First Marking Of Southern King Crab On Freshwater Vessels

The National Institute for Fisheries Research and Development (INIDEP) together with the Secretariat of Fisheries of Chubut and the National University of Patagonia San Juan Bosco (Chubut) started marking tasks for king crab.

This work is carried out within the framework of the Interjurisdictional Marking Program under which the marking of crab in freezer vessels is being carried out and now the marking of adult males in freshwater vessels is added with the participation of biologists of said University.

The objective of the marking is to know biological aspects, displacement, directionality and walking speed in the Patagonian spider crab (Lithodes santolla). During the crab campaign, still in development, 1500 specimens will be marked.

The tagged specimens could be recaptured by the different fishing vessels that work in the area, therefore it requires the collaboration of the personnel on board who must register the place and date of the recapture with the brand number or bring said information to the observer to board.

The marking of crabs will be developed on board freezer and freshwater vessels in the area comprised by Golfo San Jorge and adjacent waters.

The crabs will bear a temporary mark that is observed externally, is red, is located on the third treadmill and has a number that belongs to a correlative series. The data that must be registered in case of capturing a spider crab with marks are the position (latitude and longitude), day-time and the brand number, this information must be sent to the electronic mail (centolla@inidep.edu.ar) or near the observer on board.

Finally, all the tagged and recaptured crabs must be returned alive to the sea as soon as possible. The success of this activity depends on the collaboration of the fishermen and observers on board both the Nation and the provinces of Chubut and Santa Cruz.

This activity arises within the framework of the Interjurisdictional Marking Plan that the INIDEP scientists belonging to the Bentonic Crustacean Fisheries Program have been developing since 2014, as part of the fisheries management measures for spider crab defined by the Federal Fisheries Council (CFP).

In Argentina, INIDEP has carried out other marking experiences with temporary brands with a recovery rate of 21%. The spatial displacement of most of the recaptured crabs (67%) was within a range less than 30 kilometers from the point of release.

The fact of finding most of the recaptured specimens in this limited range, and few specimens distributed at greater distances, has confirmed the view that the spider crab has a persistent population structure with nuclei defined as centers of high fishing performance.