Seine fishing

As a purse seine nets are called to fish, which may be long in the deep-sea fishing to 2000 m and extend to a depth of 200 m. Even in inland fisheries purse seines are used, which, however, are small-scale ( 50 to 200 m long and up to 20 m deep).

The purse seine is designed ring shape around a school of fish. Then the net is pulled closed with the Schnürleine located at the bottom line, so that the fish are completely enclosed by the network. In the lower part of the net purse seines have very small mesh sizes, so that a gentle catch of fish is guaranteed and skin and gill injuries largely ruled out.

Environmental impact of purse seine net fishing

Purse seine nets are used worldwide to capture valuable food fish, particularly in the tuna fishery, but also targeting sardine and mackerel. It is, apart from the situation in the Tropical Eastern Pacific, a relatively selective and environmentally safe fishing method.

Influence on the seabed

Compared with demersal trawl fisheries or beam trawls have purse seine nets hardly any negative impact on the seabed and on living organisms.

Selectivity and bycatch

With purse seine nets can individual schools of fish selectively Fishing out. Fishing season is not random, as is the case with drift nets or in the shrimp, cod and pelagic trawl fisheries. The bycatch rate ( sea turtles, sharks, marine mammals, seabirds and non-target fish species ) of purse seine nets is, according to the FAO at about 5% of the total catch, which is below the global average catch rate of all fishing methods by 8%.

Overfishing

Since purse seine individual schools of fish are almost completely removed from the ecosystem, they can compromise the reproductive capacity strongly harvested species. Thus, the EU adopted on 11 June 2007, Regulation (EC ) No 41/2007 for the conservation of tuna stocks in the Atlantic, with among other things the use of purse seines when fishing for bluefin tuna in the East Atlantic during the period from 1 July to December 31, was banned in 2007.

In June 2008, the EU banned because of massive violations of international rules agreed for the sustainable management of bluefin tuna at an early stage the use of purse seine nets in the hunt for these fish in the Mediterranean and Eastern Atlantic. The catch stop was for the tuna fleets from Greece, France, Italy, Cyprus, Malta and Spain. According to official figures had until June 2008, half of the French fleet caught nothing, while the other half had already exhausted more than 90 % of each quota, but all ships were similarly active. Italian purse seiners had exceeded their quotas even as early as 100-240 %. In addition, at least eight search aircraft were identified, still collaborating with purse seine vessels from the EU to track shoals of bluefin tuna, although the use of such aircraft is illegal.

Environmental organizations doubt the effectiveness of the measure. Shortly after the Italian purse seiners fishing ban on fishing trip and were further discovered with the fishermen cooperating search aircraft.

Special case Tropical Eastern Pacific

In Tropical Eastern Pacific in particular yellowfin tuna Fish ( Thunnus albacares ) are associated with Slim and spinner dolphin schools. Under a floating on the water surface dolphin school holds up to 150 m depth with high probability a school of tuna on. This biological phenomenon is puzzling to this day and only occurs in this marine region. For tuna fishing keep fishing by helicopter or by speedboats from specifically for dolphin schools out, they hunt and then circling them with the purse seine net to abzufischen including the floating of tuna.

Use of purse seines until the beginning of 1990

The targeted hunting of dolphins in the tuna fishery in the eastern Pacific Tropical intended to the early 1990s, have been killed in the period of the late 1950s more than 7 million dolphins, according to the U.S. Earth Iceland Institute (EII ). The EII refers to this as the greatest mass extinction of marine mammals in the history of mankind.

In 1986, the EII launched a US-wide campaign against the purse seine fishery in the eastern Pacific Tropical. Subsequently, sales of canned tuna product in the USA so much went back that large tuna importers such as Star Kist, Bumblebee and Chicken of the Sea were forced in 1990 to accept prepared by the EII guidelines for dolphin- safe tuna. The U.S. tuna importers undertook to introduce no more tuna caught by chasing and circling of dolphin schools with purse seine nets. In the same year, the U.S. Congress worsened the existing since 1972 Marine Mammal Protection Act ( MMPA ) and laid down the guidelines for the EII dolphin safe tuna caught as a legal standard.

Use of purse seines today

Given caused by the purse seine fishery in the eastern tropical Pacific dramatic dolphin mortality and the amended U.S. import regulations for canned tuna in 1990 adopted the agency responsible for fisheries management in the eastern tropical Pacific Inter- American Tropical Tuna Commission ( IATTC) in 1992, the La Jolla Agreement, the continuous reduction of Delfinbeifänge by defining allowable mortality rates for dolphins provides. Based on allowable 19,500 killed dolphins in 1993, the ratio fell to less than 5,000 in 1999. According to the IATTC dolphin bycatch rate of operating in the eastern tropical Pacific purse seine fishing fleet in 2006 was 900, or about 0.01 % of the estimated population size for the affected dolphin species.

Bycatch reduction and dolphin mortality

Technically, the reduction of dolphin bycatch rate is achieved in that the inmates in the use of purse seine dolphin school is released after the merger of the power circuit. Current scientific studies of the fisheries department of the National Oceanic and Atmospheric the United States, NOAA ( National Oceanic and Atmospheric Administration ), and the Blue Ocean Institute, that does not recover, despite the use of this alternative method of fishing in the tuna fishery in the eastern tropical Pacific, the Slim and spinner dolphin stocks have. The researchers attribute this to the fact that during the hunting of purse seine fishing are separated on the pods of dolphins dolphin mothers and their calves, who have to fend for themselves no chance of survival.

AIPCD Dolphin Safe label

To " dolphin friendly " to avoid the sharp U.S. rules for the import of so-called tuna caught, was established with its own Dolphin Safe label of the IATTC, 2001, the Agreement on the International Dolphin Conservation Program ( AIPCD ).

International conservation organizations like the EII reject this label from a Death Certificate for Dolphins since it tolerates a dolphin bycatch in the purse seine fishery in the eastern tropical Pacific. Since it despite several out delegated to court attempts by the U.S. government under Presidents Bill Clinton and George W. Bush failed to change the Marine Mammal Protection Act, excellent canned tuna product in the USA may with the AIPCD label not be sold as before.

Purse-seine tuna goods in the EU

In contrast to the situation in the U.S. imports of excellent with the AIPCD Dolphin Safe label canned tuna goods are not banned from the eastern tropical Pacific in the EU. On 19 May 2003 the EU Regulation 882/2003 entered into force with which the AIPCD Dolphin Safe label was anchored within the EU.

In Germany, an agreement between large parts of the tuna industry and the EII, not to be processed under the terms of the IATTC caught with purse seines in the eastern tropical Pacific tuna and introduce exists. This Agreement shall eV from the German partner organization of the EII, the society for the rescue of dolphins monitored. For the control in the other EU Member States, which was founded by the EII European Dolphin Safe Monitoring organization is responsible.