TY - JOUR
T1 - Sailfish (Istiophorus platypterus) spawning and larval environment in a Florida Current frontal eddy
AU - Richardson, David E.
AU - Llopiz, Joel K.
AU - Leaman, Kevin D.
AU - Vertes, Peter S.
AU - Muller-Karger, Frank E.
AU - Cowen, Robert K.
N1 - Funding Information:
Sample collection and processing benefited greatly from the assistance of C. Guigand, A. Exum, J. VanWye, L. Gundlach, S. Trbovich, the captain and crew of the R/V F.G. Walton Smith , and many others. S. Sponaugle and K. Denit provided the otolith age data. Discussions with A. Bakun, S. Sponaugle, J. Serafy, E. Prince, J. Kool, T. Lee, N. Shay, and C. Paris improved the manuscript substantially. This study was supported by grants to R.K.C., S. Sponaugle, K. L., S. Smith, and D. Olson from the National Science Foundation (OCE-0136132), R.K.C. and S. Sponaugle from the Gulf States Marine Fisheries Commission (Billfish-2005-017), and R.K.C. from the Large Pelagics Research Center at the University of New Hampshire (National Oceanic and Atmospheric Administration award NAO4NMF4550391). Additional support came from a University of Miami Maytag Fellowship, the Harding Michel Memorial Fellowship and the Captain Harry Vernon Scholarship to D.E.R.
PY - 2009/9
Y1 - 2009/9
N2 - Fronts and eddies are widely hypothesized to be critical spawning habitat for large pelagic fishes, due to increased larval and/or adult feeding opportunities at these features. We examined sailfish (Istiophorus platypterus) spawning around a cyclonic, submesoscale (∼13 × 7 km) Florida Current frontal eddy. The temporal progression of eddy dynamics over a 65 h period was determined using ocean color satellite imagery, continuous surface measurements along the cruise track, and non-linear least-squares fitting of the positions of three drifters deployed within the eddy. A peak in larval sailfish densities (n = 2435, stations = 49), composed primarily of yolk-sac and first-feeding larvae, occurred at the eddy frontal zone. A majority of these larvae were estimated to have been spawned during the formation of the eddy. A comparison between the distribution of similar-age sailfish and scombrid larvae indicated that the peak in larval sailfish density likely resulted from spawning directly at the front, rather than transport by convergent flow. The first-feeding prey items of larval sailfish (Farranula and Corycaeus copepods) were most abundant at the frontal zone and to a lesser extent inside the eddy. Egg distributions were used to indirectly assess the distribution of adult sailfish prey items. Euthynnus alleteratus and Auxis spp. eggs were in highest abundance outside the eddy, while the eggs of small carangids were in highest abundance at the eddy frontal zone. Overall, this study indicates that sailfish spawn at small-scale oceanographic features that provide a favorable feeding environment for their larvae and potentially also for the adults.
AB - Fronts and eddies are widely hypothesized to be critical spawning habitat for large pelagic fishes, due to increased larval and/or adult feeding opportunities at these features. We examined sailfish (Istiophorus platypterus) spawning around a cyclonic, submesoscale (∼13 × 7 km) Florida Current frontal eddy. The temporal progression of eddy dynamics over a 65 h period was determined using ocean color satellite imagery, continuous surface measurements along the cruise track, and non-linear least-squares fitting of the positions of three drifters deployed within the eddy. A peak in larval sailfish densities (n = 2435, stations = 49), composed primarily of yolk-sac and first-feeding larvae, occurred at the eddy frontal zone. A majority of these larvae were estimated to have been spawned during the formation of the eddy. A comparison between the distribution of similar-age sailfish and scombrid larvae indicated that the peak in larval sailfish density likely resulted from spawning directly at the front, rather than transport by convergent flow. The first-feeding prey items of larval sailfish (Farranula and Corycaeus copepods) were most abundant at the frontal zone and to a lesser extent inside the eddy. Egg distributions were used to indirectly assess the distribution of adult sailfish prey items. Euthynnus alleteratus and Auxis spp. eggs were in highest abundance outside the eddy, while the eggs of small carangids were in highest abundance at the eddy frontal zone. Overall, this study indicates that sailfish spawn at small-scale oceanographic features that provide a favorable feeding environment for their larvae and potentially also for the adults.
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U2 - 10.1016/j.pocean.2009.07.003
DO - 10.1016/j.pocean.2009.07.003
M3 - Article
AN - SCOPUS:70349900766
VL - 82
SP - 252
EP - 264
JO - Progress in Oceanography
JF - Progress in Oceanography
SN - 0079-6611
IS - 4
ER -