Phytoplankton blooms in the new Southern Ocean sea-ice regime
Bibliographic Data
| ID | 19568625 |
|---|---|
| Authors | Tamara L Schlosser (0000-0001-7779-7255), Peter G Strutton (0000-0002-2395-9471) |
| Year | 2025 |
| Volume | 13 |
| Issue | 1 |
| Publication date | 2025-09-12 |
| Peer Reviewed | Yes |
| Open Access | Yes |
| Type | ARTICLE |
| Venue | Elementa Science of the Anthropocene (JOURNAL) |
| Journal identifiers | ISSN: 2325-1026 • E-ISSN: 2325-1026 |
| Publisher | University of California Press (PUBLISHER • US) |
| DOI | 10.1525/elementa.2024.00055 |
| Language | EN |
| References cited | 69 |
Over the last decade, record highs and lows have been recorded for Antarctic sea-ice extent (SIE). The anomalous low in 2023 suggested a new reduced sea-ice state, with unknown impacts on phytoplankton blooms, including phenology and magnitude. Analysing both Biogeochemical (BGC) and Core Argo floats, we compared annual SIE anomalies and sea-ice volume to physical and biological variables over this reduced sea-ice period (2013–2023). We focused on average winter and summer variability over the circumpolar Southern Ocean and 5 subregions, and over 5° × 2° longitude and latitude bins. Over the seasonal ice zone, anomalously low sea ice led to warmer and saltier surface waters, deeper mixing layers and thermocline depths, and weaker upper ocean stratification due to weaker vertical salinity gradients. These relationships between sea ice and observed variability were generally strongest in the Indian sector and the eastern part of the Atlantic, and weakest in the Pacific sector and Weddell Sea. Low SIE years typically had shorter phytoplankton blooms with less average summer biomass than high SIE years. However, the anomalously low SIE in 2023 led to longer blooms with large total biomass, among large spatial variability in bloom metrics. The sea-ice conditions in 2023 were unique in that even winter SIE decreased significantly, increasing surface ocean exposure at more southern regions and allowing a longer productive period than would typically be possible. Whether a warmer and more ice-free Southern Ocean can continue to support longer and more productive blooms among other controls on phytoplankton growth (e.g., nutrient availability, grazing) remains an open question. These results were sensitive to float spatial distributions and density of sampling, highlighting the need for a persistent and widespread BGC-Argo network in the Southern Ocean to enable adequate monitoring of change in this critical environment
Seasonality of phytoplankton growth limitation by iron and manganese in subantarctic waters
Iron in sea ice
Microalgal community structure and primary production in Arctic and Antarctic sea ice
Climate change impacts on sea-ice ecosystems and associated ecosystem services
Diverse impacts of sea ice and ice shelf melting on phytoplankton communities in the Cosmonaut Sea, East Antarctica
| Citation velocity | historical |
|---|---|
| Highly cited | No |