Ethics is usually defined in relation to standards of conduct or as a set of moral principles or moral judgments (between right and wrong). Research is not a purely technical or instrumental activity - it should be a reflective activity with moral underpinnings.
It is important to remember that ethical issues do not only arise during the conduct of research, e.g. when gathering data, but also in its dissemination through publication, academic talks and public engagement. There is both an obligation to share your research but also to consider and mitigate its potential negative impact on audiences if it is controversial or upsetting.