SUMMER - Sustainable Management of Mesopelagic Resources

Abstract

The mesopelagic layer is one of the least understood ecosystems on Earth. Recent research suggests that the fish biomass in the mesopelagic ecosystem might be 10 times higher than previously thought. However, this estimate is subject to a high degree of uncertainty in the fraction of the community that is fish. The potential high biomass has raised interest in its exploitation. Nevertheless, if the biomass is as high as estimated, mesopelagic fish may play a key role in ecosystem services, such as sustaining other commercially relevant species, and on carbon sequestration. Combining trawls, in situ acoustics and eDNA, SUMMER seeks to obtain an accurate assessment of the composition and biomass of the mesopelagic community. Gut content analysis, molecular markers and stable isotopes will allow quantification of the vertically integrated trophic network, linking to commercial and charismatic species. Models will be used to estimate the impact of fishing scenarios on trophic network stability and carbon sequestration. Mesopelagic organisms will be tested for their potential as fish meal, nutra and pharmaceuticals. The project will develop a decision support tool to enable accounting for trade-offs between services in when considering sustainable use of mesopelagic resources