Mesopelagic fish larval assemblages during El Niño-southern oscillation (1997-2001) in the southern part of the California Current

Abstract

Mesopelagic species are the principal constituents of larval fish assemblages inhabiting the southerly California Current region. Seasonal larval abundance is influenced by circulation of the California Current and subtropical Countercurrent, including regional changes of the physical, chemical, and biological characteristics during the El Niñ o-Southern Oscillation. This study examines the mesopelagic fish larvae distribution and abundance patterns between seasons and years, with the aim of describing the mesopelagic larval assemblages during dynamic environmental changes induced by El Niñ o (1997)(1998) and the rapid transition to La Niñ a (1998)(1999)(2000) along the west coast of the Baja California Peninsula (25-31°N). Despite large oceanographic variability, larval assemblages varied principally on a seasonal basis, related to reproductive periods and the north-south gradient influenced by the seasonal pattern of the California Current. An increased diversity, number of species, and abundance of tropical species was noticeable during the northward expansion of warm-water taxa during El Niñ o, principally in the northern areas (Ensenada and Punta Baja). After El Niño, population adjustments and rapid recovery occurred during La Niñ a conditions, which reflected seasonal differences in the mesopelagic community structure that are closely related to the seasonal pattern of oceanic currents.

Oceanographic mechanisms that possibly explain dominance of neritic tropical zooplankton species assemblages around the Islas Marias Archipelago, Mexico

“…In the present study we attempted, from a modest sample size, identify as precise as possible most of the zooplankton assemblage of the tropical Islas Marías Archipelago. As a region not previously studied we found a large proportion of fish larvae not previously observed at ichthyoplanktonic surveys done along the west coast of Baja California Peninsula, Gulf of California, or Cape Corrientes regions during the more three decades of research (1980 to 2014) (Aceves-Medina et al, 2003, 2004Franco-Gordo et al, 1999, 2004Aceves-Medina et al, 2003, 2004Funes-Rodríguez et al, 2011;SilvaSegundo et al, 2008;León-Chávez et al, 2010;FunesRodríguez et al, 2011;Avendaño-Ibarra et al, 2013, 2014. These are most likely fish larvae of benthic or demersal coastal fish species, which larval description and taxonomy is still highly fragmented (Brogan, 1992;Moser, 1996).…”

Preferential distribution of fish larvae in the California Current System: Time, space, and temperature

“…These species might benefit from nutrient incorporation (200–400 km out at sea) through advection processes (cyclone gyres or jets) and subarctic flow at large scales (Bernal & Chelton, ; Chelton, , ), as has been suggested to explain zooplankton biomass increases in oceanic zones (Bernal, , ; Bernal & McGowan, ; Chelton, , ). In the oceanic area of the southern part of the CCS, assemblage structures of mesopelagic larvae are highly variable and influenced by cold and warm conditions associated with La Niña and El Niño events, but these structures principally varied on a seasonal basis (Funes‐Rodríguez, Hinojosa‐Medina, Aceves‐Medina, Jiménez‐Rosenberg, & Bautista‐Romero, ; Funes‐Rodríguez, Zárate‐Villafranco, Hinojosa‐Medina, & González‐Armas, ; Funes‐Rodríguez et al., ). In the present study, a large amount of data were used, and these were sampled over a wide spatiotemporal range.…”

Ecologia De Ictioplâncton: Uma Abordagem Cienciométrica

“…Oecol. Aust., 20(4): 436-450, 2016 investigaram efeitos do El Niño e La Niña nos padrões de distribuição e abundância das assembleias larvais e observaram diferenças correlacionadas à estrutura das comunidades e suas associações com a temperatura e salinidade das massas d'água em uma Península costeira do México (Funes-Rodríguez et al 2011).…”