«

»

Print this Post

New study: Chain sweep catches more flounder

WOODS HOLE, MA – This past summer, NOAA Fisheries Northeast Fisheries Science Center undertook a second experimental trawl study to test the efficiency of the research vessel Henry Bigelow’s flatfish catch, this time focused on witch flounder.

In the catchability study, a comparative trawl method was used:  one reel carried a trawl rigged with a rockhopper sweep; the other a chain sweep. (Calvin Alexander/NOAAFisheries Cooperative Research Branch photo)

In the catchability study, a comparative trawl method was used: one reel carried a trawl rigged with a rockhopper sweep; the other a chain sweep.
(Calvin Alexander/NOAAFisheries Cooperative Research Branch photo)

The two-week study compared a trawl net rigged with a modified chain sweep gear with that of a trawl net and rockhopper sweep, set up to imitate the Bigelow, to determine relative efficiencies in catch.

The chain sweep system had a four-fold increase in catchability for witch flounder.

The study was performed at the request of the newly-formed Northeast Trawl Advisory Panel (NTAP) established by the Mid-Atlantic and New England fishery management councils and comprised of fishermen, managers, and researchers.

The Science Center provided $600,000 in funding for the NTAP and catchability studies.

The fishing industry has often questioned the estimates of relative abundance for species of flatfish, in part because of how the research vessel catches fish.

In order to cover vast areas to sample multiple species, the Bigelow uses a trawl net with a rockhopper sweep with 16” discs to traverse a variety of bottom types.

Flatfish obviously, lie flat on the seafloor, often burying themselves in the soft sand and mud…

 

cfn-10_16-cover

To get the rest of this story and much more you’ll need the October 2016 issue of Commercial Fisheries News – please choose from the following options:

BUY a Single PRINT edition of CFN that is delivered by MAIL. PRINT EDITION

Quickly enjoy ONLINE access with our Hi-DEF flip-book. PURCHASE ONLINE EDITION  

(Read online flip-book immediately with purchased access key and download a copy for yourself to keep.  Not sure if it works for you? Try a FREE SAMPLE HERE.)

SAVE BIG when you SUBSCRIBE

Permanent link to this article: http://fish-news.com/cfn/new-study-chain-sweep-catches-more-flounder/