Understanding Hypoxia and the Need to Improve Monitoring

R. Lawrence Swanson

School of Marine and Atmospheric Sciences
Stony Brook University

Friday, Mar. 1, 2013, 3:00pm
Chase 130

Long Island Sound (LIS), an unusual estuary, is a consequence of glaciation, is deepest of the major East Coast estuaries, has a sill at its mouth, but is not a fjord. It is partially mixed, connected to the ocean at its mouth and head. It is enduring ecological consequences of climate change. Many of these, including hypoxic conditions, are linked to its geologic setting and altered physical setting.

There is a concerted effort to reduce nitrogen loading from point and non-point sources around the Sound in order to reduce eutrophication and hypoxia. However, physical oceanographic processes play an important role in establishing and maintaining these eutrophic conditions. Climate change may exacerbate them as water column temperature, river discharge, and wind conditions are altered. The importance of physical oceanography is generally not considered as nitrogen reductions (TMDLs) are imposed.

Monitoring has been important in developing our understanding of the physical processes contributing to eutrophication. However, it is clear that our current programs and existing technologies are limiting in that purpose. We need to rethink how, where, and how often sampling is undertaken. This is necessary as scientists and environmental managers are confronted with the need to improve understanding and optimize remedial actions with diminishing resources.

Changes in LIS’s oceanographic climate will become more dramatic in the coming decades, exceeding the impact of anthropogenic alterations that predominated in the 20th century.