Characterization of lacustrine harmful algal blooms using multiple biomarkers: Historical processes, driving synergy, and ecological shifts

Qi Lin* (Corresponding author), Ke Zhang, Suzanne McGowan, Shixin Huang, Qingju Xue, Eric Capo, Can Zhang, Cheng Zhao, Ji Shen

*Corresponding author for this work

Research output: Contribution to journal/periodicalArticleScientificpeer-review

6 Citations (Scopus)
10 Downloads (Pure)

Abstract

Harmful algal blooms (HABs) producing toxic metabolites are increasingly threatening environmental and human health worldwide. Unfortunately, long-term process and mechanism triggering HABs remain largely unclear due to the scarcity of temporal monitoring. Retrospective analysis of sedimentary biomarkers using up-to-date chromatography and mass spectrometry techniques provide a potential means to reconstruct the past occurrence of HABs. By combining aliphatic hydrocarbons, photosynthetic pigments, and cyanotoxins, we quantified herein century-long changes in abundance, composition, and variability of phototrophs, particularly toxigenic algal blooms, in China's third largest freshwater Lake Taihu. Our multi-proxy limnological reconstruction revealed an abrupt ecological shift in the 1980s characterized by elevated primary production, Microcystis-dominated cyanobacterial blooms, and exponential microcystin production, in response to nutrient enrichment, climate change, and trophic cascades. The empirical results from ordination analysis and generalized additive models support climate warming and eutrophication synergy through nutrient recycling and their feedback through buoyant cyanobacterial proliferation, which sustain bloom-forming potential and further promote the occurrence of increasingly-toxic cyanotoxins (e.g., microcystin-LR) in Lake Taihu. Moreover, temporal variability of the lake ecosystem quantified using variance and rate of change metrics rose continuously after state change, indicating increased ecological vulnerability and declined resilience following blooms and warming. With the persistent legacy effects of lake eutrophication, nutrient reduction efforts mitigating toxic HABs probably be overwhelmed by climate change effects, emphasizing the need for more aggressive and integrated environmental strategies.
Original languageEnglish
Article number119916
JournalWater Research
Volume235
DOIs
Publication statusPublished - 01 May 2023

Keywords

  • Climate warming
  • Critical transition
  • Cyanotoxin
  • Harmful cyanobacterial bloom
  • Lake paleoecology
  • Variability

Research theme

  • Sustainable water and land use

Fingerprint

Dive into the research topics of 'Characterization of lacustrine harmful algal blooms using multiple biomarkers: Historical processes, driving synergy, and ecological shifts'. Together they form a unique fingerprint.

Cite this