Norwegian Veterinary Institute, Ås, Norway; University of Oslo, Department of Biosciences, Oslo, Norway.
University of Oslo, Department of Biosciences, Oslo, Norway; Norwegian Institute for Water Research, Oslo, Norway.
Harmful Algae. 2024 Nov;139:102709. doi: 10.1016/j.hal.2024.102709. Epub 2024 Aug 16.
The haptophyte Chrysochromulina leadbeateri formed the most devastating fish-killing algal bloom ever recorded in Norway, in May and June 2019. The bloom resulted in the death of 14,500 tons of farmed salmon in Nordland and Troms Counties and large economic losses to the aquaculture industry in the region. Fish mortalities due to blooms of this species have occurred before in this region in 1991. Environmental conditions promoting bloom formation and growth of C. leadbeateri are, however, still poorly understood. Here we investigated growth as a function of temperature, salinity and irradiance in combinations using a high throughput experimental set-up. Three strains of C. leadbeateri isolated from the 2019 event and an earlier bloom in 1991 were examined. The highest maximal specific growth rate was found at salinities 28-30 and temperatures between 13 and 15 °C, with growth rate generally increasing with irradiance. The upper temperature tolerance for growth for all strains was at 17-19 °C. Further, analyses of the geographical distribution of C. leadbeateri in previous DNA-based studies compiled in the metaPR2 database revealed several ribotypes, and that a cold-water ribotype of C. leadbeateri caused both the 1991 and 2019 blooms.
甲藻 Chrysochromulina leadbeateri 曾在 2019 年 5 月和 6 月形成了挪威有记录以来最具破坏性的鱼类致死性藻华。这场藻华导致诺尔兰和特罗姆瑟县的 14500 吨养殖三文鱼死亡，给该地区的水产业造成了巨大的经济损失。该物种引发的藻华以前在该地区的 1991 年也发生过。然而，促进 C. leadbeateri 藻华形成和生长的环境条件仍知之甚少。在这里，我们使用高通量实验装置研究了温度、盐度和光照组合对生长的影响。我们研究了从 2019 年事件和 1991 年早期藻华中分离出的三种 C. leadbeateri 菌株。在 28-30 盐度和 13-15°C 之间的温度下，发现最高的最大比生长率，并且生长率通常随光照强度的增加而增加。所有菌株的最高生长温度耐受值在 17-19°C。此外，对 metaPR2 数据库中以前基于 DNA 的 C. leadbeateri 地理分布的分析显示了几个核糖体型，冷水型 C. leadbeateri 引起了 1991 年和 2019 年的藻华。
