Fishing technique

Fishing techniques embrace hand-gathering, spearfishing, netting, angling and trapping. Recreational, industrial and artisanal fishers use completely different techniques, and also, sometimes the similar techniques. Recreational fishers fish for pleasure or sport, whereas industrial fishers fish for profit. Artisanal fishers use ancient, low-tech strategies, for survival in third-world countries, and as a cultural heritage in alternative countries. Mostly recreational fishers use sport fishing strategies and industrial fishers use netting strategies.

Different fishing Technique

Trawling is the most common commercial fishing method used in New Zealand waters.  It is generally used for deep-water fisheries like orange rough , hooky, ling, hake and squid.  A fishing boat tows a large net behind it, sometimes in the middle of the water, and sometimes on the sea floor.  Sometimes two fishing boats might tow a big net together.

Seining involves dropping a net to surround and trap a school of fish. There are two types of seining – Danish seining, which is used to catch fish near the bottom of the sea, and purse seining, which is used to catch fish near the surface.

Dredging is used to gather scallops and oysters from shallow water. A fishing boat tows a steel net (dredge) along the sea floor, and the net scrapes up all the shellfish living there.

 Most common line fishing methods are hand-lines and long-lines.

Hand-lines are mainly used by recreational fishers.  A hand-line is a single fishing line, usually attached to a rod, and held by hand.

Long-lines have a main fishing line, with lots of shorter lines hanging off it. The shorter lines have bait and hooks attached to them.  The main line is anchored at each end, and floats stop the line from sinking. Line fishing doesn’t bruise or damage the fish as much as net fishing, but you can’t catch as many fish as quickly on a line as you can in a net.

Electric pulse fishing

Electric fishing is a technique whereby electrical energy is put into the water and fish .Electric fishing relies on two electrodes which deliver direct current at high-voltage from the anode to the cathode through the water. When a fish encounters a large enough potential gradient on this path, it becomes affected by the electricity. Usually pulsed direct current (DC) is applied, which causes muscular vibration in the fish, intercepting this energy, are drawn toward the probes and incapacitated in such a way that they can be captured with nets. The movement of fish toward the source of electricity is called galvanotaxis (uncontrolled involuntary muscular convulsion that results in the fish swimming toward the anode) and is believed to be a result of direct stimulation of the central and autonomic nervous systems which control the fish‘s voluntary and involuntary reactions.

The effectiveness of electric fishing is influenced by a variety of biological, technical, logistical, and environmental factors. The catch is often selectively biased as to fish size and species composition. When using pulsed DC for fishing, the pulse rate and the intensity of the electric field strongly influence the size and nature of the catch. The conductivity of the water, which is determined by the concentration in the water of charge carriers (ions), influences the shape and extent of the electric field in the water and thus affects the field's ability to induce capture-prone behavior in the fish.

How it actually works

When a fish swims into a weak electrical field, it's going to not be affected in the slightest degree. There's a threshold of electrical charge that has to be emitted into the water in order to effect on the fish. Once the electrical charge within the water is sufficient to allow transport of the charge across the nerve cells within the body, then the fish‘s muscles can endure involuntary contraction. The contractions can cause increased exercise of the muscle and a buildup of feed within the blood stream. This method is incredibly almost like what happens to the muscles of a runner or a swimmer UN agency exerts a great deal of exercise. The runner or swimmer might eventually get a cramp within the muscle and can't move it effectively. once the fish cramps up, it floats to the surface and removed from the electrical field. The method to stun a fish is sometimes five – ten seconds.