A Samoan environmental organisation, O le Siosiomaga, says Pacific Nations must reject flawed solutions to climate change.
The research vessel, Polarstern, is on its way to the Scotia Sea to begin a large scale ocean fertilisation experiment.
That will see iron added to the ocean to cause large algal blooms absorbing carbon dioxide as they grow, and is seen as a possible solution to global warming.
But the organisation's executive director, Fiu Elisara, says it defies an United Nations agreement.
"Germany and India are contravening a global moratorium that was agreed in a convention held in Bonn last year. That meeting was very concerned about the impact of ocean fertilisation, especially if it's promoted as a quick-fix solution to climate change."
Fiu Elisara adds no proper impact assessment has been made.
Germany's environment minister, Sigmar Gabriel, has called for a halt of the project, but the Helmholtz Research Institute in Germany maintains the experiment is safe.