IMIS - Marine Research Groups

Maps of biomass of micronecton (6 groups, covering the diversity of the diel vertical migration behaviour) and biomass of albacore (Thunnus alalunga) and skipjack (Katsuwonus pelamis), averaged over 2 periods: historical (1985-2014) and projection (2015-2070). For the projection period, two climate scenarios were used (SSP3-7.0 and SSP1-2.6). For the tunas, the averaged biomass is given per quarter (quarter1= january-march; quarter2= april-june; quarter3= july-september; quarter4= october-december), over the historical and projection periods. Maps cover the whole Atlantic Ocean.

The six micronecton groups encompass the variety of the diel vertical migration behaviours: D1N1 = epipelagic, D2N1 = migrant upper mesopelagic, D2N2 = upper mesopelagic, D3N1 = highly migrant lower mesopelagic, D3N2 migrant lower mesopelagic, D3N3 = lower mesopelagic (from Lehodey, P., Conchon, A., Senina, I., Domokos, R., Calmettes, B., Jouanno, J., Hernandez, O., & Kloser, R. (2015). Optimization of a micronekton model with acoustic data. ICES Journal of Marine Science, 72(5), 1399–1412. https://doi.org/10.1093/icesjms/fsu233)

The CNRM and GFDL are two ESMs (earth system models) have a behaviour at mid-term warming levels (2041-2060) that enable to explore the range of the existing climate change scenarios. More precisely, CNRM model models for a faster warming up compared to GFDL. Overall, for micronekton and tuna biomasses, CNRM model leads to higher biomass in the Gulf of Guinea than the GFDL, while GFDL model leads to higher biomass in the tropics.