4.6 Article

Development and testing of fish-retention devices for pots: transparent triggers significantly increase catch efficiency for Atlantic cod (Gadus morhua)

Journal

ICES JOURNAL OF MARINE SCIENCE
Volume 78, Issue 1, Pages 199-219

Publisher

OXFORD UNIV PRESS
DOI: 10.1093/icesjms/fsaa214

Keywords

catch efficiency; fish-gear interaction; fish pots; fish-retention device; passive fishing gear; pot entry-to-exit ratio

Funding

  1. German Federal Agency for Nature Conservation (Bundesamt fur Naturschutz) [3516821300]

Ask authors/readers for more resources

Fish pots have lower catch efficiency than gillnets and trawls, but using transparent acrylic triggers can significantly improve catch efficiency, especially for Atlantic cod. Transparent acrylic fingers have higher entry-to-exit ratios compared to conventional Neptune fingers, and combining them with funnels further enhances catch efficiency.
Fish pots have lower catch efficiency than gillnets and trawls and, therefore, are rarely used for catching Atlantic cod (Gadus morhua) and similar species. Fish-retention devices (FRDs), non-return devices that permit fish to enter the pot while impeding exit, reduce the pot exit rate and therefore can increase catches. Conventional FRDs, however, also reduce entry rate and may not improve catches. To increase pot-catch efficiency, we developed and tested a new trigger-type FRD, made of transparent acrylic glass, which we named acrylic fingers (AFs). AFs are almost invisible underwater and offer little resistance to entering cod. We compared AFs with Neptune fingers (NFs), a conventional trigger-type FRD with a distinct visual outline, by observing cod entry and exit rates through both trigger types rigged to a pot in a net pen. Both trigger types significantly reduced exit rates compared with a funnel without triggers; however, NFs also reduced entry rates by visually deterring cod. Specifically, AFs have higher entry-to-exit ratios and therefore improve catch efficiency. Combining AFs with funnels further increased catch efficiency. Thus, transparent acrylic triggers present a promising new approach to increasing pot-catch efficiency and may increase the uptake of the cod pot, an environmentally low-impact gear.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.6
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available