Iole  Leonori

ABSTRACT Subject :

Krill dynamics in the Ross Sea pelagic ecosystem

Tipe of Presentation: Poster

Topic: Marine biology and ecology

COAUTHORS :

Andrea  De Felice
CNR IRBIM
State : Italy
e-Mail : andrea.defelice@cnr.it

Ilaria  Biagiotti
CNR IRBIM
State : Italy
e-Mail : ilaria.biagiotti@cnr.it

Giovanni  Canduci
CNR IRBIM
State : Italy
e-Mail : giovanni.canduci@cnr.it

Giordano  Giuliani
CNR IRBIM
State : Italy
e-Mail : giordano.giuliani@cnr.it

Ilaria  Costantini
CNR IRBIM
State : Italy
e-Mail : ilaria.costantini@cnr.it

Abstract    Published : 01/03/2023 17:31:21

Krill is a core resource for aquatic animals in the Ross Sea, being food basic element for whales, seals, penguins and many other marine birds and mammals. They are among the most important pelagic animals constituting the Middle Trophic Level that substantially link primary producers to top predators in the local pelagic ecosystem. Since 1989, with intervals of around 5 years in average between one campaign to another, acoustic surveys were held in western Ross Sea to estimate the biomass and spatial distribution of Euphausia superba and Euphausia crystallorophias, the two main krill species in the area and their evolution in relation to environmental changes. The results have shown that E. superba is by far the most abundant species over time and that the spatial distribution of the two species is more similar in austral spring (November), but tends to show separated patterns during austral summer (December-January), with E. superba moving northwards, reaching the border with the Southern Ocean, allowing a reduction of competition for food between the species. A different behaviour in relation to the environmental conditions was also observed in the two pelagic species.