Katsumori Hatanaka

Instrumentation for the measurement of shallow seabed topography by a fishing echo sounder

The multi-beam bathymetry can provide a detailed view of the seafloor and is successfully utilized in oceanography; however its expense makes it impractical for many uses. In this paper, the authors present a low-priced system for surveying shallow sea bottom topography by using a fishing echo sounder in such a way that the many areas of the industry in which the information of the sea depth is required can use it easily get the information they need. The system is based on sensor network technology, namely Micro Cube, which allows for the collection of the data from the fishing echo sounder via the Internet. In this paper, the planning of the system is presented and the experiments on the west coast of Hokkaido, Japan are discussed to show the accuracy and to demonstrate the applicability of the present system. Measurements generated by the proposed system are in good agreement with the measurements observed by the multi-beam echo sounder, Sea Bat, with accurately positions data using Star Fire (high performance differential GPS sensor). Since the Micro Cube is easily connectable to other standard digital-equipment which is common among fishing vessels in the inshore fishery and exploits them as sensors to collect marine information, other useful real time sensor applications are anticipated in the fishing industry.

Digital diary system for fishery and applications of fishery management

To assist coastal fisheries, we have been working to utilize IT. This paper reports on sea cucumber resource management using a digital diary system that we have developed. At Rumoi, which is located in western Hokkaido, fishing for sea cucumber is carried out in the summer each year by dredge net fishing. Although fishing for sea cucumber has been conducted for over 30 years, since 2003 the price of sea cucumber has risen sharply due to growing demand in China, and there are concerns over sea cucumber depletion due to the rapid increase in catch sizes. During the fishing seasons from 2007 to 2009, we estimated resource amounts by using the swept area method by fitting data loggers that record GPS position information to 3 vessels from among the total of 16 sea cucumber dredge net fishing vessels in Rumoi and matched the vessel trajectories with fishing diaries written in notepads by the fishers. The results showed that sea cucumber resources were decreasing year by year. We then developed a real-time fishery resource management system with the aim of allowing the fishers themselves to perform autonomous resource management by using estimates of the resource amount. The system consists of a digital diary system and a vessel monitoring system. Both of these system components are connected to the Internet via mobile phone lines, with fishing operation information and catch information from the digital diary system and position information from the vessel monitoring system collected on a server in real time. In 2012, the fishery resource management system was installed on all 16 vessels, with real-time resource estimates carried out on a weekly basis. The fishers worked toward autonomous resource management where they decided the resource amount to leave behind, and used the difference from the estimated resource amount as the permissible catch limit for that year. Furthermore, the sharing of position information using the vessel monitoring system enabled efficient utilization of the fishing grounds and coordination of fishing operations. The fishers closed the fishing season early based on variations in the catch per unit effort that was updated in real time as an indicator. These results show that the sea cucumber resource amount was maintained and demonstrate the usefulness of the developed real-time fishery resource management system.

Compact Buoy System for Scallop Cultivation Using Sensor Network Technologies

In this paper, the authors present a compact buoy system used to observe seawater temperatures for scallop cultivation. The system is based on the sensor network technology, namely Micro Cube, which makes it possible to collect seawater temperatures from thermometers via the Internet. Thermometers adopted with a multi-drop interface for measuring the multi-layer seawater temperatures were also developed in this study. A low power micro controller is used as the A/D converter for thermistor in the thermometer. The thermometer has an accuracy of plusmn0.5 degree of Celsius. The buoy system developed for the scallop cultivation is extremely smaller and lighter than the general buoy system and designed for easy handling on the sea. That makes the present system easily applicable to fishery. The measured data are sent by an email from Micro Cube to the web database server via a dial up connection (PPP). The web database system for storing and showing measurements through the Internet has been configured by a free database engine on the Linux operating system. In this paper, the development of the system is described and the experiments carried out on the west coast of Hokkaido, Japan are discussed to demonstrate the applicability of the present system

Developing a Water Temperature Observation Network based on a Ubiquitous Buoy System to Support Aquacultures

The authors have been working on the support of the fishery industry using the information and communication technology. A water temperature observation network is proposed for supporting aquacultures, and a ubiquitous buoy system developed for this purpose is described. The ubiquitous buoy system was created by leveraging ubiquitous sensing technology with water temperature observation buoys that can be executed for

