In this paper, based on the analysis of the process and work during the handling of fish catch, a questionnaire on the fatigue and awareness of danger on each work was conducted at two fishing ports. the questionnaire was prepared using SD (Semantic differential) method. As a result, it was shown that carrying heavy box containing fish made workers feel fatigued. The work associated with transporting the catch of fish with the forklift and the work on slippery floor gave rise to dangers.
In enclosed coastal seas in Japan, water quality has been getting better and even more in "oligotrophic" state in some areas due to the reduction measure of land loads enacted in 1970s. On the other hand, the sediment is deteriorated with organic matter and sometimes produces hydrogen sulfide forming oxygen depleted water. To remediate such two contradictory conditions, in the present study, we developed a kind of fertilizer which supplies excess iron along with other nutrients. Iron can be a key essential element simultaneously to enhance the primary production and to suppress hydrogen sulfide. Iron powder that was used as a reference material to steelmaking slag was much effective in terms of iron elution. On the other hand, coal ash was useful to release macronutrients (N, P and Si) and Mn and Zn. To elute iron effectively from the pan-granulated materials, citric acid was selected as both a chelating agent of iron ion and a binder. Carbon pitch cokes which is believed to form an electrochemical cell and release divalent iron ion into the water was not so effective. The final product developed in the present study elutes iron excessively compared to macronutrients. Therefore, the products can be utilized for restoration of coastal marine ecosystems where the water is in the oligotrophic state and the sediment is as much eutrophic as producing hydrogen sulfide.
Kansai International Airport is located in the waters of the eastern part of Osaka Bay. The airport consists of two artificial islands. This is the first airport in Japan where gradually sloped seawalls, which are suitable for algae growth, are employed on a large scale. The ecosystem services of seaweed beds have been evaluated to some extent. However, the actual conditions of benthic communities have not been identified. Against this backdrop, we investigated the standing stock in nitrogen equivalent and characteristics of feeding habits of benthic communities on each seawall. The average standing stock in nitrogen equivalent per seawall of the airport islands was found to be 222 gN/m, with suspension feeders accounting for 55.2%, feeders primarily of subsurface deposit 23.0%, other carnivores 13.5%, herbivores 6.1%, and fish 2.1%. The component ratio differs depending on the seawall. The standing stock in nitrogen equivalent in waters where the flow field is stagnant was the smallest, and this was attributed to the low percentage of suspension feeders. The component ratio differs depending on the seawall. The percentage of suspension feeders was high on gradually sloped seawalls facing the outer waters. This tendency was strong on seawalls subject to strong wave flows. The standing stock distribution in nitrogen equivalent in benthic communities on each seawall is similar to the standing stock distribution of algae. The standing stock of seaweed beds was found to highly correlate with the standing stock of fish and macrobenthos in nitrogen equivalent (the standing stock of fish in nitrogen equivalent in particular). It was found that seawalls that are suited for algae to grow serve as a suitable growth environment for benthic communities.
On sandy shores, drift of sandy sediment, which affects habitat characteristics of the bottom environment, is one of the important environmental factors for burrowing benthic animals, especially at saturated environment in lower shoreline. But no simple method for measuring drift has been proposed. In this study, we proposed new simple methods to characterize the drift by measuring the change of the bottom current velocity and the amount of bottom drift. In order to evaluate these measurements as critical physical environment, we also investigated the lower limit of the distributional zone of gammaridean amphipod Haustorioides japonicus and the occurrence of ripples on the sandy bottom. The results of this study demonstrated that the both of two methods, one by measuring the bottom current velocity and the other by measuring the amount of bottom drift, were useful to estimate the drift and both of the measurements decreased immediately in the bottom area with ripples. The lower limit of the main distributional zone of H. japonicus correspond to the occurrence of ripples. This avoiding distribution pattern of H. japonicus from ripples was discussed in relation to its lifestyle and sediment reworking by drift.
There are many duties done by hand that are associated with the transportation of fish catch in fishing ports in Japan, and there are concerns with an excessive burden on the lumbar. This paper estimated the compression force in the lumbar intervertebral disk based on the weight carried and the work posture for six cases, and assessed the size of the burden by comparing the force with permissible values. The result of this assessment was that four of the cases exceeded the permissible values.
In the paper, the evaluation of the saving-energy and the measures of reducing fuel consumption in fishing boats are explained. The saving-energy is to efficiently use the fuel oil on the fishing boats, put another way, it is to reduce a ratio of fuel consumption and catch of fish as the period of one navigation, one month, one year etc. Therefore, the saving-energy is not the saving-cost, it is important to recognize that the saving-energy is one of the countermeasures for saving-cost in the fishing vessels.
The increasing fuel oil prices in recent years have increased expenditures for fuel oil costs as percentage of expenditure, putting pressure on the business management of fishermen. Since 2010, the National Research Institute of Fisheries Engineering of the Fisheries Research Agency, in collaboration with the Marine Fisheries Research and Development Center of the same agency, have conducted an investigative study to ascertain the actual consumption of fuel oil on fishing boat and promote energy conservation in the fishing industry. Based on this study, a "Guide the Energy Saving measures of the Fishing Boat Fishery" and a "Leaflets for Fishing Boat Operators" were prepared for the purposes of research and information dissemination to convert to an energy-conserving fishing industry. In addition, "visualization equipment" (Mieruka Souchi) was developed to display fuel oil consumption of a fishing boat in real-time at the bridge. An application software called "Dr. Shou-Ene" was also developed which calculates the approximate fuel savings by reducing navigation speed. Changing the mindset of fishermen will be crucial to promoting energy conservation in the fishing boat based fishing industry. Therefore, efforts will continue to be necessary in the future to help fishermen realize the effects of energy conservation, such as visiting workshops for fishery extension workers and workshops at the site of fishing work, and explaining measures for promoting energy conservation to fishermen in a language they can understand.
Increasing fuel costs, decreasing fish prices and changing fisheries resources are causing many fishing practices to become uneconomic. Therefore, the application and dissemination of new fishing technologies to fishing sites is necessary to save fuel and reduce costs. However, such fishing technologies must reduce costs without affecting fish catch or quality, even when widely used. The present study examines fishing gear technologies and methods for cost and fuel reduction in bottom trawling. One such method is the lowering of towing speed to reduce the effects of drag on the trawl, thereby conserving fuel. An example of this fuel conservation through lowered towing speed in Alaskan bottom trawlers is discussed, along with other examples of cost-saving fishing technologies and fishing practices in small-scale Japanese bottom trawlers.
Fisheries reconstruction project in Kujyuukuri was formulated. Authors have supported technically introductions of the energy saving measures such as full form improvement and fuel consumption monitoring system to the ships to new construction. Reducing the number of two-boat purse seine fleet, It is necessary to substitute to the outboard motor boat from the present boats with measures to reduce the back rowing force.
The remarkable increase of fuel oil prices in recent years has serious influence on fisheries due to the rising operational cost for fishing vessels. Particularly, in the fisheries that are highly dependent on fuel oil cost, such as saury stick-held dip net fishery, squid jigging fishery, offshore trawl fishery and skipjack pole and line fishery, it is required to undertake effective measures to save fuel oil and reduce the operational costs. In this paper, three energy-saving measures deriving from an improved operational management for the fishing vessels are recommended. These energy-saving measures do not incur extra costs and they include the following: 1) Reduction of the navigation speed, 2) Periodical cleaning of hull, rudder and propeller, 3) Management of the shipload. The Fisheries Research Agency (FRA) has been continuously holding several seminars to help fishermen realize the effects of energy conservation for promoting of energy savings on fishing vessel fisheries.