| Title | Analysed nutrient data from the Gough Island Relief Voyage on the SA Agulhas II 068, September 2025 |
|---|---|
| Authors |
Mdutyana, Mhlangabezi Mtshali, Thato Vena, Kanyisile Khauleza, Nompofane |
| Publisher | Department of Forestry, Fisheries and the Environment (2026) |
| Contributors |
Contact Person: Mdutyana, Mhlangabezi |
| Abstract | Dissolved inorganic macronutrients nitrate (NO3), nitrite (NO2), silicate (PO4) and phosphate (PO4) in the upper waters of the ocean. The availability of these macronutrients limits and regulates the production of organic matter during photosynthesis. Therefore, phytoplankton uptake of the macronutrients plays a necessary role concerning biogeochemical cycling of carbon around Gough Island and the Southern Ocean. Here we present macronutrients data collected along the upstream, near island and downstream of the Gough Island (39.8 °S, 9.5 °W and 40.8 °S, 10.4 °W) during the yearly logistical voyage of the Department of Forestry, Fisheries and the Environment (DFFE) from the 15 September to 15 October 2025. We sampled 10 stations which were grouped into three categories: upstream stations, near island stations and downstream stations. Seawater samples were analysed for macronutrients concentrations within three months of collection, with detection limits of 0.03 μM for nitrate + nitrite, 0.01 μM for phosphate, 0.02 μM for silicate and 0.01 μM for nitrite, respectively. |
| Methods | Unfiltered seawater samples for macronutrients analysis were collected following a Global Ocean Ship-Based Hydrographic Investigations Program (GO-SHIP) protocol [1, 2]. Macronutrients concentrations were measured using SEAL AA 500, with detection limits of 0.02 μM for nitrate + nitrite, 0.01 μM for phosphate, 0.10 μM for silicate and 0.01 μM for nitrite, respectively. 1. Sloyan BM, Wanninkhof R, Kramp M, Johnson GC, Talley LD, Tanhua T, McDonagh E, Cusack C,O’Rourke E, McGovern E, Katsumata K, Diggs S, Hummon J, Ishii M, Azetsu-Scott K, Boss E, Ansorge I, Perez FF, Mercier H, Williams MJM, Anderson L, Lee JH, Murata A, Kouketsu S, Jeansson E, Hoppema M and Campos E (2019) The Global Ocean Ship-Based Hydrographic Investigations Program (GO-SHIP): A Platform for Integrated Multidisciplinary Ocean Science. Front. Mar. Sci. 6:445.doi: 10.3389/fmars.2019.00445. 2. Becker S, Aoyama M, Woodward EMS, Bakker K, Coverly S, Mahaffey C and Tanhua T (2020) GO-SHIP Repeat Hydrography Nutrient Manual: The Precise and Accurate Determination of Dissolved Inorganic Nutrients in Seawater, Using Continuous Flow Analysis Methods. Front. Mar. Sci. 7:581790. doi: 10.3389/fmars.2020.581790 3. Grasshoff, K. (1976). Methods of seawater analysis. Verlag Chemie, Weinheim and New York. |
| Data | |
| Temporal extent | 15 Sep 2025 – 15 Oct 2025 |
| Geographic extent |
South Atlantic Ocean
North: -37.43 |
| Keywords | Data status: completed , Gough Island Relief , NITRATE , NITRITE , NUTRIENT PROFILES , NUTRIENTS , OCEANS , PHOSPHATE , PHYTOPLANKTON , SILICATE , SOUTH ATLANTIC OCEAN , SOUTHERN OCEAN , textTable , WGS84 |