NEMOte BARCODing, project summary

Monitoring biodiversity changes is critical to understand how ecosystems respond to disturbance. This is dependent on effective methods to assess biodiversity and ecological status of ecosystems.

Such methods are particularly valuable for habitats under severe pressure like the Baltic Sea soft-sediments. Monitoring programs for benthic ecosystems rely on macrofauna for evaluation of ecosystem health, but the Baltic’s low macrofauna diversity is problematic for ecological status assessment.

Nematodes are the most abundant and diverse faunal group in the benthos, but due costs necessary for its analysis, its use in monitoring has not been tested despite its potential to resolve difficulties in assessing Baltic benthic ecological status.

Advances in DNA metabarcoding now allow for large-scale analysis of nematode taxon richness, reducing the time and work necessary for its analysis. However, the quality DNA reference databases for species relevant for environmental monitoring, and the retrieval of quantitative data from metabarcoding are important constraints hindering the application of these techniques in monitoring.

Here we aim to address these hinders and use DNA metabarcoding to improve monitoring tools that assess benthic ecological status of the Baltic. We will collaborate with existing monitoring programs to sample nematodes from 50-60 stations ranging from the Bothnian Sea to the Bornholm basin.

We expect to deliver outcomes like:

• An enhancement of DNA reference databases for Baltic nematodes.

• Development of quantitative metrics from nematode sequencing data.

• Investigation of how nematode integration in biotic indices improves the assessment of quality status of Baltic benthos.

• Validation of potential improvements from an ecological and economical perspective. Ultimately, this project will be important to improve how to monitor Baltic benthic ecosystems and help SwAM to assess national and international environmental quality goals.