Abstract

Foraminifera, as single-celled organisms encased in shell-like structures known as tests, play pivotal roles within marine ecosystems. Their ubiquitous presence and fossilized remains provide invaluable insights into past environmental conditions. However, contemporary challenges posed by human activities imperil foraminiferal populations, notably through pollution-induced hypoxia, a condition characterized by oxygen depletion in aquatic environments. This study focuses on utilizing foraminifera as bioindicators to assess hypoxia within Florianópolis’s North Bay, situated in Brazil. Sediment samples collected in May and October 2014 served as the basis for this investigation. By analyzing both abiotic and biological data, the study uncovered concerning trends, including low oxygen levels and elevated organic matter content in the bay’s sediments. These environmental conditions create favorable habitats for opportunistic species such as Ammonia tepida, known for their resilience to fluctuating environmental parameters. Additionally, the presence of an invasive species, Trochammina hadai, further complicates the ecological dynamics of the bay. This invasive species, originally from San Francisco Bay and Japan, underscores the interconnectedness of marine ecosystems and the potential consequences of biological invasions. The findings from this study shed light on the ecological imbalance within Florianópolis’s North Bay, highlighting the urgent need for comprehensive management strategies. Addressing the root causes of pollution and hypoxia is paramount to safeguarding the bay’s biodiversity and ecological health. Implementing effective conservation measures will be essential to ensure the long-term vitality of this marine ecosystem for future generations.

Keywords

sustainability, oxygenation, foraminifera, environmental indicators