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

  • Published source details Van Marlen B., Wiegerinck J.A.M., van Os-Koomen E. & van Barneveld E. (2014) Catch comparison of flatfish pulse trawls and a tickler chain beam trawl. Fisheries Research, 151, 57-69.


This study is summarised as evidence for the following.

Action Category

Use a pulse trawl instead of a beam trawl

Action Link
Subtidal Benthic Invertebrate Conservation

Use an electric (pulse) trawl

Action Link
Marine Fish Conservation
  1. Use a pulse trawl instead of a beam trawl

    A replicated, controlled study in 2011 in sandy areas in the North Sea, Netherlands (Van Marlen et al. 2014) found that pulse trawls caught fewer unwanted invertebrates compared to traditional beam trawls, but the effects varied with species. Fewer unwanted invertebrates were caught when using pulse trawls compared to using beam trawls (pulse: 142 vs beam: 177 individuals/ha). However, when sorted by groups, pulse trawls caught fewer invertebrates living on the sediments (131 vs 175) but more living inside the sediment (11 vs 2), compared to beam trawls. In particular, pulse trawls caught fewer echinoderms (82 vs 113) and gastropods (sea snails; 0.0 vs 0.1), compared to the beam trawl, similar numbers of anthozoan (0.0 vs 0.1), bivalves (0.1 vs 0.2), cephalopods (0.1 vs 0.2), and crustaceans (60 vs 64). Pulse trawls also caught 57% less total discards (non-commercial unwanted catch of invertebrates and fish) by volume (0.25 vs 0.29 basket/ha). The pulse trawl reduced the volume of commercial catch by 19% compared to the traditional trawl (0.08 vs 0.1 basket/ha). Pulse (electrical) trawling was prohibited in European fisheries in 1998, but a system of derogations set up in 2006 has allowed the practice to continue, including experimental trials. Comparison trials were conducted in May 2011 with three vessels fishing side-by-side (two boats using pulse trawls, one using traditional flat-fish tickler chain beam trawls). Catches from 33 trawls/vessel were assessed. The total discard volume was measured. Invertebrate discards were identified and counted from one subsample of total catch/trawl (35 kg basket). As of 2019, the practice has been fully banned in European waters.

    (Summarised by: Anaëlle Lemasson & Laura Pettit)

  2. Use an electric (pulse) trawl

    A replicated, paired, controlled study in 2011 in an area of seabed in the North Sea, Netherlands (van Marlen et al. 2014) found that fishing for flatfish using an electric pulse trawl reduced the catches of discarded fish and undersized plaice Pleuronectes platessa and sole Solea solea compared to a conventional beam trawl. Average catch rate of all discarded fish (mainly bottom dwelling species – see paper for data for individual species/groups) was reduced by 57% in the pulse trawl (108 fish/ha) compared to the beam trawl (62 fish/ha). Fewer individuals of smaller sizes of the target species plaice and sole were caught in the pulse trawl than the beam trawl (data reported graphically). Data were collected in May 2011 from 126 trawl by three vessels fishing near each other. Two vessels used different types of pulse equipment (data pooled) and the other was a conventional tickler chain beam trawl (see original paper for specifications). Discarded catch was sampled from 33 hauls from each vessel.

    (Summarised by: Chris Barrett)

Output references
What Works 2021 cover

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 21

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.

Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape ProgrammeRed List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Mauritian Wildlife Supporting Conservation Leaders
Sustainability Dashboard National Biodiversity Network Frog Life The international journey of Conservation - Oryx Cool Farm Alliance UNEP AWFA Bat Conservation InternationalPeople trust for endangered species Vincet Wildlife Trust