Application of an analytical approach to characterize the target strength of ancillary pelagic fish species.
Antonio Palermino; Andrea De Felice; Giovanni Canduci; Ilaria Biagiotti; Ilaria Costantini; Michele Centurelli; Iole Leonori;
The lack of data on the species-specific Target Strength (TS) on ancillary species limits the application
of acoustic surveys in assessing their abundance and distribution worldwide. The TS values of Scomber
colias and Trachurus mediterraneus in use in the Mediterranean Sea rely on studies conducted on
other species in the Atlantic and Pacific oceans. Nevertheless, the application of backscattering
models offers the possibility to overcome the absence of empirical data handling the parameters
that most affect the TS. X-ray scans were performed on 82 specimens to get digital representations
of the swimbladder and the fish body which were used as input for the application of the Kirchhoff
Ray Mode model to measure the TS as a function of frequency and tilt angle. The morphometric
differences between the two species produced divergent relative frequency responses and broadband
TS patterns. Moreover, comparing the results with one ex-situ experiment, we found a good
agreement considering a mean tilt angle of – 10°, standard deviation = 12°. Our results provide the first
theoretical insights into the use of backscattering models as a tool to distinguish between species in
the Mediterranean Sea by acoustic method, increasing the knowledge of the acoustic reflectivity of
ancillary species.
2023 - Journal article
Scientific reports (Nature Publishing Group) 13 (2023). doi:10.1038/s41598-023-42326-4
Keywords: Animals *Fishes *Acoustics Air Sacs Knowledge Mediterranean Sea Journal information eISSN 2045-2322 Current Publisher NATURE PORTFOLIOHEIDELBERGER PLATZ 3