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Sea turtles are susceptible to a wide range of impacts. In Brazil, the loggerhead turtle Caretta caretta (Linnaeus, 1758) is the main sea turtle species caught incidentally by longline fishing fleets that target the blue shark Prionace glauca (Linnaeus, 1758) and swordfish Xiphias gladius (Linnaeus, 1758). The latter is well known for its predation strategy, which consists of using the rostrum to injure and catch prey. In this study, we recorded for the first time the impalement of a juvenile loggerhead sea turtle by a swordfish during a fishing operation of a Brazilian longline vessel in 2018. Two videos of this interaction were recorded by the shipmaster around 260 km from the Brazilian coast. The sea turtle was incidentally caught with a hook and subsequently attacked by the swordfish. The rostrum initially pierced the anterior left shoulder of the turtle and passed through the body, exiting from the right posterior carapace. Given the position of the attack, considerable internal damage was most certainly done to the turtle. Although the turtle was hauled aboard to remove the hook and then returned to the sea alive, it probably died due to the extent of the injuries caused by the rostrum having passed through the center of the body. Since both swordfish and turtle are pelagic and these interactions are poorly recorded, such encounters may be relatively common. Therefore, this type of information should be included in the data collection protocols of fishery monitoring programs to better understand and scale the bill-stab phenomenon, not only for sea turtles but also in relation to other groups of fauna., Las tortugas marinas son susceptibles a una amplia gama de impactos. En Brasil, la tortuga cabezona Caretta caretta (Linnaeus, 1758) es la principal especie de tortuga marina capturada incidentalmente por las flotas pesqueras de palangre que tienen como objetivo la tintorera Prionace glauca (Linnaeus, 1758) y el pez espada Xiphias gladius (Linnaeus, 1758). Este último, es muy conocido por su estrategia de depredación, que consiste en utilizar el rostro para herir y atrapar presas. En este estudio, se registró por primera vez el empalamiento de un juvenil de tortuga cabezona por un pez espada en 2018 durante una operación de pesca de un palangrero brasileño. El capitán del barco grabó dos videos de esta interacción a unos 260 km de la costa brasileña. La tortuga marina fue atrapada incidentalmente con un anzuelo y posteriormente atacada por el pez espada. El rostro perforó inicialmente el hombro izquierdo anterior de la tortuga y atravesó el cuerpo, saliendo por la parte posterior derecha del caparazón. Dada la posición del ataque, la tortuga sufrió un daño interno considerable. Aunque la tortuga fue subida a bordo para quitarle el anzuelo y luego fue devuelta viva al mar, probablemente murió debido a la extensión de las heridas causadas por el paso del rostro a través del centro del cuerpo. Dado que tanto el pez espada como la tortuga son pelágicos y estas interacciones no se registran acabadamente, estos encuentros pueden ser relativamente comunes. Por lo tanto, este tipo de información debe incluirse en los protocolos de recopilación de datos de los programas de monitoreo de pesquerías para comprender mejor y escalar este tipo de fenómenos, no solo para las tortugas marinas sino también en relación con otros grupos de fauna.

This is an open access article, free of all copyright. The definitive version was published in PLoS ONE 12 (2017): e0172839, doi:10.1371/journal.pone.0172839., Marine animals, such as turtles, seabirds and pelagic fishes, are observed to travel and congregate around eddies in the open ocean. Mesoscale eddies, large swirling ocean vortices with radius scales of approximately 50–100 km, provide environmental variability that can structure these populations. In this study, we investigate the use of mesoscale eddies by 24 individual juvenile loggerhead sea turtles (Caretta caretta) in the Brazil-Malvinas Confluence region. The influence of eddies on turtles is assessed by collocating the turtle trajectories to the tracks of mesoscale eddies identified in maps of sea level anomaly. Juvenile loggerhead sea turtles are significantly more likely to be located in the interiors of anticyclones in this region. The distribution of surface drifters in eddy interiors reveals no significant association with the interiors of cyclones or anticyclones, suggesting higher prevalence of turtles in anticyclones is a result of their behavior. In the southern portion of the Brazil-Malvinas Confluence region, turtle swimming speed is significantly slower in the interiors of anticyclones, when compared to the periphery, suggesting that these turtles are possibly feeding on prey items associated with anomalously low near-surface chlorophyll concentrations observed in those features., A Woods Hole Postdoctoral Fellowship awarded to PG and NASA grant NNX13AE47G funded this work. CB is grateful for support from NOAA and the NSF-GRFP (Grant No. 1314109). DJM gratefully acknowledges support from NASA and NSF.