Mesozooplankton structure and seasonal dynamics in three coastal systems of Argentina: Bahía Blanca Estuary, Nuevo Gulf and Ushuaia Bay

BERAZATEGUI; ABATE; D´AGOSTINO; PRESTA MARIA LAURA; UIDRIG; GARCIA; NAHUELHUAL; CHAZARRETA; GARCIA, ML; DUTTO; CAPITANIO, F; HOFFMEYER, MONICA

Plankton Ecology of the Southwestern Atlantic, from Subtropical to the Subantarctic realm.

springer

Año: 2018; p. 327 - 348

Mesozooplankton communities of coastal ecosystems are successfully adapted to a wide environmental range. However, the current rate of coastal modification is challenging the survival of resident species. In this chapter, we describe the structure and annual dynamics of mesozooplankton community in the recent years in three coastal systems of Argentina subject to human disturbance: 1) Bahía Blanca Estuary, 2) Pirámides Bay in Nuevo Gulf and 3) Ushuaia Bay. The seasonal dynamics of mesozooplankton in Bahía Blanca Estuary during 2009-2010 showed a unimodal pattern with an increase towards the warm seasons, while organism abundance increased linearly with both salinity and turbidity. In Nuevo Gulf, research on the seasonal dynamics of mesozooplankton conducted during 2014-2015 showed a bimodal pattern with two peaks of abundance in late summer and spring. No significant relationships between mesozooplankton and the environmental variables included in Nuevo Gulf were found. The seasonal dynamics of mesozooplankton in Ushuaia Bay in the years 2006-2008 showed a bimodal pattern with two peaks of abundance in summer and early autumn, and this pattern was mainly driven by the concentration of chlorophyll a. In Bahía Blanca Estuary, a gradual decrease of species richness was observed throughout the last four decades, while changes in species composition were also observed, evidencing that some species have the ability to acclimate to higher salinity and turbidity as well as to pollution. In Nuevo Gulf, mesozooplankton community showed no significant modifications along time, which may be related to low anthropogenic pressure. Although no profound shifts in mesozooplankton were observed in Ushuaia Bay, we warn on the future potential impact that eutrophication may have through its effect on primary producers.