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A pioneering approach for reducing unwanted bycatch and discards

A pioneering approach for reducing unwanted bycatch and discards

Skippers fishing on the west coast of Scotland are using an innovative by-catch avoidance tool, BATmap, to reduce catches of unwanted species, and to improve catch efficiency.

Skippers fishing on the west coast of Scotland are using an innovative by-catch avoidance tool, BATmap, to reduce catches of unwanted species, and to improve catch efficiency.

BATmap is an award-winning collaboration between Scottish skippers, producer organisations and scientists that develops and deploys state-of-the-art technology to avoid unwanted catches.

Skippers on the west coast of Scotland are now using a bespoke software system to record hauls of these unwanted species in ‘real-time’. If catches are higher than an agreed threshold, an automatic alert is triggered informing other participating vessels so they can avoid these areas.

What's the problem?

A mixed fishery exists where different species mingle on the fishing grounds, making it difficult to target one species without catching others. In the west of Scotland mixed fishery a single haul typically contains a mix of species including cod, haddock, hake, spurdog, skates, and whiting. 

The EU Common Fisheries Policy and now the UK Fisheries Act 2020 aim to eliminate discarding of fish at sea through policies such as the Landing Obligation, where all quota-managed fish caught must be brought to shore. 

The Landing Obligation can result in a phenomenon known as ‘choking’ whereby vessels have to stop fishing when the most limiting quota is caught, thus ‘choking’ or closing the fishery prematurely. In the west of Scotland fishery, cod potentially acts as a ‘choke’ species. 

These policies incentivise EU and Scottish skippers to avoid encountering ‘choke’ species in the first place through better gear and spatial selectivity.

Using real-time reporting to avoid unwanted catches

Real-time reporting is the rapid, semi-automated collation, processing and dissemination of catch data to improve decision-making at sea. Developed by the fishing industry in Alaska in the mid-1990s, it has been successfully used to meet strict Federal limits on salmon by-catch for over two decades. 

In Alaska, a ‘cooperative’ of fishing vessels share information with each other via automated software. Vessels report their catches of  chum and chinook salmon shortly after each haul comes onboard. If the catch is above an agreed threshold an alert is triggered and automatically sent to all participating vessels. 

This real-time information enables Alaskan skippers to avoid fishing in areas where salmon by-catch is high thereby complying with Federal legislation. It is also used by the cooperatives to designate temporary area closures (known as “rolling hotspots”) when high catch rates of salmon are recorded in that area. Skippers avoid fishing in those areas while closures are in place.

What is BATmap?

BATmap, or By-catch Avoidance Tool using mapping, is an app for Scottish skippers to share real-time information about the location of hotspots of fish species that are choke species or of conservation interest with other participating skippers.


BATmap collects data from participating vessels. Position data is automatically reported via a satellite network, and catch data is collected from the mobile app.

Skippers report the start and end time of a haul, the location, and the total catch of cod and spurdog.


If the catch of a given species exceeds a set threshold, an alert is sent to all participating vessels.

The alerts are displayed on a map showing the time and location of the catch and the amount of by-catch.  


The real-time data allows skippers to make informed decisions about where to fish and provide information that can improve spatial avoidance of cod and spurdog by-catch. 

A co-designed, ‘bottom up’ approach

The involvement of Scottish skippers in BATmap is key, and this innovative approach would not work without their buy-in or expertise. They have been involved in the design of BATmap from the outset.

The inclusion of spurdog illustrates the benefits and flexibility of this co-design process. They are a protected species that cause significant by-catch issues in some west of Scotland fisheries at certain times of the year. Skippers recognised that BATmap could let them share information about local hotspots of spurdog thereby improving spatial avoidance of the species. 

Any Scottish skipper fishing for whitefish or Nephrops on the west of Scotland can use BATmap providing they agree to contribute data. This bottom-up approach will put data into the hands of skippers to help them make more informed decisions at sea.

An industry-led, cooperative solution

BATmap’s cooperative approach reflects the fishing industry’s shared commitment to avoiding by-catch. The project is a first for the UK and Europe, and is a great example of innovative collaboration between industry and science. 

BATmap is working with fisheries experts worldwide to develop a system that works for Scottish fisheries. Our experience using BATmap on the west coast of Scotland is being used to inform the development of real-time reporting elsewhere.

About the App

BATmap is a web-based app that can be used on phones (iOS and Android), tablets and desktops. Skippers use the app to log the start and end time of a haul, and the total catch of cod, whiting, haddock, hake, skates, and spurdog.

Catches and alerts are displayed on a map as a series of ‘hexbins’. These hexbins are graded in colour to help visualise areas of low by-catch and areas of high by-catch. 

The map has a number of functions that allows skippers to view catch and alert information in a range of different ways. They can control the following elements:

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More information

Frequently Asked Questions about BATmap

How secure is the data and who is it shared with? What information is being shared? How is a vessel’s position recorded? How do I download the app and start using it? Read our FAQ for the answers to these and other questions. 

BATmap: user guide and instructions

How do I enter the details of a new catch? What information can I find out about each catch? Read the BATmap user guide and instructions. 

BATmap pilot project report

“Design, development and deployment of a software platform for real-time reporting in the West of Scotland demersal fleet”
Read our report on the findings on the initial pilot project here.

Our partners

BATmap brings together the Scottish fishing industry and a Scottish university in a unique collaboration. The pilot project was funded and led by the Scottish Fishermen’s Organisation (SFO), the University of Aberdeen, and Fisheries Innovation Scotland (FIS), with additional support from the Scottish White Fish Producers Association, and Seafish.

Funding for further development has been provided by Seafish, Scottish Fishermen’s Trust and The Fishmongers’ Company’s Fisheries Charitable Trust.

Aberdeen Fish Producers Organisation, North East of Scotland Fishermen’s Organisation and Orkney Fish Producers Organisation are project partners and funders, with contributions from the Scottish Association of Fish Producer Organisations

Chordata LLC, an IT company based in Juneau, Alaska, developed the software.