On 5 February 2025,  approximately 240 scientists, environmental consultants, and authorities attended the Danish Freshwater Symposium at VINGSTED Hotel in Denmark, where findings and experiences related to FERRO project Work Package 7 (WP7) — using sonar scans to identify areas of interest for in-lake phosphorus management — were presented.

This research forms part of a long-term monitoring of Lake Ormstrup (2020–2025, the University of Southern Denmark), where in 2024, significant quantities of surface sediments were dredged using novel, less invasive dredging technologies to remove legacy phosphorus. In alignment with WP7 objectives, multiple sonar analyses were conducted before and after dredging to assess its efficiency in sediment removal and its impact on submerged macrophyte coverage, greenhouse gas dynamics, and water quality.

Given that many Danish lakes face similar ecological challenges, the sediment dredging and sonar methodology tested at Lake Ormstrup has garnered significant interest from the Danish Environmental Protection Agency, municipalities, and environmental consultancies. Post-dredging sonar analyses have demonstrated the method’s value in identifying areas and processes that should be optimised in dredger design. These insights can contribute to improving lake restoration efforts in other nutrient-polluted lakes worldwide.

During the symposium's  1.5-hour poster session, findings were visually displayed on a poster and communicated through a presentation and discussion led by Emma Polauke. 

FERRO project representatives from WP7 attending the Freshwater Symposium included Emma Polauke, Jonas Stage Sø, and Theis Kragh.