Βοηθήστε μας να κάνουμε καλύτερη την υπηρεσία eJournals. Αν έχετε χρησιμοποιήσει την υπηρεσία eJournals στο παρελθόν και έχετε κάποια εμπειρία ως προς τη χρήση της, παρακαλούμε αφιερώστε ένα λεπτό και συμπληρώστε το σύντομο ερωτηματολόγιο!

Acoustic correction factor estimate for compensating vertical diel migration of small pelagics


Published: Dec 27, 2021
Keywords:
Day-night acoustic comparison small pelagics Mediterranean Sea MEDIAS.
ANGELO BONANNO
https://orcid.org/0000-0002-3868-751X
MARCO BARRA
https://orcid.org/0000-0002-8621-504X
ANDREA DE FELICE
https://orcid.org/0000-0002-5395-6896
MARIANNA GIANNOULAKI
MAGDALENA IGLESIAS
IOLE LEONORI
ANA VENTERO
SALVATORE ARONICA
ILARIA BIAGIOTTI
VJEKOSLAV TIČINA
GIOVANNI CANDUCI
https://orcid.org/0000-0001-7150-7114
SIMONA GENOVESE
Abstract

Differences in acoustic estimates of small pelagic fish biomass, due to data acquisition during daytime and nighttime surveys, have been recognized for many years as a problem in acoustic surveys. In the absence of a single rule for all species and for all locations, some expert groups identified specific time intervals for acoustic data acquisition in relation to the schooling behavior of the target species. In the Mediterranean Sea, the research groups working in the MEDIAS (Mediterranean International Acoustic Survey) agreed on the importance that acoustic sampling are conducted only during day-time. Only when available time does not permit to complete the survey during daytime, data collection might be extended. In this case, working on data collected during both daytime and nighttime, a bias may occur in the biomass estimates. In order to evaluate and correct such bias, specific experiments were performed in some geographical sub-areas of the Mediterranean Sea. The data analysis allowed the estimation of a mean correction factor for the Strait of Sicily, where five surveys were carried out in different years. The correction factor was estimated also for the Adriatic Sea, Tyrrhenian Sea and Northern Spain; the observed variability among areas highlighted the importance of the spatial and temporal coverage of the survey area in order to obtain reliable estimates of the correction factor. Further studies are necessary to improve the interpretation of the obtained estimates in relation to area-related peculiarities such as zooplankton composition and abundance along with small pelagic fish community structure.

 

Article Details
  • Section
  • Special Issue MEDIAS
Downloads
Download data is not yet available.
Most read articles by the same author(s)