Status of activities and outcomes in the MEESO project's work package 4 from 1 March 2021 to 31 August 2022.
Summary
MEESO has collated data from all major areas of the North Atlantic to assess the current state of mesopelagic communities with the focus on potential fishing areas and use of mesopelagic resources in the human food chain.
Within the first reporting period the focus was on collecting field data on abundance, spatial distribution, oceanography, and biology of mesopelagics using scientific cruises and fishing vessels. Now, during mid time of the project, regional maps of acoustic abundance have been assembled in several study sites across the N -Atlantic.
Maps of fish biomass distribution and fish abundances in N-Atlantic based on trawl catches have partly been assembled or are being developed.
Highlights
- Based on various field campaigns, assembled regional maps of acoustic abundance (NASC values) of the mesopelagic layers along cruise transect in large areas of the N-Atlantic have been produced.
- A template and manual for pre-processing and semi-automated acoustic identification of Maurolicus has been produced.
- Maps of biomass distribution of main fish components in N-Atlantic based on trawl catches have partly been produced or are being developed.
- Acoustic biomass of a key species Maurolicus has been estimated in BoB.
- Biology of Maurolicus and Benthosema from three study regions have been analysed to determine key population attributes, such as maturity ogive, sex ratio, growth parameters and fecundity.
- Analysis of food web interactions of organisms in Irminger Sea, Iceland basin and on mid Atlantic Ridge/Azor are ongoing using comprehensive stable isotope analysis (SIA) of all main components of the mesopelagic layers.
- Data of abundance and size spectra of marine snow is being evaluated with models to estimate passive flux for assessment of passive versus active carbon flux.