Diel variation in the vertical distribution of fish larvae forced by upwelling filaments off Punta Angamos (northern Chile)

Pablo Manuel Rojas Venegas


DOI: https://doi.org/10.3856/vol42-issue3-fulltext-2

Abstract


The role for diel vertical migration (DVM) on fish larvae assemblages off Punta Angamos (23°29'S; 70°59'W) northern Chile was examined. In September 1998 and January 1999 two bio-oceanographic surveys during coastal upwelling events were carried out. Fish larvae were collected during day/night at three depth strata (0-20, 20-80 and 80-200 m depth) inside/outside the upwelling filaments. The study area was dominated by a southward flow throughout 200 m depth, while Ekman layer did not exceed 20 m depth. Higher accumulation of fish larvae was found in the mid-depth stratum (20-80 m), where seawater speed was lower and did not interacted with circulation associated to upwelling filaments formation. Most of larval fish groups were found in nonupweling waters at mid depth. Irrespective of seawater origin (upwelling/nonupwelling), larval Diogenichthys laternatus (Myctophidae), Engraulis ringens (Engraulidae) and Bathylagus nigrigenys (Bathylagidae) showed deeper vertical distribution during day than night, suggesting diel vertical migration. This larval behaviour potentially may increase coastal retention in a productive area through the vertical avoidance of the offshore Ekman layer during upwelling events.


Rojas Venegas P. Diel variation in the vertical distribution of fish larvae forced by upwelling filaments off Punta Angamos (northern Chile). Lat. Am. J. Aquat. Res.. 2017;42(3). Available from: doi:10.3856/vol42-issue3-fulltext-2 [Accessed 20 Jan. 2019].
Rojas Venegas, P. (2017). Diel variation in the vertical distribution of fish larvae forced by upwelling filaments off Punta Angamos (northern Chile). Latin American Journal of Aquatic Research, 42(3). doi:http://dx.doi.org/10.3856/vol42-issue3-fulltext-2