The Peacetime-MERMEX campaign observed the reactivity of Mediterranean zooplankton to Saharan dust.
Two dust events, one tracked by satellite, which enabled a study to be made as soon as the dust was deposited at sea (in the Algerian basin), and the other which occurred a few days before passing through the impacted zone (south of the Tyrrhenian Sea), enabled the response of the pelagic ecosystem in a naturally highly oligotrophic environment to be studied in situ for the first time.
The addition of nutrients by the dust induced an immediate response in the planktonic micro-autotrophic compartment, which rapidly had repercussions on the zooplanktonic compartment, creating a trophic habitat that was attractive to certain species (large migratory grazers and their predators) and inhospitable and dangerous to others (small particle filter feeders), leading to major changes in the planktonic biocoenosis.
The dynamic study of these changes, made possible by combining the two events, enabled us to estimate that the zooplankton communities returned to their initial state within 2 or 3 weeks.
The frequency of Saharan events therefore appears to be an important factor in the productivity of the southern Mediterranean basins and the export of materials.
==> Guillermo Feliú, Marc Pagano, Pamela Hidalgo, Francois Carlotti. Structure and function of epipelagic mesozooplankton and their response to dust deposition events during the spring PEACETIME cruise in the Mediterranean Sea. Biogeosciences, European Geosciences Union, 2020, 17 (21), pp.5417-5441. ⟨10.5194/bg-17-5417-2020⟩. ⟨hal-03002613⟩