The number of anglers in Japan in 2015 was estimated using data from the White Paper on Leisure and an original web research. Survey subjects consisted of 1,000 people aged 15 to 79 years. The numbers (×1,000) and ratios of anglers were 4,875 (48.7%) for seas, 3,360 (33.6%) for inland waters (rivers, lakes, ponds, and artificial channels), and 1,777 (17.7%) for fishing ponds. For natural water areas excluding fishing ponds, the numbers (×1,000) and ratios of anglers were 4,875 (59.2%) for seas and 3,360 (40.8%) for inland waters. The numbers (×1,000) of anglers targeting each of the top 10 inland species were 1,188 for Oncorhynchus masou, 887 for Salvelinus leucomaenis, 824 for O. mykiss, 776 for Plecoglossus altivelis altivelis, 767 for Carassius spp., 666 for Micropterus spp., 561 for Cyprinus carpio, 355 for Tribolodon hakonensis, 288 for Hypomesus nipponensis, and 278 for Opsariichthys platypus. The number of anglers targeting P. altivelis altivelis was comparable to that of those targeting Carassius spp. In Japan, anglers in inland waters are plentiful and inland water angling is an important leisure activity.

　To explore the method of constructing nursery habitat for the stock recovery of large-sized abalone species (e.g. Haliotis discus discus and H. gigantea) distributed over the warm current region in Japan, we conducted continuous observations of the occurrence and growth of abalone juveniles and habitat environmental factors such as coverage of crustose coralline algae for approximately 2 years at the experimental site created in 2016 adjacent to the coast of Nagai, Kanagawa Prefecture, Japan. Artificial substrates set at the site showed good habitat conditions no worse than natural stone and were maintained during the monitoring period. Age-0 juveniles of large-sized abalone species appeared at the site in the spring of both 2017 and 2018. The maximum density per surface area of H. gigantea observed on the artificial substrates reached 6.2 ind. m⁻² (May in 2017). Age-0 juveniles of H. gigantea around the site in 2017 showed remarkable growth stagnation before 20 mm in shell length, possibly influenced by the shortage of food resources due to the decline of kelp beds surrounding the site.

　We examined the fish toxicity of slaked lime, a strong alkaline agent that is used in invasive fish eradication operations in drained farm ponds. Lime exposure tests showed no substantial difference in 6-h lethal concentration among the four species used (two invasives and two natives). The addition of pond sediments to the lime water to simulate pond conditions significantly increased the lethal lime concentration but did not affect the lethal pH (~12.0). The sediment-added lethal-concentration lime water kept a high pH value even 2 weeks after preparation, while 50-fold or higher dilutions of the lime water showed a neutral pH value immediately after preparation. Based on these findings, we discuss the piscicidal properties of lime and techniques of applying lime to eradicate invasive fish in farm ponds.

　In recent years, there have been issues in the transfer of knowledge about skill education in fisheries high schools due to busy work and the retirement of skilled teachers. There are two kinds of such issues: first, the passing of information between teachers, and second, the transfer of information from teachers to students. One solution is to create teaching materials containing the knowledge of skilled teachers. We formalized the tacit knowledge of veteran teachers and developed a method to create video teaching materials. A study on the effect of the video teaching materials showed that it is possible to obtain the same educational effect as knowledge transfer by skilled teachers.

　This study aims to find a way to increase the number of new fishers considering the decrease in number. We conducted a questionnaire survey to clarify the perceptions and demographics of respondents at a fisheries job fair in Tokyo and collected 223 answered questionnaires. We then employed descriptive statistics analysis, and logit and ordered logit regression analyses. We found the following characteristics of those who wish to gain fisheries experience: young; no children; preference for blue-collar than white-collar work; and hobbies related to marine, river, or lake activities. The results suggest that promotions that reflect our results and collaboration with companies related to recreational fishing and scuba diving would be effective to attract potential fishers to fisheries job fairs. The results will also be useful for developing countermeasures to address the labor shortage in the fisheries industry.