Ocean Sciences Department, 1156 High Street, University of California, Santa Cruz, CA 95064, USA.
Ocean Sciences Department, 1156 High Street, University of California, Santa Cruz, CA 95064, USA; San Francisco Estuary Institute, 4911 Central Avenue, Richmond Ca 94804, USA; Native Environmental Science, Northwest Indian College, 2522 Kwina Rd, Bellingham, Wa, 98226, USA.
Harmful Algae. 2016 Nov;59:59-66. doi: 10.1016/j.hal.2016.09.007. Epub 2016 Oct 3.
The occurrence of freshwater harmful algal bloom toxins impacting the coastal ocean is an emerging threat, and the potential for invertebrate prey items to concentrate toxin and cause harm to human and wildlife consumers is not yet fully recognized. We examined toxin uptake and release in marine mussels for both particulate and dissolved phases of the hepatotoxin microcystin, produced by the freshwater cyanobacterial genus Microcystis. We also extended our experimental investigation of particulate toxin to include oysters (Crassostrea sp.) grown commercially for aquaculture. California mussels (Mytilus californianus) and oysters were exposed to Microcystis and microcystin toxin for 24h at varying concentrations, and then were placed in constantly flowing seawater and sampled through time simulating riverine flushing events to the coastal ocean. Mussels exposed to particulate microcystin purged the toxin slowly, with toxin detectable for at least 8 weeks post-exposure and maximum toxin of 39.11ng/g after exposure to 26.65μg/L microcystins. Dissolved toxin was also taken up by California mussels, with maximum concentrations of 20.74ng/g after exposure to 7.74μg/L microcystin, but was purged more rapidly. Oysters also took up particulate toxin but purged it more quickly than mussels. Additionally, naturally occurring marine mussels collected from San Francisco Bay tested positive for high levels of microcystin toxin. These results suggest that ephemeral discharge of Microcystis or microcystin to estuaries and the coastal ocean accumulate in higher trophic levels for weeks to months following exposure.
淡水有害藻类 bloom 毒素对沿海水域的影响是一个新出现的威胁，而无脊椎动物猎物浓缩毒素并对人类和野生动物消费者造成危害的潜力尚未得到充分认识。我们研究了海洋贻贝对微囊藻肝毒素的颗粒相和溶解相的毒素吸收和释放，微囊藻肝毒素由淡水蓝藻属微囊藻产生。我们还将我们对颗粒相毒素的实验研究扩展到包括商业养殖的牡蛎（Crassostrea sp.）。加利福尼亚贻贝（Mytilus californianus）和牡蛎在不同浓度下暴露于微囊藻和微囊藻毒素 24 小时，然后置于持续流动的海水中，并通过模拟河流向沿海海域冲流的时间进行采样。暴露于颗粒微囊藻的贻贝缓慢清除毒素，至少在暴露后 8 周内仍可检测到毒素，暴露于 26.65μg/L 微囊藻毒素后最大毒素为 39.11ng/g。溶解毒素也被加利福尼亚贻贝吸收，暴露于 7.74μg/L 微囊藻毒素后最大浓度为 20.74ng/g，但清除速度更快。牡蛎也吸收颗粒毒素，但清除速度比贻贝快。此外，从旧金山湾采集的天然海洋贻贝检测出高水平的微囊藻毒素。这些结果表明，微囊藻或微囊藻毒素的短暂排放到河口和沿海水域，在暴露后的数周至数月内会在更高的营养级中积累。
