Bacterial Metabolism, Aromatic Biodegradation, and Lignin Biogeochemistry in Sediment Cores from Pearl Harbor, Hawaii
Abstract
Heterotrophic bacteria require a source of oxygen to rapidly metabolize complex and recalcitrant carbon sources like lignin, 2,4,6 trinitrotoluene (TNT), and polycyclic aromatic hydrocarbons (PAHs). The activities of burrowing macrofauna can increase oxygenation, which may stimulate bacterial metabolism of PAHs and heterotrophic production. We measured bacterial production, PAH mineralization, and lignin subunit concentration with depth in cores taken from South Loch and Bishop's Point in Pearl Harbor, Hawaii. Bacterial metabolism decreased rapidly with depth but was much higher at South Loch than Bishop's Point. PAH mineralization rates were higher at South Loch than at Bishop's Point and extended down to the depths of bioturbation at each site: upper 4 to 6 cm at Bishop s Point and upper 9 cm at South Loch. Phenolic moieties of lignin at South Loch and Bishop's Point suggest there are different sources of organic matter to the two sites. PAH mineralization was elevated in bioturbated zones from both sites relative to those below this zone. Ambient PAH concentrations were also higher at the less bioturbated site. This is consistent with the hypothesis that benthic infauna stimulate PAH metabolism.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 14, 2004
- Accession Number
- ADA422667
Entities
People
- Christopher L Osburn
- Michael T. Montgomery
Organizations
- United States Naval Research Laboratory