Ocean acidification poses a myriad of challenges, particularly to marine environments and ecosystems. Its negative repercussions are equally obvious from a human-centric perspective. Despite efforts to address ocean acidification through various international legal frameworks, current international legal frameworks, such as the United Nations Convention on the Law of the Sea and the United Nations Convention on Climate Change, which represent the climate change regime and the ocean regime, respectively, fall short of adequately addressing ocean acidification challenges. Because of the climate change regime's atmospheric-centered perspective and the ocean regime's pollution-oriented perspective, ocean acidification falls between the cracks and is not a priority for either regime. To adequately address the issues posed by ocean acidification, a concerted effort between the the legal regime addressing climate change and the legal regime regulating maritime affairs is crucial. This effort might be realized by developing a robust governance system that encompasses both of these regimes, which are specifically tailored to tackle ocean acidification. Given the complexity of ocean acidification governance, the distribution of roles for both regimes should be thoroughly examined. Due to its broad reach, the ocean regime might take the lead in directing the trajectory of ocean acidification, while the climate change regime might provide assistance within the context of ocean acidification governance. Active mutual reference and due diligence obligations could be employed in this scenario to bridge the gaps created by both the climate change regime and the ocean regime regarding ocean acidification. The active interaction between these regimes might pave the way for proper ocean acidification governance in order to meet the challenges posed by ocean acidification.

Melosira nummuloides (KNU-HAPCC-101), which is a biological resource for fucoxanthin extraction, was separated from single cells, and optimal growth conditions were derived according to temperature, salinity, light intensity, light emitting diode, N:P ratio of culture medium, and dilution ratio of culture medium. These parameters were assessed to ascertain the best culture conditions for the most economical and efficient indoor mass production. The specific growth rate was the highest at 25℃ in temperature, but there was no significant difference between 15℃ and 20℃. M. nummuloides died at 0 psu in salinity, and the specific growth rate was the highest at 30 psu in respect to salinity. The light intensity was similar in all experimental groups except for 5 µmol photons m^-2 s^-2. The maximum biomass and specific growth rate in the light-emitting diode experiment were revealed at the red wavelength, but the concentration of chlorophyll-a was the lowest at the red wavelength whereas the white wavelength produced the highest chlorophyll-a concentration. In the experiment according to the ratio of nitrogen and phosphorus (N:P) based on the f/2 culture medium, the growth rate was significantly higher in the 15:1 to 50:1 ratio range. The growth rate according to the dilution concentration of the f/2 culture medium was the highest in the f/2 culture medium, but did not show a significant difference from the f/4 culture medium. M. nummuloides can be mass-cultured under conditions of a temperature of 15-25℃, a salinity of 15-35 psu, light intensity of 25-150 µmol photons m^-2 s^-2, and f/4 media concentration level with an N:P ratio 15:1 or more. Based on the data of this study, it is expected that fucoxanthin can be produced in a highly efficient manner through the development of a mass culture system.

Commonly occurring on a shallow subtidal coarse sand bottom in the northwest Pacific region, the Jedo Venus clam Leucoma (=Protothaca) jedoensis (Lischke, 1874) is one of the valuable shellfish resources supporting the local fisheries industry on the south coast of Korea. In this study, we surveyed the pathologic condition of L. jedoensis from a shallow subtidal sand flat in Gamakman Bay on the south coast using histology and Ray's fluid thioglycollate medium (RFTM) assay to diagnose infection by the protozoan pathogen Perkinsus olseni. In September 2022, a total of 200 clams with shell length (SL) ranging from 29 to 50 mm were obtained from Gamakman Bay, and each clam was subjected to histology and RFTM assay. Histology revealed that all clams collected in September were in the resting stage, indicating that L. jedoensis in the study area completed spawning before September. Perkinsus olseni and unidentified trematode in the sporocysts stage were observed in histology with a low prevalence of 1.5% and 1%, respectively. Contrary to the histology, the RFTM assay indicated that 4.5% of the Jedo Venus clams examined in this survey were infected with P. olseni, with an average infection intensity of 1.1 x 104 cells/g gill, highlighting the presence of P. olseni in the area. The histology and RFTM assay suggested that P. olseni may not exert a substantial impact on Jedo Venus clam health, compared to Manila clams, the host of P. olseni occurring in the south coast exhibiting extremely high levels of P. olseni infection intensities and prevalence.

One reason for the constant change of coastlines is related to natural factors such as waves, tides, changes in ocean currents, and sea level rise, and another reason is with regard to artificial factors such as man-made structures in coastal areas. The recent intensification of climate change is accelerating common efforts around the world to cope with the phenomenon of beach regression. Korea designates Coastal Erosion Management Zones under the 'Coast Management Act' to mitigate its coastal erosion. France, on the other hand, enacted the 2021 Climate Act that promotes adaptation to territory due to beach regression, while gradually limiting development activities at the urban planning level according to the proximity of the coastline through Loi Littoral (The French Coastal Law). This paper reviews the coastal erosion management legislation of both countries, derives implications for legislation in Korea based on an assessment ofFrench legislation, and presents an improvement plan.