ICT application of real-time monitoring and estimation system for set-net fishery

1,000, a figure designed to meet the demands of scallop cultivation fishermen. Since there are no base stations and gateways in marine environments, we selected mobile phones for the Internet connection to send the water temperature data by email. The ubiquitous buoys developed are light weight and of a compact design, and can be easily installed in marine fishery environments. Furthermore, the economic cost allows the buoys to be used in multiple point observation systems. Consequently, not only does the system allow water temperature observations in real time, but it can also be used in future applications to build water temperature observation networks using multiple ubiquitous buoys that share water temperature data and allow analysis of multipoint, multi-layer water temperature data, and thus facilitate efforts to visualize the makeup of water temperature distributions below the surface. Forty ubiquitous buoys have been placed in scallop cultivation regions along the coast of Hokkaido, and the water temperature data is starting to be used.

Real time seawater observation network for aquaculture

In this paper, we propose an ICT application of real-time monitoring system to estimate the catch amount within set-net. Generally, set-net fishermen do not know the catch amount in advance before arriving to set-net area, in which they tend to unable to perform the fishing operation effectively. It means that the fishermen might suffer a loss of time, gasoline and labor cost, along with extra effort. In order to support the fishermen to avoid such condition, in our previous study, we have presented the real-time monitoring system based on ICT aided echo sounder for the set-net fishing. Besides, the algorithm based on multiple regression analysis (MRA) for estimation of catch amount was proposed so that fishermen could predict the catch amount before they leave the port for harvesting. However, the catch estimation was not sufficiently accurate in practical application. The reason of this is because the daily catch amount varies from some few tons to 250 tons, whereas statistics of ping intensity do not vary so much, thus, it is not easy to build a model of MRA adequately. This study aims to develop a more accurate catch estimation algorithm based on our previous study. The experiment of this study is conducted in Hokkaido and Toyama Prefecture. To transform the catch record appropriately for MRA, Box-Cox transformation (BCT) as pre-processing transformation is applied in this paper. The catch estimation has been done based on fishermens empirical estimation through a pre-processing transformation and statistical analysis of reflection data in each layer depth. The study showed that the present system could improve the estimation accuracy. In order to measure the differences between catch estimation by the developed algorithm and the real catch record, Relative Absolute Error (RAE) is used in this study. The RAE for Hokkaido experimental site was 1% and in Toyama is 22%, respectively. The results show that the estimation accuracy of the present method is sufficiently adequate for practical application.

Applications of Marine Broadband Framework for coastal fishing

We propose the construction of a seawater temperature observation network that utilizes many compact “ubiquitous buoys” to measure water temperature at different locations and depths. Seawater temperature is an important consideration when determining a suitable timing for various aquacultural operations up to and including shipping products to market. Conventionally, fishermen have used satellite-based and hull-mounted sensing technologies to determine water temperature and its distribution, information which they combine with experience and intuition to schedule their operations. One limitation of this approach, however, is that it cannot be confidently applied to the determination of the seawater temperature distribution below the surface (as it varies with, for example, the movement of water masses). There is thus a strong interest in compact, inexpensive seawater observation buoys that can monitor underwater temperature distributions in real time. In 2004, we began to develop such devices, which we call “ubiquitous buoys.” More than 100 such buoys have been installed to date within aquacultural installations and other areas along the Japanese coast; the buoys are used to provide fishermen and other operators with data on seawater temperature at various depths. We are currently working to construct a seawater observation network consisting of densely placed buoys and thereby capable of determining three-dimensional seawater temperature distributions. If this network proves successful in measuring, for instance, the speed and direction of currents or the size of water masses, it should become possible to predict changes in temperature distributions. In this report, we introduce a 20-buoy seawater observation network currently under construction within the Tsugaru Strait, off the southern coast of Hokkaido, Japan.

