Otolith chemistry indicates large-scale connectivity in Chilean jack mackerel (Trachurus murphyi), a highly mobile species in the Southern Pacific Ocean

Insight on population structure of the Chilean jack mackerel (Trachurus murphyi)

“…These results were confirmed by Ashford et al (2011): by comparing the chemistry of the otolith nucleus between the western and eastern South Pacific Ocean, Chile and Peru. These authors observed a significant heterogeneity among population sampling areas,but no consistent differences, and they concluded that "discrete population hypotheses do not account for the data".…”

“…This patchy population hypothesis generally implies the existence of a common spawning area for the different subpopulations. According to Ashford et al (2011), different spawning areas can exist together as long as there is no particular preference on the part of the adults towards one of them. Also, a major characteristic of a patchy population is the absence of a "source population": any part of the population that is reproducing is theoretically able to "regenerate" the whole population after a collapse.…”

Variabilidad ambiental y recursos pesqueros en el Pacifico suroriental: estado de la investigacion y desafios para el manejo pesquero

“…Posterior a la reproducción, dos procesos co-ocurren: una migración estacional hacia la costa a hábitats de alimentación, donde se sugiere que la disponibilidad de alimento es el factor determinante de la migración (CornejoRodríguez, 1991;Quiñones et al, 1997;Miranda et al, 1998), como también el transporte/ advección de huevos y larvas eclosionadas hacia la zona disponible de crianza (Norte de 30ºS, Elizarov et al, 1993;Gretchina et al, 1998;Arcos et al, 2001). Estudios de química de otolitos (Ashford et al, 2010), de estructura de edad de larvas de jurel océano-costa, y su asociación a procesos oceanográficos (Vásquez, 2012), sustentan la hipótesis de conectividad entre las zonas de desove oceánico y de crianza. A lo largo de la costa de Perú y Chile, las inestabilidades baroclínicas gatillan una alta actividad de mesoescala, con remolinos que se propagan hacia el oeste , con contribución de clorofila hacia fuera de la costa (Correa-Ramírez et al, 2007), en sentido inverso a la dirección de conectividad con zonas de crianza costera.…”

Testing early life connectivity supplying a marine fishery around the Falkland Islands

“…Inputs and assumptions are rigorously specified but nonetheless, the uncertainties involved in reproducing physical processes often undermine conclusions from these tests. Combined with otolith chemistry, however, particle simulations provide a quantitative means of constructing spatially explicit hypotheses that incorporate the physical circulation, with well-defined predictions of expected trajectories that can be empirically tested against observed distributions in the otolith chemistry (Ashford et al, 2010(Ashford et al, , 2011b.…”