Do pingers cause stress in fish? An experimental tank study with European sardine, Sardina pilchardus (Walbaum, 1792) (Actinopterygii, Clupeidae), exposed to a 70 kHz dolphin pinger

Date of acceptance: 06/12/2014 Acknowledgments The study was funded by the Portuguese Ministry of Science (Fundac¸a˜o para a Cieˆncia e Tecnologia– FCT) through a PhD Grant of SG (SFRH/BD/47931/2008). We would like to thank the captain of the purse-seiner (Jose´ Manuel Saveedra) and his crew for facilitating the capture and transport of live fish. Moreover, we want to thank Ana Marc¸alo for suggestions on the experimental design, Manuel Garci for technical advice on underwater video recordings and James Turner from the company Future Oceans for providing technical details on the 70 kHz dolphin pingers. We would also like to acknowledge the scientific advice of Dr. Jose´ Iglesias and the technical and logistic support for the preparation of the laboratory and the materials for tank experiments by Enrique Martı´nez Gonza´lez, Ricardo Pazo´and other staff at the aquaculture facilities of the Spanish Institute for Oceanography (IEO) and the Marine Sciences Station of Toralla (ECIMAT) in Vigo. Furthermore, we are grateful to Francisco de la Granda Grandoso for his practical assistance during the fish tank experiments and to Juan Santos Blanco for helping with statistical analysis. Finally, we would like to thank Pilar Riobo´ Agula, Amelia Fernandez Villamarin, Jose´ Franco Soler, Jose´ Luis Mun˜oz, Angela Benedetti, Marcos Antonio Lopez Patin˜o and Marta Conde Sieira for scientific advice and practical support with cortisol analysis and Rosana Rodrı´guez for preparing histological samples for us.