Combined Optical and Acoustic Monitoring of Fishes in the Demonstration Site of Marine Renewable Energy Development

Author(s):  
Daisuke Kitazawa ◽  
Yoichi Mizukami

Before the installation of marine renewable energy devices, fish species and abundance should be examined for selecting the proper site where the effects of the devices on the environment and fish will be as small as possible. Fish species and abundance can be examined in a variety of methods such as a fish finder using an acoustic wave and fishing gears such as a gill net. However, the fish finder cannot specify the species of fish that is sometimes estimated from the experience of fishermen or scientific researchers. Some amounts of fish must be removed from the target sea area in case of using the fishing gear, while the species of fish can be specified. In the present study, an underwater optical video camera is combined with the fish finder using an acoustic wave to specify the species of fish. A circular fish-eye digital video camera is inserted into a waterproof container. A part of the container is made of glass in a dome shape for the circular fish-eye lens. The container is attached to polyethylene ropes and is towed by a fishing vessel. First, the hydrodynamic characteristics of the container was examined by a towing test with the three kinds of towing speed in a water tank. Then the container was towed in the real sea, which is the demonstration site of offshore wind and wave energy developments off Kamaishi of Iwate Prefecture. The depth of the video camera with the container was not constant since the moving speed of the fishing vessel was slow and fluctuating. The image of video camera could be captured successfully together with that of the acoustic video camera, while fish could not be found in both the optical and acoustic measurements in the present investigation. The investigation will be continued, and the effects of transparency of water should be discussed as future works. Also the actual or model fish should be captured by the underwater video camera to evaluate if it can specify the species of fish.

Author(s):  
Takero Yoshida ◽  
Daisuke Kitazawa ◽  
Yoichi Mizukami

Assessment of local ocean environment is significant when devices of marine renewable energy are installed at a demonstration site. A concern about how these devices affect the existence of fish is remained among local fishermen. To confirm variation of fish before and after installing the devices of marine renewable energy, we investigated fish using an underwater camera before installation as a main objective of this paper. First, fish-eye video camera was tested to monitor in a fish cage off Kamaishi city, Iwate prefecture, Japan. We aimed to observe the abundance of fish and to specify the species of fish. The fish-eye video camera is composed of a dome-shaped lens, a container, and a digital video equipped into the container. The recorded video showed outlines of fish, consequently it may be possible to know the abundance of fish. However, specifying the species of fish has a difficulty if we use fish-eye camera since the recorded image is unclear enough to identify correctly. In addition, we examined horizontal transparency of fish-eye camera using a fish-shaped target. Before recording by the video camera, vertical transparency was measured using a white plate. Then we recorded the images by varying the water depth and the distance between the camera and target. When the target was close to the camera, it can be displayed clearly, nevertheless the outline of the target was smeared with increasing the distances between them. Our measurement suggested that the horizontal transparency might be relating to the parameters of water depth and vertical transparency. The investigation was conducted under the one condition, thus we need to obtain further data to understand horizontal transparency qualitatively. Next time, we will conduct another test using additional underwater optical video camera, which is attached on the fish-eye video camera. The combination of these two types of video cameras may enable to observe the abundance of fish as well as to specify the species of fish.


Marine Policy ◽  
2009 ◽  
Vol 33 (4) ◽  
pp. 635-642 ◽  
Author(s):  
Mark A. Shields ◽  
Lora Jane Dillon ◽  
David K. Woolf ◽  
Alex T. Ford

Author(s):  
Takero Yoshida ◽  
Yoichi Mizukami ◽  
Jinxin Zhou ◽  
Daisuke Kitazawa

Abstract Environmental impact assessment is important when marine renewable energy device is installed. Fishermen concern the effect of device on local fish. To confirm the effect before and after installation of marine renewable energy device, we developed wireless monitoring system using an underwater fish eye camera. The camera system is composed of a dome-shaped fish eye lens, a container, and a float. Two thrusters are attached on the container to change the monitoring directions. In the current research, this system was developed to monitor underwater situation around device remotely and in real time. We tested to monitor a target and fish in a fish case at the site off Kamaishi city. The recorded video showed the target and fish. Effectiveness of this system was shown through the field test for real time monitoring around marine renewable energy device.


2014 ◽  
Vol 51 (2) ◽  
pp. 330-338 ◽  
Author(s):  
Thomas P. Adams ◽  
Raeanne G. Miller ◽  
Dmitry Aleynik ◽  
Michael T. Burrows

2016 ◽  
Vol 139 (4) ◽  
pp. 2174-2174
Author(s):  
Shaun Fraser ◽  
Benjamin Williamson ◽  
Beth E. Scott ◽  
Vladimir Nikora

PLoS ONE ◽  
2017 ◽  
Vol 12 (11) ◽  
pp. e0188780 ◽  
Author(s):  
Pál Schmitt ◽  
Ross Culloch ◽  
Lilian Lieber ◽  
Sverker Molander ◽  
Linus Hammar ◽  
...  

Author(s):  
Takero Yoshida ◽  
Daisuke Kitazawa ◽  
Yoichi Mizukami ◽  
Qiaochu Chen ◽  
Akito Mochizuki

Assessment of any significant effects on the local marine environment when considering the installation of a marine renewable energy device is of the utmost importance. In particular, the effect of such device on fish is concerned by local fishermen. To confirm variation of fish before and after installing the device of marine renewable energy, we investigated effective monitoring system using an underwater fish-eye camera. In this paper, visibility of the fish-eye camera was tested off Kamaishi city, Iwate prefecture, Japan, which is a test site of marine renewable energy in Japan. Device of wave power generation is planning to install at this site in the future. We confirmed the visibility of the fish-eye camera using a fish-shaped target by changing the distance between the target and camera. The water depth and photon were simultaneously measured. From the result, the horizontal visibility was discussed, and then we made a plan to observe around wave power generator using this fish-eye camera.


2016 ◽  
Author(s):  
Jarlath McEntee ◽  
Brian Polagye ◽  
Brian Fabien ◽  
Jim Thomson ◽  
Levi Kilcher ◽  
...  

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