Zooplankton communities in the Drake Passage through environmental boundaries: a snapshot of 2010, early spring

Andrey A Vedenin; Eteri I Musaeva; Daria N Zasko; Alexander L Vereshchaka

doi:10.7717/peerj.7994

Zooplankton communities in the Drake Passage through environmental boundaries: a snapshot of 2010, early spring

PeerJ. 2019 Nov 7:7:e7994. doi: 10.7717/peerj.7994. eCollection 2019.

Authors

Andrey A Vedenin¹, Eteri I Musaeva¹, Daria N Zasko¹, Alexander L Vereshchaka¹

Affiliation

¹ Laboratory of Plankton Communities Structure and Dynamics, P.P. Shirshov Institute of Oceanology, Moscow, Russia.

Abstract

Background: Spatial distribution of zooplankton communities influenced by various environmental factors is always important for understanding pelagic ecosystems. The area of the Drake Passage (Southern Ocean) is of particular interest owing to the high spatial and temporal variability of hydrological parameters affecting marine fauna. This study provides a survey of zooplankton composition and spatial distribution along a transect in the Drake Passage sampled during the 31th Cruise of RV "Akademik Sergey Vavilov" in November, 2010. The main aim was to trace the main regularities in spatial zooplankton structure and its relationships with the environmental parameters.

Methodology: A total of 43 vertical hauls from the surface to 1,000 m depth were made at 13 stations using the Juday plankton net. 60 taxa were recorded, abundance and biomass of each were assessed. Environmental parameters including temperature, salinity, depth, horizontal distance between stations and surface chlorophyll concentration were tested as environmental factors possibly explaining plankton distribution.

Results: Higher zooplankton abundance and biomass with lower diversity were observed near the Polar Front. Cluster analysis revealed five different groups of zooplankton samples, four of which were arranged mostly by depth. Along the transect within the 1,000 m depth range, the qualitative taxonomical composition differed significantly with depth and to some extent differed also among horizontal hydrological regimes, while the quantitative structure of the communities (abundance of taxa) was mainly determined by depth. Plankton assemblages within the upper 300-m layer depended on hydrological fronts. Abundance of dominant taxa as well as total zooplankton abundance showed a clear correlation with depth, salinity and surface chlorophyll concentration. Some taxa also showed correlations with temperature and latitude. Between the stations the similarity in zooplankton structure was clearly dependent on the distance among them which indicates an importance of latitudinal gradient. Surface chlorophyll concentration was not correlated with zooplankton biomass, which can be explained by the uncompleted seasonal migrations of zooplankton from deeper waters in early spring.

Keywords: Drake passage; Spatial distribution of zooplankton; Zooplankton communities.

Grants and funding

This research was performed in the framework of the state assignment of Minobrnauka Russia (theme No 0149-2019-0010), supported by RSF (project No. 18-17-00177) (data analysis). There was no additional external funding received for this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.