Background:

The ocean’s chemistry is changing, observations show decreasing concentrations of oxygen and pH and carbonate ions (so called ocean acidification) all over the world ocean. Ocean acidification is a result of the oceanic uptake of human-induced CO2 from the atmosphere, which has occurred over unprecedented rate, resulting in a shift in the ocean’s carbonate chemistry. Experiments have shown that some organisms suffer at low pH, high-CO2 concentrations thus ocean acidification is likely to have a negative effect on ocean ecosystems. Since 2017, the EAF Nansen Program, included studies of ocean acidification as part of their measuring program thus installation of instrumentation for measurements of seawater pH (spectrophotometer) and total alkalinity (potentiometric titration)were installed onboard the Dr Fridtjof Nansen (DFN). When two parameters are measured all the other variables in the carbonate system can be calculated. Since 2017, there were a number of cruises, where measurements of ocean acidification went parallel to the education of expertise at IMR and in partner countries in African region as well as in the Indian Ocean.

Objectives:

The primary goal is to train participants to determine seawater for pH and total alkalinity onboard DFN. In addition, there will be short introduction to ocean acidification and how it is studied. The focus of the course is methodology to study and measure the chemical change of the ocean.

The course consists of a theory part describing what ocean acidification is, how to measure it, and what the effects may be OA. Following the theory part of the programme, practical work will be undertaken, including:

• sampling seawater for analysis of carbonate chemistry;
• performing seawater measurements of pH and using a spectrophotometer with pH sensitive dye (m-cresol purple) and total alkalinity (AT) by potentiometric titration with 0.1 N hydrochloric acid in an open cell;
• post processing of pH and AT data including correction, precision and accuracy calculations;
• based on pH and AT, derive other carbonate system variables

Expected results:

Participants will understand the marine carbonate chemistry, how to measure it, knowledge on cause and effects of ocean acidification. Participants will be familiar and use the analytical techniques applied onboard DFN for measurements of pH and AT using hands-on measurements of state-of-the-art instrumentation onboard DFN. Participants will know how to calculation of carbonate system variables and will obtain necessary excel files and literature about ocean acidification

A survey of the resources of ecosystems of south east Africa was carried out by the RV Dr. Fridtjof Nansen from 20 January to 18 April 2018, covering the east coast of South Africa, Mozambique and Tanzania1. The survey was multidisciplinary and addressed research questions relevant to all the EAF-Nansen science themes, with different emphasis according to national priorities. Survey objectives were related to:

• Fish resources (demersal and pelagic) status, distribution, early life stages,
• Resource connectivity
• Abundance, diversity and ecological role of jellyfish in marine ecosystems of East Africa.
• Presence of microplastics and marine debris
• Heavy metal contamination of deep-water sediments and marine organisms
• Benthic communities
• Vulnerable habitats
• Climate change (baseline conditions for the establishment of long-term environmental monitoring lines).

Meeting objectives:

• Finalize the survey reports
• Discuss follow-up activities, including processing of samples and data collected during the survey
• Discuss possible research projects (in the framework of the EAF-Nansen Science Plan)
• Discuss needs for capacity development and opportunities