JP2008220238A - Method for detecting bitten damage of shells, and monitoring system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a state of damage of shells bitten by Aetobatus flagellum to be monitored, without especially requiring complex device formation. <P>SOLUTION: The method for detecting the bitten damage of the shells includes installing a hydrophone 1 in water, in the sea area in which the Aetobatus flagellum infests and preys on bivalves such as short-necked clam by utilizing a buoy 2; enabling crushing sound caused when the short-necked clam is crushed with the tooth and catched by the hydrophone 1 to be properly treated and sent to a base 5 with wireless; analyzing the sea area of the data sent from each of the hydrophones and the change of the measured value with time; and predicting the region at which the bitten damage of the bivalves, such as the short-necked clam will occur to enable protective measure to be carried out. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for detecting the damage of clams, particularly clams such as clams, and a monitoring system using the method, and a monitoring system for quickly detecting clams caused by Naruto Ray which has become a problem in recent years. About.

On the coast of Japan, clams and other clams caused by naruto rayei have been pointed out, and it has been reported that clams have been annihilated and their catch has been zero.
Conventionally, the damage caused by a large number of animals that prey on seafood such as clams is detected only by observing the drastic decrease in the catch of seafood and the fact that a large number of predators are actually generated in the sea. However, it was difficult to take appropriate measures in advance, and it was difficult to prevent the marine products from being damaged.
JSCE Proceedings No.713 / VII-24 69-79,2002.8 “Estimation of the population density of teppo webs by underwater acoustic observation for the purpose of environmental assessment in shallow waters”

If the occurrence of food damage can be detected at an early stage, it can be eliminated by intensively carrying out preventive measures and removal activities at the place of occurrence, or by removing only those that attempt to enter the main habitat of marine products. Thus, it is possible to prevent the ecosystem from being affected.
This invention is made | formed in view of such a situation, and it aims at enabling it to detect the damage of clams, such as clams.

The detection of the damage of the bivalve by the predatory organism is detected by detecting the crushing sound of the shell generated when the predatory organism in the sea bites the bivalve.
When Narutobei prey on bivalves, it has a sharp mouth, thrusts the face into the sand, adds clams, breaks the shell with a strong jaw, eats only the body, and the shell spits out from the mouth, It detects the occurrence of food damage by capturing the sound of crushing shells.

Furthermore, it is a system that can monitor the distribution and frequency of crushing sound when shells are bitten.
In other words, when a large amount of Naruto Ray is generated and begins to prey on a large amount of clams, the monitoring hydrophone installed in the water or on the sea bottom captures and transmits the crushed sound. It is intended to be able to predict the occurrence area.

  When performing monitoring, first install hydrophones and transmitters at appropriate points in the sea where damage is expected to occur, and analyze the bases that receive data transmitted from each hydrophone and the received data. Install an analysis device (computer). Each hydrophone selectively detects a crushing sound of a shell generated when Naruto Ray preys on a clam at a place where the hydrophone is arranged, and transmits it to a receiving base. It analyzes the data received from each hydrophone and predicts the sea area where Narutovi will head by the frequency and the spread and change of the location of the crushing sound.

  As described above, according to the present invention, it is only necessary to detect the occurrence of food damage at an early stage in the sea area where there is a possibility of food damage, and to effectively prevent the damage by removing the Naruto Ray before the big damage occurs. Is possible.

Hereinafter, the monitoring system for preventing damage according to the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a conceptual diagram showing the overall configuration of the monitoring system of the present invention.
An appropriate number of Hydrophones 1 is installed in the sea area where clams are inhabited and the damage caused by Naruto Bay is predicted.

Each hydrophone 1 is assigned an individual ID. In data communication between the base 5 and the hydrophone, the ID is transmitted together with the data, and the base 5 stores and manages the received data for each ID. To do.

  The hydrophone 1 has a weight attached from a buoy 2 installed on the sea and is suspended by a rope, and the sound receiving part is installed at a position about 1 m from the bottom of the water. The rope is provided with a power supply line or built in, and the buoy 2 is provided with a solar cell 4 for supplying power.

  The frequency distribution of the shell crushing sound generated when Narutobei crushes clams and the pulse shape at the time of generation are standardized and stored, and the sound captured by Hydrophone 1 is compared with the stored sound, and similar. Only the crushed sound is judged to be a sound related to the occurrence of food damage, and is transmitted from the transmitter 3 to the base 5.

  Since the sound captured by the hydrophone 1 includes sounds generated by ships, waves, and other marine organisms, those determined to be unrelated to these damages are determined as noise and eliminated as much as possible. As a removal method, a filter function such as waveform analysis software is used to remove frequency components other than the sound produced when Naruto Ray breaks shells.

  Installation of hydrophones 1 at multiple locations is expensive for installation work and subsequent maintenance, so that a single measuring point can cover a wide range of sea areas at the apex of a regular tetrahedron with a side of 3 m. The number of installations can be reduced by arranging four hydrophones 1 so that the position of the sound source can be specified.

The electric power generated by the solar cell 4 installed in the buoy 2 as the power source of the hydrophone 1 is stored in a storage battery composed of an electric double layer capacitor so that the necessary electric power can be supplied even if no sunshine continues for about 15 days.
Data transmission may be set at regular time intervals, and data may be transmitted by polling from the base as necessary. Even if no crushing sound is observed, once every day, the base 5 is informed that the number of captured sounds is zero and the equipment is operating normally. An appropriate data communication mode is selected.

  At the base 5, a computer for analyzing data receives transmission signals from a plurality of installed hydrophones 1, collects data such as measured values, performs time-series analysis, etc., and monitors the occurrence of damage to clams. Do it.

The conceptual diagram of the monitoring system of this invention.

Explanation of symbols

1 Hydrophone 2 Buoy 3 Transmitter 4 Solar cell 5 Base

Claims (4)

A method of detecting the occurrence of damage to bivalves by predatory organisms by detecting the crushing sound of shells generated when predatory organisms in the sea chew bivalves. A monitoring system for predicting the damage of bivalves caused by mass generation of predators by detecting the crushing sound of shells generated when predators in the sea chew clams.
A plurality of hydrophones installed in the sea, a storage device for the standard value of the crushing sound of the shells accompanying the predatory behavior, a comparison device for comparing the sound captured by the hydrophone with the standard value of the storage device, a transmission device, and a transmission Shellfish damage monitoring system comprising a base for receiving the received content and a processing device for analyzing the received content. The shellfish damage monitoring system according to claim 2, wherein filter means for removing sound other than the standard value is provided. 4. The shellfish damage monitoring system according to claim 2 or 3, wherein the analyzing means is provided with an alarm device that issues an alarm when the frequency of the crushing sound exceeds a set value.