T1 AM Contaminat Cycling Assessment and Prevention in the NY/NJ Harbor (Part 1)
Tuesday, 15 November 2005: 8:00 AM - 11:40 AM in Ballroom 1

(LIT-1117-136328) Landscape, agriculture, demographics and the delivery of suspended sediment to New York Harbor.

Litten, S¹, Wall, G², ¹ New York State Department of Environmental Conservation, Albany, New York, USA² U.S. Geological Survey, Rensselaer, New York, USA

ABSTRACT- Ninety percent of the freshwater entering New York Harbor comes through the 150 mile long Hudson Estuary. Most of the mercury, DDT, and dioxins and much of the PCB move attached to suspended sediment (SS). Initial questions about the timescale of transport from upstream sites where loads were measured to the harbor are being examined through daily monitoring of SS at head-of-tide sites and data generated by an acoustic Doppler current profiler located in the mid-Hudson. SS loading events seen upstream are very quickly mirrored downstream and spring-neap tides are seen to play an important role in SS concentration. Examination of these data raises other questions about the sources of SS and approaches to reducing sediment yield. Management of the harbor is helped by reduction of toxics and by reduction of sediment. Sediment yield is known to be a function of topography, soil type, rainfall, and land use. GIS tools permit the visualization of land use throughout the entire Hudson watershed. Historically, the Hudson basin has greatly recovered from former more abusive land practices. Interesting trends include a basin-wide decrease in population largely due to negative economic trends in the Mohawk valley. Roads, a significant type of impervious surface, are most prevalent in densely populated areas but the area of road per person is very much greater in rural areas. Roads are a major source of wildlife mortality and ecosystem disruption. All regions of the basin are experiencing increasing population dispersion or sprawl. Twenty percent of land in the Hudson basin is agricultural but much of that, particularly in the lower Hudson Valley, has a negative return on investment thus making many farmers advocates for suburban development. Better management of lands in the basin might reduce delivery of toxics and sediment to New York Harbor.

Key words: hudson estuary, suspended sediment, watershed management, toxics transport