Development of catch control devices Results from: Industral - PowerPoint PPT Presentation

Eduardo Grimaldo / Manu Sistiaga Development of catch control devices Results from:  Industral project (FHF) " Development of a selection system for mid-water trawls"  SINTEF project "Catch controls for trawls"  NFR project "Development of catch control devices for trawls" Teknologi for et bedre samfunn 1

Developmet of catch control devices for mid-water trawls Bacground One of the problems by fishing with mid-water trawls is the risk of taking too big catches. High densities of fish means that large quantities of fish enter the trawl in few minutes, and this is difficult to control even with a lot of electronic monitoring sensors in the trawl. 70 m thick layer of pelagic cod 54 tons of cod taken in 8 min towing time Teknologi for et bedre samfunn 2

Developmet of catch control devices for mid-water trawls A) Working principle: B)  The codend closes and partially detaches from the rest of the trawl when it has been filled with a certain amount of fish.  The fish that is still inside the trawl have C) the chance to escape unharmed. D) The codend can be adjusted to hold a extension piece codend catch of 10, 15 eller 20 tonns of fish Teknologi for et bedre samfunn 3

Method nr. 1 Acoustic releaser - ring-ring – flitting of rope A) The combination of an acoustic releaser, ring-ring and flitting of a Acoustic releaser rope is a technique that was used by Soldal et al (Institute of Marine Research of Norway) in the early 90s for survival studies in trawls. IXSEA 3# Ring-ring and flitting of rope Acoustic releaser 3# 8 m SPECTRA 30# 44 # circunference Teknologi for et bedre samfunn 4

Method nr. 1 Acoustic releaser - ring-ring – flitting of rope A) Acoustic releaser IXSEA 3# Video: Prototype testing in Hirtshals 3# 8 m SPECTRA 30# 44 # circunference Teknologi for et bedre samfunn 5

Method nr. 1 Acoustic releaser - ring-ring – flitting of rope Video: R/V Jan Mayen nr 3 Teknologi for et bedre samfunn 6

Method nr. 1 Acoustic releaser - ring-ring – flitting of rope Photographs which shows a detached codend in its way to the boat (left) and the same codend with a 3 tons cod catch. The released mechanism which was used in this test was the “acoustic release based system”. The experiments were performed on board the RV Jan Mayen in May 2011. (Photographs: Manus Sistiaga, SINTEF) Teknologi for et bedre samfunn 7

Method nr. 2 Acoustic releaser – weak link – supporting rope B) Much simpler system that eliminates risk of assembling failure … . Acoustic releaser IXSEA 3# 3# 30# 44 # circunference Teknologi for et bedre samfunn 8

Teknikk nr. 3 Svaklink-fangstsensor teknikk C) Catch sensor 3# 3# 30# 44 # circunference Teknologi for et bedre samfunn 9

Teknikk nr. 3 Svaklink-fangstsensor teknikk Fullskalaforsøk om bord F/F Jan Mayen, mars 2012 The trawl is at the bottomat start fishing The trawl has beenfishingfor 10 min. The catch The trawl has beenfishingfor 15 min and the rate is ~10 tonns/hour codendstart to expand The trawl has beenfishingfor 25 min . The In the min. 29 the thin PE twine brakes and the ~2 tonns of fish are gently releasedfrom the trawl codendand the extensionpiece are full of fish codenddetachesfrom the extensionpiece. Video:R/V Jan Mayen nr 8 Lot of fish escapingfrom the trawl Fishstill comming outof the trawl The extensionpiece is now empty og the codend with3 tonns of fishis hangingfrom the extensionpiece Teknologi for et bedre samfunn 10

In collaboration with: • SINTEF F&H • Norges Fiskerihøgskole • NTNU • Fiskeridirektoratet • Univ. i Massachusetts Teknologi for et bedre samfunn 11