Immature Bass Acoustic Stock Surveillance (I-BASS)

Marine Conservation Research Group
Antique illustration of European seabass (Dicentrarchus labrax)

Antique illustration of European seabass (Dicentrarchus labrax)

Funded by the European Maritime and Fisheries Fund (£241,000), the Immature Bass Acoustic Stock Surveillance (I-BASS) project investigates how European bass, Dicentrarchus labrax, use nursery areas through the tagging of juvenile bass and installation of acoustic arrays in three bass nursery areas in the southwest of England.

The research will assess the effectiveness of different nursery areas at protecting immature bass from capture within commercial fisheries, and help to identify habitats or features which are of importance to bass development. The outcomes of this research will provide vital knowledge to support decision-making for the future management of this high value, iconic species.

Recorded numbers of bass in the North Atlantic have fallen dramatically in the past ten years despite heavy restrictions having been put in place for both commercial and recreational fishing practices.

Working with fishermen in north and south Devon, we are looking to track the bass’ movements in order to develop a clearer understanding of their feeding patterns. Liaising with officials and organisations, we hope to use this information to inform local and national policies with the aim of conserving the species for the future.

Working with fishing groups and the Devon & Severn Inshore Fisheries and Conservation Authority (Devon and Severn IFCA), we are looking to tag 150 juvenile fish across the Salcombe, Dart, and Taw and Torridge estuaries. We will also be installing a network of acoustic sensors out at sea which will then be used to construct a picture of each individual’s movements.

By tracking the fish in this way, we hope to identify any hotspots where they congregate regularly so we can examine those habitats and assess why they are proving especially popular. Ultimately, we hope the project will shed light on whether the fish are leaving the legally protected confines of their nurseries and venturing into areas of open fishing.

“Bass is an iconic species that is both economically and ecologically valuable to our coastlines and estuaries. But there has been a recent crash in numbers and it is currently not clear why. By establishing monitoring sites, we can look at what proportion of time the juveniles spend in various habitats such as saltmarsh. We can also examine whether they are moving outside protected nursery areas which would obviously pose a threat to their survival.”

Dr Emma Sheehan, Senior Research Fellow in the University’s Marine Institute and project lead

“Historically, there have been extensive coastal and intertidal developments which have led to the loss of habitats which may have had a negative effect on bass populations. There have been efforts to address this and through this project we will be able to assess whether they are having the desired effect.”

Thomas Stamp, PhD student

The work in the Taw and Torridge estuaries was undertaken in conjunction with the Bass Anglers Sportfishing Society (B.A.S.S) and the Fishing Collective operating out of Appledore Fish Quay. 

The Devon and Severn IFCA has also committed significant officers’ time and money. It hopes the study will help determine whether its current management approach, particularly in and around estuaries, is suitably aligned to the use of these sites by bass and therefore provides the intended protection.

Salcome, Dart, Taw and Torridge estuaries. I-BASS project
The project is working across the Salcombe, Dart, Taw and Torridge estuaries
I-BASS project
Thomas Stamp with fishermen on the Taw and Torridge estuary
I-BASS project
One of the bass that was tagged and released