Fishermen generally use light as a common way to attract fish in the fishing industry. This study aimed to design a model of an underwater fishing using Light Emitting Diode (LED) lamp which is less costful and suitable for fishermen of Tanzania. Most fishermen currently use kerosene based lamps like candela which consumes lots of energy leading to high cost in terms of money used to regenerate the energy. This running cost automatically rises up the price of fish in the market. Thus with the use of LED lamp the cost will be reduced. The findings from this study showed that the LED lamp consumes little amount of energy (energy saving) compared to candela lamp which consumes 6 liters of kerosene per 36 hours which is equivalent to three nights, while the LED lamp takes 7 batteries at once for 36 hours. The 6 liters of kerosene cost around 7 USD and that of 7 batteries cost is near 2 USD. The LED lamp can be accessed by only 15 USD the price which is nearly half the price of the candela lamp. The candela lamp in the market is sold around 31 USD. This shows that LED lamp is more efficient in terms of conserving energy and cost effective than candela lamp. It is recommended that fishermen in the fishing industry in Tanzania should employ the usage of underwater LED fishing lamps as they are energy efficient. This will help the fishermen of Tanzania to undertake the fishing activity at low cost which will result to the decrease of price of fish in the market. This shows that this LED lamp has high efficiency and effectiveness to be used by fishermen compared to traditional method used by majority of them.
Fishermen use light to attract fish to form a large shoal using artificial light source at night or when the weather is cloudy [
Most fishermen in Tanzania particularly are still using candela lamp to attract fish so that they can capture them using the nets they have. These candela lamps are expensive to run as they consume a lot of energy (kerosene fuel consumption in particular). Since fuel consumption is large, then expenditures (money) becomes very high in buying kerosene fuel (that its price is increasing everyday) to regenerate energy in those lamps. Thus, to solve these problems the research aimed to design underwater fishing lamp which is expected to be more efficient than candela lamps. The device will enable the fishermen to attract more fish which leads to more production. Also it is expected that the price of fish in the market to be reduced because the running cost of the device will be low compared to the running cost of candela lamp.
In order to design the LED underwater fishing lamp, the following material were required; Two green LEDs (1.7 V - 2 V), A hollow glass beaker/test tube-housing, A resistor (50 Ω - 100 Ω), Connecting wires-including the long one that will be used as a suspender of the lamp (approximately 5 m), The cork/rubber stopper that fits in the tube, The key/switch, The source/battery (6 V - 12 V), and The battery holder.
First, the two LEDS were connected in series the correct way round that is, anode to cathode connection as shown in
LEDS can be damaged by heat when soldering, but the risk is small unless you are very slow. No special precautions for soldering most LEDS. Second, connect such LEDS in series with a resistor to limit the current to a safe value because if the LEDS are directly connected to a battery or power supply they can be destroyed almost instantly since too much current will pass through and burn them out. Third, Connect the LEDS & resistor to the power supply/battery as shown in
Fourth, Calculating LEDS resistor value, to figure out which resistor to use, the following formula used;
R = ( V S − V L ) / I . (1)
where: V S = power supply voltage, V L = sum of LEDS voltage ( V L = V d 1 + V d 2 + ⋯ ) as shown in
Fifth, drill a hole into the middle of the cork/rubber stopper that fits into the beaker/test tube. This hole is used to thread out the wires, for positive and negative terminals of the circuit which will be connected to the switch and battery. Then, place the LEDS into the test tube, and then secure the cork/rubber stopper into the test tube top. Wrap the seam with black tape, and then wrap black tape securely around the wire and stopper to cover up the gaps in this hole. After completing all the steps, thus connect the two wires to their respective terminals-positive and negative of the battery to complete the circuit; the device is ready for use.
The testing of the LED lamp, it was dipped into the container of water to check the intensity of light produced. This is to check if the intensity of light will attract fish. The LED lamps were left on for 6 hours as we expect that the device will work during the night for those 6 hours. These 6 hours is the corresponding time which the candela lamp consumes one liter of kerosene. The target is to check the rate of energy consumption.
The following were observed when testing the LED lamp; the minimum voltage at which the LED lamp with two LEDS connected in series will light is from 6 V to 12 V maximum, below 6 V the lamp cannot light. The LED lamp produced a satisfactory amount of light which could reasonably attract fish. The 7 batteries managed to run the LED lamp for three nights consecutively. This shows that the voltage was decreasing very slowly as measured by the voltmeter which indicates that the LED lamp conserve the energy much than the candela lamp. The voltage drop was recorded after every two hours and the results are presented in Tables 1-3 and the graphs of voltage drop are presented in Figures 6-8.
Time (hours) | 0 | 2 | 4 | 6 | 8 | 10 | 12 |
---|---|---|---|---|---|---|---|
Voltage (V) | 10.5 | 10.45 | 10.40 | 10.00 | 9.75 | 9.50 | 9.25 |
Time (hours) | 0 | 2 | 4 | 6 | 8 | 10 | 12 |
---|---|---|---|---|---|---|---|
Voltage (V) | 9.25 | 9.00 | 8.75 | 8.50 | 8.25 | 8.00 | 7.75 |
Time (hours) | 0 | 2 | 4 | 6 | 8 | 10 | 12 |
---|---|---|---|---|---|---|---|
Voltage V | 7.75 | 7.50 | 7.25 | 7.00 | 6.75 | 6.50 | 6.25 |
Lamp | Energy Source | Energy Consumption for 3 Days | Cost US Dollar |
---|---|---|---|
Candela | Kerosene | 6 liters | 7 |
LED | Dry cells | 7 dry cells | 2 |
From Tables 1-3, it was observed that the amount of light decreased as days goes on, for day one it was greater as batteries were new and for the two days the voltage was dropping very slowly but the LED lamp managed to produce the reasonable intensity of light for 36 hours. Thus it is assumed that the device can work properly when used in real context of fishing.
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The LED lamp is designed and the device is tested to check if it functions well. The device can be run at lower cost than candela lamp. The device is portable, affordable at half a price of candela lamp and is more efficient. During the construction of the LED lamp device it was very difficult to find the white LEDS in our environment (Iringa municipal), that was why we decided to use the green LEDS which are readily available and are functioning in the same way as the white LEDS. It is advised to design underwater using white LEDS. This is due to the reason that light produced by white LEDS is clearer than that of the colored ones. In this way more fish products will be obtained and the price of fish in the market will be reduced more. Also it is recommended that fishmen in the fishing industry employ the use of underwater LED fishing lamps so as to replace the kerosene based fuel lamps in Tanzania. This cost reveals itself in kerosene price which is increasing daily. The cost of operation can also be reduced by using rechargeable batteries.
Telemka, G., Mghamba, M. and Ntarisa, A. (2018) Design of a Low-Cost Underwater LED Fishing Light Attractor. Circuits and Systems, 9, 67-73. https://doi.org/10.4236/cs.2018.94007