Cruise report from R/V Argos week 24, 2005

Type: Report
Author: Arne Svensson


An early blue-green algal bloom of Aphanizomenom baltica and Nodularia spumigena was found near the northern and northwest coast of Gotland. Phosphate concentrations in the south and western Baltic Proper remain much higher than normal. Silicate measurements also showed high levels, while nitrate levels were normal. Nutrient concentrations in the Skagerrak and Kattegat were normal. In the Baltic Proper oxygen concentrations below 2 ml/l were found at depths exceeding 70 to 90 metres. Hydrogen sulphide was found in the bottom water in the Hanö Bight and the Bornholm Basin and also in the bottom waters exceeding 220 metres east of Gotland and 150 metres in the bottom waters west of Gotland.