日本水産工学会誌
Online ISSN : 2189-7131
Print ISSN : 0916-7617
ISSN-L : 0916-7617
最新号
選択された号の論文の8件中1~8を表示しています
学会賞受賞講演
  • 桑原 久実
    2022 年 58 巻 3 号 p. 157-166
    発行日: 2022/02/15
    公開日: 2022/02/09
    ジャーナル 認証あり

    Reduction of seaweed beds called ‘isoyake’ has happen in most of coastal prefectures in Japan, most of are due to excessive grazing by sea urchins and herbivorous fish. Several studies and countermeasures have been undertaken to recover from barren ground, but there were problems such as one-off trials and impracticality, therefore, it was necessary to show the concept and procedure of systematic measures. First, Isoyake Recovery Guideline (First Edition, Fisheries Agency, 2007) showed the basic concept and concrete procedure for countermeasures as follows. (i) adaptive management for successful reforestation through continuous learning and feedback control, (ii) flow chart consisted for selecting appropriate recovery techniques, (iii) organized cooperation of volunteers, citizens, enterprises, specialists, and local governments to support fishermen. Next, from the elemental technology development for tangible/intangible measures, reforestation facilities that control of sea urchin grazing with stones and blocks, development of sea urchin suction device and technological development to remove the gathering Kyphosua bigibbus with a gill net were briefly outlined.

研究論文
  • 江幡 恵吾, 茨木 勇斗, 小澤 壱生, Boutson Anukorn, 田中 秀治, 追立 昭政, 浦添 孫三郎
    2022 年 58 巻 3 号 p. 167-174
    発行日: 2022/02/15
    公開日: 2022/02/09
    ジャーナル 認証あり

    浮式かごに対するアオリイカの行動とかごの姿勢の関係を明らかにすることを目的として,鹿児島県桜島および種子島沿岸で実験を行った。かご底面にインターバルカメラを取り付けて5分間隔で撮影した。かごが浮いた状態の時にかご内部や入口周辺にアオリイカが観察された。かごが着底した時にはコウイカ,甲殻類,魚類がかごの中に入り,コウイカがイセエビに捕食される様子が観察された。

  • 上野 公彦, 村上 敬
    2022 年 58 巻 3 号 p. 175-181
    発行日: 2022/02/15
    公開日: 2022/02/09
    ジャーナル 認証あり

    フーリエ変換によってスペクトルを推定した場合,時間領域から周波数領域にうつるため,時間に関する情報が失われてしまう.またフーリエ変換の定義からも明らかなように,理論的には時間領域全域における情報が必要となる.このような問題に対処するための時間・周波数解析が生み出された。本論文では,まず短時間フーリエ変換であるGábor変換について説明し,その後Morletらによって改良されたウェーブレット変換を用いて実測された東京湾の海洋波の時系列データを時間・周波数解析し,新たに得られた知見について述べる。小型漁船に多大な影響をおよぼす有義波高が1[m]程度の風波を時間・周波数解析した論文は更に少ない。19GTの小型漁船では有義波高が1[m]に満たなくても両振幅30[deg]を越す横揺れが生じることが上野らによって報告されている。この場合,転覆には至らないが,甲板上での作業者が海中転落する可能性は高く,寒冷海域での海中転落は死に直結する。

  • 志田 崇, 久保田 健, 本田 明弘, 桑原 久実, 桐原 慎二
    2022 年 58 巻 3 号 p. 183-190
    発行日: 2022/02/15
    公開日: 2022/02/09
    ジャーナル 認証あり

    Model experiments were conducted in the circulation tank and the wave tank in order to investigate the shapes of concrete structures with an air layer to be installed into the opening of fishing ports water area for confining and cultivating sea cucumbers, taking advantage of the property that the air layer inhibits the behavior of creeping aquatic animals. As a result of the experiment in the oscillating water tank, it was found that the models of the longer the basal plate, the shorter the top edge, the lower the both side edges were the less sand accumulation just below the air layer. While, the result of the experiment in the wave tank showed that the sand accumulated just below the air layer of the model originated from the sand scoured contact with the edge of the model. In addition, a negative correlation was found between the amount of sand accumulated below the air layer and the amount of air leaked from the air layer. If the air layer is lost, the ability to confine and cultivate sea cucumbers in the fishing port waters will be lost. Based on these results, the concrete structure with a width of 3 m, a depth of 1.84 m, and a height of 0.6 m was designed based on the model of the shape with the least amount of sand accumulation just below the air layer, and would be used for the demonstration test.

