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The identification and quantification of okadaic acid (OA)/dinophysistoxin (DTX) analogues and pectenotoxins (PTXs) in Dinophysis samples collected from coastal locations around Japan were evaluated by liquid chromatography mass spectrometry. The species identified and analyzed included Dinophysis fortii, D. acuminata, D. mitra (Phalacroma mitra), D. norvegica, D. infundibulus, D. tripos, D. caudata, D. rotundata (Phalacroma rotundatum), and D. rudgei. The dominant toxin found in D. acuminata was PTX2 although some samples contained DTX1 as a minor toxin. D. acuminata specimens isolated from the southwestern regions (Takada and Hiroshima) showed characteristic toxin profiles, with only OA detected in samples collected from Takada. In contrast, both OA and DTX1, in addition to a larger proportion of PTX2, were detected in D. acuminata from Hiroshima. D. fortii showed a toxin profile dominated by PTX2 although this species had higher levels of DTX1 than D. acuminata. OA was detected as a minor toxin in some D. fortii samples collected from Yakumo, Noheji, and Hakata. PTX2 was also the dominant toxin found among other Dinophysis species analyzed, such as D. norvegica, D. tripos, and D. caudata, although some pooled picked cells of these species contained trace levels of OA or DTX1. The results obtained in this study re-confirm that cellular toxin content and profiles are different even among strains of the same species.

To elucidate the factors that influence the interannual variation in the density of cultured Japanese scallop ( Mizuhopecten yessoensis ) spat, we analyzed the relationship between spat density (Ds), monthly chlorophyll a (chl a) concentration, water temperature, and adductor muscle weight of spawners over 15 years (1992–2006) in Funka Bay (Japan) on the western North Pacific Ocean. The interannual variation of spat density was best explained by a campaniform model that used chl a concentration in February ([chl]Feb) and a categorical variable that indicates whether growth of spawners in a year is low or not as independent variables (R2 = 0.91). The gonadosomatic index increased fastest in February. Low growth years were detected as outliers in the Ds – [chl]Feb relationship and were characterized by an average weight of adductor muscles in February of <12 g. Therefore, food availability during gonadal development and growth conditions of spawners were the main factors determining spat density. The proportion of ovary necrosis was high in the years of low [chl]Feb and low growth. Those years corresponded with El Niño and La Niña years, respectively. Thus, global climatic anomalies apparently affect reproduction of the scallop in Funka Bay.