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Explained by Offshore Sensing: Acoustic data in fisheries: meaning, types, and examples

Written by Author | March 24, 2026

Quick answer: Acoustic data in fisheries is the recorded output from instruments like a scientific echosounder: transmitted pings, received echoes, and metadata (time, position, settings). It’s used to estimate fish and biomass distribution by analyzing backscatter strength across depth and along survey routes, then converting it into indicators, maps, and full-resolution datasets for later processing.

Key facts

Data type What it contains Typical use
Raw / full-resolution acoustic data High-detail ping-by-ping records Post-processing, QA, reporting
Reduced “indicators” Summaries (depth bins, time windows) Live monitoring, quick decisions
Echogram (visual) Display of backscatter vs depth/time Interpretation and quality checks
Metadata Position, time, settings, platform state Traceability and correct processing

What “acoustic data” actually is

Acoustic data is not a single file type—it’s a family of records that together describe what was transmitted, what was received, and under what conditions.

At minimum, fisheries acoustic data includes:

  • Timestamped ping records
  • Backscatter strength values across depth ranges
  • Platform metadata (GNSS position, speed, heading)
  • System configuration (frequency, power, pulse settings)

Common types of acoustic data in fisheries

1) Full-resolution (raw) data

This is the most detailed record. It’s larger, but it supports:

  • Reprocessing with different settings
  • Noise removal and quality control
  • Traceability for reporting

2) Live indicators

These are compressed summaries that can be transmitted during a mission (e.g., over Iridium) and used for operational steering:

  • Density indicators per depth band
  • Along-track summaries per km
  • Trend metrics over time windows

3) Derived products

These are processed outputs:

  • Maps/grids of backscatter
  • Transect comparisons over time
  • Layer statistics (e.g., “scattering layer depth”)

Examples operators recognize

  • “A strong layer at 80–120 m depth”
  • “Higher backscatter on the eastern leg than the western leg”
  • “Density increased after sunset”
  • “Patchy distribution—clusters separated by low-return gaps”

These are interpretations of patterns in the echogram and derived metrics.

Where acoustic data fits in an end-to-end workflow

  1. Plan routes (transects, grids)
  2. Collect acoustic data while logging platform metadata
  3. Produce live indicators for situational awareness (optional)
  4. Recover and analyze full-resolution dataset for reporting
  5. Archive for comparison across seasons and years

FAQ

Is acoustic data the same as an echogram?

An echogram is a visualization made from acoustic data. The data itself is the underlying record.

Why keep full-resolution data if indicators exist?

Indicators are great for steering a mission. Full-resolution is needed for defensible analysis and reprocessing.

Can acoustic data be collected from a USV?

Yes—provided the platform can hold stable operation, log metadata, and manage power/data handling for long missions.