Martin Collins

Cefas

Tristan Da Cunha and St Helena

39 days

(March & April)

Protecting the biodiversity of the UK South Atlantic islands

St Helena and Tristan da Cunha form part of the UK Overseas Territory of St Helena, Tristan da Cunha and Ascension Island.  The EEZs of St Helena and Tristan da Cunha account for around 1.25 million square kilometres of the South Atlantic Ocean. These regions are home to important biodiversity, but also play an important role in the economy and culture of the island communities.

Discovery 100 will be split between the EEZs of Tristan da Cunha and St Helena EEZs (22 science days, 11 in each territory), each with a suite of survey objectives relevant to fisheries and marine biodiversity in each territory. The Tristan da Cunha leg of the survey will focus upon the biodiversity and habitats associated with the seamounts in the centre of the EEZ (the main area for demersal fishing). The St Helena leg will focus upon pelagic ecosystems, with a view to improving the understanding of pelagic food webs that underpin tuna fisheries around St Helena and Cardno Seamount in the north of the EEZ.

The cruise will consist of the following:

1. Mapping the seamount habitats of the RSA and McNish seamounts in the Tristan EEZ;
2. Investigating the biodiversity and productivity of the Tristan seamounts using acoustics, nets, cameras and a small benthic sledge;
3. Investigating the impacts of demersal fishing on the benthic communities of the seamounts;
4. Mapping the Cardno Seamount and the area around St Helena;
5. Investigating the biodiversity and productivity of the St Helena area and the Cardno Seamounts using acoustics, nets, cameras and a small benthic sledge;
6. Deploying acoustic receivers as part of an array to track tuna and whale sharks.

Discovery 100 is funded by a combination of the UK Overseas Territories Blue Belt Programme (Cefas) and UK Overseas Development Assistance (British Antarctic Survey).  Scientists from BAS and Cefas will be supported by colleagues from the Natural History Museum, Plymouth University, RSPB, Stanford University and will include active participation from scientists from both Tristan and St Helena.

The EEZs of St Helena and Tristan are poorly sampled and samples collected during the cruise will contribute to a range of research projects and many specimens will lodged at the Natural History Museum in London.

Follow the cruise on Twitter

Further information can be found here and here