During the survey 167 hauls will be made, using fishing lines with 100 traps (Photo: INIDEP)
Southern king crab assessment begins in Patagonian waters
Tuesday, January 14, 2020, 07:10 (GMT + 9)
The National Fisheries Research and Development Institute (INIDEP) has begun a scientific survey to assess the Southern king crab resource (Lithodes santolla) in its central Patagonian distribution area. This is the fourth consecutive year when this study is carried out in the San Jorge gulf and platform waters, between 43 ° 30 ’and 48 ° south latitude, including the jurisdictions of Chubut and Santa Cruz and national waters.
The main objective is to estimate relative indices of abundance, describe the spatial distribution of this year, mainly of commercial concentrations, and monitor different biological aspects of the stock.
This survey is carried out simultaneously with the king crab freezer vessels that fish for this resource in the area, and counts as every year with the collaboration of the embarked personnel and the support of the participating companies.
The scientific-technical personnel must collect all the bridge information, quantify the capture and make size-sex samples in all the sets that are carried out daily. Due to the many projected activities, members of the Benthic Crustacean Fisheries Subprogram and the On-Board Observer Program in Commercial Vessels participate in each vessel. Through a joint research agreement between the San Juan Bosco University of Comodoro Rivadavia and INIDEP, Nair Ramos, a researcher at CONICET , also embarks for the second year.
Photo: INIDEP ►
During the survey 167 hauls will be made, using fishing lines with 100 traps, at depths that vary between 30 and 120 meters. Scheduled activities include: crab count by trap, length and weight measurements, determination of the reproductive stage and percentage of eggs in the case of females, data collection of loss of appendages, morphometric relationships and tissue sampling for genetic and egg mass studies to determine egg quality.
Scientists will also record and quantify all the accompanying fauna, usually composed of other crabs, stars, ophiuroidea and sea urchin. Studies of the selectivity of the escape rings on the most important component of the discard, the South American spider crab (Libidoclaea granaria), will be also carried out this year.
The novelty of this survey is underwater filming in the openwork lines in order to evaluate their behavior during anchoring. This new knowledge will provide a fundamental contribution when it comes to understanding the fishing operation for both the resource and the interaction with the marine fauna and the generation of proposals that mitigate the interaction.
With the information collected, a relative benchmark will be generated based on the abundance of the Southern king crab that will allow biomass estimates to be made and to suggest to the enforcement authorities the catch quotas in each jurisdiction for the 2020-21 season.
The results of the survey will be presented in a timely manner in the Bentonic Crustaceans Commission and Sub-Commission, in the Federal Fisheries Council and before the provincial authorities.