Sporophytes of the warm temperate perennial kelp Ecklonia cava typically mature after two years, but some populations mature in the first year. To understand the dynamics of these early-maturing forms of E. cava, one isolated population (5 ha) was monitored at Moroiso, Miura City in Sagami Bay, Japan from 2015 to 2020. From 2015 to 2018, the sporophytes were able to repeatedly recruit due to high maturation rates (92% at maximum) in the summer. However, these sporophytes disappeared due to browsing by the rabbitfish Siganus fuscescens and/or typhoon-related high waves in autumn or winter. The early maturing nature of the strain appears to help maintain the kelp forest despite these harsh conditions and could be a candidate for seed production and transplantation to deforested areas.

However, in 2019 and 2020, the kelp forest was completely destroyed by unusual high water temperatures (the highest in 40 years) and increased browsing by S. fuscescens and the parrotfish Calotomus japonicus, as well as larger typhoon waves. To avoid extinction, this strain should be kept in laboratory stock culture for further use.

The purpose of this study was to investigate the most used viewing media for viewing publicly available data in computerized wholesale market of fisheries products, and to consider the means to provide data in a way that would best suit for each user. The survey was conducted on users of the production area electronic information network (PAEIN). In total, the PAEIN had 782 registered users. The analysis results showed that 56.5% of the users employed only a personal computer to browse the data of the PAEIN. Because information can be shared more effectively by a designated person in an office rather than having each user view the information with a mobile terminal. In addition, the frequency of browsing differed depending on the type of industry and was highest for sorting workers and longshoremen because of the need to repeatedly confirm the date and time of arrival of fishing vessel, among others, to determine work schedules for the employees. Sorting workers and longshoremen frequently used a mobile terminal. As a suggestion for improvement for sorting workers and longshoremen, it would be effective to send notifications to mobile terminals when data such as landing times are updated.

Permeability may be an important habitat for submerged sand organisms. Therefore, a simplified permeability test method was tried and compared with the Creager's permeability coefficient to verify the validity of the measured value as a permeability index. As a result, we found that the two methods were in good agreement, with a sharp decrease in permeability at an effective diameter of 0.2 mm. This method may be used to obtain a low-cost and easy-to-use measure of permeability indicators on site.

The 2023 JSFE Spring Symposium on “Sustainable Fisheries in Southern Kyushu Under Cooperation Among Industry, Government and Academia” was held on 28 May 2023 at Faculty of Fisheries, Kagoshima University. Four case studies were introduced by the fisherman, local government staff, and the staff of private companies. This report summarized the symposium.