Chile and Argentina hold a longtail hake assessment workshop
February 26th, 2018
Within bilateral cooperation agreement among Fisheries Development Institute (IFOP) from Chile and National Development and Fisheries Research Institute (INIDEP) from Argentina’s framework, in January 2018 a workshop on longtail hake resource assessment was held in Mar del Plata city. IFOP participated, stock evaluator, Ignacio Payá, and from INIDEP, stock evaluator Dr. Analía Giussi and biologists Federico Gorini, Gonzalo Troccoli and Francisco Zumpano.
A second joint evaluation exercise was carried out during this workshop, the first exercise had been carried out a couple of years ago and the need to conduct a workshop to compare age readings and age assignment among IFOP and INIDEP age laboratories had arised since then, it was first held in November 2017 at INIDEP. From that age workshop it was concluded that annual growth rings identification is the same but there is an age allocation difference. Therefore, for this second joint assessment exercise, catches at Argentinian fleets were reprocessed using IFOP age allocation criterion.
This improvement allowed a greater consistency among Pacific and Atlantic data, and facilitated evaluation model adjustment. Different evaluation scenarios were analyzed considering different combinations of abundance indices. Preliminary results showed biomasses higher than those estimated individually by country. The historical biomass trend was similar, except in the last 4 years where biomass fluctuated depending on density index campaign extension in Argentina. Due to this, stock status for the entire southern America cone remains uncertain, with very wide confidence intervals. The steps to follow in future data analysis, indicators and evaluation models were discussed.