An unprecedented outbreak of pelagic molluscs Creseis acicula in Daya
Bay, South China Sea
Creseis acicula is a pteropod species, widely distributed in the world’s
ocean. The latest report of its bloom was in the Mediterranean Sea in
1990. On June 12, 2020, an unprecedented bloom of C. acicula was
observed in Daya Bay, China, that lasted for over a month and caused
economic losses. The maximum abundance of C. acicula was up to 5595 ind.
m-3, 1000 times the local record high, and 10 times the highest number
recorded elsewhere. Higher abundance (≥ 1000 ind. m-3) was found in the
warm water of ≥ 30℃ along the southwest shore of Daya Bay. The
initiation of the bloom matched a sharp increase of temperature and
chlorophyll a and an abrupt decrease of salinity attributed to heavy
rainfall that lasted for more than 20 days. Considering rising
occurrences of extreme weather due to global change, possibilities of
recurrent C. acicula blooms worldwide certainly deserve attention.