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Eutrophication of Cape Cod estuaries: Effect of decadal changes in global-driven atmospheric and local-scale wastewater nutrient loads

Authors:

Ivan Valiela

Caroline Owens

Elizabeth Elmstrom

Javier Lloret

Publication Type:
Journal Article
Year of Publication:
2016
Secondary Title:
Marine Pollution Bulletin
ISSN:
0025326X
DOI:
10.1016/j.marpolbul.2016.06.047
Pages:
309-315
Volume:
110
Year:
2016
Date:
Sep-15-2016

Abstract

Nitrogen (N) supply by atmospheric deposition, wastewater, and fertilizers controls estuarine eutrophication. In New England, atmospheric N loads recently decreased by 50% and land-derived contributions rose about 80%, owing to national-scale emission controls and local urban development. The decrease in atmospheric deposition was large enough to balance increases in land-derived N loads, so total N loads to Waquoit Bay estuaries in Cape Cod did not change significantly between 1990 and 2014. Unchanged N regimes were corroborated by finding no differences in estuarine nutrient concentrations and macrophyte biomass between pre-2005 and in 2015. Coastal zones, subject to reasonably rapid changes in global and local driver variables, will require that assessment and management of eutrophication include adaptive strategies that capture effects of changing baselines. Management initiatives will be constrained by spatial scale of driver variables: local efforts may address wastewater and fertilizer N sources, but atmospheric sources require national or international attention.