NIFS said the East Sea has seen a long-term decrease in primary production*, and the reason for the decrease is ocean-warming drived reduction in nutrients supply.

*Primary production refers to the process where phytoplanktons convert inorganic substances into organic matter using energy from sunlight (photosynthesis), forming the base of the food web, providing energy and nutrients for other organisms. 

The R/Vs observation results also showed that primary production in 2024 was decreased by 13% compared to the average of recent six years (2018-2023). Moreover, distribution range of macro- and megaplankton decreased by 1.1% per year(1,630㎢/year), confirming that the structure of marine ecosystem is changing clearly. 

Such physical and chemical changes, in turn, lead to the decrease of primary production in the East Sea.