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Full-Text Articles in Physical Sciences and Mathematics

Barium Chronologies From South Florida Reef Corals - Environmental Implications, D. Anderegg, Richard E. Dodge, Peter K. Swart, L. Fisher Jan 1997

Barium Chronologies From South Florida Reef Corals - Environmental Implications, D. Anderegg, Richard E. Dodge, Peter K. Swart, L. Fisher

Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures

Benthic algal blooms (e.g., Codium isthmocladum) have become increasingly common on reefs and hardgrounds of Southeast Florida. The contribution from possible responsible nutrient sources, including natural upwelling and local pollution, has not been quantified. In an attempt to differentiate each potential source, lattice-bound barium concentrations in the skeletons of two common Southeast Florida stony coral species (Montastraea faveolata and Solenastrea bournoni) were measured by isotope dilution inductively coupled mass spectrometry (ICP/MS). Specimens were collected offshore between 26˚01'-57'N at shallow (10m) and deep (20m) reefs. X-rays of skeletal slabs revealed annual density bands which guided annual and subannual …


Regulation Of Algal Blooms In Antarctic Shelf Waters By The Release Of Iron From Melting Sea Ice, Peter N. Sedwick, Giacomo R. Ditullio Jan 1997

Regulation Of Algal Blooms In Antarctic Shelf Waters By The Release Of Iron From Melting Sea Ice, Peter N. Sedwick, Giacomo R. Ditullio

OES Faculty Publications

During summer 1995-96, we measured iron in the water column and conducted iron-enrichment bottle-incubation experiments at a station in the central Ross Sea (76°30'S, 170°40'W), first, in the presence of melting sea ice, and 17 days later, in ice-free conditions. We observed a striking temporal change in mixed-layer dissolved iron concentrations at this station, from 0.72-2.3 nM with sea ice present, to 0.16-0.17 nM in ice-free conditions. These changes were accompanied doubling of algal (diatom) biomass. Our incubation experiments suggest that conditions were iron-replete in the presence of sea ice, and iron-deficient in the absence of sea ice. We surmise …