Growth, Toxin Content and Production of Dinophysis Norvegica in Cultured Strains Isolated from Funka Bay (Japan).

The successful cultivation of Claparède & Lachmann, 1859, isolated from Japanese coastal waters, is presented in this study, which also includes an examination of its toxin content and production for the first time. Maintaining the strains at a high abundance (>2000 cells per mL) for more than 20 months was achieved by feeding them with the ciliate Lohmann, 1908, along with the addition of the cryptophyte (W.Conrad) D.

Identification of timing of scallop morphological deformity and mortality from shell oxygen isotope records.

The Yesso scallop, Patinopecten yessoensis (Jay), is one of the most important bivalve species in the Japanese and Chinese mariculture industry. In recent years, however, high incidences of scallop shell deformity and mortality have occurred with increasing frequency, but timing of onset and underlying causes are often unclear. Here, we proposed a promising δO-based method for constraining the onset of shell deformity and mortality of P.

Iron uptake by bloom-forming freshwater cyanobacterium Microcystis aeruginosa in natural and effluent waters.

Studies on Fe uptake by phytoplankton have been often conducted using artificial culture media. However, Fe chemistry in freshwater can be influenced by riverine anthropogenic impacts and other factors causing water quality changes. In this study, therefore, Fe uptake in natural (river and reservoir) and effluent waters was investigated for the notorious bloom-forming freshwater cyanobacterium Microcystis aeruginosa.

Evidence of increased toxic Alexandrium tamarense dinoflagellate blooms in the eastern Bering Sea in the summers of 2004 and 2005.

The eastern Bering Sea has a vast continental shelf, which contains various endangered marine mammals and large fishery resources. Recently, high numbers of toxic A. tamarense resting cysts were found in the bottom sediment surface of the eastern Bering Sea shelf, suggesting that the blooms have recently occurred.

Importance of allochthonous and autochthonous dissolved organic matter in Fe(II) oxidation: A case study in Shizugawa Bay watershed, Japan.

Ferrous iron (Fe[II]) oxidation by dissolved oxygen was investigated in the Shizugawa Bay watershed with particular attention given to the effect of dissolved organic matter (DOM) properties on Fe(II) oxidation. To cover a wide spectrum of DOM composition, water samples were collected from various water sources including freshwater (e.g.

The physiological adaptations and toxin profiles of the toxic Alexandrium fundyense on the eastern Bering Sea and Chukchi Sea shelves.

Abundant cyst distributions of the toxic dinoflagellate Alexandrium fundyense (previous A. tamarense north American clade) were recently observed on the north Chukchi Sea shelf and on the eastern Bering Sea shelf, suggesting that A. fundyense is both highly adapted to the local environments in the high latitude areas and might cause toxin contamination of plankton feeders.

Germination fluctuation of toxic Alexandrium fundyense and A. pacificum cysts and the relationship with bloom occurrences in Kesennuma Bay, Japan.

While cyst germination may be an important factor for the initiation of harmful/toxic blooms, assessments of the fluctuation in phytoplankton cyst germination, from bottom sediments to water columns, are rare in situ due to lack of technology that can detect germinated cells in natural bottom sediments. This study introduces a simple mesocosm method, modeled after previous in situ methods, to measure the germination of plankton resting stage cells. Using this method, seasonal changes in germination fluxes of toxic dinoflagellates resting cysts, specifically Alexandrium fundyense (A.