PatrÃcia P B Eichler
Universidade do Sul de Santa Catarina, Brazil
Title: The occurrence of the invasive foraminifera Trochammina hadai (Uchio) in Ubatuba, SP, Brazil
Biography
Biography: PatrÃcia P B Eichler
Abstract
The estuarine foraminifera Trochammina hadai (Uchio) from Japan was first identified as an invasive species in sediments of San Francisco Bay in 1995. Later it was determined that it first appeared in that bay in 1983, comprising 1.5% of the fauna. However, by 2000, the taxon had been found in 96% of the samples from brackish and marine waters. The proliferation of T. hadai in San Francisco Bay is associated with a decline in relative abundance of one of the most common foraminifera, Elphidium excavatum. The sharp decline of E. excavatum suggests the arrival and proliferation of this species has profoundly influenced the native foraminiferal fauna. The impact T. hadai has had on the microfauna of San Francisco Bay prompted us to investigate other environments outside the US. We began examining foraminiferal distributions to observe populational dynamics and geo-and microhabitats from eighteen sediment surface samples in a small harbor in Saco da Ribeira, Ubatuba, Sao Paulo, Brazil. Previous studies show that this species was not found before 2005. However, samples collected in 2014 provided us with the opportunity to document the existence of T. hadai in at least 80% of the sampled area, which were found alive in the majority of the samples. Following this finding, we intend to investigate when and how this species first arrived in Brazil, if it has expanded in other estuarine and coastal zones and how it is impacting the native fauna.