The fish-killing raphidophytes Chattonella spp. have a resting cyst stage. To investigate the abundance and distribution of Chattonella cysts and determine their relationship to the population dynamics of vegetative cells, we conducted field observations from 2002 to 2017 in the Yatsushiro Sea, a semi-enclosed embayment in Japan, and analyzed the data including environmental conditions. Analysis of sediment sampled in the spring (mid-April to early June), shows that cysts are relatively abundant in the northern to middle area, where initial vegetative cells and large blooms are frequently detected. The maximum density of cysts was 616 cysts cm^–3 in the northern area in 2016. Mean cyst abundance in the spring varied interannually, ranging from 5 to 138 cysts cm^–3. A significant positive correlation between mean cyst abundance in the spring and maximum density of vegetative cells the preceding summer was seen, but no significant correlation was observed the following summer. The first detected date of vegetative cells (FDD) each year, which is likely related to cyst abundance and environmental conditions influencing cyst germination and/or growth characteristics of vegetative cells, also varied interannually from mid-April to early June. Regression analyses showed that FDD tended to be early when cyst abundance and bottom-water temperature were high. However, no significant correlation was observed between mean cyst abundance and bloom timing (the period from FDD to the occurrence date of the bloom), and bloom duration the following summer, as was the maximum density of vegetative cells. Instead, the timing and duration of blooms were correlated significantly with meteorological factors (e.g., solar radiation) for a month after FDD. The results suggest that cyst abundance reflecting the bloom magnitude of the preceding summer contributes to the timing of the appearance of vegetative cells in the year, but that bloom occurrence is likely to be controlled by the growth dynamics of vegetative cells through environmental conditions rather than by cyst abundance. The three distinct peaks in Chattonella cysts and vegetative cells from 2002 to 2017 correspond to the timings just after the El Niño. Large-scale atmospheric variability and its global teleconnection are possibly linked to long-term population dynamics of Chattonella in the area through local meteorological conditions and their life cycle.

杀死鱼类的水生藻类沙门氏菌。有一个静止的囊肿阶段。为了调查沙门氏菌囊肿的丰度和分布并确定其与营养细胞的种群动态之间的关系，我们在2002年至2017年期间对日本半封闭巢穴八代海进行了实地观察，并分析了包括环境条件在内的数据。对春季（4月中旬至6月初）采样的沉积物进行的分析表明，在北部至中部地区，囊肿相对丰富，那里经常发现初始的营养细胞和大花。最大囊肿密度为616个囊肿，厘米^–3在2016年北部地区。春季平均囊肿丰度每年变化，范围从5到138个囊肿cm ^–3。春季前平均囊肿丰度与前一个夏季营养细胞的最大密度之间存在显着的正相关，但次年夏季未观察到显着的相关。每年的第一个检测到的营养细胞（FDD）日期，可能与囊肿丰度和影响囊肿萌发和/或营养细胞生长特征的环境条件有关，从每年的4月中旬到6月初也不同。回归分析表明，当囊肿丰度和底水温度高时，FDD趋于早期。但是，平均囊肿丰度与开花时间（从FDD到开花发生日期的时间）和第二年夏天的开花持续时间之间没有发现显着相关性，营养细胞的最大密度也是如此。代替，FDD后一个月的开花时间和持续时间与气象因素（例如太阳辐射）显着相关。结果表明，反映前一个夏季开花程度的囊肿丰度有助于一年中营养细胞的出现时间，但开花的发生可能受环境条件下营养细胞的生长动态控制，而不是受环境条件的影响。囊肿丰度。在三个不同的高峰 但是开花的发生可能是受环境条件下营养细胞的生长动力学控制的，而不是受囊肿丰度的控制。在三个不同的高峰 但是开花的发生可能是受环境条件下营养细胞的生长动力学控制的，而不是受囊肿丰度的控制。在三个不同的高峰2002年至2017年的沙通氏囊和营养细胞与厄尔尼诺事件刚发生的时间相对应。大规模的大气变化及其全球遥相关性可能通过当地的气象条件及其生命周期与该地区查顿氏菌的长期种群动态联系在一起。