SEAWEED AQUACULTURE IN KOREA: STATUS AND FUTURE DIRECTIONS

Korea is one of the leading countries in seaweed aquaculture around the world, and harvested over 1.1 million tons of seaweed in 2013. Three genera, including the brown seaweed, Saccharina and Undaria, and the red seaweed Pyropia (formally known as "Porphyra"), occupies nearly 98% of entire seaweed production in Korea.  Seaweed aquaculture technologies in Korea have developed dramatically past decades, but there are still challenges to overcome.  There are many efforts to develop strains of seaweeds with traits of fast growth, better flavor, disease resistance and high temperature tolerance. Epiphyte control is also a major issue especially on Pyropia farms. Some farms use desiccation control methods by exposing the Pyropia nets to the air to kill epiphytes and competing organisms (e.g. Ulva spp.). However, most Pyropia farmers prefer using a pH control method by spraying organic acids onto the nets, but this is a costly approach. In some seaweed farms, nutrients are limiting factors, causing a loss of pigments that produce a lower quality product.  This has resulted in significant loss of production.  In contrast, in areas where there are fish farms, eutrophication and harmful algal blooms are major issues due to excess nutrients.  To resolve these issues, recently, integrated multi-trophic aquaculture (IMTA) technologies are being applied to some seaweed farm areas in Korea.   In addition, aquaculturalists and coastal managers in Korea have started to put more attention to the ecosystem role of seaweed farming.  It is roughly estimated that seaweed harvest can sequestrate approximately 66,000 tons of carbon and 4,400 tons of nitrogen every year.