Blog post

Summary week 34

Published on
August 26, 2012

After the first week it is time for a short evaluation of the achievements.

Figure 1 shows the stations fished (blue) and planned (grey). We plan to trawl in the middle of a square, but the figure shows that this is not always possible. Mostly, the reason is that the bottom on the planned location is not suitable for beam trawls. If we trawl there, we risk net damage or loss. We however try to keep the distance between stations between 20 and 30 nautical miles in order to cover the complete area. the only area where that is impossible, is the Moray Firth (northwesterly stations on the map) as there the rectangles are partly on land.
Figure 1. Stations week 34
Figure 1. Stations week 34
Figure 2 shows the bottom temperature for the stations (darker=warmer). After every haul, we do a vertical measurement with a so-called CTD (measuring conductivity and temperature at depth), which gives information about the conductivity and temperature in the water column.
Figure 2.
Figure 2.

Figure 3 gives information about he catches (only fish species), in total numbers caught (21 hauls, approx. 10 hours fishing) on a logarithmic scale. Dab (Limanda limanda, a flatfish species) is by far the most dominant species in the catches, followed by European plaice (Pleuronectes platessa). The order of the list will change in the coming weeks, as some species only occur in specific area. Dab, European plaice and grey gurnard (Eutrigla gurnardus) will stay on a high position in the list.

Figure 3.
Figure 3.

We are looking forward to the next week, after our the weekend in Aberdeen. Some changes in personnel took place. First of all, Hendrik Romkes replaced Jan de Boer as representative from the fishing sector, and Lorna is replaced by John. He is head of the department Fish, and likes to experience the work at sea.