Evaluating the impact of experimenting with different hook types on catch rates of target species and by-catch.

MINOUW partner & Lead scientist:

HCMR (Hellenic Centre of Marine Research) , George Tserpes

Fishing method and species:

Surface drifting longlines. Species targeted is Swordfish.

What is the discards problem?

Two types of unwanted by-catch are produced: incidental catches of protected species such as Sea-turtles and undersized individuals of the target species.

What activities did the MINOUW project carry out?

Experimental fishing with different hook types. The following parameters are monitored:

  • Catch rates of target species (both commercial and undersized fractions).
  • Catch rates of other commercial by-catch species.
  • Incidental catches of sensitive species such as Sea-turtles and Pelagic sharks.
  • Economic performance of the fisheries.
What outcomes were expected?
  • Evaluate the impact of gear modifications (i.e employment of circle hooks instead of the traditional J-type ones) on the catch rates of the target species and on unwanted by-catch.
  • Encourage fishing practices and technologies that minimize fishing impact on ecosystems.

Employment of circle hooks seems to be promising, but given the limited number of the current trials and the fact that past works revealed variable results in different fisheries, further field studies are needed to confirm the effectiveness of circle hooks on a Mediterranean-wide level.

For a full summary of results download the PDF here: (637kb)