Drift net fishing - a fishing, which is carried out drifters - fishing vessels.The ship is drifting on currents and winds, together with a very long network, the so-called drift-net procedure, floating or networks, making a single system.The length of the network can reach 50 km.These nets catch fish moving.The need for drift nets arose from the need of production of certain types of fish that are held sparsely.In this way, tuna fishing is carried out, is produced salmon, mackerel and herring.
Features networks
Drift (or smooth) networks are netting that the fish is not regarded as a barrier, so much pulls the mesh, tightly entangled in them without the possibility of escape.Rectangular separate networks height of 10-12 m and a length of 30 meters are interconnected in a single drift-order basis which can serve as a rope-leader, and buoys and floats maintain the system at a given depth.Driftnets used for industrial production of fish drifters.
materials used
Catchability gear depends on many factors, including fabric and thread thickness, cell size, color, landing on the canvas rebounds.If the previously used vegetable yarns, including cotton, from twisted yarns, it is now the most frequently used and more durable Catchability fishnets nylon and nylon, and the like amilanovye of synthetic fibers.
demonstrate the high efficiency of fishing nets monofilament (fishing line), so-called Zhilkova.The main advantage of these gears is their transparency.Even in daylight catchability in the clear water is very high, while the well-painted network of other materials may scare off the fish.In addition, they have higher rigidity than the twisted yarns that support the mesh straightened, does not allow the network to get confused and dirty.Although rigidity bit harder to work with them and increases the volume, requiring more space on the deck.
Constructive types of networks
In structure fit for fishing can be single-walled gill, double-walled or trójścienna.The last two types are called "thread waste."The most effective are fishing trójścienna network consisting of three paintings netting.Outside located krupnoyacheynye fabric called rezhyu (ryazhyu, rezhoy), and in the middle is a small chastik (Del).All three paintings are planted on one selection, but chastik is long and is located between the outer layers with considerable slack.Passing through I cut the fish entangled in Chastikov getting into the netting bag.Double-walled consist of two webs of different size cells and effective in the case where it is known which side is fish.
to drift-net fishing is most often used fishing nets monofilament nylon or nylon monofilament.Rebounds also taken nylon.The most effective trójścienna smooth network.
design types of drift orders
Network can connect with each other in different ways.There are three main types: simple, with the upper or lower leader.In the coastal strip can be used simple small orders, but the high seas require more robust construction, so the orders are applied with the leaders, providing the integrity and reliability of the order.
Simple order
For a small drift of order at times simply connect several separate networks in series between a lower and upper priuhami.So get a simple order of drift.It is used in lakes and coastal areas, small craft.In most cases, it includes only 15-20 networks, but when taking more, generally not exceeding 1-1.5 km.
In snoods buoy buoys attached to the order and kept afloat.The desired level exhibited by adjusting the length of the streamer line.Bottom Network heavier, putting the goods into the lower selection.On both sides there are also about ottugi.Their front end is secured with a locking - rope, which goes directly to the ship and back ottugi podmayachnym connected to the end - a rope fixed to the lighthouse.This lighthouse (flashlight or pennant attached to the buoy with a worsening) shows where the procedure ends.
organize such an order is easy, but for the long chains, and especially for use in open sea, it is not suitable.Tension networks during the drift is very high, so such an arrangement order can detach from the vessel or it will be destroyed.
Appointment leader
to significantly reduce the risk of breakage, used the so-called leader - thick rope, which is attached to the order for all over.Fisheries involves pooling together to 100-150 networks.The tension in the drift accounted for a reliable leader, not the networks themselves.Some networks are attached not only to each other but also to the leader, that also enhances the design.
himself the leader can be divided into three parts: the leader, the stop (parking) end for connection to the vessel and podmayachny end for securing the lighthouse.It turns out that it is attached to the ship leader, who keeps the network.Lay the end is the most durable.Its length can be up to 200-500 meters, which depends not only on the depth to which the submerged order but also the condition of the sea and wind strength.
When the sample is carried out for the traction network leader.This allows to mechanize the production process.In addition, machines are used that control the tension of the leader, if necessary bleed it to reduce excess tension.
Features leader
Depending on fishing technique and type of vessel set the desired length of the streamer line, it was convenient to choose drift-nets: the leader is chosen by malgoger, and the network should reach the designated place on the board, snoods just have to provide the necessary distance.For small vessels, it is only 1.5-2 meters, and at high might be 10 m.
Due to the fact that the tension of the leader as the distance from the vessel to the beacon decreases leader often make composite, reducing the thickness of the rope.Additionally, it reduces the cost of the procedure and reduces the weight order.But that does not sag appeared towards the end of the network due to the reduction of tension, sometimes added to the lighthouse sea anchor or change the distance between the buoys.
order of the lower leader
To arrange the order of the leader of the lower individual drift-nets are connected into a whole and for the upper and lower priuhi, but a network throughout the order is the leader.It is connected with the networks of branch lines vozhakovymi using bystrorazvyazyvaemyh nodes.In order keep afloat buoys that streamer lines are attached at the attachment of networks, or to the top of the selection.From the length of the streamer line networks depend on the depth of immersion.Additional cargo below is not required, as the load itself serves as the leader, stretching network.
Apply this procedure for small depths, sinking a network of 30-40 m. It is easy to operate.For vymetki sample and order have to work only with vozhakovymi snoods, without the hassle of a sinker.
Procedure with the top leader
If necessary, fishing in deep water often used in order with the top leader.In this case, it passes over the networks.Snoods buoy is attached to it, sometimes reaching a length of more than a hundred meters.Between a connecting rope, buoys guide for easy sampling.Vozhakovye streamer lines are connected to the top of the selection or priuhami networks.On the lower rebounds need to add a load of iron weights.
work with such procedure is more complicated than using the bottom of the leader, as it is necessary to organize the download, and requires further attention buoy conductor.However, such a drift-net fishing - it is a necessity when fishing at greater depths.In this case, the lower leader may even when the sample or the wound tension of the network, so is not applicable.In addition to the pluses top leader can also add damping jerks by buoys, so the network will be more calm.The downside is the risk of separation of the displacer in the big waves.
In fact sometimes used midwater order to determine where there is one or the other fish.For this often creates combined types of orders.
harm from the use of drift nets
In some areas, commercial fishing using drift nets is prohibited.So, do not apply it in the North Pacific to maintain stocks of some fish species.Large-scale drift-net fishing is forbidden by UN General Assembly in the open waters of the oceans.Permitted fishing researcher such networks, but this opportunity is often abused.While no total ban drift-net fishing, but already installed a shorter period and some limitations for this type of fishing.
in drift nets are often caught marine mammals and seabirds, which then die.The numbers simply awesome.Thus, only in the Far East in the Russian economic zone because of that kill more than 100 thousand. Birds and 2.5 thousand. Mammals each year.And salmon populations themselves are reduced.
Another serious threat is the attitude of the fishermen.Often it is produced sockeye - most valuable of the salmon, and the rest of the fish, including juvenile sockeye salmon, other species of salmon, pink salmon and chum salmon simply thrown overboard.This rearrangement ruins aimlessly huge number of fish, which is a violation of fishing regulations.
