Blog post

First survey day – First hauls and little fish

Published on
October 18, 2011

Not too much fish to see up to now, but we just finished our first fishing track.

First haul

As expected it was not a very big catch (app. 30 kg), containing 10% young herring, 90% sprat and one sea trout.

Second haul

The second haul we did was a surface trawl. We decided on this, as we saw loads of noise near the surface and we wanted to see where these bubbles (bubbles create acoustic noise which makes data in this area unusable) come from. As more or less expected we found only jellyfishes, which could contribute to a noise enhancement.

 Echogram with loads of bubbles near the surface, a few small fish schools and the detected bottom
Echogram with loads of bubbles near the surface, a few small fish schools and the detected bottom

Third haul

Still only very small schools to be seen on the echograms. We fished on the first reasonable dense appearance of tiny schools. This time herring (60%; 40% sprat of the 60kg catch) dominated with few sprat.

Previously we decided, because of the wind, that it would be a good idea to skip going out of the sheltered area ,we are in at the moment, as it was initially planned. Now we just got to know that the wave heights out there are of about 3.4 m. SO in brief good decision to stay sheltered! No only for the sake of us but also our data would become absolutely unusable, resulting in echograms filled up with bubbles.

Herring in the catch
Herring in the catch
The entire catch
The entire catch
The catch gets taken in
The catch gets taken in
Gerrit has a first look at the species composition
Gerrit has a first look at the species composition