Passive Tracking

Capture data on tagged fish using grids of independent acoustic receivers.

When can you benefit from passive tracking?

This setup is based on strategically placed independent receivers, supporting monitoring of tagged animals in a variety of aquatic systems. Passive tracking lets you collect data with minimal disturbance to your study area. The long battery life of our units allows for little maintenance and are perfect for long term studies.

Key Advantages

Advanced signal processing for better data

For robust data collection in noisy environments.

Open protocols

Collaborate with fellow researchers worldwide using equipment supporting interoperability.

Multifrequency for more data

Spread your tags out on up to three frequencies to mitigate signal collisions in areas where your tagged animals accumulate.

Receivers with 2 years battery life

Spend less time changing batteries with up to 2 years battery life on one battery.

Storage capacity of 3 million detections

Worry less about full memory with large storage capacity.

Flexible and user friendly design

The robust nature, small size and modular design of our receivers allow for deployment in a variety of aquatic environments.

Mooring recovery and reuse

Ensure minimal ecological disruption with our mooring recovery solution. Leave the seabed clean from disposable parts.

Remote mountain lake with illustrated acoustic waves as orange circles

Simple and unobtrusive deployment

Receivers are placed in strategic locations, adapted to current conditions, habitat, and research objectives. Once deployed, they operate independently for extended periods and require minimal maintenance. The setup can be adjusted based on species and terrain.

How it works

The system captures underwater movement through acoustic signals. By combining transmitters and receivers, it creates a reliable foundation for tracking and analysis in aquatic environments.

Signal range in your environment

Are you conducting your first telemetry study, or are you planning a project in a new area? We always recommend performing a range test to familiarize yourself with the local environmental conditions and understand how they affect signal strength.

Fish are tagged with transmitters

Fish are tagged with small acoustic transmitters that emit uniquely coded ID signals. Sizes range from 6 to 16 mm in diameter, with optional sensors for depth, temperature, activity or mortality. Each tag is configured for the species and study duration.

Receivers log detections

Receivers are placed at key locations to detect passing tagged fish. They log tag ID, timestamp, and signal strength with high time-sync accuracy. Typical detection range is up to 800 meters.

Retrieving and analyzing data

Data is downloaded via Bluetooth after deployment. The logs reveal movement patterns, presence, and environmental conditions. Arrays of receivers can enable precise 2D or 3D tracking.

Configured to your study

Every study is different. Configure your system with the sensor types, receiver layout, and deployment method that fit your goals and environment.

Transmitter sensor options

Choose between transmitters with only ID, or add sensors for depth, temperature, activity or mortality. Each transmitter is programmed to match species size, battery life needs, and sampling intervals.

Deployment setup and receives

Deploy a single receiver for presence/absence, or scale up to a full array for positioning. Combine with mooring systems or release brackets for reliable placement and retrieval—even in remote or deep-water environments.

Specifications

Specification	Value	Remark
Output options	ID, temperatur, depth, activity and mortality	Depends on your study goal
Transmitter size	6, 7, 9, 13 or 16 mm in diameter	Depends on species, size of individual and battery needs
Receiver model	TBR-800 (standard, release & deep release)	The modular design allows for flexibility in receiver setup
Deployment accessories	Mooring recovery system or tailored buoys, DeckBox field kit, Focus kit	Optional; for deep or remote use

Get Started

From first questions to final analysis, we help you build a setup that fits your goals, timeline, and study species.

Define your study

Clarify the objectives, species, and environment. We assist in matching these needs with the right tools and approach.

Design your configuration

Select the number of receivers, tag types, and deployment layout. Our support team brings research experience to help you plan an effective and realistic setup.

Get support throughout

We support you from planning to data retrieval. Whether you're experienced or just starting out, our team is here to help.

Examples of Use

Explore how Thelma Biotel acoustic receivers and transmitters have been used for passive tracking by other researchers.

Customer Stories

Aquatic Animal Tracking

Investigating the Aquatic Ecosystems in the Chic-Choc Mountains

Read

Related Components

Cover the full data gathering process using Thelma Biotel transmitters, receivers and software, tailored to your study.

Configurable 6 - 16 mm Transmitters

Thelma Biotel transmitters are energy-efficient and versatile, designed for studies of aquatic species and underwater equipment. They come in five sizes: 6, 7, 9, 13, and 16 (based on diameter in mm). They can be tailored in length, power output, and battery life to fit your needs. They are used in wildlife tracking, aquaculture monitoring, and equipment monitoring. Whether you need an off-the-shelf solution or a tailor-made design, our transmitters can be configured for your exact requirements.

TBR 800

The TBR 800 is a robust, low-power digital acoustic receiver operating at 63–77 kHz. Used with Thelma Biotel transmitters, it supports customizable code sets. Paired with the DeckBox, it can send status updates on battery and power use.

TBR 800 Release

TBR 800 Release is a robust, low-power digital acoustic receiver operating at 63–77 kHz. Used with Thelma Biotel transmitters, it supports customizable code sets. It features an acoustic release module that can be triggered when paired with the DeckBox

TBR 800 Release Deep

The TBR 800 Release Deep features a motorized release three times stronger than the standard version, ensuring reliable operation under high pressure. The release is triggered acoustically from the DeckBox.

DeckBox Field Kit

The DeckBox is a versatile topside kit for manual logging of acoustic transmitters, retrieving TBR 800 Release units, and performing status checks on deployed equipment. With its rugged, waterproof tablet and our free LiveView software, you get flexible, real-time control and monitoring right in the field.

Mooring Recovery System

The DeckBox is a field kit for manual logging, retrieval, and status checks of TBR 800 units. It includes the TB Live (multi-frequency transceiver), Link BT (Bluetooth logger), and a waterproof tablet with LiveView software. The graphical interface enables easy use in noisy environments without disturbing sounds.

ComPort

Upload, view and analyse your tracking data quickly and easily with Thelma Biotel’s software, ComPort. By using the built in Bluetooth connection on the TBR 800, uploading substantial amounts of data is seamless and fast. With ComPort’s many viewing options, visualizing and understanding your tracking data is easier than ever.

LiveView

LiveView is the Live tracking and data visualization software delivered by Thelma Biotel. It provides live streaming of acoustic data to your computer or with the Deckbox field kit. LiveView is used as a visual reference when starting and stopping transmitters, for active tracking, communicating with deployed TBR family receivers, and calling up acoustic releases.