Ympäryslerjestöjä

Ympäryslerjestöjä, known in English as encircling nets or surrounding nets, are a type of fishing gear used in fisheries management and scientific research. These nets are designed to be deployed around a school of fish, effectively trapping them within the net's perimeter. The principle of operation involves encircling the target fish and then gradually closing the net or hauling it in to concentrate the catch.

The design of ympyräslerjestöjä can vary depending on the target species, the fishing environment, and the specific purpose of their use. They are often characterized by a large, curtain-like mesh that is deployed from a vessel or by hand. The net is typically anchored at one end or held in place by the vessel, and then the other end is maneuvered to complete the circle. Once the encirclement is achieved, the net can be pursed at the bottom to prevent escape, or the entire net can be hauled aboard.

Ympäryslerjestöjä are employed in various fishing methods, including purse seining and some forms of trawling. In purse seining, the net is used to encircle schools of pelagic fish like tuna, mackerel, and sardines. The bottom of the net is then closed like a purse string, preventing the fish from escaping downwards. Scientific research also utilizes similar netting techniques for sampling fish populations, studying their behavior, and conducting stock assessments. The effectiveness of ympyräslerjestöjä lies in their ability to capture a significant portion of a targeted school of fish in a single operation.