Fishing methods

To ensure that the herring are caught gently and carefully the fishermen use what are known as pelagic trawl nets and purse seines.

 

Trawl net fishery

The term "pelagic" comes from the Greek and means "living in the open water". Pelagic trawl nets are designed for catching fish species living in the open seas, such as ocean perch, cod, Atlantic salmon, mackerel, herring, sprats, anchovies and sardines.

Their funnel shape ends in a bag, the tail. This is where the fish are collected. The opening of the net is 50-70 metres deep and 80-120 metres wide. The total length is usually 1,500 metres. Steaming at a slow speed of 3-4 knots (approx. 5 km/h), two trawlers pull the nets in a water depth of around 50-300 metres. The fish are located using sonar and echo sounding.

 

Trawl net fishery

Purse seine fishery

The fishery using purse seines – which are used in both deep-sea fishing and in inland waters – is equally careful.

In deep-sea fishing the nets are up to 2,000 metres long and reach to a depth of 200 metres. In contrast, in shallow waters they only have a length of 50-200 metres and reach a depth of 20 metres. In this method the fishermen lay the purse seine in a ring around the shoal of fish and then close the net using the bottom rope. The nets have a very small mesh size in order to prevent injuries to the skin and gills.
The tuna used for Rügen Fisch tuna fillets is Skipjack tuna (Katsuwonis pelamis), which is caught in the FAO fishing area 51 (West Indian Ocean).

It is caught using what are called long-lines. This employs what is known as a "dolphin safe" method which avoids the by-catch of dolphins.

 

Purse seine fishery