Recruitment of the Argentine hake, Merluccius hubbsi, from Patagonian stock: A review of main features affecting the reproductive potential and survival during early life stages

MACCHI GJ; ÁLVAREZ-COLOMBO, GUSTAVO; BELLEGGIA, MAURO; BETTI, PAOLA; BROWN, DANIEL; CEPEDA, GEORGINA; DERISIO CARLA; DIAZ MV; EHRLICH, MARTIN; LEONARDUZZI, EZEQUIEL; MACHINANDIARENA, LAURA; MARTOS, PATRICIA; SANTOS, BETINA A.; SCHIARITI, AGUSTÍN; SOBRERO, LUCILA; TEMPERONI BRENDA

Marine and Fishery Sciences (MAFIS)

INIDEP

Lugar: Mar del Plata; Año: 2023

Understanding the causes that generate variability of recruitment in marine populations constitutes one of the greatest challenges in fishery science. Our predictive capacity to explain these variations is relatively low, due to the interaction of exogenous and endogenous factors, which vary across time and space within populations. In order to gain information on recruitment fluctuations of the Argentine hake (Merluccius hubbsi) from Patagonian stock, we reviewed the results obtained analyzing the reproductive ecology, trophic and energetic dynamics during different stages of development of this species, and its relationship with environmental variables. We observed that the reproductive potential is strongly influenced by characteristics of the parental stock, particularly of females, in terms of their size, age and condition. This feature, called ‘maternal effect’, suggests that the Spawning Stock Biomass, commonly used as an index of productivity in fishery assessment, is a poor predictor of recruitment. We also observed that survival during hake early life is affected by the spatial coincidence with the North Patagonian Frontal System, characterized by a high concentration of nutrients, high productivity, and food availability. The physical conditions and the larval density in the nursery area affected the nutritional state and mortality of hake, mainly by competition for food or predation. It was observed that the transition from the pelagic to the demersal habitat in juveniles occurs over a longer period than previously recognized for this species, stressing the importance of using acoustic information to complement data from bottom trawls. This is one of the main topics to be further developed in order to estimate new recruitment indices for Argentine hake, along with other research items proposed to improve stock assessment.