IIMYC   23581
INSTITUTO DE INVESTIGACIONES MARINAS Y COSTERAS
Unidad Ejecutora - UE
artículos
Título:
Benefits of frontal waters for growth and food availability of Engraulis anchoita larvae.
Autor/es:
SPINELLI, MARIELA; BROWN, DANIEL; DIAZ, MARINA VERA; CAPITANIO, FABIANA; SPINELLI, MARIELA; DIAZ, MARINA VERA; BROWN, DANIEL; CAPITANIO, FABIANA; DO SOUTO, MARINA; PÁJARO, MARCELO; DO SOUTO, MARINA; PÁJARO, MARCELO
Revista:
FISHERIES RESEARCH
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2018 vol. 204 p. 181 - 188
ISSN:
0165-7836
Resumen:
We studied the abundance, size and growth rates of Engraulis anchoita larvae during the end of the species? spawning season in relation to environmental variables. Two sampling transects, one in Península Valdés (northern transect: NT) and the other in Isla Escondida (southern transect: ST), with four stations each, were established in late summer. Both locations are characterized by high concentrations of E. anchoita larvae in spring, strongly associated with the presence of frontal waters, at the beginning of the species? spawning season. Zooplankton and ichthyoplankton were sampled, and temperature profiles and chlorophyll-a satellite images were analyzed for each sampling station. Zooplankton samples were divided in size fractions, and composition and abundances were estimated. Standard length (SL), ontogenetic stages, and abundance (including eggs) were estimated. Additionally, age and growth rates were determined by otolith analysis. Two different scenarios were observed in both transects. In the NT, a frontal structure was found, while at the ST, the water column was completely homogeneous. Total zooplankton abundance was maximum at frontal waters, with 22,195 ind. m-3 36 , being the small size fraction (< 200 μm) the most abundant, mainly composed of nauplii (9,000 ind. m-337 ) and cyclopoid copepodites (4,000 ind. m-3). The NT showed higher abundance (mean of 126.5 ind. m-2 38 per station in NT; 29.75 ind. m-2 39 in ST), faster growth rates of E. anchoita larvae (NT: 0.45 ± 0.04 mm day-1; ST: 0.34 ± 0.09 mm day-140 ; n= 90), and higher mean SL at frontal waters (7.57 ± 1.52 41 mm SL) than the ST. In the NT, E. anchoita growth rates were constant in time, whereas in 42 the ST, they decreased with age. Our results support the classical theory, which states that frontal waters provide advantageous e 43 nvironmental conditions for fish larvae feeding, growth and, thus, survival.