Electrofishing surveys

Need an electrofishing survey? – call us at +353 61 419477

Fish are a prominent feature of most freshwater systems, and are amongst the most highly protected fauna. Fish surveys are usually required when assessing the implications of developments affecting all types of watercourses (i.e. bridge construction, channel realignment, abstraction, waste water discharges, small hydroelectric schemes, or indeed any type of instream works). Fish surveys are also required for assessments of developments which have the potential to indirectly affect watercourses, for example the streams draining a proposed wind farm site.

We are the leading independent provider of fisheries consultancy and electrofishing survey services in Ireland

Electofishing can also be used to move fish out of the way of works or a development which directly affects their habitats. Fish translocation is the preferred approach here and involves moving fish out of the way prior to works taking place. Fish salvage involves rescuing fish from an aquatic area which has already been impacted on.

This is a typical backpack electrofishing survey – on the Owenboliska River in Co Galway.

Electrofishing is a key survey method used to assess fish stocks in watercourses and provide data to inform both Natura Impact Statements (Habitat Directive Assessments) and Environmental Impact Statements for proposed developments. ECOFACT staff are national fisheries management experts, and provide a range of electrofishing survey services.

Electrofishing (or electrical fishing) is a method for sampling fish, and is one of the most important fisheries surveys tools that is used to assess the value and importance of watercourses, and also to provide baseline fisheries data. Electrofishing involves placing a pair of electrodes (anode and cathode) into the water and passing an electric current through it. The voltage attracts the fish to the anode (electrotaxis), allowing them to be easily collected using a dip net. Output voltage can be altered to reflect different conditions.

Electrofishing is a non-destructive sampling method, and fish are released unharmend after capture and measurement

Fisheries survey 2014
We often find coarse fish, such as these roach, at river sites in the Midlands. These are from the Slate River which a tributary of the River Barrow.
Aquatic ecology survey (1)
We use teams of up to 4 duirng backpack electrofishing surveys.
Adult brown trout captured at one of electrofishing sites on a tributary of the upper River Shannon.
Fisheries survey 2014
Typical electrical fishing surveys using a Smith-Root LR24 backpack.
We also work in Northern Ireland and regularly hold electrofishing permits issued by the Lough's A
We also work in Northern Ireland and regularly hold authorisation permits for electrofishing issued by the Lough’s Agency and DCAL.

Electrical fishing work we undertake follows the Environment Agency ‘Guidelines for Electric Fishing Best Practice‘: R&D Technical Report W2-054/TR’ (EA, 2002).

The methodology followed for lampreys is different that that used for mobile fish such as salmonids and coarse fish. See the following link for information on the methods we use when using electrofishing for juvenile lampreys:-

We maintain range of electrofishing survey gear in-house, including Smith-Root LR-24 back pack units, which are ideal for use in surveying juvenile salmonids (salmon and trout) and lampreys in Irish rivers. All our staff who undertaken electrofishing surveys are full members of of the Institute of Fisheries Management (IFM) and have undertaken relevant safety training courses.

Electrofishing can also be used to assesses the fish populations that occur in the littoral areas of lakes. Larger electrical fishing gear can also be used in lakes, canals and larger rivers. However other methods of fish stock assessment may be more appropriate here. Contact to discuss your requirements at +353 61 419477.

Electrofishing survey for juvenile lampreys within an enclosure.
Electrofishing survey for juvenile lampreys within an enclosure.

Electrofishing permits

We have held numerous electrofishing licences over the past 20 years, and have worked throughout Ireland. Electrofishing licences are issued by the Dept. of Communications, Energy and Natural Resources under Section 14 of the Fisheries (Consolidation) Act (1959). In Northern Ireland, licences are granted by the Loughs Agency (under Sections 69 of the Foyle Fisheries Act (Northern Ireland) 1952 and 70 of the Foyle Fisheries Act 1952) and the Department of Culture, Arts and Leisure (DCAL) (under Section 14 of the Fisheries Act (Northern Ireland) (1966)). We have held numerous licences from these bodies (and their predecessors) going back almost 20 years.  We are the most capable and experienced independent electrical fishing survey team, and fisheries consultants, working in Ireland today.

Timing of electrical fishing surveys

These surveys are normally authorised and undertaken during the period July to September each year. For further information please refer to our ‘Ecology Survey and Mitigation Calendar‘. There are other types of surveys which can be important and can be undertaken outside this survey window, so contact us to discuss your requirements.

Need an electrofishing survey? – call us at +353 61 419477

For further details on electrofishing surveys please contact Dr. William O’Connor at +353 61 419477 or william.oconnor@ecofact.ie.

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