[1] Nelson is particularly interested in the biosystematics of seaweeds/macroalgae of New Zealand, with research on floristics, evolution and phylogeny, as well as ecology, and life history studies of marine algae.

[3] As a child she describes herself as obsessed with rock pools, beginning snorkeling at age 12, and was strongly influenced by Morton and Miller's 1968 book The New Zealand Seashore.

[8] She is also involved in the CARIM (Coastal acidification – rate, impacts and management)[9] research project funded by the Ministry of Business Innovation and Employment.

The project is generating new knowledge on ocean acidification, to enhance protection and management of New Zealand coastal ecosystems.

[17] In the 2008 Queen's Birthday Honours, Nelson was appointed a Member of the New Zealand Order of Merit, for services to the marine environment.

[21] Her Nancy T Burbidge lecture, titled "New perspectives on species recognition and the distribution of non-indigenous marine macroalgae in New Zealand", was given on 13 July 2021 (the 2020 conference was postonied due to the Covid-19 pandemic.