Viability of Alexandrium tamarense cysts in the sediment of Funka Bay, Hokkaido, Japan: Over a hundred year survival times for cysts

Hyperspectral optical discrimination of phytoplankton community structure in Funka Bay and its implications for ocean color remote sensing of diatoms

“…Dinoflagellates were not predominant over the study period. Although Tsunogai and Watanabe (1983) showed that dinoflagellates dominated after the spring diatom bloom of 1981, Kudo, Miyazono, Shimada, and Isoda (2005) and Miyazono, Nagai, Isao, and Tanizawa (2012) recently showed that a massive A. tamarense bloom started in the early 1960s and has continued until the late 1980s, but also that A. tamarense abundance has been declining since the 1990s. (443) 2 nd deriv.…”

Coupling planktonic and benthic shifts during a bloom of Alexandrium catenella in southern Chile: Implications for bloom dynamics and recurrence

“…the revision of Anderson et al, 2012). Cysts of some Alexandrium species are known to remain viable for up to 100 years (Miyazono et al, 2012), and their presence is a cause for concern even in the absence of cells in the water column. However, Alexandrium catenella cysts were rapidly depleted from the surface sediments in the present study, and therefore, we got no evidence pointing to a role of resting cyst beds in the recurrence of blooms in this area.…”

Changes in abundances of Alexandrium tamarense resting cysts after the tsunami caused by the Great East Japan Earthquake in Funka Bay, Hokkaido, Japan

“…It is impossible to distinguish between cysts of Alexandrium tamarense and Alexandrium catenella by morphological observation using a microscope (Fukuyo, 1985). However, vegetative cells were only detected as A. tamarense type in this study (having a ventral pore), and Miyazono et al (2012) reported that all cysts collected from a sediment core sample in Funka Bay before the 2011 tsunami were genetically identified as A. tamarense. Therefore, we regarded the cysts and vegetative cells present in the bay as A. tamarense.…”

“…Further, it strongly suggested that this 'abnormal' increase in the cysts in the bay was due to the bottom-mixing effect by the 2011 tsunami, which affected the vertical distribution of the depositing Alexandrium tamarense cysts. Miyazono et al (2012) investigated the vertical distribution and survivability of the A. tamarense resting cysts in a sediment core in Funka Bay before the 2011 tsunami. They discovered abundant viable cyst deposition in the deeper layer and over 100-year survival of some of the cysts that were collected from the approximately 30-cm depth of the sediment core.…”