China’s kelp farming industry, a global leader in aquaculture, is facing a growing threat: genetic homogeneity. A new decade-long study led by Professor Pang Shaojun from the Institute of Oceanology, Chinese Academy of Sciences (IOCAS), reveals how the widespread cultivation of genetically uniform Saccharina japonica strains could jeopardize the future of this vital seaweed industry.
Published in the peer-reviewed journal Aquaculture Reports, the research highlights the urgent need to diversify kelp genetics across China to ensure long-term sustainability, disease resistance, and improved productivity.
🔬 Study Overview: Genetic Uniformity in Kelp Cultivation Across China
The research team conducted a 10-year genetic monitoring program in Rongcheng, Shandong Province—a major hub for kelp production. They analyzed six dominant Saccharina japonica cultivars and discovered that five out of six showed significant genetic similarity, lacking the variability essential for resilience. Only one hybrid cultivar demonstrated notable genetic diversity.
Using molecular marker technologies and open-sea cultivation trials, the researchers linked the issue to:
- Standardized parental selection
- Uniform seedling production techniques
🌱 The Solution: Hybridization and External Germplasm
To combat the genetic bottleneck, the team introduced diverse external germplasm through targeted hybridization breeding. This approach not only increased genetic variation but also boosted overall productivity and environmental resilience.
A breakthrough came with the development of the hybrid cultivar “205–24”, which showed:
- Improved resistance to early sporulation
- Reduction in sori formation at harvest from 70% to just 28%
- Enhanced commercial value and farming efficiency
⚠️ Why Genetic Diversity Matters in Kelp Aquaculture
Genetic uniformity leaves kelp farms vulnerable to disease outbreaks and environmental stress. This risk became reality during a severe mortality event between 2021 and 2022 in Rongcheng, where only a few genetically diverse hybrid strains survived.
Prof. Pang emphasized the need for urgent action:
“We suggest kelp farming enterprises develop independent breeding systems, improve genetic monitoring, and introduce diverse external germplasm to reduce risks of inbreeding and genetic drift.”
✅ Recommended Sustainable Strategies for Kelp Farmers
To future-proof China’s kelp aquaculture industry, the study recommends:
- 🔁 Developing sustainable, in-house breeding programs
- 👨🌾 Improving parental line management
- 🧬 Applying routine genetic monitoring
- 🌍 Introducing new germplasm from diverse sources
- 📈 Investing in hybrid cultivars with proven resilience
📚 Source and Further Reading
Research Title: Challenges of genetic homogeneity in aquaculture of the kelp Saccharina japonica: Insights from China in ten year’s retrospect
Authors: Xiaodong Li, Shaojun Pang, et al.
Published In: Aquaculture Reports (2025)
DOI: 10.1016/j.aqrep.2025.102904