MEPS 551:31-44 (2016)  -  DOI: https://doi.org/10.3354/meps11712

Acoustic detection of larval fish aggregations in Galician waters (NW Spain)

Eva García-Seoane1,6,*, Gustavo Álvarez-Colombo2, Joan Miquel3, José María Rodríguez4, Carlos Guevara-Fletcher5, Paula Álvarez5, Fran Saborido-Rey

1Instituto de Investigaciones Marinas (CSIC), C/Eduardo Cabello 6, 36208 Vigo, Pontevedra, Spain
2Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP), Paseo Victoria Ocampo 1, CC 175, B7602HSA Mar del Plata, Argentina
3Instituto Español de Oceanografía, Centre Oceanogràphic de les Balears (IEO), Moll de Ponent, s/n, PO Box 291, 07080 Palma de Mallorca, Spain
4Instituto Español de Oceanografía, Centro Oceanográfico de Gijón (IEO), Avda. Príncipe de Asturias 70Bis, 33213 Gijón, Asturias, Spain
5AZTI-Tecnalia, Marine Research Division, C/ Herrera Kaia, Portualdeaz.g. 20110 Pasaia, Gipuzkoa, Spain
6Present address: Instituto Português do Mar e Atmosfera (IPMA), Av. Brasília, s/n, 1449-006 Lisboa, Portugal
*Corresponding author:

ABSTRACT: An acoustic study was conducted on the Galician shelf (NW Spain) during late winter 2012 to detect and assess larval fish abundance. An echo sounder operating with 18, 38, 70, 120 and 200 kHz split-beam, hull-mounted transducers was employed. We analysed the acoustic records in order to describe vertical and horizontal distribution patterns of larval fish aggregations. Regressions between acoustic backscattered energy and density of the most abundant species (Micromesistius poutassou) indicated that larvae with a swimbladder incremented notably the acoustic response at 38, 70 and 120 kHz. However, the predicted acoustic resonance at larval size and depth shows that the frequency of 120 kHz was likely ineffective in detecting fish larvae. The contribution of zooplankton (fish larvae excluded) to total scattering was negligible, even at the higher frequencies, except for several groups of fluid-like zooplankton, such as chaetognaths and polychaetes. Horizontal and vertical distributions of acoustic backscattering also indicated that larval fish aggregations can be detected in Galician waters with acoustics and suggest that this technique is a useful tool for overcoming difficulties associated with larval ecology and fish recruitment studies.


KEY WORDS: Acoustics · Fish larvae · Zooplankton · Frequency response · Galician shelf


Full text in pdf format 
Cite this article as: García-Seoane E, Álvarez-Colombo G, Miquel J, Rodríguez JM, Guevara-Fletcher C, Álvarez P, Saborido-Rey F (2016) Acoustic detection of larval fish aggregations in Galician waters (NW Spain). Mar Ecol Prog Ser 551:31-44. https://doi.org/10.3354/meps11712

Export citation
Mail this link - Contents Mailing Lists - RSS
- -