To develop a method for forecasting fluctuations in a macrobenthic community with changes in the hypoxic environment, water temperature and dissolved oxygen saturation levels were monitored continuously and the macrobenthic community was sampled around a borrow pit in Mikawa Bay during seasons of hypoxia from 2005 to 2007. The influence of hypoxia on each species of sampled macrobenthos was expressed as a new index, oxygen-deficient sensitivity index (OSI), which was calculated from the dissolved oxygen and water temperature data. The relation between the biomass of each species and OSI was fitted using numerical formulae. The results indicate that as hypoxic water developed in June/July, macrobenthic biomass decreased; and as the hypoxic water dissipated from September to November, biomass increased. In addition, the recovery of macrobenthic biomass required higher levels of dissolved oxygen saturation than those recorded when macrobenthic biomass decreased as hypoxia developed. Additionally, fluctuations in species biomass forecasted using the OSI method and the formulae correlated well with field observations. As this method accurately forecasts changes in the macrobenthic community based on dissolved oxygen and water temperature data, it is very effective at forecasting the recovery of the macrobenthic community. It can also be used to predict the water quality purification function of the macrobenthic community after environmental restoration (for instance, backfilling borrow pits or creating artificial shallow sea areas, etc.).

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デジタルステレオカメラを用いて,生簀内を自由遊泳する養成クロマグロの3次元計測を実施した。生簀内の養成個体の尾叉長と体長組成の推定は,DLT法を用いることで行った。養成魚管理を行ううえで必要とされるこれらの情報をステレオ撮影画像から取得することができた。本研究では,これまでは特殊な方法となっていたステレオ画像解析を,DLT法を用いた簡便な養殖時の養成魚モニタリング手法として構築することを試みた。さらに,同一個体の繰り返し計測から,推定値の妥当性を評価した結果,ステレオカメラシステムからの距離が9.2m以内で撮影された対象魚は,誤差率が養殖業者に望まれる値となる5%以内で,尾叉長を推定できることが確認できた。これらの結果から,今回提案する簡便なステレオ解析手法は,養成魚に負荷を与えることなく,養成魚管理に非常に役立つ情報を提供できることが明らかとなった。

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Spherical FADs (Fish Aggregating Devices) are one of several kinds of buoyant fishing attractants, designed to enhance coastal and offshore fishing grounds. To obtain fundamental data for the rational design of a series of spherical FADs, we investigated the drag force on spherical floats, changing the diameter and number of spheres linked in series in a circulating water channel. We used three kinds of spheres, 4.8cm, 9.2cm and 11.0 cm in diameter and moored them horizontally in the channel, to a maximum number of twenty. We measured the drag force increasing the flow velocity. Furthermore, we measured the drag force on the two linked spheres changing the distance between them. The drag force on two or three linked spheres was slightly less than that on one sphere. However, when the number of linked spheres was increased (>3), the drag force gradually increased although the rate of increase of drag force was much smaller than that of the increase in number of spheres. When the distance of two linked spheres became two to three times that of the diameter, it was considered that the linked spheres were independent.

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植食動物であるアシナガモエビモドキについて,ホンダワラ類アカモクおよびヤツマタモク幼体への摂食状況を確認し,ホンダワラ類幼体の生残に及ぼす摂食の影響を検討した。室内実験において,アカモクおよびヤツマタモクとも,実験開始直後から摂食され始め,4〜6日後にはほとんどが消失した。藻場が衰退する海域や藻場造成が成功していない海域おいて,アシナガモエビモドキ等小型十脚類による摂食については,摂食量では少ないが,海藻類の発芽初期の幼体への摂食影響に特に着目すべきことが示唆された。

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At 11 March 2011, with the outbreak of "the 2011 off the Pacific coast of Tohoku Earthquake", the giant tsunami attacked the Miyagi coastal areas, caused great loss of human life, and gave serious damage to most of the private institution and the public community facilities. In particular, most of the fishing ports and the fishing villages in these areas had unexpectedly severe damages by tsunami. Now, the state does not yet show a process to all-out revival of the fishing village areas. By the conventional disaster-relief project, it is basic to restore to the original form. However, in this earthquake disaster, it is very difficult to restore all of fishing port facilities, fishery institutions, fishery-processing plants that were had serious damages by tsunami. For the revival of the coastal fishery areas and fishery industries in Miyagi, it is important to review fishing port functions that are necessary for fishery industries from various aspects, to reflect the demand of stakeholder such as anglers, inhabitants, local governments and so on. Moreover, it is very essential to practice deliberately/steadily the restoration of the fishing port facilities and the restructuring of fishing port functions.

