Volume backscattering strength samples from demersal aggregations associated with hake (Merluccius productus), cusk-eels, scorpionfish, and houndsharks from the Gulf of California, Mexico.

This dataset contains mean volume backscattering strength (SV, dB re 1 m⁻¹) samples extracted from echograms corresponding to different demersal species aggregations in the Midriff Islands Region and the northern Gulf of California, Mexico. Acoustic data were collected using a SIMRAD EK60 scientific echosounder equipped with split-beam transducers operating at 38 kHz and 120 kHz.
The dataset includes the following columns:
-"Latitude": Geographic latitude of each sample (decimal degrees).
-"Longitude": Geographic longitude of each sample (decimal degrees).
-"Depth": Sample depth (m).
-"Sv038": Volume backscattering strength values at 38 kHz (dB re 1 m⁻¹).
-"Sv120": Volume backscattering strength values at 120 kHz (dB re 1 m⁻¹).
-"Sum_20": Sum of Sv 38 + Sv 120.
-"Dif_20": Difference of Sv 120 - Sv 38.
-"Set_number": Number of fishing set associated to the echogram where Sv values were extracted.
-"Survey": Acoustic-trawl survey code. 
-"Species": Species code.
These combined values (Sum_20 and Dif_20) were derived from composite echograms, which were used to enhance species classification.