The dinoflagellate Alexandrium catenella is responsible for paralytic shellfish poisoning and negative socioeconomic impacts on the fishing industry and aquaculture. In Chilean Patagonia, the reasons underlying the significant increase in the geographical extension (from south to north) of A. catenella blooms during the last five decades are not well understood. To assess the potential spreading risk of A. catenella during an intense austral summer bloom, we conducted an in situ experiment in a "hotspot" of this dinoflagellate in southern Chile. The objective was to assess the accumulation of A. catenella resting cysts in passive (fishing nets) and active (mussels) dispersal agents during the phase of bloom decline. Large numbers of resting cysts were detected in fishing nets (maximum of 5334 cysts net⁻¹ per month) at 5 m depth and in mussels (maximum of 16 cysts g⁻¹ of digestive gland) near Vergara Island. The potential of these vectors to serve as inoculum sources and the implications of our findings for A. catenella population dynamics are discussed.

甲藻链状亚历山大藻是造成麻痹性贝类中毒以及对渔业和水产养殖业的负面社会经济影响的罪魁祸首。在智利巴塔哥尼亚，过去 50 年中链状藻水华地理扩展（从南到北）显着增加的原因尚不清楚。为了评估A. catenella在强烈的南方夏季开花期间的潜在传播风险，我们在智利南部这种甲藻的“热点”进行了原位实验。目的是评估A. catenella的积累在开花衰退阶段，在被动（渔网）和主动（贻贝）分散剂中静息孢囊。在 5 m 深的渔网（每月最多 5334 个包囊网^-1 ）和Vergara 岛附近的贻贝（消化腺最多 16 个包囊 g ^{-1 ）中检测到大量静息包囊。}讨论了这些载体作为接种源的潜力以及我们的研究结果对A. catenella种群动态的影响。