Plankton Laboratory, Graduate School of Fisheries Sciences, Hokkaido University, 3-1-1 Minato-cho, Hakodate, Hokkaido, 041-8611, Japan.
Marine Biotoxins Program, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 2725 Montlake Blvd. E., Seattle, WA, 98112, United States.
Harmful Algae. 2017 Feb;62:136-147. doi: 10.1016/j.hal.2016.04.004. Epub 2016 Aug 3.
The algicidal and growth-inhibiting bacteria associated with seagrasses and macroalgae were characterized during the summer of 2012 and 2013 throughout Puget Sound, WA, USA. In 2012, Heterosigma akashiwo-killing bacteria were observed in concentrations of 2.8×10CFUg wet in the outer organic layer (biofilm) on the common eelgrass (Zostera marina) in north Padilla Bay. Bacteria that inhibited the growth of Alexandrium tamarense were detected within the biofilm formed on the eelgrass canopy at Dumas Bay and North Bay at densities of ∼10CFUg wet weight. Additionally, up to 4100CFUmL of algicidal and growth-inhibiting bacteria affecting both A. tamarense and H. akashiwo were detected in seawater adjacent to seven different eelgrass beds. In 2013, H. akashiwo-killing bacteria were found on Z. marina and Ulva lactuca with the highest densities of ∼10CFUg wet weight at Shallow Bay, Sucia Island. Bacteria that inhibited the growth of H. akashiwo and A. tamarense were also detected on Z. marina and Z. japonica at central Padilla Bay. Heterosigma akashiwo cysts were detected at a concentration of 3400cystsg wet weight in the sediment from Westcott Bay (northern San Juan Island), a location where eelgrass disappeared in 2002. These findings provide new insights on the ecology of algicidal and growth-inhibiting bacteria, and suggest that seagrass and macroalgae provide an environment that may influence the abundance of harmful algae in this region. This work highlights the importance of protection and restoration of native seagrasses and macroalgae in nearshore environments, in particular those regions where shellfish restoration initiatives are in place to satisfy a growing demand for seafood.
2012 年和 2013 年夏季，在美国华盛顿州普吉特湾对与海草和大型藻类相关的杀藻和生长抑制细菌进行了研究。2012 年，在外层有机层（生物膜）中观察到浓度为 2.8×10CFUg 湿重的杀赤潮异弯藻细菌，这些细菌存在于北帕迪拉湾常见的鳗草（Zostera marina）上。在杜马湾和北湾的鳗草冠层生物膜中检测到能抑制亚历山大藻生长的细菌，密度约为 10CFUg 湿重。此外，在毗邻七个不同鳗草床的海水中，检测到影响亚历山大藻和赤潮异弯藻的杀藻和生长抑制细菌，浓度高达 4100CFUmL。2013 年，在浅湾和斯夸伊岛的鳗草和浒苔上发现了杀赤潮异弯藻细菌，最高密度约为 10CFUg 湿重。在中帕迪拉湾的鳗草和日本鳗草上也检测到抑制赤潮异弯藻和亚历山大藻生长的细菌。在西科特湾（圣胡安岛北部）的沉积物中，检测到浓度为 3400cystsg 湿重的赤潮异弯藻胞囊，该地点的鳗草于 2002 年消失。这些发现为杀藻和生长抑制细菌的生态学提供了新的见解，并表明海草和大型藻类为赤潮异弯藻和亚历山大藻等有害藻类的丰度提供了可能影响的环境。这项工作强调了保护和恢复近岸环境中本地海草和大型藻类的重要性，特别是在贝类恢复措施到位以满足海鲜需求增长的地区。
