The Norwegian pelagic fishing vessel Vendla is taking part this summer’s annual mackerel survey
This week, the Norwegian pelagic fishing vessels, Eros and Vendla set out on this summer’s mackerel surveying expedition for the Institute of Marine Research in Norway.
The two vessels are part of an international research song that together will cover from 3 to 3.5 million square kilometers of the Northeast Atlantic, says researcher Leif Nøttestad who will be on the second half of the cruise, ie from July to 3 August.
The other three vessels will sail for researchers in Iceland, Greenland, the Faroe Islands and the EU, who will use a Danish vessel.
As in recent years, all equipment and trawls on the various vessels are the same, so that the results will be easier to coordinate when the research reports are to be presented to ICES in order to establish quota councils for next year.
The mackerel stock is spreading enormously in the Atlantic Ocean. But in recent years, both the distribution and the population size have had a declining trend; it has had a tendency to pull out of Greenlandic and Icelandic waters and was found increasingly north in the Norwegian Sea.
“Especially in the last two years, much of the mackerel was all the way north in the Jan Mayen zone and partly southwest of Svalbard into the Fram Strait. There we did not manage to follow the mackerel to the zero line, ie to the point where it stops being mackerel. We hope to make it this year, says Nøttestad. Last year, the researchers were as high as 76 degrees, so it is possible that they will go even further north this year, perhaps past Longyearbyen and into Framstredet,” according to Nøttestad.
“Now that there is a lack of quota agreement on mackerel, and Norway will not have access to fish the stock in the British zone, there will probably be extra focus and interest this summer from mackerel fishermen etc. on the mackerel’s distribution in the Norwegian Sea,” says Nøttestad.
“We at the Institute of Marine Research will try to keep relatively frequent updates about especially the spread of mackerel during the mackerel ecosystem cruise with “Eros” and “Vendla” on our websites www.hi.no,” he says.
In the first part of the survey, Eros will take a more westerly route while Vendla follows the coast. If possible, an attempt should also be made to map the mackerel within the fjord lines in Lofoten. It has been in demand from the fisheries organisations.
This year, equipment from Deep Vision will also be tested, which has a camera and software that will be able to measure length and identify the fish without taking it on board. Read more about the technology at TEKFISK here:
The survey equipment also registers several other fish species with echo sounders, mainly Norwegian spring-spawning herring and blue whiting. These indices will be six years old after this year’s cruise. Then the time series are long enough for ICES to evaluate them, and consider including them as a knowledge base in the stock advice for Norwegian spring-spawning herring and blue whiting.
“While we are still on such an extensive voyage, we use the hay, as long as we have the time and opportunity, to monitor a number of conditions in the ecosystem. There are herring and blue whiting, horse mackerel, lump fish, Atlantic salmon, quail and zooplankton. From binoculars to a microscope, in other words,” says Nøttestad who will also keep an eye out for mackerel sturgeon on the cruise.
“There are many research orders both nationally and internationally that we are asked to carry out during this cruise. This year, as last year, we will notice a total of 200 roe biscuits on board “Eros” and “Vendla” to study the migrations of this exciting species.”
Furthermore, this year the focus will be on collecting otoliths (ear stones) and genetic samples for new methods to separate different herring populations, own investigations of the parasite Kudoa thyrsites which gives “jelly mackerel” and quality of mackerel, and collection of mackerel in the Norwegian Sea for genetic identification of the stomach contents of the mackerel.
In addition, there are extensive studies of sea temperature, currents and other environmental conditions.