Nitrogen isotope tracer techniques were used to measure rates of NO3-, NH4+, urea, and glycine uptake during the blooms. High inorganic nitrogen (N), but low phosphorus (P) loading from the Changjiang River led to high dissolved inorganic N:dissolved inorganic P ratios in the sampling area and indicate the development of P limitation. The rates of N-15-uptake experiments enriched with PO43- were enhanced compared to unamended samples, suggesting P limitation of the N-uptake rates. The bloom progression was related to the change in availability of both organic and inorganic N and P. Reduced N forms, especially NH4+, were preferentially taken up during the blooms, but different bloom species had different rates of uptake of organic N substrates. K mikimotoi had higher rates of urea uptake, while P. donghaiense had higher rates of glycine uptake. Changes in the availability of reduced N and the ratios of N:P in inorganic and organic forms were suggested to be important in the bloom succession. Nutrient ratios and specific uptake rates of urea were similar when compared to analogous blooms on the West Florida Shelf.