Concept Note

Concept Note

Research on mesopelagic communities has been included in the EAF-Nansen Science Plan as part of a dedicated theme (Theme 3) due to the increasing awareness of their ecological role and potential for sustained harvest.

Recent acoustic studies suggest substantial mesopelagic biomasses (10 billion tons or more) in the world’s subtropical and tropical oceans (between 40 ̊ S and 40 ̊ N), which is an order of magnitude higher than the previous global estimate based primarily on net and trawl sampling, triggering considerable international efforts towards research and harvest of these resources.

Dedicated surveys with the R/V Dr. Fridtjof Nansen were carried out in 2017 and in 2018 in the Atlantic and Indian Oceans to collect acoustic data, obtain biological samples, and carry out experimental work with the overall objective of developing survey methodology and increasing the knowledge on abundance and ecology of this poorly known community. Mesopelagic transects, from shallow productive waters to offshore oligotrophic waters, were carried out off Morocco and Namibia in contrasting conditions in terms of overall productivity, while oceanic spatial distribution across oceanographic gradients and structures were investigated off Tanzania, in the central Indian Ocean and in the Bay of Bengal.

The upcoming meeting aims to:

• review data and samples collected so far and identify gaps;
• establish protocols for mesopelagic surveying and sample/ data collection
• as part of Theme 3, review the status of proposed research tasks
• Inform on status of the production of the mesopelagic fish guide, including the production of a species guide
• provide inputs for planned future survey work on mesopelagic fishes (with special emphasis on the 2019 and 2020 survey plans)
• review draft survey reports for finalization