Temporal bloom dynamics of the marine dinoflagellate Tripos furca in the Penang Strait
Document Type
Article
Publication Date
2-1-2025
Abstract
The dinoflagellate Tripos furca, known for its frequent and massive blooms in coastal waters, has been associated with significant fish mortality in aquaculture areas. In mid-May 2022, a notable bloom event, characterized by intense red discoloration, was observed along the Penang Strait in the northern Malacca Strait. Our field survey identified a high-density bloom of T. furca. To investigate the mechanisms driving the bloom dynamics of this species, monthly sampling was undertaken until the bloom subsided, covering 19 stations across the Penang Strait. Our results showed that the abundances of T. furca changed over time and space, a bloom peak of 8.2 x 105 cells L-1 was observed in late June, triggered by elevated sea surface temperatures and phosphate availability, while nitrogen was consistently abundant. The bloom's persistence was associated with the influence of the 2020-2022 La Nina and Indian Ocean Dipole, which caused warmer sea temperatures. Metabarcoding of the V7- V9 18S rDNA region revealed high intraspecific genetic diversity within the T. furca bloom subpopulations, suggesting both clonal reproduction and possible sexual processes. The bloom termination was linked to a seasonal shift in temperatures and changes in nutrient regimes that caused a transition of phytoplankton compositions to Noctiluca- and diatom-dominated populations contributed to the bloom's decline. Early detection of the bloom has successfully prevented severe losses to the aquaculture farms in the area, emphasizing the importance of early intervention. This study also enhances our understanding of T. furca bloom dynamics and provides insights into managing harmful algal blooms in tropical coastal regions.
Keywords
Aquaculture, Environmental DNA, ENSO, Harmful algal blooms, Metabarcoding, Ocean warming, Tripos
Divisions
ocean
Funders
Malaysian Government through the Ministry of Higher Education (MOHE) Long-term Research Grant Scheme [Grant No: LRGS/1/2020/UMT/01/1/3],MOHE Higher Education Center of Excellence grant [Grant No: HICoE IOES-2023B],LRGS postgraduate research assistantship
Publication Title
Harmful Algae
Volume
142
Publisher
Elsevier
Publisher Location
RADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS