A blog by ACCELERATE – November 2025
Interim results on benthic communities across the Eastern Irish Sea, comparing habitat and benthic assemblages inside/outside OWF
Lisa Skein (National Oceanography Centre) is leading a report based on a study that characterised benthic biotopes across the Eastern Irish Sea. As future baseline and monitoring surveys will increasingly include autonomous approaches (e.g. Autonomous Underwater Vehicles (AUVs), camera work, AI-based data analysis), this study focused on epibenthic megafauna captured in seabed imagery. After analysing >1300 seabed images collected by the ACCELERATE project, the team found indications that benthic communities, on similar substrata, may be different inside and outside OWFs. Additional images, ideally from multiple OWFs, would help confirm these results. The data were classified into biotopes using the Marine Habitat Classification of Britian and Northern Ireland and combined with a larger biotope dataset, made possible through contributions from ACCELERATE’s industry partners, who similarly used imagery to classify benthic biotopes as part of pre-construction ecological characterisation. The unified datasetis now being used as part of the ACCELERATE work, to model changes in biotope (habitat) distributions following the development of offshore windfarms under a changing climate.
The study highlights the importance of consistency in the collection and analysis of seabed imagery, and of data collected at the relevant spatial and temporal scales. This leads to the following advice on effective and scalable assessment and monitoring of epibenthic communities to strengthen baselines and the ability to detect changes:
- Seabed imagery data from underwater cameras mounted on towed sledges, remotely operated vehicles (ROVs) or AUVs provide direct visual evidence of seafloor habitats, including information on substrata and resident biological communities. These images reflect some of the biotic and abiotic features that influence ecosystem processes, like sediment grain size and stabilisation, bioturbation and organic matter deposition. To understand how these features and the processes change inside windfarms, seabed images are best collected both within and outside of an operational windfarm at comparable substrata and depths, both before and after windfarm construction. We advocate for researchers to have access to such monitoring datasets to support more strategic, data-driven decisions on monitoring, impact assessment, and marine spatial planning.
- Consistency and comparability in seabed imagery between different studies, regions, and time periods will impact scalability of results that are needed for strategic and adaptive decision making. This depends on imagery acquisition, analysis, annotation, and data flows, including archiving and sharing in accessible standards. Data acquisitionplatforms and camera settings are best not too dissimilar, and analysis of seabed imagery will be more robust via collaboration across academia and industry, with stronger datasets as a result. This is also an important step towards Machine Learning algorithms trained on high-quality datasets that can significantly speed up analysis in the near future. These recommendations are in line with the Benthic Imagery Action Plan from The Big Picture initiative led by the Joint Nature Conservation Committee.
- Marine benthic habitats and ecological communities in the Eastern Irish Sea are heterogeneous, where communities vary over multiple spatial scales linked to burrows over several centimetres to gradients in hydrodynamics over multiple kilometres, within or outside windfarms. The design of seabed imagery acquisition surveys must therefore explicitly account for the scale of ecological variability driven by physical environmental properties and processes, ensuring representation of communities from different environmental niches (e.g. substratum type and depth). Benthic communities and processes also vary over temporal scales, from diurnal to seasonal, to windfarm operational lifetime and climate change. Whilst not all temporal scales can be covered in a monitoring framework, the design must be tuned to the important drivers of expected ecological change. The temporal design of seabed imagery surveys can be adaptive as systems stabilise at different rates, but we can’t monitor the future seabed. The ACCELERATE team are therefore using imagery and biotope datasets alongside high-resolution environmental data to develop predictive models that can estimate future changes in the distribution of habitats, biodiversity and the ecosystem services under scenarios of offshore windfarm expansion and forecasted climate change.
