de la Riva Gretel Torres, Johnson Christine Kreuder, Gulland Frances M D, Langlois Gregg W, Heyning John E, Rowles Teri K, Mazet Jonna A K
Wildlife Health Center, School of Veterinary Medicine, University of California, Davis, 1 Shields Ave., California 95616, USA.
J Wildl Dis. 2009 Jan;45(1):109-21. doi: 10.7589/0090-3558-45.1.109.
During 2002, 2,239 marine mammals stranded in southern California. This unusual marine mammal stranding event was clustered from April to June and consisted primarily of California sea lions (Zalophus californianus) and long-beaked common dolphins (Delphinus capensis) with severe neurologic signs. Intoxication with domoic acid (DA), a marine neurotoxin produced during seasonal blooms of Pseudo-nitzschia spp., was suspected. Definitively linking harmful algal blooms to large-scale marine mammal mortalities presents a substantial challenge, as does determining the geographic extent, species composition, and potential population impacts of marine mammal die-offs. For this reason, time series cross-correlation analysis was performed to test the temporal correlations of Pseudo-nitzschia blooms with strandings occurring along the southern California coastline. Temporal correlations were identified between strandings and blooms for California sea lions, long-beaked common dolphins, and short-beaked common dolphins (Delphinus delphis). Similar correlations were identified for bottlenose dolphins (Tursiops truncatus) and gray whales (Eschrichtius robustus), but small sample sizes for these species made associations more speculative. The timing of the blooms and strandings of marine mammals suggested that both inshore and offshore foraging species were affected and that marine biotoxin programs should include offshore monitoring sites. In addition, California sea lion-strandings appear to be a very sensitive indicator of DA in the marine environment, and their monitoring should be included in public health surveillance plans.
2002年期间，2239只海洋哺乳动物在南加州搁浅。这一不同寻常的海洋哺乳动物搁浅事件集中在4月至6月，主要包括出现严重神经症状的加利福尼亚海狮（Zalophus californianus）和长吻真海豚（Delphinus capensis）。怀疑是由拟菱形藻属季节性大量繁殖期间产生的一种海洋神经毒素——软骨藻酸（DA）中毒所致。将有害藻华与大规模海洋哺乳动物死亡明确联系起来面临着重大挑战，确定海洋哺乳动物死亡事件的地理范围、物种组成以及对种群的潜在影响同样如此。因此，进行了时间序列交叉相关性分析，以检验拟菱形藻大量繁殖与南加州海岸线沿线搁浅事件之间的时间相关性。确定了加利福尼亚海狮、长吻真海豚和短吻真海豚（Delphinus delphis）的搁浅与藻华之间存在时间相关性。宽吻海豚（Tursiops truncatus）和灰鲸（Eschrichtius robustus）也发现了类似的相关性，但这些物种的样本量较小，使得关联性更具推测性。海洋哺乳动物藻华和搁浅的时间表明，近岸和近海觅食物种均受到影响，海洋生物毒素监测项目应包括近海监测点。此外，加利福尼亚海狮搁浅似乎是海洋环境中软骨藻酸的一个非常敏感的指标，对其监测应纳入公共卫生监测计划。