The development of a remote fish finder system for set-net fishery

With the objective of promoting sustainable costal fishing, we propose a transition to ICT-based fishing that uses real-time information. In this report, we introduce an information and communications technology (ICT)-based approach to sea cucumber dredge net fishing that uses “Marine Broadband Framework”, a wireless network environment that can be used in coastal areas. In association with the Fisheries Research Institute, we analyzed handwritten daily operation logs and GPS log data from small fishing vessels from 2007 in order to conduct a resource evaluation of sea cucumbers. Until 2009, the resource evaluation was carried out all at once after the fishing season had ended. The sea cucumber resource distribution and fishing grounds usage rate was then presented to the fishermen in an easily readable map form, but it was not possible to use the resource evaluation results to adjust fishing operations during the fishing season; thus, the development of a method for more timely resource evaluation became an important task. In 2010, we introduced daily operation logs that can be input using a touch panel PC. By using Marine Broadband Framework to collect the operation information and positioning information in real time, we were able to construct a system to conduct weekly resource evaluations. Moreover, we are supporting the fishing operations by developing a global positioning system (GPS) plotter with simplified geographic information system (GIS) functionality that can display each type of map from the resource evaluation results as its background image. Currently, the digital daily operation logging system and GPS plotter with simplified GIS functionality have been installed on three small fishing vessels and weekly real-time resource evaluations are being performed. Moreover, by sharing the operations information and positioning information in real time between the three vessels, cooperative operations are underway with the objective of making operations more efficient and protecting and managing the sea cucumber resources. With the construction of wireless networking environments in coastal areas, such as Marine Broadband Framework, we believe that next-generation GPS plotters will become the primary information device on small fishing vessels in the future. We are continuing development of the next-generation GPS plotter, which uses Linux and has network functionality.

Marine Broadband Framework for coastal fishings

A remote fish finder system for effective set-net fishery, which enable to visualize as well as recognize catch amount and the fish kind, is proposed in this paper. In order to improve fishing efficiency and obtain the highest possible profit of set-net fishery, set-net monitoring is needed by coastal fishermen. Set-net monitoring can be used to estimate fish catch amount within the set-net, fish kind trapped or to estimate the adequate timing to lift the set-net. Set-net monitoring has been practiced for several decades using conventional equipment. However, the equipment has many weaknesses, namely, high priced, large sized, troublesome maintenance and poor data record (paper based data record). This study aimed to develop a remote fish finder system for set-net monitoring to meet those problems. The development of remote fish finder system is based on a floating echo sounder for data acquisition, a cloud server for data storage, and an iPad application for data display. The experiment for this study has been conducted from June 28 until December 25, 2013 in two experimental sites in Hakodate, Hokkaido, Japan. The algorithm development for estimations in this study was based on empirical estimation of fishermen when they observed the printed-out sounder reflection data. The empirical estimation was practiced by observing the intensity of signs of fish in certain depth. Statistics of reflection data in several layers depth during sunrise were used as indicators to estimate. Catch amount within set-net could be estimated through multiple regression analysis, while fish kind classification was through linear discriminant analysis. The results of catch estimation via multiple regression analysis has been obtained with multiple R2 = 0.89. Yet, single dominant fish kind could be estimated better than by catch using this algorithm. On the other hand, fish kind within set-net could be classified with 83% of correctness. In order to improve the accuracy, the data sampling must be continued at least a whole fishing season.

Data Analysis of a Low-Cost Bathymetry System Using Fishing Echo Sounders

This report provides an account of a ldquomarine broadband frameworkrdquo wireless LAN coastal communication system constructed for the purpose of improving productivity and safety of commercial fishing operations. The marine broadband framework proposed in this report is a wireless communication network that can maintain a regular Internet connection at fast xDSL transmission speeds for low cost in coastal areas worked by small fishing vessels. The wireless LAN system uses an OWS 2400 (Strix Systems, Inc.) with IEEE802.11j specifications. An initial trial using small fishing vessels and ferries demonstrated that a wireless LAN connection could be maintained within a range of 10,000 m, along with actual throughput of around 6,000 Kbps. This trial was followed by a detailed assessment of transmission quality within the service area using a scientific research vessel. As a result, it was found that stable transmission with a receiving signal of -90 dBm and higher was maintained within a range of 14,000 m from a stationary base station. Additionally, actual throughput of 8,000 Kbps and higher from within about 2,000 m of a station, and 4,000 Kbps and higher from within about 12,000 m of a station was also confirmed. Consequently, these trials confirmed that a wireless LAN network with IEEE802.11j specifications can be used to construct a marine broadband communication framework in coastal regions with xDSL transmission speeds.