Sargassum horneri is a highly invasive macroalgae species from Chinese archipelago. Nowadays, it has been influence in Jeju which is the biggest island of South Korea and famous for popular Korean tourist attractions because of its landscape and ocean. The seaweed is the cause that has damaged the ocean by giving out bad smell and ruined the beach. Also, the sea's landscape has been messed up. Most of people often visit Jeju Island to inhale clean air in the island and look around its landscape like Sabine Silver sand Beach and Hyeopjae Beach. However, it has ruined many tourist attrations, and the seaweed is not giving a good impression.

 

 It is not only this harmful but also gives bad influence on many aquafarms grows like kelp or abalone in southern sea. It makes fish, and shellfish grow slowly by stealing nutrient which the aquafarmer gives. Also, it makes many holes to kelp, which let the kelp not to sell or fall down its commercial value. A lot of aquaculturists cannot help being damaged and are having monetary problems because most of aquafarms are distributed by sargassum horneri in Korean southern sea.

 This seaweed has flown about twelve thousand one hundred tons in 2015 and four thousand four hundred eighteen tons in 2017 for first half year. Let's examine how much amount of the seaweed flew to southern sea. It is piled up about one thousand six hundred twenty tons in Haenam-gun, one thousand one hundred tons in Wando-gun and seventy tons in Sinan and Jindo.

 Here are two reasons why the seaweed comes to Korean southern beach. One is China has large aquafarms in Zhejiang that can grow the seaweed. The sequence listing is same in the seaweed that found in Jeju and being grown in China. The other is Chinese waters moves northward riding on the Kuroshio current and then transfer to Tsushima warm current before arriving in Korea. For these reasons, we know that Korean aquaculturists are damaged by Chinese aquafarms.

 Korean government and Chinese government may have discussion and make solutions in order to fall down Korean aquaculturists' harms.