Jonas Patrik Fredriksson, Karl Attard, Christian Stranne, Inga Monika Koszalka, Ronnie N. Glud, Thorbjørn Joest Andersen, Christoph Humborg, Volker Brüchert
{"title":"Hidden seafloor hypoxia in coastal waters","authors":"Jonas Patrik Fredriksson, Karl Attard, Christian Stranne, Inga Monika Koszalka, Ronnie N. Glud, Thorbjørn Joest Andersen, Christoph Humborg, Volker Brüchert","doi":"10.1002/lno.12607","DOIUrl":null,"url":null,"abstract":"The expansion of transient and permanent coastal benthic anoxia is one of the most severe problems for the coastal ocean globally. We report frequent, hidden hypoxia in the bottom 5 cm of the water column of a coastal site in the central Baltic Sea by continuous high‐resolution profiling of oxygen (O<jats:sub>2</jats:sub>) directly above the sediment surface. This hypoxia stood in stark contrast to 30‐yr O<jats:sub>2</jats:sub> monitoring records at this site that suggest apparent continuous well‐oxygenated conditions. In situ measurements showed highly dynamic conditions in the bottom 30 cm recording frequent gradual and abrupt changes between normoxic (> 63 <jats:italic>μ</jats:italic>mol L<jats:sup>−1</jats:sup>) and hypoxic (< 63 <jats:italic>μ</jats:italic>mol L<jats:sup>−1</jats:sup>) conditions that would remain undetectable by conventional bottom water O<jats:sub>2</jats:sub> monitoring. The temporal variability of these “hidden” hypoxia is tied to the dynamic current field and to changes in O<jats:sub>2</jats:sub> consumption following resuspension events. Our observations suggest that transient benthic hypoxia is much more common than routine monitoring data indicate.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"31 1","pages":""},"PeriodicalIF":3.8000,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Limnology and Oceanography","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1002/lno.12607","RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"LIMNOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
The expansion of transient and permanent coastal benthic anoxia is one of the most severe problems for the coastal ocean globally. We report frequent, hidden hypoxia in the bottom 5 cm of the water column of a coastal site in the central Baltic Sea by continuous high‐resolution profiling of oxygen (O2) directly above the sediment surface. This hypoxia stood in stark contrast to 30‐yr O2 monitoring records at this site that suggest apparent continuous well‐oxygenated conditions. In situ measurements showed highly dynamic conditions in the bottom 30 cm recording frequent gradual and abrupt changes between normoxic (> 63 μmol L−1) and hypoxic (< 63 μmol L−1) conditions that would remain undetectable by conventional bottom water O2 monitoring. The temporal variability of these “hidden” hypoxia is tied to the dynamic current field and to changes in O2 consumption following resuspension events. Our observations suggest that transient benthic hypoxia is much more common than routine monitoring data indicate.
期刊介绍:
Limnology and Oceanography (L&O; print ISSN 0024-3590, online ISSN 1939-5590) publishes original articles, including scholarly reviews, about all aspects of limnology and oceanography. The journal''s unifying theme is the understanding of aquatic systems. Submissions are judged on the originality of their data, interpretations, and ideas, and on the degree to which they can be generalized beyond the particular aquatic system examined. Laboratory and modeling studies must demonstrate relevance to field environments; typically this means that they are bolstered by substantial "real-world" data. Few purely theoretical or purely empirical papers are accepted for review.