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

MACCHI, G.; ÁLVAREZ COLOMBO G.; BELLEGIA, M.; BETTI, P.; BROWN, D.; CEPEDA, G.; DERISIO, C.; DIAZ, M. V.; MACHINANDIARENA, L.; MARTOS, P.; SANTOS, B.; SOBRERO, L.; SCHIARITI, A.; TEMPERONI, B.

Marine Fisheries Science

Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP)

Lugar: Mar del Plata; Año: 2023

2683-7951

Understanding the causes thatgenerate variability of recruitment in marine populations constitutes one ofthe greatest challenges in fishery science. Our predictive capacity to explainthese variations is relatively low, due to the interaction of exogenous andendogenous factors, which vary across time and space within populations. Inorder to gain information on recruitment fluctuations of Argentine hake (Merluccius hubbsi)from the Patagonian stock, we reviewed the results obtainedanalyzing the reproductive ecology, trophic andenergetic dynamics during different stages of development of this species, andits relationship with environmental variables. We concluded that reproductivepotential is strongly influenced by the characteristics of the parental stock,particularly of females, in terms of their size, age and condition. Thischaracteristic, called “maternal effect”, suggests that the Spawning StockBiomass, commonly used as an index of productivity in fishery assessment, isnot a good predictor of recruitment. We also observed that survival during the earlylife of hake is affected by the spatial coincidence with the North PatagonianFrontal System (NPFS), characterizedby a high concentration of nutrients, high productivity, and availability offood for the early developmental stages. The physical conditions and the larvaldensity in the nursery area affected the nutritional state and mortality ofhake, mainly by competition for food or predation. It was demonstrated that the change frompelagic to the demersal habitat in juveniles takes place over a longer periodof time than previously recognized for this species, showing the importance touse acoustic information to complement data from bottom trawls. This is one ofthe main topics to be developed in order to estimate new recruitment indicesfor Argentine hake, along with other research items proposed to improve thestock assessment in the future.