The objective of the document was to analyze mackerel landings made by the Argentine commercial fleet, characterize their composition by age and length, and estimate population parameters. In 2020, mackerel landings reached 13,532 tons, of which 92% was obtained in the area known as “El Rincón”.

 

Most of the specimens were adults and the researchers identified two members of the resource: the northern one, where 90% of the specimens were between 310 and 410 millimeters in total length and age group 4 and 5, while those of the stock southern individuals prevailed between 280 and 400 millimeters in total length and specimens of age 2, 3 and 4.

 

In Argentina, mackerel has a presence up to 45ºS in the intermediate platform, although the distribution has expanded to 47º30´S. It represents one of the main pelagic resources of the Argentine continental shelf with a population structure of two troops separated from each other by the parallel of 39 ° S.

 

 

Although the two troops are exploited by the commercial fleet, both areas differ in terms of the intensity of that exploitation. "Unlike what happened in 2018 when it was the Mar del Plata roadstead / estuary fleet that operated mostly on the northern shoal, in 2019 and 2020 the commercial dynamics of mackerel fishing responded to the historical pattern," the researchers warned. That is, "two annual extraction pulses, one in winter and the other in late spring and early summer," says the document accessed by REVISTA PUERTO.

 

The total number of mackerel fishing trips last year was similar to that of 2019. However, the number of trips discriminated by stock varied significantly. Those made on southern shoal increased due to the greater participation of the coastal fleet in the landings of mackerel. "There were 148 trips in the northern cash and 288 trips in the southern one," the document specifies.

 

 

Due to the pandemic, there were no possibilities to carry out sampling of landings that INIDEP personnel usually do. "The studies of southern shoal were achieved thanks to the contribution of companies in the Mar del Plata canning industry," the report reveals.

 

The studies on northern shoal were achieved by having an onboard technician who was in charge of taking samples on board and also landed one box per trip to be analyzed at INIDEP.

 

 

44 samples were studied, of which 12 corresponded to the northern stock and 32 from the southern stock, the latter being the largest number of samples from this population analyzed during the year. The technical scientific staff also analyzed samples to determine length, weight, sex, age, and maturity.

 

Of the total mackerel catch last year, 12,454 tonnes corresponded to southern shoal, the highest figure in the last five years. Those of the northern shoal were 1,077, the lowest figure in the last two years.

 

Southern mackerel is caught mainly between August and October. It is the deep-sea weetfish vessels that had a greater preponderance in landings (6,755 tons) followed by coastal ones (5,280 tons) and freezers (419 tons) that also catch it as by-catch. The number of deep-sea and coastal weetfish vessels increased compared to last year.

 

 

Mackerel from the northern stock is caught between November and December and the bay / estuary fleet (10,008 tonnes) off the coast of Mar del Plata plays a major role. The price of this fish depends on what has been landed in the previous months from southern shoal. The year 2020 showed less landings because there were a lot of bad weather days and there were fewer ships from the smaller fleet that operated on the resource.

 

Author: Roberto Garrone / Revista Puerto (article available only in spanish)

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