Inclined Separator Panels

Summary

An inclined separator panel is similar to a separator panel in that its main purpose is to separate the catch into the bottom living species and the higher swimming species and direct them into two separate cod ends. The main difference is that the leading edge of an inclined separator starts close to the belly panel of the trawl and about half way down its length.  It is inclined upwards to direct the round fish into the upper chamber of the trawl. There is a small opening in the leading edge of the inclined separator to allow the ground fish and shell fish to pass into the lower chamber of the trawl.

Size selectivity

The inclined separator is effective for separating the larger haddock and whiting into the upper chamber of the trawl and bottom dwelling fish into the lower chamber. The advantage of this is that a secondary selection device such as a larger diamond mesh cod end can be fitted to either chamber to further select the catch in that codend. In this way it should be possibly to reduce bycatch in the gear.

Unlike the larger haddock and whiting the smaller, immature fish have a tendency to stay low as they enter a trawl, probably for security staying close to the seabed. As a result of this, many of them will pass into the lower chamber of a separator trawl. This is the same for inclined separator panels and full length horizontal separator panels.
Cod and flats tend to stay low in the trawl and enter the lower chamber, as do nephrops and other shell fish.

As well as decreasing by-catch the separator trawl can delivery  better quality fish and nephrops. The relatively soft fleshed haddock and whiting in the top cod end stay in much better condition because they are not exposed to the abrasion from the shellfish, bottom fish and seabed debris that is now in the lower cod end. The nephrops in the lower cod end will also see and increase in numbers and in quality. This is a result of there being less bulk in the cod end thereby the meshes are not getting forced open and allowing nephrops to escape. With less bulk in the codend there is less chance of the nephrops getting damaged as well and there is usually a noticeable improvement in the quality of nephrops from a separator cod end.

Other information

Inclined separators were developed as follow on from a full length separator panel to try to keep the selective device clear of the belly of the net just aft of the lower bosom. This is the area of the trawl that regularly gets ripped and the fishermen need easy access to this area for repairing it. For this reason the leading edge of an inclined separator is usually fitted about 5-8 metres behind the lower bosom of the trawl.

Selection type

  • Pre-selection