Catch comparison of flatfish pulse trawls and a tickler chain beam trawl

Abstract

Pulse trawling is used to a growing extent in the Dutch flatfish beam trawl fleet, and deemed as a promising alternative to tickler chain beam trawling. A comparative fishing experiment was carried out with one vessel using conventional beam trawls, and the other two using flatfish pulse trawls supplied by two different companies. Pulse trawl landings were lower both expressed in kgh−1 (67% based on auction data) or baskets per hectare (81%).The pulse trawls had fewer fish discards (57%, p<0.0001), including 62% undersized plaice (Pleuronectes platessa L.) (p<0.0001), and 80% discarded weight of benthic invertebrates (p=0.0198) per hectare. The pulse fishing technique resulted in a lower fuel consumption (37–49%), and consequently in spite of lower landings net revenues were higher. A downside of using pulse trawls is the possible spinal damage of marketable cod (Gadus morhua L.), but because total cod landings by beam trawls are low (4–5%), the implication will likely be limited.