Science Serving Maryland's Coasts

Research Publications: UM-SG-RS-2014-12

Title: 

Eutrophication of a Maryland/Virginia coastal lagoon: a tipping point, ecosystem changes, and potential causes.

Year: 

2014

Authors: 

Glibert, PM; Hinkle, DC; Sturgis, B; Jesien, RV

Source: 

Estuaries and Coasts 37(1):128-146

DOI: 

10.1007/s12237-013-9630-3

Open Access: 

This article is freely available online. You can use the DOI number to find it through the journal's website or through a search engine.

Abstract: 

Water quality in the Maryland/Virginia Coastal Bays has been declining for many years from anthropogenic inputs, but conditions appear to have worsened abruptly following a shift from long-term dry to long-term wet conditions in the early 2000s. Annually and regionally averaged total nitrogen concentrations are approximately twofold higher, but ammonium (NH4+) concentrations are up to an order of magnitude higher than in the early 1990s. Averaged nitrate concentrations, however, changed to a lesser degree throughout the time course; water column concentrations remain very low. Total phosphorus has only increased in some bay segments, but increases in phosphate (PO43-) have been more pervasive. There were differences in the year in which large increases in each nutrient were first noted: PO43- in similar to 2001-2002, followed by NH4+ similar to a year later. The effects of a combination of steadily increasing anthropogenic nutrient increases from development, superimposed on nutrient loads from farming and animal operations, and groundwater inputs were accelerated by changes in freshwater flow and associated, negatively reinforcing, biogeochemical responses. Regionally, chlorophyll a concentrations have increased, and submersed aquatic vegetation has decreased. The system is now characterized by sustained summer picoplanktonic algal blooms, both brown tide and cyanobacteria. The retentive nature of this coastal lagoon combined with the reducing nature of the system will make these changes difficult to reverse if the current dual nutrient management practices are not accelerated.

Related Research Project(s) Funded by Maryland Sea Grant: 

Maryland Sea Grant Topic(s): 

'Related Research Project(s)' link to details about research projects funded by Maryland Sea Grant that led to this publication. These details may include other impacts and accomplishments resulting from the research.

'Maryland Sea Grant Topic(s)' links to related pages on the Maryland Sea Grant website.