Contemporary condition of macrozoobenthos in ultrashallow zone of Taman Bay,Sea of Azov

The distribution of macrozoobenthic communities was studied in a vast ultrashallow (0–1.2 m deep) zone of northwestern Taman Bay (separated from the Kerch Strait by Chushka spit) in 2008–2009. Fifty-two species of benthic invertebrates were recorded. The species number, as well as Shannon and Pielou diversity indices, increased along Chushka spit from base to tip. The usual inhabitants of lagoons and estuaries of the Mediterranean Basin and the open Sea of Azov dominated in benthic communities: mollusks Abra segmentum and Hydrobia acuta and polychaetes Heteromastus filiformis and Hediste diversicolor (the latter only in summer). Changes in the community structure were largely determined by the seasonal dynamics of dominant species populations, which was similar to their dynamics in certainother transitional water bodies of the Mediterranean Basin. These changes indicate normal running of seasonal processes in the macrobenthic communities of Taman Bay in 2008 rather than the consequences of a catastrophic black oil spill in the Kerch Strait in November 2007.     

大型水母沙海蜇暴发的温带贫营养海洋生态系统中细菌和浮游植物的关系

Bacterial abundance, phytoplankton community structure and environmental parameters were investigated to study the relationships between bacteria and phytoplankton during giant jellyfish Nemopilema nomurai blooms in the central Yellow Sea during 2013. N. nomurai appeared in June, increased in August, reached a peak and began to degrade in September 2013. Results showed that phosphate was possible a key nutrient for both phytoplankton and bacteria in June, but it changed to nitrate in August and September. Phytoplankton composition significantly changed that pico-phytoplankton relative biomass significantly increased, whereas other size phytoplankton significantly decreased during jellyfish bloom. In June, a significantly positive correlation was observed between chlorophyll a concentration and bacterial abundance(r=0.67, P0.001, n=34).During jellyfish outbreak in August, there was no significant correlation between phytoplankton and bacteria(r=0.11, P0.05, n=25), but the relationship(r=0.71, P0.001, n=31) was rebuilt with jellyfish degradation in September. In August, small size phytoplankton occupied the mixed layer in offshore stations, while bacteria almost distributed evenly in vertical. Chlorophyll a concentration significantly increased from(0.42±0.056) μg/L in June to(0.74±0.174) μg/L in August, while bacterial abundance just slightly increased. Additionally, the negative net community production indicated that community respiration was not entirely determined by the local primary productivity in August. These results indicated that jellyfish blooms potentially affect coupling of phytoplankton and bacteria in marine ecosystems.     

春季长江口富营养化水域浮游植物群集对冲淡水和上升流的响应

A comprehensive study on the phytoplankton standing stocks, species composition and dominant species in the eutrophic Changjiang(Yangtze River) Estuary(CE) was conducted to reveal the response of phytoplankton assemblage to Changjiang Diluted Water(CDW) and upwelling in the spring. Phytoplankton presented peak standing stocks(13.03 μg/L of chlorophyll a, 984.5×103 cells/L of phytoplankton abundance) along the surface isohaline of 25. Sixty-six species in 41 genera of Bacillariophyta and 33 species in 19 genera of Pyrrophyta were identified, as well as 5 species in Chlorophyta and Chrysophyta. Karenia mikimotoi was the most dominant species, followed by Prorocentrum dentatum, Paralia sulcata, Pseudo-nitzschia delicatissima and Skeletonema costatum. A bloom of K. mikimotoi was observed in the stratified stations, where the water was characterized by low nitrate, low phosphate, low turbidity, and specific ranges of temperature(18–22 °C) and salinity(27–32). K.mikimotoi and P. dentatum accumulated densely in the upper layers along the isohaline of 25. S. costatum was distributed in the west of the isohaline of 20. Benthonic P. sulcata presented high abundance near the bottom,while spread upward at upwelling stations. CDW resulted in overt gradients of salinity, turbidity and nutritional condition, determining the spatial distribution of phytoplankton species. The restricted upwelling resulted in the upward transport of P. sulcata and exclusion of S. costatum, K. mikimotoi and P. dentatum. The results suggested that CDW and upwelling were of importance in regulating the structure and distribution of phytoplankton assemblage in the CE and the East China Sea.     

