Logan Brenner

Foundational to an estuarine ecosystem is the composition of its sediments, with benthic foraminifera serving as a key component. While it is common to find intact and deformed tests, foraminiferal organic linings (FOLs; foraminifera whose tests dissolved) are not always present in sediment samples. Identifying where FOLs are preserved is a necessary first step towards determining what promotes their development and burial. Here we document the prevalence of globothalamean FOLs in the Hudson River Estuary (HRE) at the Pier in Piermont, New York, USA. We also identified six agglutinated foraminifera species and successfully imaged foraminifera that were collected while in the process of losing their tests. There are a multitude of factors that can lead to test dissolution with FOL preservation, but most are related to suboptimal growth conditions. While the HRE has a history of sediment pollution, studies utilizing foraminifera or FOLs to study the modern benthic environment are not common. Our study provides some of the first evidence for FOLs preserved in the HRE. This exploratory work is a critical step towards utilizing foraminifera as a proxy for benthic conditions, with specific recommendations for future FOL sampling to monitor sediment conditions in the HRE.