Image: Havforskningsinstituttet / FIS

Significantly larger mackerel further north - and Lumpfish almost everywhere

Favorable weather and wind conditions have led to good progress and efficient trawling for "Eros" and "Vendla".

After a change of crew in Tromsø, "Eros" and "Vendla" have so far mapped the sea areas south-southwest and north-west of Bjørnøya, and from the coast west of Tromsø to the south in the Jan Mayen zone in addition to in international waters.

Photo: Havforskningsinstituttet

Bigger mackerel, but lower trawl catches

There have been lower trawl catches of mackerel in these northern areas compared to further south during the first part of the trip.

Provisional distribution of mackerel catches (kg). Source: Havforskningsinstituttet

In contrast, the mackerel that now graze far north in summer have been significantly larger than further south, with average weights up to 580 grams in trawl halls south of the Jan Mayen zone, with individuals > 600 grams and up to 17 years old.

Source: Wiki / FIS -->

Increased quantities of nvg herring northward

There has been a clear increase in the acoustic recordings of Norwegian spring-spawning herring during the second part of the trip. It is mainly small schools of herring with herring between 10-40 m deep that dominate.

The trawl catches in the upper water bodies document younger herring – fry (0-group) and juveniles (1-3 years) – in the north-eastern areas towards the Barents Sea. Larger herring, dominated by the 2016 year class, we simultaneously record acoustically and capture in surface trawling both with "Vendla" south and south-west in the Jan Mayen zone, and with "Eros" north-west of Bjørnøya.

Average weight (kg) of mackerel in the catches. Source: Havforskningsinstituttet

Both young and older blue whiting (Micromesistius poutassou) in the north

We acoustically record the grayling in varying amounts in the summer over the entire Norwegian Sea. We register the pollock based on sonar, and get confirmation of the nature and size of the acoustic measurements based on pelagic trawling from approx. 150 m to 350 m deep, depending on the time of day.

The blue whiting migrate vertically throughout the day, and are generally higher in the water column at night than during the day, and young mullet are higher in the water column than adults.

Source: Havforskningsinstituttet

The blue whiting are usually larger and older in the northern areas of the Norwegian Sea compared to further south. But this year we also find a lot of young coal mullet that are 2 and 3 years old from the strong 2020 and 2021 year classes in the trawl catches, for now as far north as between Svalbard and Bjørnøya.

The blue whiting in the northern seas range from 60 grams to 435 grams, from 2- to 9-year-old individuals.

The fascinating Lumpfish (Cyclopterus lumpus) is almost everywhere 

The lumpfish is not so numerous in the trawl catches of the mackerel ecosystem trip in the summer, but it has an impressive distribution in the north-east Atlantic in the summer. The lumpfish is almost like a mascot on this cruise, as we usually get it in almost every trawl hall on both vessels during the more than month-long ecosystem cruise.

Source: Havforskningsinstituttet

So far, 145 lumpfish of various sizes (>20 cm) have also been marked and released on board "Eros" and "Vendla". You can't say that the roe biscuit is particularly streamlined and elegant, but it certainly comes a long way during the year, as we have found out from, among other things, preliminary results from the brand tests. The lumpfish is well helped by the various sea and coastal currents which they can use during their migrations during the year.

The size of the lumpfish has varied from tiny individuals of 5.5 cm and 9 grams up to adults of 47 cm and 4.73 kg, so there is a wide range in size of lumpfish that now swim around and feed in the upper bodies of water in the entire Norwegian Sea.

Good weather makes good progress

Source: Havforskningsinstituttet

There have generally been favorable weather and wind conditions dominated by easterly winds so far during the second part of the mackerel ecosystem tour. This has led to "Eros" and "Vendla" making good progress. It has also contributed to surface trawling with kites and blowers, and the deep trawl tails at a depth of 200-350 m have been fast and efficient.

In addition, the good weather and wind conditions along the way have meant that we have logged acoustic echo sounder and sonar recordings with little noise, which thus contribute to representative acoustic measurements of herring and grayling during the voyage.

Source: Havforskningsinstituttet

It will be exciting to observe over the next week until the end of the trip, what we catch and record of mackerel, herring and blue whiting, in addition to all the other species we survey along the way.

Blue whales were observed on board "Vendla" west of Jan Mayen now in the realm of the midnight sun in the summer, so we are excited about which marine mammals we will meet north of Jan Mayen, Bjørnøya and south-southwest of Svalbard until the end of the voyage.

Authors: Leif Nøttestad and Åge Høines | Institute of Marine Research (Traslated from the original in Norwegian)

[email protected]
www.seafood.media

Address:	Nordnesgaten 50, P.O. Box 1870 Nordnes
City:	Bergen
State/ZIP:	(N-5817 )
Country:	Norway
Phone:	+47 55 23 85 00
Fax:	+47 55 23 85 31
E-Mail:	[email protected]
More about:

Print