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At 11 March 2011, with the outbreak of "the Great Eastern Japan Earthquake", the giant tsunami attacked the Iwate coastal areas, caused great loss of human life, and gave serious damage to local community in these areas. In particular, the most of fishing ports and fishing villages were damaged extremely. The author is in charge of disaster restoration works projects on fishery infrastructures such as fishing port, fishing ground and so on, in Miyako, Iwate where was disaster stricken area. The quick restoration constructions were carried out while having the support of the organization concerned, in six months from directly after the earthquake disaster. In this paper, the author would like to report specific examples for the local revival from the earthquake and tsunami disaster. The main issues of report are as follows. 1) The ideas and propositions of author for fishery regional revival 2) Specific examples for quick restoration construction

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"The Great East Japan Earthquake" that occurred on March 11, 2011 gave devastating destruction to fishing ports, fishing grounds and fishing villages in Pacific coastal areas such as Iwate, Miyagi, Fukushima and so on. The fishery is a main industry in these coastal areas. The damage caused by this earthquake disaster gave serious influences on inhabitants communities in these areas. The outflow of fishing boats, fishing implements and aquaculture facilities by tsunami caused serious damage to regional fishery activities, and most of inhabitants lost the workplace and home. The damage caused by this earthquake disaster was far beyond expectation, was not to watch an example in the past. For restorations and revival of these coastal areas, the arguments on "relocation of residential street from coastal area to high ground area", "separation between workplace and home", "selection and concentration of fishing port function" and so on, have been practiced by regional administrative bodies and inhabitants. However, it is not easy to practice the proposal. The fishery production activities were performed in cooperation with inhabitant's communities. It is important to respect the intention of inhabitants, and is necessary and important to push forward planning based on the inhabitants agreement in these areas. The Japanese Institute of Technology on Fishing Ports, Grounds and Communities (JIFIC) set up a fishery area reconstruction aid project team, performed proposal for the restoration and revival of these coastal fishery areas. Based on the reasonable understanding of the disaster risk, the proposal showed the logical way of approach and viewpoints on the institution placement plan in fishing ports and fishing villages.

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Most of fishing ports and communities in Sanriku region are perfectly destroyed by "Eastern Japan Great Earthquake and Tsunami Disaster", 11 March 2011. However, the restoration and reconstruction of fishing ports and communities are late very much. The coastal fishery such as aquaculture has many seasonal operations to do immediately for next year's harvest. For positive restoration of fishing communities performing aquaculture, the restart of anglers' livelihoods must be simultaneous with reopening of fishery production, it is very important to perform the concrete and realistic restoration according to fishery seasonal operation. If major fishing ports preferentially restore, and small/regional fishing ports subordinately restore, the restoration of fishery production and regional fishery communities are inefficient. There are many arguments such as the entry of the private company to coastal fishery, and the selection and concentration of the fishing port function. Those arguments will delay the restoration of fishery area.

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The fisheries-related damage caused by "the Great East Japan Earthquake" was devastating. In Iwate, Miyagi and Fukushima, the crushing damage occurred at the most of coastal area. The early fisheries revival of the stricken area is connected directly with revival of regional economy and livelihood foundations. Furthermore, the early revival is extremely important in securing the steady supply of the marine products. For revival of the regional fisheries, the Fisheries Agency devised the master plan of fisheries revival that was the guidance of the concrete measure of the fisheries revival. The aims of the master plan are as follows. 1) Promotion of the revival on the basis of local intention. 2) Practical use of the marine resources in the disaster area. 3) Securing of steady supply of safe marine products. 4) Restoration corresponding to the fishing season. 5) Revival beyond the restoration. The reconstruction of the fishing port must secure necessary functions on the basis of reconsideration of function concentration and role allotment of the fishing port. The major fishing port which is distribution and processing base of marine products will plan the reinforcement of the distribution and processing function. For the reproduction of rich fishing grounds, the restoration of the fishing grounds will perform the removal of the debris, the environmental research of the fishing ground, the maintenance of fishing ground institution.

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