Analysis of benthic foraminifera in the reproductive area of right whales (Eubalaena australis) in the Western South Atlantic

Abstract

Susceptibility and vulnerability to impacts make Cetaceans and Benthic Foraminifera sentinels of health in marine environments. A breeding population of Right whales (Eubalaena australis) annually migrates to the “Environmental Protection Area” in Santa Catarina, Brazil, where Ribanceira/Ibiraquera Bay, and its harbor, are located. Since Right whales rest in shallow areas, their stomachs touch the marine sediment bottom, where foraminiferal assemblages inhabits. Temperature, salinity, pH, turbidity, grain size, morphometry, and magnetic susceptibility correlated to foraminiferal species, contribute to the understanding of habitat preference for right whales. Here we show saline waters in the northern areas associated with Pseudononion atlanticum, Elphidium sp., Buccella peruviana, Quinqueloculina patagonica, and 21°C of temperature is the preferred by mother and calf pairs. The harbor has lower pH, higher temperatures, magnetic susceptibility, and turbidity, and high depth is due to dredging. These characteristics do not support the presence of the Right whales, the top of the food pyramid, so decline or increase in their population indicates changes in their habitat. We stress the importance of unravelling signals of Benthic and Nekton coupling by understanding whales’ habitat; to ensure the recovery of their populations, and the survival of other species in the marine ecosystem.