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SHIMAZU, YASUHIKO

doi:10.2331/suisan.69.439

Cited by 7 publications

(4 citation statements)

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“…The Ariake Sea is approximately 90 km long, 20 km wide, and 20 m deep, on average, and has a total area of almost 1700 km 2 (Shimazu 2003).…”

Section: Field Investigationmentioning

confidence: 99%

“…The major production regions in Japan are the Ariake Sea (see Fig. 2) (Shimazu 2003, Watanabe et al 2004) and the Seto Inland Sea (Nishikawa et al 2007, Oyama et al 2008; however, cultivation of Pyropia is at risk due to blooms of a marine diatom species (Imai et al 2006).…”

Section: Introductionmentioning

confidence: 99%

“…In February 2008, the pennate diatom Asteroplanus karianus (Grunow) Gardner et Crawford (formerly Asterionella kariana or Asterionellopsis kariana) (Crawford & Gardner 1997) suddenly formed massive blooms of 10 4 cells ml −1 in the Pyropia cultivation farms in the Ariake Sea (Matsubara et al 2014). This region produces approximately 40% of Japanese nori products (Shimazu 2003). Since that year, winter blooms of A. karianus have occurred annually in the Ariake Sea.…”

Section: Introductionmentioning

confidence: 99%

“…In the Ariake Sea, A. karianus has been observed putatively since at least the 1980s, but did not form massive blooms (Matsubara et al 2011) or cause economic damage until 2008. To date, centric diatoms, such as E. zodiacus (Sasaki & Kito 2003) and R. imbricata (Sasaki & Kito 2003, Shimazu 2003, have been considered to be the causative agents of the underdevelopment of cultivated Pyropia in Japan. The pennate diatom A. karianus, like most diatom species, was therefore considered to be an 'inconspicuous' primary producer rather than a 'nuisance'.…”

Section: Introductionmentioning

confidence: 99%

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Novel blooms of the diatom Asteroplanus karianus deplete nutrients from Ariake Sea coastal waters

Yamaguchi¹,

Minamida²,

Matsubara³

et al. 2014

Mar. Ecol. Prog. Ser.

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In the Ariake Sea, Japan, the pennate diatom Asteroplanus karianus has formed massive blooms each winter since 2008. During the peak of the bloom, seaweeds of the genus Pyropia, which are cultivated to make nori products, are discolored due to nutrient deficiency. We investigated the nutrient dynamics associated with A. karianus blooms in the Ariake Sea and measured the uptake of nitrate and phosphate by an axenic strain of A. karianus. Dissolved inorganic nitrogen and dissolved inorganic phosphorus in the coastal waters were significantly lower in areas where A. karianus cells were proliferating (r ≤ −0.955, p < 0.01), and these nutrients were severely depleted during the period of blooming. In the laboratory, the maximum uptake rate and half-saturation constant of A. karianus cultures were 27.3 fmol N cell −1 h −1 and 7.44 µmol N l −1 , respectively, for nitrate and 22.6 fmol P cell −1 h −1 and 3.61 µmol P l −1 , respectively, for phosphate. This study demonstrates that A. karianus blooms significantly deplete nutrients in the water column. The winter blooms presumably deplete dissolved inorganic nitrogen and dissolved inorganic phosphorus from the water column and may indirectly cause Pyropia nutrient deficiency.

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“…The Ariake Sea is approximately 90 km long, 20 km wide, and 20 m deep, on average, and has a total area of almost 1700 km 2 (Shimazu 2003).…”

Section: Field Investigationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Novel blooms of the diatom Asteroplanus karianus deplete nutrients from Ariake Sea coastal waters

Yamaguchi¹,

Minamida²,

Matsubara³

et al. 2014

Mar. Ecol. Prog. Ser.

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Historical Distribution of PCDDs, PCDFs, and Coplanar PCBs in Sediment Core of Ariake Bay, Japan

Kim

Eun

Katase

2007

Arch Environ Contam Toxicol

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Persistent organic pollutants, particularly polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), coplanar polychlorinated biphenyls (co-PCBs) and toxic equivalent quantity (pg TEQ g(-1)) were determined in sediment samples collected from Ariake Bay, Japan. The total concentration of PCDDs/DFs in surface sediment of the Yabe River (17,000 pg g(-1) dry wt) was approximately 2.5-fold higher than that of the Chikugo River (7,000 pg g(-1) dry wt) which has the highest flow amount of about 40% inputting to the northern Bay. The congener profile suggested that dioxin sources could be close to the study area. The PCDDs concentration (12,000 pg g(-1) dry wt) in the sediment layer, which was corresponding to the 1960s, was reflected on the pentachlorophenol (PCP) contamination occurring at that time in Ariake Bay. The reflecting of PCP in the sediment core was significantly considered by hierarchical cluster analysis. Based on isomer-specific analysis, the tetrachlorodibenzo-p-dioxin composition showed a gradual increase from 1978-1982 toward the surface, indicating that the pollution source at that period might be more influenced by chloronitrofen than PCP. This fact was supported, based on the ratio of Sigma PCDD to Sigma PCDF concentration. The PCDDs/DFs-derived TEQ contributed more than 90% of the SigmaTEQ (PCDDs/DFs and co-PCBs) in all the detected sediment layers. The contribution of PCBs to the total TEQ was low; however, an increasing historical trend of concentration was clearly observed.

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Analysis of hypoxia in the western interior parts of the Ariake Sea, Japan, using a box model

Koriyama

Seguchi

Ishitani

et al. 2010

Environ Monit Assess

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To clarify the mechanism of hypoxia in the western interior parts of the Ariake Sea (WIAS), field observation data collected in the period of 1972-2004 were analyzed using a two-layer box model. Monthly averages of advection velocity, vertical diffusion coefficient (K(z)), and biochemical oxygen consumption rate (R) in WIAS were evaluated quantitatively during the above period. The estimated advection velocity comparatively corresponded to the observed residual flow pattern of bay head in summer and winter. The estimated K(z) was relatively high (0.6-5.3 cm(2) s( -1)) from September to March but lower (0.2-0.4 cm(2) s( -1)) from April to August. The estimated R ranged from 0.30 to 0.46 mg L( -1) day( -1) during May to August. In summer, the temporal variation of dissolved oxygen (DO) concentration in the lower layer was controlled largely by K ( z ) and R. Monthly variations of K(z), R, and degree of density stratification (P) in the 1970s, the 1980s, and the 1990s-early 2000s were analyzed. P, K ( z ), and R were not significantly different among the calculated periods (p = 0.93, 0.23, and 0.49). However, the variations of R in summer between the 1970s and the other calculated periods changed. DO consumption period was longer in the 1980s and the 1990s-early 2000s than in the 1970s. R in the 1980s was highest among the calculated periods. The increase in R in the 1980s was caused by the increase in organic matter load originating from red tide phytoplankton due to a decrease in the suspension feeders.

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Cited by 7 publications

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Novel blooms of the diatom Asteroplanus karianus deplete nutrients from Ariake Sea coastal waters

Novel blooms of the diatom Asteroplanus karianus deplete nutrients from Ariake Sea coastal waters

Historical Distribution of PCDDs, PCDFs, and Coplanar PCBs in Sediment Core of Ariake Bay, Japan

Analysis of hypoxia in the western interior parts of the Ariake Sea, Japan, using a box model

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