Feeding of the Dominant Herbivorous Plankton Species in the Black Sea and Their Role in Coccolithophorid Consumption

The feeding of abundant herbivore plankton species has been investigated during different stages of coccolithophorid development in the northeastern Black Sea, namely, at the initial stage of development (March 2009) and at the massive bloom stage (June 2011 and May 2013). The role of coccolithophorids as a food source for Black Sea copepods Calanus euxinus, Acartia clausi, and Pseudocalanus elongatus; the heterotrophic dinoflagellate Noctiluca scintillans; and the larvacean Oikopleura dioica has been characterized for the first time. The contribution of coccolithophorids to copepod ration was low (0.2 to 13% of total carbon intake) during all study periods. The content of these organisms in the diet of N. scintillans ranged from 17 to 100%. The coccolithophorid bloom apparently had a stronger positive effect on the nutrition of fine filter feeders, such as N. scintillans and O. dioica, than on copepod nutrition. Daily coccolithophorid consumption by zooplankton ranged from 0.7 to 39.4% of the biomass in different study periods. The grazing of N. scintillans and O. dioica populations made the greatest contribution to coccolithophorid consumption (up to 26 and 23% of the coccolithophorid biomass, respectively).     

Fine-scale Microbial Communities Associated with Manganese Nodules in Deep-sea Sediment of the Korea Deep Ocean Study Area in the Northeast Equatorial Pacific

Despite its potential significance for industrial utilization, any activities associated with the mining of manganese (Mn) nodules might have substantial impacts on benthic ecosystems. Because microorganisms respond quickly to changing environmental conditions, a study of microbial communities provides a relevant proxy to assess possible changes in benthic ecosystems associated with mining activities. We investigated fine-scale microbial community composition and diversity inside and on the surface of Mn nodules and in nearby deep-sea sediments in the Korea Deep Ocean Study (KODOS) area located in the Clarion-Clipperton Fracture Zone (CCFZ) of the northeast equatorial Pacific. Although microbial cell density was lower within nodules (3.21 × 10⁶ cells g^-1) than in sediment (2.14 × 10⁸ cells g^-1), nodules provided a unique habitat for microorganisms. Manganese-oxidizing bacteria including Hyphomicrobium and Aurantimonas in Alphaproteobacteria and Marinobacter in Gammaproteobacteria were abundant in nodules, which implied that these bacteria play a significant role in nodule formation. In contrast, Idiomarina in Gammaproteobacteria and Erythrobacter and Sulfitobacter in Alphaproteobacteria were abundant in sediments. Meanwhile, Thaumarchaeota, a phylum that consists of ammonia-oxidizing chemolithoautotrophs, were the predominant archaeal group both in nodules and sediment. Overall, microbial communities in Mn nodules were unique compared to those observed in sediments. Furthermore, the phylogenetic composition of microorganisms in the KODOS area was distinguishable from that in the nodule provinces claimed by China and Germany in the CCFZ and nodule fields in the central South Pacific Gyre, respectively.     

温度、盐度和光照对浒苔生长和光合作用的影响

Intensive Pyropia aquaculture in the coast of southwestern Yellow Sea and its subsequent waste, including disposed Ulva prolifera, was speculated to be one of the major sources for the large-scale green tide proceeding in the Yellow Sea since 2007. It was, however, unclear how the detached U. prolifera responded and resumed growing after they detached from its original habitat. In this study, we investigated the growth and photosynthetic response of the detached U. prolifera to various temperature, salinity and irradiance in the laboratory. The photosynthetic rate of the detached U. prolifera was significantly higher at moderate temperature levels(14–27°C)and high salinity(26–32), with optimum at 23°C and 32. Both low(14°C) and highest temperature(40°C), as well as low salinity(8) had adverse effects on the photosynthesis. Compared with the other Ulva species, U. prolifera showed higher saturated irradiance and no significant photoinhibition at high irradiance, indicating the great tolerance of U. prolifera to the high irradiance. The dense branch and complex structure of floating mats could help protect the thalli and reduce photoinhibition in field. Furthermore, temperature exerted a stronger influence on the growth rate of the detached U. prolifera compared to salinity. Overall, the high growth rate of this detached U. prolifera(10.6%–16.7% d~(–1)) at a wide range of temperature(5–32°C) and salinity(14–32) implied its blooming tendency with fluctuated salinity and temperature during floating. The environmental parameters in the southwestern Yellow Sea at the beginning of green tide were coincident with the optimal conditions for the detached U. prolifera.     

