Spatial distribution of the mesozooplankton community in the coastal polynyas of the Ross Sea region marine protected area (RSR MPA) during early summer

The mesozooplankton community in the Ross Sea region marine protected area (RSR MPA) was investigated to explain the community structure and spatiotemporal distribution of mesozooplankton in early summer. Environmental variables were analyzed to determine their effects on the mesozooplankton community structure. Based on these results, the mesozooplankton community of the RSR MPA in December was divided into three groups. Two groups were located in the main polynya region, while another group was in the marginal polynya region. The two main polynya groups, which were separated based on geographic region, were the Terra Nova Bay polynya (TNBP) and Ross Sea polynya (RSP) groups. Euphausiids were the dominant taxa in the main polynya regions, whereas copepods were dominant in the marginal polynya region. Salinity, sea ice, and dissolved oxygen (DO) were the main environmental parameters to distinguish the main polynya and marginal polynya regions. The key environmental variable separating the three groups was salinity. In accordance with the relatively high mesozooplankton abundance in the polynya regions, the spatial distribution of mesozooplankton was likely related to the development of the polynyas in December.