Foraminiferal Assemblages in Biscayne Bay, Florida, USA: Responses to Urban and Agricultural Influence in a Subtropical Estuary

Elizabeth A. Carnahan, A. M. Hoare, Pamela Hallock, Barbara H. Lidz, Christopher D. Reich, Pamela Hallock Muller

Research output: Contribution to journalArticlepeer-review

Abstract

This study assessed foraminiferal assemblages in Biscayne Bay, Florida, a heavily utilized estuary , interpreting changes over the past 65 years and providing a baseline for future comparisons. Analyses of foraminiferal data at the genus level revealed three distinct biotopes . The assemblage from the northern bay was characterized by stress-tolerant taxa, especially Ammonia , present in low abundances (∼2.0 × 103 foraminifers/gram) though relatively high diversity (∼19 genera/sample). The southwestern margin of the bay was dominated by Ammonia and Quinqueloculina , an assemblage characterized by the lowest diversities (∼12 genera/sample) and highest abundances (∼1.1 × 104 foraminifers/gram), influenced by both reduced salinity and elevated organic-carbon concentrations. A diverse assemblage of smaller miliolids and rotaliids (∼26 genera/sample) characterized the open-bay assemblage, which also had a significant component (∼10%) of taxa that host algal endosymbionts . In the past 65 years, populations of symbiont-bearing taxa, which are indicators of normal-marine conditions, have decreased while stress-tolerant taxa, especially Ammonia spp., have increased in predominance.

Original languageAmerican English
JournalMarine Pollution Bulletin
Volume59
DOIs
StatePublished - Jan 1 2009

Keywords

  • ammonia
  • archaias
  • eutrophication
  • foram index
  • heavy metals
  • hypoxia

Disciplines

  • Life Sciences

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