one publication added to basket [3123] | Initial tests of a flexible grate for size selection of trawl caught fish
Rose, C.S. (1999). Initial tests of a flexible grate for size selection of trawl caught fish. Mar. Technol. Soc. J. 33(2): 57-60
In: Marine Technology Society Journal. Marine Technology Society (MTS): Washington, D.C.. ISSN 0025-3324; e-ISSN 1948-1209, more
| |
Abstract |
The fish size selection and handling features of a trawl-mounted flexible grate weretested. The grate was constructed of fiberglass rods and neoprene strips to beflexible enough to bend around a net reel, but rigid enough to maintain consistent,long, rectangular openings for fish size selection during trawling. A 244 cm x 140 cmgrate, installed in the extension section of a bottom trawl, was tested for sizeselection of walleye pollock (Theragra chalcogramma) in the Bering Sea by means ofa small mesh auxiliary net that collected escapees. A grate with 44 mm spacing hadan L sub(50), the length at which 50% of the fish escaped, of 37 cm and a selection range estimated at 10 cm. Few fish longer than 44 cm escaped, corresponding topollock with head widths equal to the 44 mm bar spacing. The grate was easilydeployed and retrieved from a net reel, without any special gear handling proceduresrequired. In-situ video observations using infrared illumination confirmed that thepanel and collection net assumed their correct configurations and that escapingpollock passed easily through the grate. |
|