National Oceanic and Atmospheric Administration, National Ocean Service, Beaufort Laboratory, 101 Pivers Island Road, Beaufort, North Carolina, United States of America.
CSS Inc. (Under Contract to National Oceanic and Atmospheric Administration, National Ocean Service, National Centers for Coastal Ocean Science, 1305 East-West Highway, Silver Spring, MD 20910, United States of America).
Harmful Algae. 2022 Jan;111:102165. doi: 10.1016/j.hal.2021.102165. Epub 2021 Dec 25.
Consumption of toxic butter clams (Saxidomus gigantea) is the most frequent cause of paralytic shellfish poisoning (PSP) in Alaskan coastal communities. This study examines seasonal variation in total paralytic shellfish toxin concentrations and congener distribution in tissues of butter clams collected in three communities in the Kodiak Islands, Alaska: the City of Kodiak, Ouzinkie and Old Harbor. In response to questions from local harvesters, the efficacy of removing particular clam tissues on total toxin levels was also assessed. Butter clam samples were collected ∼monthly during 2015-2020 in each community to monitor shellfish toxin levels. Results were combined with clam monitoring data collected previously (2013-2015) to document the seasonal distribution of saxitoxin (STX) and its congeners (neosaxitoxin, gonyautoxin) in clam tissues. Seasonally, paralytic shellfish toxin levels in butter clams were highest in summer, declined in winter, but often remained above regulatory limits throughout the year in the three Kodiak communities. Butter clams collected from Ouzinkie (2013-2020) averaged 165 ± 87 µg STX equivalents (Eq.) 100 g , compared to Kodiak 73 ± 54 µg STX Eq. 100 g and Old Harbor 143 ± 103 µg STX Eq. 100 g . STX accounted for 59-71% of the total toxin concentration in clams at Ouzinkie, Kodiak, and Old Harbor, while neosaxitoxin (neoSTX) accounted for 12-18%. Gonyautoxins (GTXs) represented 31-60% of the total toxin concentration during the seasonal Alexandrium catenella bloom in June-July, with lower percentages in other months. The fraction of total toxin varied among clam tissues: the siphon tip (2-29%), the neck (3-56%), the gut (3-65%) and the body (6-85%). Removal of the siphon tip reduced total toxin content substantially in some samples but had little effect in others. Saxitoxin congeners varied greatly and somewhat unpredictably among clam tissues, and the results indicate removal of specific tissues was not an effective strategy for reducing paralytic shellfish toxin levels in butter clams for safe consumption.
食用毒性贻贝（Saxidomus gigantea）是导致阿拉斯加沿海社区麻痹性贝类中毒（PSP）的最常见原因。本研究调查了在阿拉斯加科迪亚克群岛的三个社区（科迪亚克市、奥赞基和奥尔德港）采集的黄油贻贝组织中总麻痹性贝类毒素浓度和同系物分布的季节性变化。为了回应当地采集者的问题，还评估了去除特定贻贝组织对总毒素水平的效果。在每个社区，2015-2020 年期间每月收集一次黄油贻贝样本，以监测贝类毒素水平。结果与之前（2013-2015 年）收集的贻贝监测数据相结合，记录了贻贝组织中石房蛤毒素（STX）及其同系物（neosaxitoxin、gonyautoxin）的季节性分布。季节性地，黄油贻贝中的麻痹性贝类毒素水平在夏季最高，冬季下降，但在三个科迪亚克社区，全年毒素水平经常高于监管限值。2013-2020 年期间，从奥赞基采集的黄油贻贝平均含有 165 ± 87 µg STX 当量（Eq.）/100 g，而科迪亚克为 73 ± 54 µg STX Eq. 100 g 和奥尔德港为 143 ± 103 µg STX Eq. 100 g。在奥赞基、科迪亚克和奥尔德港，STX 占贻贝总毒素浓度的 59-71%，而 neoSTX 占 12-18%。GTX 在 6 月至 7 月的亚历山大藻赤潮期间占总毒素浓度的 31-60%，而在其他月份则占较低比例。总毒素在贻贝组织之间存在差异：虹吸管尖端（2-29%）、颈部（3-56%）、肠道（3-65%）和身体（6-85%）。在一些样本中，去除虹吸管尖端会大大降低总毒素含量，但在其他样本中影响不大。石房蛤毒素同系物在贻贝组织之间变化很大，且有些不可预测，结果表明，去除特定组织并不是降低黄油贻贝中麻痹性贝类毒素水平以确保安全食用的有效策略。