Morphological characteristics and distribution of Pleuronectidae (Pisces) eggs in the western margin of the East Sea

Seven species of Pleuronectidae (Platichthys stellatus, Kareius bicoloratus, Pseudopleuronectes herzensteini, Microstomus achne, Glyptocephalus stelleri, Hippoglossoides dubius, and Limanda punctatissima) were identified based on eggs collected from the western margin of the East Sea (east coast of Korea), using DNA barcoding. The eggs of P. herzensteini and G. stelleri were relatively widely distributed along the east coast of Korea, whereas those of P. stellatus and K. bicoloratus were narrowly distributed; in particular, the eggs of P. stellatus were restricted to areas near bays. The eggs, which share common morphological characteristics (such as a homogeneous yolk and smooth membrane) were divided into three groups according to egg size: group A (more than 1.60 mm in egg diameter, including genera Hippoglossoides and Microstomus), group B (1.00–1.60 mm, including genera Kareius, Glyptocephalus, and Platichthys), and group C (less than 1.00 mm, including genera Limanda and Pseudopleuronectes). This paper provides an overview of the morphological characteristics of the eggs of the family Pleuronectidae collected from the east coast of Korea. Our approach to the analysis of eggs, based on DNA barcoding, morphological characteristics, and geographic distributions, provides a rapid and accurate basis for identifying spawning areas and spawning periods, thus facilitating the assessment and management of fisheries stocks and resources.     

鱼耳石碳氧同位素在黄、渤海小黄鱼种群识别中的应用

Oxygen and carbon isotope ratios(δ~(18)O and δ~(13)C) in otoliths were used to identify the stock structure of small yellow croaker,Larimichthys polyactis.Otoliths were collected from fish at five locations across the Yellow Sea and the Bohai Sea representing most of their distributional range and fisheries areas.The significant differences in the isotopic signatures showed that the five locations could be chemically distinguished and clearly separated,indicating stock subdivision.Correlation of δ~(18)O and δ~(13)C values suggested that population of L.polyactis could be divided into the Bohai Sea group,the southern Yellow Sea group and the central Yellow Sea group.Discriminant analysis of δ~(18)O and δ~(13)C values demonstrated a high significant difference with 85.7% classification accuracy.The spatial separation of L.polyactis indicated a complex stock structure across the Yellow Sea and the Bohai Sea.These results indicate that optimal fisheries management may require a comprehensive consideration on the current spatial arrangements.This study has provided further evidence that measurement of the stable isotopes ratios in otolith can be a valuable tool in the delineation of fishery management units.     

Presence of high nitrate to phosphate ratio subsurface water in the Tsushima Strait during summer

To identify water with an excess nitrate concentration to phosphate ratio and its potential source, the nutrient concentrations in the Tsushima Strait (TSS) were investigated over ten cruises in August and September 2007–2014, excluding 2010. On the basis of the Redfield ratio, water with an excess nitrate concentration of >1 μM (positive ExNOx water) was identified below the surface mixed layer during four cruises in 2011–2013. Positive ExNOx water was present mainly in less-saline (<34) waters with a density of 22–25 σ _θ , and 25–75 m depth. However, in August 2012, positive ExNOx was detected in dense (25–25.5 σ _θ ) and deep (50–110 m depth) waters near the salinity maximum, although the salinity during this period was significantly lower than that in other years. The horizontal length of positive ExNOx water was >100 km across the TSS during two cruises in August 2012 and September 2013, respectively. According to multi-regression analysis conducted on the silicate concentration, temperature, and salinity, the silicate concentration was increased in the less-saline subsurface water. The required amount of original freshwater was 10^8–9 m³ day^?1 based on the excess nitrate concentration. This evidence indicates that the positive ExNOx water originated from large river waters such as the Changjiang. Thus, discharged water from the rivers of the East Asia is contributing to the increased N:P ratio in the Tsushima Warm Current, southern Japan Sea.     

