Study

Mortalities of fish escaping from square and diamond mesh codends in the Aegean Sea

  • Published source details Düzbastılar F.O., Özbilgin H., Aydın C., Metin G., Ulaş A., Lök A. & Metin C. (2010) Mortalities of fish escaping from square and diamond mesh codends in the Aegean Sea. Fisheries Research, 106, 386-392

Actions

This study is summarised as evidence for the following.

Action Category

Use a square mesh instead of a diamond mesh codend in a trawl net

Action Link
Marine Fish Conservation
  1. Use a square mesh instead of a diamond mesh codend in a trawl net

    A replicated, paired, controlled study in 2009 of an area of seabed in the Aegean Sea, Turkey (Düzbastılar et al. 2010) found that the short-term survival of two of six fish species after escaping from bottom trawls was higher in square mesh codends compared to diamond mesh codends. Overall, average survival rate was greater in square than diamond mesh codends for escaped red mullet Mullus barbatus (square: 95% of 950 fish; diamond: 81% of 225 fish) and blotched picarel Spicara maena (square: 97% of 460 fish; diamond: 91% of 174 fish). For annular seabream Diplodus annularis (82 fish) and common pandora Pagellus erythrinus (46 fish), survival rate was 100% for both codend types. In addition, average brown comber Serranus hepatus post-escape survival was 97% (of 332 fish) and 95% (of 126 fish) for square and diamond mesh codends, whilst all 355 scaldfish Arnoglossus laterna did not survive. For all species, most mortality occurred in the first 48 h after escape. Six, 15-min experimental bottom trawl deployments were done by research vessel off the southern coast of Yassica Island, Izmir Bay, in October 2009: three using a square mesh and three a diamond mesh codend (both 40 mm). Small mesh (24 mm), hooped detachable covers fitted over each codend collected escaped fish and at the end of each deployment were detached, sealed, and deployed on the seabed. Fish were fed and survival monitored in the anchored covers for seven days by divers.

Output references

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, terrestrial 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 18

Go to the CE Journal

Subscribe to our newsletter

Please add your details if you are interested in receiving updates from the Conservation Evidence team about new papers, synopses and opportunities.

Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape Programme Red List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Bern wood Supporting Conservation Leaders National Biodiversity Network Sustainability Dashboard Frog Life The international journey of Conservation - Oryx British trust for ornithology Cool Farm Alliance UNEP AWFA Butterfly Conservation People trust for endangered species Vincet Wildlife Trust