Climate Change and Environmental Drivers of Gim (Pyropia yezoensis) Aquaculture: Evidence from Wando, South Korea

Gim ( Pyropia yezoensis ) is Korea’s most commercially significant marine product, accounting for 82% of global exports and playing a vital role in the national diet and fisheries economy. The export value of Gim has increased dramatically from $100 million in 2010 to $996 million in 2024, boosting the livelihoods of Gim farmers and contributing to the growth of the aquaculture sector. However, marine algae like Gim are highly sensitive to environmental changes, particularly those driven by climate change. This study examines the relationship between Gim production and key environmental factors including water temperature, rainfall, sunlight duration, and wind speed. The analysis identifies water temperature as the most influential variable, explaining over half of the variation in production. A nonlinear relationship is observed, where both excessively low and high temperatures negatively impact yields. Additionally, moderate wind speed and sufficient rainfall enhance nutrient distribution and availability, supporting healthy crop growth. Sunlight duration is also found to play an important role during the main cultivation season from December to April. To address climate-related risks, short-term adaptation strategies should include optimized seeding times and the wider use of land-based seeding methods. Long-term strategies involve breeding heat-resistant Gim varieties, diversifying cultivation sites, and investing in advanced seed technologies. The findings highlight the need for integrated policy and technological responses to ensure the sustainability of Gim aquaculture, promote food security, and build resilience in the face of ongoing environmental change.