This study completed the setting up of 3 floating seaweed aquaculture facilities in the offshore wind farm of Miaoli on March 27, 2021, for breeding Sargassum hemi phyllum var. chinense. On April 26 and May 26, one floating aquaculture facilities and four underwater aquaculture facilities were completed subsequently, for breeding Crassostrea angulata, Pinctada margaritifera and Perna viridis. All of seaweed aquaculture facilities were broke during the survey on April 26. The growth and mortality survey of shellfishes were conducted on May 26 and August 30. All kind of shellfishes had marked grow during our survey periods. At the time of the survey on August 30, three flatworms were found in the single oyster cage, resulting in a cumulative mortality rate of 33.3%, but it was not found in traditional aquaculture oysters. The mortality rates of Pinctada margaritifera and Perna viridis were 0 %, and both had newborn mussels. The 3Dprinted seedling equipment was used in the seedling test in the traditional oyster farm of Changhua Wanggong on April 8, 2021, and there were 1608 single oyster seedlings falling on the bottom of cage on August 19.
The upper limit of metal content in shellfish was set by the Ministry of Health and Welfare, including of Cr, Pb, As and Hg, and the limited value was 1, 1.5, 0.5 and 0.5 ppm, respectively. These four metal were not detected in the single oyster that were breed in offshore wind farm of Miaoli on April 26; and these metals were not detected also on August 30, except As (0.01 ppm). During this experiment, the metal contents in the single oyster were lower than the upper limit that were set by the Ministry of Health and Welfare.
Shellfish breeding facilities in the offshore wind farm of Miaoli have the function of fish aggregation, like the artificial reef. We recorded a lot of Serio la dumerili and some Parastromateus niger, Psenes cyanophrys and Aluterus scriptus gathering in the vicinity water of shellfish breeding facilities during the diving survey on 26 May, 2021.