POSTER SESSION 1
15:30–17:30, Monday, September 14
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
ABSTRACT 1330 | POSTER 85
REMOTE OBSERVATIONS OF BLOOMS OF RED NOCTILUCA SCINTILLANS IN THE NORTH SEA BETWEEN 2000 AND 2025
The North Sea is the site of yearly blooms of red Noctiluca scintillans (RNS), a heterotrophic dinoflagellate that can aggregate at the surface of the ocean in certain conditions, causing harmful algae blooms. Previously, RNS cell counts were sampled several times a week at the Helgoland Roads station, and models have been developed to predict where RNS may spread in the North Sea. To evaluate such models and assess RNS distributions over time in the North Sea region, we analyzed the spectral characteristics of image features captured in medium resolution satellite remote sensing imagery between 2000 and 2025, from which RNS surface scums were inferred and delineated. Large scale surface RNS features were observed from spring to summer, and span from the Belgian coast in the south to the southern Norwegian coast in the north, with some detections in the Skagerrak strait, which largely agrees with previously developed predictive models. However, in some recent years, RNS blooms covered larger than expected areas, sometimes reaching more than >20,000 km² during a single day. Seasonal evolution of RNS cell counts seemed strongly linked to diatom and copepod dynamics at the Helgoland Roads location. Over the 26 years of remote observations, the first appearance of RNS bloom during a year shifted by 0.88 days earlier per year (p<0.05) and climatologies showed that RNS blooms peaked ~5 weeks earlier between 2013-2025 compared to 2000–2012, likely induced by the trend of increasing temperature in the region (+0.0343°C per year from 1982 to 2024).
Madjid Hadjal, University of South Florida, [email protected], https://orcid.org/0009-0006-4212-1865
Brian Barnes, University of South Florida, [email protected], https://orcid.org/0000-0003-0056-3500
Chuanmin Hu, University of South Florida, [email protected], https://orcid.org/0000-0003-3949-6560
Inga Kirstein, Alfred-Wegener-Institut, [email protected], https://orcid.org/0000-0003-2580-2694
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
