A group of people in wading boots are electrofishing in a small stream surrounded by lush forest. — Electrofishing in progress! After fishing, you can use the ElReg app and enter catch, electrofishing data, location and impact. Photo: Josefine Karlsson.

The Electrofishing App El-Reg

Page reviewed: 11/02/2026

Have you been electrofishing and want to report your data to SLU? You should do so by using the El-Reg app.

El-Reg is an app for recording and reporting electrofishing data in the field.
Select your location from a map, or create a new location. Go through the steps and upload the data to the Swedish Electrofishing Register (SERS) for review. The data is used in research projects, and much more.

The new app – El-Reg – is an offline-based digital tool for reporting electrofishing data. In the app, users can plan upcoming electrofishing events and record completed ones for reporting to the Swedish Electrofishing Register (SERS). El-Reg is intended to replace the current Excel protocol and streamline the handling of electrofishing data by providing clearer instructions to the operator. An important improvement also takes place behind the scenes, as data from the app are delivered directly to the database without manual handling, which will significantly reduce processing times. At present, the app is only available to a test group, but it will soon be opened to all electrofishing practitioners.

The user selects an existing location or registers a new one from a map in EL-Reg. Then, the user is guided through the data registration, which is divided into five steps:

1. Planning

The user enters information about the electrofishing event, such as its purpose, date, number of fishing sessions, performers, and the client commissioning the fishing.

2. Catch data

The user records the catch per fishing session. In this section, the species is selected, and the length and, if applicable, the weight of each measured individual are reported. Also, 0+/>0+ threshold length fvalues for salmonid fish are recorded here.

3. Electrofishing data

Here, the user records information about how the fishing was carried out. The date, generator model, voltage (V), etc., are also entered here.

4. Feature of the location

Here, the user records all information about the site, such as dimensions (length, width), water level, depth, water velocity, temperature, bottom substrate, surrounding environment, and migration barriers.

Data for research, red lists, and ecological status

Database for fish monitoring in rivers and streams is officially called the Swedish Electrofishing Register (SERS). Data submitted to SERS is used in national evaluations, such as in assessing the ecological status of our watercourses, as well as in the follow-up of fisheries management measures (e.g., liming, the construction of fishways, habitat restoration). Data from the database is also used in research projects and national summaries, such as the SLU Swedish Species Information Centre's Red List.