Abstract

The aim of the present study is to characterize the distribution and abundance of larval P. occidentalis in the northern Gulf of Mexico (NGoM). Here, we report on summer ichthyoplankton cruises conducted in the NGoM from 2009 to 2011. Samples were collected using neuston nets towed through the upper meter of the water column in the outer shelf and slope waters of the NGoM. Over the three year sampling period, a total of 9,533 bluntnose flyingfish larvae were collected representing 77% of the total flyingfish catch. Interannual variation was detected with densities of P. occidentalis larvae higher in 2009 and 2010 (11.3 and 7.9 larvae/1,000 m2, respectively) than 2011 (1.9 larvae/1000 m2). P. occidentalis larvae were present in each month and year sampled, and percent frequency of occurrence ranged from 40% in July 2011 to 100% in June 2010, suggesting that bluntnose flyingfish represent a common and important component of the ichthyoplankton assemblage. Generalized additive models were used to evaluate the influence of oceanographic conditions on the density of P. occidentalis. Several environmental variables (month, year, sea surface height anomaly, distance to Loop Current, and salinity) were retained in the final model. Habitat suitability was linked to physicochemical properties of the seawater, and higher larval abundances were found at higher salinities and negative sea surface heights. Additionally, a positive relationship with distance to the Loop Current (dominant mesoscale feature) was detected, suggesting that the abundance of bluntnose flyingfish larvae increases away from this frontal feature.

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