On March 10, 2026, the IOW project BenthQual started its active research phase with the first sampling. Its goal is to genetically catalogue all known macrozoobenthic organisms of the Baltic Sea and to advance molecular biological monitoring methods for this animal group. The project, which officially started on December 1, 2025, is funded by the Federal Agency for Nature Conservation (BfN) and will run until the end of November 2030.

Macrozoobenthic organisms – that is, animals visible to the naked eye that live in or on the seafloor – are important indicators of marine ecosystem health. Changes in their communities are early warning signs of environmental changes. The BenthQual project (short for “Benthos quality assurance – Further development of monitoring principles and methodological standards for benthic species and habitats”), which has now been launched at the IOW, focuses on how the biological diversity of this group can be assessed more precisely and efficiently for the Baltic Sea in the future, and causing less harm through sampling.

A key component of the project is the creation of a comprehensive genetic reference library for the Baltic Sea macrozoobenthos. BenthQual uses the so-called COI gene for this purpose, a DNA segment in the mitochondria that is present in nearly all animals. This gene is particularly well-suited for the unambiguous species identification, as it varies very little within any given species but significantly between them. Even developmental stages that are difficult to identify, such as eggs or larvae, can be reliably assigned to a specific species by this method. The BenthQual genetic reference library is ultimately intended to encompass all known Baltic Sea species – including non-native neozoans.

At the same time, a technique known as metabarcoding is being tested as an innovative molecular biology monitoring method for the Baltic Sea. This involves simultaneously analysing the entire DNA from environmental samples – such as water or sediment. The result is a kind of genetic inventory of all the organisms present in the sample, which can then be assigned to specific species by using reference databases. This approach makes it possible to identify even rare or previously hard-to-detect species – with significantly less disruption to habitats than using traditional benthological methods.

The project is carried out by the IOW’s “Ecology of Benthic Organisms” working group, led by Michael Zettler. The scientific and operational work of BenthQual is largely in the hands of Katharina Kniesz, who, as project coordinator, organizes and conducts the sampling. The IOW researcher, who combines classical benthic ecology with expertise in the latest molecular biological biodiversity research, is also responsible for advancing the methodological aspects of the project. Kniesz plans to collect samples from the shore and during research cruises in various regions of the Baltic Sea about five times a year. She will analyze these samples using both traditional morphological and genetic methods; the results will be directly incorporated into the reference library and used to evaluate new monitoring approaches.

In the long term, BenthQual aims at fundamentally modernizing benthic monitoring and thereby improving the foundations for marine habitat protection and sustainable Baltic Sea management.