Location: 230 miles west of Donegal
Fish!
Early this morning we noted marks of blue whiting on the south-eastern corner of the Rockall Bank at around 550m depth. The presence of blue whiting in this area is a good indication that spawning is still taking place and that the survey timing is correct. Peak spawning time can vary by up to 3 weeks from year to year due to environmental conditions such as temperature but we aim to keep the time of the survey the same each year. One less variable to worry about !
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| Echogram of small marks of blue whiting. |
Big shoals of blue whiting can be 30 miles long, and show up as bright red on the echosounder. Less dense shoals, like these, show up as blue. There is an instrument on the net, the headline transducer, which indicates the density of fish that have entered the net.
Work by the two biologists in the wetlab showed that these were all mature, spawning fish. They ranged in age from 3-12 years old.
Blue Whiting Research Fleet:
The Dutch, Russian and Norwegian vessels are now making their way towards a rendezvous point to the north of the Porcupine Bank. The Dutch and Russian vessels began surveying further south, while the C. Explorer covered Rockall. The vessels are due to meet tomorrow and proceed as a coordinated group northwards through the main spawning areas along the shelf edge. The Norwegian fishing vessel the FV Brennholm has the furthest distance to travel, around the top of Scotland through the Pentland Firth, and will join the survey tomorrow. However, the record for distance travelled stands firmly with the Russian research vessel the Fridjof Nansen which travelled from the Russian Polar research Institute in Murmansk. This journey can take almost 2 weeks…..each way!
Later this evening, just before dinner, our Marine Mammal Observer finally saw some cetacean activity. A pod of about 10 pilot whales approached the boat and stayed around for a few minutes.
Blog: Graham Johnston & Ciaran O'Donnell
Blog: Graham Johnston & Ciaran O'Donnell
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