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Ohio Sea Grant College Program
and Stone Laboratory

Ohio Sea Grant and Stone Laboratory

Organic Matter Decomposition Rates in Polluted and Unpolluted Bottom Sediments

Project Number: R/ER-005, Completion Report

Start Date: 9/1/1984

Completion Date: 8/31/1986

Revision Date: 12/3/1998

Principal Investigator(s)1.Peter L. McCall, Geological Sciences Case Western Reserve University*
Co-Principal Investigator(s)2.Gerald Matisoff, Geological Sciences Case Western Reserve University*
This shows the current affiliation and may not match affiliation at time of participation. *

Funding Record

Source: Ohio Sea Grant College Program
Source FundState MatchPass Through
Total$ 34,000.00$ 17,300.00$ 0.00

Objectives

The objectives of this study are to: 1) Measure total bacterial numbers, macrobial activity rates, and production rates of organic decomposition products as a function of sediment depth, sediment type, macrofauna abundance and depth in the sediment in western Lake Erie. 2) Assay western Lake Erie sediment bound pesticides and determine pesticide decay rate in sediments. 3) Determine the accumulation and mixing rate of sediments in Western Lake Erie. 4) Use the above information to model the depth distribution of particulate burial and diagenesis.

Rationale

Toxic materials sorb to particulates and are deposited in sediment where they may be released or buried. To describe the diagenetic process, we need to know how microbial activities (which control sediment geochemistry) vary as a function of environment, and we need to know how they are mixed and buried in the sediment. In addition, all inventories of toxics sequestered in lake sediments depend on knowing sediment accumulation rates.

Methodology

Microbial activity is measured by tritiated thymidine incorporation; bacterial abundance is measured by direct count of epiflourescent microscopy; and organic decomposition by measuring accumulation of inorganic nutrients in sediment pore water. Measurements are performed on driver-collected cores and in laboratory incubation experiments. Pesticide analyses are subcontracted to K. Krieger of Heidelberg University.

Benefits & Accomplishments

Our results will be useful in the construction of mass balance models of nutrient cycling and inventories of toxic material, because we will gain a better understanding of the effects of macrobenthos in loading of organic and toxic materials on nutrient regeneration and organic decomposition, and because we will better understand nearshore sedimentation and mixing.

Publications & Media

Peer-reviewed reprints
Peer-reviewed reprintsMatisoff, G. and J. Robbins. 1988, A Model for Biological Mixing of Sediments
J. Geological Education 35:144-149, 1987. Made available by Ohio Sea Grant as OHSU-RS-087.
Peer-reviewed reprintsMatisoff, G., J. Fisher and S. Matis. 1986, Effects of Benthic Macroinvertebrates on the Exchange of Solutes Between Sdeiments and Freshwater
Hydrogiologia 122:19-33, 1985. Made available by Ohio Sea Grant as OHSU-RS-056.

Supported Students

StudentGereby, Clarissa (Graduate, M.S.)
Case Western Reserve University
Title: Bacterial Activity and Remineralization Rates in Nearshore Lake Erie Sediments