Light fishing

Light FishingGeronimo R. Rosario

Light Fishing- type of fishing aid where fishermen used lights in their fishing gear to attract the target species.

It has been known for a long time that a light attracts fish, shrimp

and insects at night. The smaller size group congregate under the lighted area then followed by the larger, bigger size group. This behavior of fishes has guided the fishermen to use light in the operation of their gears to increase their catch.

Fishing Light Attractor - refers to a fishing aid which employs

lights using, among others, mercury vapor, high pressure sodium vapor, standard tungsten, tungsten halogen, fluorescent or light-emitting diode, that are attached to a structure above water or suspended underwater to attract both fish and members of their, food chain to specific areas in order to harvest them

Light fishing

High-intensity light ( incandescent lamp, halogen, pressure mercury, metal halide)

Low-intensity lights (LED and fluorescent lights) Many high intensity are so power hungry that they

can only be operated for very short periods of time on a battery, thus compromising convenient portability. While LEDs and fluorescent lights draw much less electrical energy, most are not very bright.

Types of light used

high intensity emit its light in a color similar to the fishes space

(blue or green) be powered by a portable electrical supply be submersible

Properties of ideal fishing light

Photomovement refers to the way an animal moves in response to light.

Four main types of movements that marine animals make: they form a group or cluster called an aggregation; they freeze or continue to move until they no longer sense

light (called photokinesis); they move either away or toward a light source (called phototaxis); or they move up and down in the water column throughout the day (called vertical diurnal migration).

Photomovement

Aggregation

A fish aggregation is a mass grouping of fish. Fish come together to form an aggregation in order to feed and spawn, and as protection against

predators. It is not known why light causes fish to aggregate, but it may be because light attracts very small organisms – called plankton – that the fish feed on, or the fish may be attracted to larger organisms that feed on the plankton.

Once fish form an aggregation, they can easily be caught using lures, baited hooks or nets.

How fish and other marine animals move in response to light

Photokinesis – positive and negative Photokinesis is the way a marine animal moves in

response to light. Positive photokinesis is when light causes an

animal to move until there is no more light, or until it arrives in a dark place. The animal does not move away from or toward the light, it moves randomly until it is out of the light.

Negative photokinesis is when a moving animal in the dark stops when it is hit by light. This behaviour is used by skin and scuba divers to easily spear or grab fish and lobsters while night diving.


Phototaxis – positive and negative Phototaxis is when a marine animal moves toward or

away from light. If the movement is toward light it is called positive

phototaxis, and if it is away from light it is called negative phototaxis.

Positive phototaxis is what initially causes marine organisms to aggregate around a light source. They move toward the light and then stay in the vicinity of the light source after arriving there.

Positive phototaxis may also cause large pelagic fish to move in the direction of a chemical or electric light stick.


Vertical diurnal migration – a fish behaviour where fishes migrate from the water column during day and night. They tend to stay at the depths during daytime and ascend in the upper column during night time.

Large aggregations of marine animals migrate vertically in the water column daily. During the day, they are in deep water (below 200 m [656 ft]) where there is little or no light. At night, they come toward the surface where there is also little light. In other words, they prefer to stay in the dark.

This area is called the deep scattering layer or DSC. Certain large pelagic fish, such as bigeye tuna and broadbill swordfish, follow DSC daily. Fishermen take advantage of this diurnal behaviour by fishing for bigeye tuna in deep water during the day, and fishing for swordfish nearer the surface at night.


History of Light fishing

Artificial lights

Philippines

Artificial lights

Placing of lights Submerged Above the water Fishing gears using lights Bag net Stationary lift nets Fish Corral Modified fyke net

Lightings

Fisheries Administrative Order No. 204 restricts the

use of superlight in fishing Superlight - also called magic light, is a type of light

using halogen or metal halide bulb which may be located above the sea surface or submerged in the water. It consists of a ballast, regulator, electric cable and socket. The source of energy comes from a generator, battery or dynamo coupled with the main engine.

Prohibited lights

Commercial and Municipal fishing boat using superlight must not excess on the prescribed wattage:

Small-Scale commercial fishing boats (3.1 to 20 GT)……………

20KW per vessel Medium-Scale commercial fishing boats (20.1 To 150 GT)….... 36

KW per vessel Large –Scale commercial fishing boats ( more than 150 GT)…..40

KW per vessel Provision: The head of the LGU may grant permit to use superlight in

municipal waters in consultation with FARMC to any government or private research and educational institution for research, experimental, educational and scientific purposes.

Penalty: 6 to 2 years imprisonment or Php 5,000 fine.

Prohibition

Light fishing

Science

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