3,000 km and 1,500‐year presence of Aureococcus anophagefferens reveals indigenous origin of brown tides in China

Abstract

The nonmotile, spherical, picoplanktonic (2‐μm‐sized) pelagophyte Aureococcus anophagefferens has caused numerous harmful blooms (“brown tides”) across global marine ecosystems. Blooms have developed along the east coast of the USA since 1985, a limited number of times in South Africa around 1997, and frequently in China since 2009. As a consequence, the harmful blooms have caused massive losses in aquaculture and coastal ecosystems, particularly mortalities in cultured shellfish. Therefore, whether A. anophagefferens was recently introduced to China via natural/artificial transport of resting stage cells or has been an indigenous species has become a question of profound ecological significance and broad interest, which motivated our extensive investigation on the geographic and historical presence of this species in the seas of China. We applied a combined approach of extensive PCR‐based detection and sequencing, germination experiments and monoclonal antibody staining of germlings to samples of surface sediment and sediment core (dated via combined isotopic measurements) collected from all four seas of China, and searched the supplementary data set of a recent Science publication. We discovered that A. anophagefferens does have a resting stage in the sediment, but it also has a wide geographic distribution both in China (covering a range of ~30° in latitude, ~15.7° in longitude and 2.5–3,456 m in water depth; temperate to tropical and coastal to open oceans) and in almost all oceans of the world and a historical presence of >1,500 years in the Bohai Sea, China. The work revealed that A. anophagefferens is not a recently introduced, but an indigenous species in China and has in fact a globally cosmopolitan distribution.

Metabarcoding Analysis of Harmful Algal Bloom Species in the Western Pacific Seamount Regions

“…As A. anophagefferens has been detected in the ballast water samples and in the bilge-water of local watercraft [4], it has been proposed that ballast water was the vector of the A. anophagefferens seeds [3]. However, a recent study using molecular markers has uncovered widespread distribution of A. anophagefferens [7], suggesting that ballast water was not an obligatory vector for the A. anophagefferens-caused brown tides to occur. Therefore, the geographical distribution patterns of HAB species remain to be better explored and determined.…”

New pelagophytes show a novel mode of algal colony development and reveal a perforated theca that may define the class

“…1997, Kang and Gobler 2017, Tang et al. 2019). Heterokont zoospores are produced by many genera, possessing an anterior flagellum bearing mastigonemes that beats as a sinusoidal wave and a short, stiff posterior flagellum that beats with a sculling motion.…”

Impacts of Marine Heatwaves on Algal Structure and Carbon Sequestration in Conjunction With Ocean Warming and Acidification

“…However, concentrations of microalgae could also reach very high levels in coastal waters where nutrient availability is high, termed red tides or brown tides. Among 5,000 + microscopic algae species existing worldwide, about 300 species can cause high concentrations of red tides, including toxic species in dinofagellates, diatoms, Haptophyceae, and Cyanophyceae (Zohdi and Abbaspour, 2019), in which the pelagophyte Aureococcus anophagefferens is the key causative species for brown tides (Tang et al, 2019).…”