Effects of temperature on growth,photophysiology, Rubisco gene expression in <Emphasis Type="Italic">Prorocentrum donghaiense</Emphasis> and <Emphasis Type="Italic">Karenia mikimotoi</Emphasis>

To explore the effects of temperature changes on dinoflagellate bloom succession in the coastal waters of the East China Sea, changes in the growth, photophysiology, and Rubisco gene expression of Prorocentrum donghaiense and Karenia mikimotoi, two harmful algal species, were investigated at different temperatures (16 to 28°C). The maximal specific growth rate and the maximal mRNA expression of Rubisco gene in P. donghaiense and K. mikimotoi occurred at 20 and 24°C, respectively. The photosynthetic activity of P. donghaiense was generally stable, but K. mikimotoi photosynthesis increased when temperatures rose from 16 to 28°C. The effective photochemical efficiency (F _q ^′ /F _m ^′ ) and the maximal relative electron transfer rate (rETR_max) of K. mikimotoi increased significantly with increasing temperature, and the lowest and highest values occurred at 16 and 28°C, respectively. It seems that P. donghaiense has higher photosynthetic capacity than K. mikimotoi due to its higher F _q ^′ /F _m ^′ , rETR_max, and photosynthetic efficiency (α). However, K. mikimotoi has a higher growth rate than P. donghaiense. These results suggest that the photosynthetic activity and genetic responses of dinoflagellates are species-dependent. It is likely that temperature changes affect species composition during blooms, leading to the observed patterns of bloom succession.     

Estimation of spawning area of <Emphasis Type="Italic">Pisodonophis sangjuensis</Emphasis> Ji and Kim, 2011 (Pisces: Ophichthidae) based on leptocephali size and distribution

Pre-metamorphic leptocephali of Pisodonophis sangjuensis (n = 91, 10.4?90.2 mm in total length, TL) were collected in the East China Sea for the first time. Pre-metamorphic leptocephali of P. sangjuensis, which were identified using mitochondrial DNA cytochrome c oxidase subunit I gene (mtDNA COI), are characterized by various combinations of morphological characters: 8 moderate to pronounced gut loops with the kidney terminating on the 6-7th loops; and 8 subcutaneous pigment patches on the tail just ventral to the notochord. Pisodonophis sangjuensis leptocephali were more numerously collected offshore than inshore around Jeju Island. The smallest leptocephali (< 15.0 mm TL) were collected from the south far from Jeju Island, and the largest leptocephali (> 100.0 mm TL) were collected from around Jeju Island and the southern coast of Korea. Our findings indicate that P. sangjuensis spawns offshore south of Jeju Island that is an area associated with high water temperature, and then the hatched leptocephali are transported to Jeju Island or the southern coast of Korea by the Tsushima Warm Current.     

Vertical turbulent exchange in the Black Sea pycnocline and its relation to water dynamics

Estimates of vertical turbulent diffusion coefficient (K _t ) in the Black Sea pycnohalocline have been obtained from data of simultaneous observations of seawater temperature, salinity, density, and horizontal current velocity, obtained in the northeastern part of the Black Sea during 2013–2014 with a moored Aqualog profiler. A Munk and Andersson (1948) type parameterization, adapted for the Black Sea environment, is proposed for calculating K _t . Strong short-period (several days) variability of turbulent exchange is revealed, induced by vertical shear variations of the current velocity.     

C波段紧缩极化SAR海冰探测能力评估

The C-band synthetic aperture radar(SAR) data from the Bohai Sea of China, the Labrador Sea in the Arctic and the Weddell Sea in the Antarctic are used to analyze and discuss the sea ice full polarimetric information reconstruction ability under compact polarimetric modes. The type of compact polarimetric mode which has the highest reconstructed accuracy is analyzed, along with the performance impact of the reconstructed pseudo quad-pol SAR data on the sea ice detection and sea ice classification. According to the assessment and analysis, it is recommended to adopt the CTLR mode for reconstructing the polarimetric parameters σ_(HH)~0,σ_(VV)~0, H and α,while for reconstructing the polarimetric parameters σ_(HV)~0, ρ_(H-V), λ_1 and λ_2, it is recommended to use the π/4 mode.Moreover, it is recommended to use the π/4 mode in studying the action effects between the electromagnetic waves and sea ice, but it is recommended to use the CTLR mode for studying the sea ice classification.     

