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Email the author (Login required) Influence of oceanographic dynamics on squid paralarvae distribution from the southern Mexican Pacific Ocean (rainy seasons 2007-2008)
Submited: 2016-06-17 17:37:21 | Published: 2017-05-22 17:40:18
DOI: https://doi.org/10.3856/vol45-issue2-fulltext-11
Abstract
The Southern Mexican Pacific Ocean presents strong seasonal changes related with the rainy and the Tehuano wind seasons that generate different mesoscale processes affecting biological productivity and marine biodiversity. In this region, we analyzed the cephalopod paralarval community collected during July 2007 and May-June 2008 in relation to the regional oceanography in absence of Tehuano winds. The samples were collected with standard Bongo net tows and CTD hauls were performed to determine the structure of the water column. No significant changes in temperature at 10 m depth were registered among the analyzed seasons. Although the number of taxa, the community composition, and the total abundance of paralarvae were similar between seasons, the percentage of close to the hatching paralarvae (≤2.0 mm) was almost twice in May-June than during July. In July, paralarvae ≤2.0 mm distributed at the edge of the cyclonic and anticyclonic eddies, related to high temperatures, low chlorophyll a concentrations and low zooplankton volumes. During May-June the geostrophic currents determined the distribution of one coastal and one oceanic paralarval groups in high and low chlorophyll a concentrations respectively separated by the upwelling front and related also, to the edge of the cyclonic eastern eddy. The distribution of the SD Complex and Abraliosis paralarvae close to the hatching size over the continental shelf and oceanic zone suggests a coupling of these cephalopods reproduction with the regional productivity pulses.
