Document Type

Article

Department/Program

Virginia Institute of Marine Science

Publication Date

2008

Journal

Marine Pollution Bulletin

Volume

56

Issue

6

First Page

1049

Last Page

1056

Abstract

The proposed plan for enrichment of the Sulu Sea, Philippines, a region of rich marine biodiversity, with thousands of tonnes of urea in order to stimulate algal blooms and sequester carbon is flawed for multiple reasons. Urea is preferentially used as a nitrogen source by some cyanobacteria and dinoflagellates, many of which are neutrally or positively buoyant. Biological pumps to the deep sea are classically leaky, and the inefficient burial of new biomass makes the estimation of a net loss of carbon from the atmosphere questionable at best. The potential for growth of toxic dinoflagellates is also high, as many grow well on urea and some even increase their toxicity when grown on urea. Many toxic dinoflagellates form cysts which can settle to the sediment and germinate in subsequent years, forming new blooms even without further fertilization. If large-scale blooms do occur, it is likely that they will contribute to hypoxia in the bottom waters upon decomposition. Lastly, urea production requires fossil fuel usage, further limiting the potential for net carbon sequestration. The environmental and economic impacts are potentially great and need to be rigorously assessed. (C) 2008 Elsevier Ltd. All rights reserved.

DOI

10.1016/j.marpolbul.2008.03.010

Keywords

Dissolved Organic Nitrogen; Aureococcus-Anophagefferens; Dinoflagellate Alexandrium; Thalassiosira-Weissflogii; Coastal Eutrophication; Marine Cyanobacterium; Iron Fertilization; Algal Bloom; Coral-Reefs; Sulu Sea

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