Biology and distribution of hyperiids in the Sea of Okhotsk

Long-term studies in the Sea of Okhotsk (1986–2012) demonstrated that hyperiids account for a small portion of zooplankton, making up only from 1.0 to 5.3% by weight. The minimum hyperiid biomass was observed in the coastal zone. The hyperiid biomass in the open water shelf community increased from spring to autumn. In the Sea of Okhotsk, hyperiids are represented by ten species, among which the most abundant in the northern regions (mainly in Shelikhov Gulf) is Themisto libellula, while the most abundant in other regions is T. pacifica. The distribution of T. pacifica in different seasons showed that the maximum biomass was concentrated in the deep-water zone. The range of T. libellula in the Sea of Okhotsk is mostly limited to the Shelikhov Gulf, but in certain years its habitation area can expand. In warm years with low ice coverage, the maximum expansion of T. libellula to the west in the shelf zone of the northern part of the Sea of Okhotsk was observed. Since variability of salinity and temperature in the northern part of the Sea of Okhotsk may be fatal for the cryophilic stenohaline T. libellula species, forecasted changes in thermohaline circulation will make it possible to predict the population dynamics of this important species.     

Spatial distribution and feeding of dominant zooplankton species in the Ob River estuary

The distribution and feeding of dominant mesozooplankton species were studied in the estuary of the Ob River and adjacent inner Kara Sea shelf waters in September 2013. It was shown that the spatial distributions of Cyclops sp., Senecella siberica, Limnocalanus macrurus, Mysis oculata, Drepanopus bungei, Jashnovia tolli and Pseudocalanus sp. are related to the specific characteristics of the hydrographic regime in the estuarine frontal zone. The distributions of Cyclops sp., Senecella siberica, and Pseudocalanus sp. are mainly limited by salinity, while other species inhabit an area with a wide range of salinity values without clear preferences. Peaks of their abundance could be either consolidated or distanced in space. The populations of Jashnovia tolli, Drepanopus bungei, and Pseudocalanus sp. permanently inhabit the layer under the pycnohalocline; the populations of Cyclops sp. and Mysis oculata inhabit the upper mixed layer. Limnocalanus macrurus demonstrates a different vertical distribution pattern: the copepod undertakes diel vertical migrations in the southern part of the estuarine frontal zone; in its northern part, the population is concentrated below the pycnocline during day and night. The differences in the distributions of the studied species determine their feeding behavior and their role in phytoplankton grazing. The most intense utilization of biomass and production of autotrophic phytoplankton by zooplankton occur in the freshened water zone and the adjacent southern periphery of the estuarine frontal zone: the total daily phytoplankton consumption makes up 10–18% of the biomass and 60–380% of primary production. Daily zooplankton consumption of phytoplankton in the estuarine frontal zone decreases to 2–7% of the biomass and to 14% of primary production; in inner shelf waters, the values do not exceed 1% for both phytoplankton biomass and production.     

Long-term changes in rocky intertidal macrobenthos during the five years after the <Emphasis Type="Italic">Hebei Spirit</Emphasis> oil spill,Taean, Korea

The Hebei Spirit oil spill reached the west coast of Taean County, Korea, on December 7, 2007. At that time, this was the largest oil spill that had occurred in the country. The incident devastated local marine ecosystems. In this study, we examined changes in these ecosystems and the recovery pattern on impacted rocky shores. Macrobenthos monitoring of polluted and control sites was performed seasonally from January 2008 through October 2013. At polluted sites, ecological indices increased gradually from 2009, thereby providing evidence of recovery. However, the mean density of macrobenthos was still less than 50% of the level at the control site, indicating that the ecological status of the polluted sites has still not recovered to that which prevailed before the oil spill. Although densities of the most dominant species were higher in the control site than in polluted sites, the densities of Lottia spp. and Odostomia aomori were higher in polluted sites. These two taxa were found in lower numbers at the control site, where they were out-competed by Chthamalus challengeri. Nonmetric multidimensional scaling ordination divided the macrobenthic community structure into three clusters according to differences in the abundance of dominant species over the 6 years after the oil spill. An ANOSIM test detected significant differences between the polluted and control sites. Consistent long-term differences indicate that complete recovery had not occurred during the duration of our study.     

The trophic position of the alien crab <Emphasis Type="Italic">Rhithropanopeus harrisii</Emphasis> (crustacea decapoda panopeidae) in the Taman Bay,Sea of Azov community

This work concerns the trophic web positioning of the alien crab Rhithropanopeus harrisii and other common marine invertebrate species and fishes in the benthic ecosystem of the shallows of Taman Bay, Sea of Azov. The base of the trophic web in this system is composed of phytoplankton, macrophytes (algae and marine grasses), and reeds that use atmospheric carbon for photosynthesis. Analysis of the isotopic composition of nitrogen and carbon has shown that although marine grasses are dominating primary producers in the shallows of the bay, primary consumers (such as Cerastoderma glaucum, Porifera gen. sp., Gammarus aequicauda, Deshayesorchestia deshayesii and Idotea balthica) only partially use this organic source; instead, they use a combination of different sources of primary production. It has been shown that the food source of the alien crab is primarily of animal origin. In Taman Bay, R. harrisii is on the same trophic level as other carnivores/scavengers: benthic fishes Syngnathus nigrolineatus, Gobius spp. and native crab Pilumnus hirtellus and shrimp Palaemon adspersus.     

