T194 Cushman Foundation Symposium: In Pursuit of Understanding the Distribution of Benthic Foraminifera: Honoring the Career of Martin A. Buzas

Tuesday, 17 October 2023
1:30 PM - 5:30 PM
321

AN OVERVIEW OF THE DISTRIBUTION AND ABUNDANCE OF FORAMINIFERA IN THE INDIAN RIVER LAGOON, FLORIDA

Paper number: T194-4
Program: Technical Sessions
Time: 2:10 PM – 2:25 PM

Authors

  • Susan Richardson Presenting Author
    Wilkes Honors College, Florida Atlantic University, Jupiter, FL

Abstract

The Indian River Lagoon (IRL) is a narrow (2-4 km), shallow (1.2-m mean depth), 260-km long, barrier-enclosed estuarine lagoon that is situated on the east coast of the Florida peninsula. The IRL system is comprised of interconnected sub-basins (Mosquito Lagoon, Banana River, Indian River) that connect to the Atlantic Ocean by a series of natural & manmade inlets (Ponce de Leon, Sebastian, Ft. Pierce, St. Lucie, Jupiter). The IRL watershed encompasses several natural freshwater rivers & creeks, as well as a network of drainage canals & ditches that have greatly enlarged the original watershed. The IRL spans the boundary between the temperate & tropical savanna climate zones & is characterized by distinct wet (mid-Jun to Oct) & dry (mid-Oct to late May) seasons. Salinities range from 21-35 & depend on seasonality of rainfall, evaporation rates, & proximity to inlets, rivers &/or creeks. Tides are semidiurnal & microtidal close to the inlets; in the interior of the lagoon, wind-driven circulation dominates. Some northern reaches of the IRL are nontidal.

Essential foraminiferal habitats within the IRL include: sediments, muck, seagrass beds, oyster reefs, tidal wetland sediments (mangrove swamps/salt marshes) & the water column. The earliest studies on the ecology of foraminiferans in the IRL were carried out by Marty Buzas & Ken Severin, who identified 94 species in sediment samples collected from 12 transects located from the northern IRL near Haulover Canal to the St. Lucie Inlet. Species diversities & population densities were generally observed to increase in a southerly direction. Buzas also conducted numerous experiments on the effects of substrate preference & predation on foram densities. Other researchers have studied the forams living in different habitats, such as seagrass beds, mangrove sediments & muck. A total of 156 foram species are currently estimated to live in the IRL, however that number may increase as more habitats are surveyed within the lagoon.

Geological Society of America Abstracts with Programs. Vol. 55, No. 6

doi: 10.1130/abs/2023AM-393135

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