報文
  • 寺田 充宏
    2022 年 58 巻 3 号 p. 191-198
    発行日: 2022/02/15
    公開日: 2022/02/09
    ジャーナル 認証あり

    Wind power generation is one of the most promising technologies for converting to renewable energy for a carbon-free society. The equipment is getting large-scale for power generation efficiency, construction efficiency, and failure rate reduction by slowing down. The site location of the Windfarm is shifting from land to offshore to minimize its impact on the environment. Competing for environmental performance is going to be the driving factor of international competition in a new era. Therefore, the requirements for business approval are also changing. Regulations for Environmental Impact Assessments are directed to the entire business life cycle, including suspension and removal, and are not limited to entrance regulations but are sustainable, including monitoring. Is changing.

  • 赤星 貞夫
    2022 年 58 巻 3 号 p. 199-201
    発行日: 2022/02/15
    公開日: 2022/02/09
    ジャーナル 認証あり

    Toward the realization of carbon neutrality in 2050, the introduction of renewable energy is an important issue in Japan. As one of the important measures for that, the introduction of offshore wind power is being promoted in cooperation with the public and private sectors. Offshore wind projects are a major investment and need to manage and reduce construction risks, and accident risks during their more than 20-year operation period. Class NK contributes to ensuring the safety of construction work through the Marine Warranty Survey work. The Survey is a condition for insurance coverage for construction work. In addition, Class NK provides wind farm certification service to evaluate the conformity of wind turbines and their supporting structures to national standards, and the suitability for local wind conditions, sea conditions, ground conditions, etc. Through this process, we contribute to stable operation and accident prevention. On the other hand, in order to spread offshore wind power generation, it is also important to reduce its lifecycle cost including operation and maintenance. NK Group will participate in the necessary technical studies and will play a role in the spread of offshore wind power.

  • 島 隆夫
    2022 年 58 巻 3 号 p. 203-205
    発行日: 2022/02/15
    公開日: 2022/02/09
    ジャーナル 認証あり

    Information on the impacts of offshore wind farms on fisheries was collected through a survey of the literature on case studies conducted overseas (Europe and United States), demonstration projects in Japan as well as interviews with experts. Based on these results, the basic concepts and the expected impacts of offshore wind farms on fisheries, the importance of monitoring surveys, survey methods for each impact, points to be considered for conducting surveys in response to concerns of fishermen, and cooperation with environmental impact assessments were summarized. In order to plan and carry out effective fishery impact surveys in Japan, it is necessary to consider specific studies to Japan in relation to the fishery and ecological characteristics of the target species.

  • 溝口 弘泰
    2022 年 58 巻 3 号 p. 207-212
    発行日: 2022/02/15
    公開日: 2022/02/09
    ジャーナル 認証あり

    Offshore wind power is attracting attention as a renewable energy source that can contribute to a carbon-free society. Toward the realization of a carbon-free society, electric vehicles have already begun to spread. In the near future, we will need the electrification of fishing boats. In addition, offshore wind power and fisheries will have to coexist in harmony. One of the issues that must be addressed to promote the fishing industry through offshore wind power generation is to promote the effective use of electric boats and hydrogen fuel cell boats for fishing. In order to promote the use of hydrogen fuel cell fishing boats, it is necessary to build a prototype boat and conduct verification tests, as well as to study how to install and operate battery charging and hydrogen filling facilities. We will also need to conduct environmental and fisheries impact assessments of the sea area where the offshore wind turbine will be installed in the future. The development of a new type of AUV for marine research will improve the efficiency of underwater surveys, and if environmental DNA analysis can be used to identify fish species living in the surrounding waters, these will be a great benefit to the fisheries impact assessment.

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