Distribution of some rare and trace elements in modern bottom sediments of the Caspian Sea

The features of the distribution of some rare and trace elements in modern bottom sediments of the Caspian Sea have been studied from samples collected during cruises 35, 39, and 41 of the R/V Rift and the cruise of the R/V Nikifor Shurekov in 2013. It was established that bottom sediments in different areas of the Caspian Sea vary to some degree in the contents of Zr, Hf, Th, V, Cr, Co, Ni, Cu, Sr, and Ba in comparison to suspended matter discharged by the Volga River and rivers originating in the Caucasus. As follows from the results of a comparison of the geochemical features of modern bottom sediments of the Volga River delta and different sedimentary subsystems of the Caspian Sea with the chemical composition of Middle Archean granitoids and Paleozoic and Mesozoic–Cenozoic basalts, which are regarded as geochemical images of such provenance areas as the basement of East European Platform, Urals, and Caucasus, none of these regions is considered the dominant provenance area for all sedimentary subsystems of the Caspian Sea region. Here, the revealed similarity between modern bottom sediments of the northern, central and southern Caspian Sea regions, the Volga River delta, and Post-Archean average Australian shale (PAAS) in some parameters, including REE spectra, assumes that the Volga River discharge plays a dominant role in the formation of the geochemical image of Caspian Sea subsystems. The role of clastics, including the fine-grained fraction, which is supplied to the Caspian Sea from the Caucasus region and Elburz Mountains, is insignificant already in the coastal area, which is determined both by influence of the marginal filter (MF) and large-scale cholestatic current circulation.     

Tendencies in Coccolithophorid Blooms in Some Marine Environments of the Northern Hemisphere according to the Data of Satellite Observations in 1998–2013

Based on the method developed for the delineation of E. huxleyi blooms, a new technique is achieved for (1) the automated detection of E. huxleyi blooms among coexisting massive blooms of microalgae species of other phytoplankton groups and (2) quantifying the boom surface of this type of coccolithophores. As a result, according to the data of the Climate Change Initiative Ocean Colour (OC CCI) for 1998–2013, we have obtained multiyear time series of variability in both the incidence of E. huxleyi bloom and its area in the North, Norwegian, Greenland, Barents, and Bering seas. It is found that E. huxleyi blooms propagate within the intra-annual cycle from the studied middle-latitude marine areas towards the northern areas of the Northern Atlantic Ocean (NAO) and the Arctic Ocean (AO) following the pathways of the main Gulfstream and its branches. It is also found that E. huxleyi blooms are formed annually, initially in the vicinity of the British Islands; then they successively emerge in the northward direction following the western coast of the Great Britain, turn over its northern extremity to reach, firstly, the North Sea (in May), the Norwegian Sea, and finally the Greenland Sea (in June). Then they burst out in the Barents Sea, where the typical period of blooming lasts until late August and, in some years, even to mid-September. We determine the patterns of maximal rates and duration of blooms for each of the seas studied in the Atlantic and Arctic Oceans. As for the Bering Sea, the temporal and spatial variability in the growth of E. huxleyi has an irregular pattern: after a period of remarkably high expression of this phenomenon in 1998–2001, there was an abrupt decrease in both the number and, especially, extent of bloom areas.     

Numerical study for specifying the major origin of low salinity water associated with <Emphasis Type="Italic">Chattonella</Emphasis> (Raphidophyceae) blooms in Tachibana Bay,Japan

In both 2009 and 2010, massive Chattonella blooms occurred in Tachibana Bay. Observation results show that high cell densities of Chattonella were distributed in the central area of Tachibana Bay with low salinity water. Model results indicate that the low salinity water originated from the Ariake Sea and intruded into Tachibana Bay during the northerly or weak winds. It is suggested that low salinity water was mainly discharged from the northern area of the Ariake Sea. Northerly wind enhanced the horizontal advection of the low salinity water intruding into Tachibana Bay originating from the northern area of the Ariake Sea.