Newly published research in Ecotoxicology and Environmental Safety has provided important insights into the accumulation and depuration of ciguatoxins (CTXs) in green-lipped mussels (Perna canaliculus), highlighting emerging seafood safety considerations linked to harmful algal blooms and climate change.
The study investigated how green-lipped mussels accumulate ciguatoxins after exposure to the toxic dinoflagellate Gambierdiscus polynesiensis, a known producer of ciguatera toxins commonly associated with ciguatera fish poisoning (CP). Traditionally linked to contaminated reef fish, ciguatera poisoning is increasingly being recognised as a broader marine food safety concern involving non-traditional vectors such as shellfish and marine invertebrates.
What Are Ciguatoxins?
Ciguatoxins are potent marine neurotoxins produced by certain species of Gambierdiscus, microscopic benthic dinoflagellates found in tropical and subtropical coastal waters. Human exposure occurs through consumption of contaminated seafood and can result in neurological, gastrointestinal, and cardiovascular symptoms, sometimes lasting for extended periods.
As ocean temperatures continue to rise, the distribution of toxin-producing species is expanding into temperate regions, increasing concern for seafood industries and environmental monitoring programs globally. The study notes that warming sea surface temperatures may support the establishment of Gambierdiscus species in regions such as New Zealand and other temperate coastal environments.
Key Findings from the Study
Researchers conducted controlled feeding trials exposing green-lipped mussels to toxic Gambierdiscus polynesiensis over a 30-day accumulation period followed by a depuration phase.
The study demonstrated that:
- Mussels rapidly accumulated ciguatoxins, particularly within the digestive system
- Peak toxin concentrations exceeded established seafood safety guidance values
- Toxin accumulation reached maximum levels around 19–21 days of exposure
- Mussels were capable of depurating toxins over time when returned to a toxin-free diet
- Complete depuration occurred after approximately 35 days under controlled laboratory conditions
Transcriptomic analysis also revealed significant molecular stress responses associated with toxin exposure, including activation of detoxification pathways, stress-response proteins, and immune-related genes. These findings may support future development of molecular biomarkers for early toxin exposure detection in aquaculture species.
Implications for Seafood Safety and Monitoring
The research highlights the importance of ongoing monitoring for marine biotoxins as harmful algal bloom dynamics continue to evolve under changing environmental conditions.
For seafood producers, regulatory laboratories, and environmental monitoring programs, understanding toxin accumulation and depuration behaviour in commercially important shellfish species is critical for:
- Seafood safety risk assessment
- Harvest management strategies
- Environmental monitoring programs
- Harmful algal bloom response planning
- Future climate-related food safety preparedness
The study also reinforces the increasing importance of advanced analytical technologies, including LC-MS/MS and molecular screening tools, in supporting marine toxin monitoring and food safety programs.
At PM Separations, we continue to support laboratories and researchers with advanced analytical solutions for marine toxin detection, sample preparation, and environmental testing applications.
For more information on analytical workflows or marine toxin testing solutions, please contact the PM Separations team.
