Although this timeline begins in 1990 at the start of the National Estuarine Eutrophication Assessment (NEEA), there was much work done at NOAA during the 1980s to put together information necessary to define the United States national resource base and to develop a national assessment capability. The resultant database that was the starting point for the NEEA represents over 90 percent of the estuarine surface water area and freshwater inflow to the coastal regions of the contiguous United States. The database include descriptive and analytical information including physical and hydrologic characteristics, trends in human and animal population, building permits, coastal recreation, coastal wetlands, classified shellfish growing waters, and point and nonpoint sources of pollution for selected parameters. Analytical topics include relative susceptibility to nutrient discharges and the structure and variability of salinity.

The following gives a brief history of the development of the National Estuarine Eutrophication Assessment Program, modifications and improvements in the transformation to NEEA/Assessment of Estuarine Trophic Status (ASSETS), ongoing Program activities, and the building of international collaborations.

1990-1998	Data and information for 138 estuaries and coastal waters was collected from approximately 400 scientists using an expert knowledge engineering approach. Five regional reports detailed conditions and trends of 16 indicator variables within US estuarine and coastal systems
1998-1999	Data and information from the Estuarine Eutrophication Survey Synthesis to NEEA and development of eutrophication assessment method
2001	Improvement of NEEA and development into ASSETS
2002	NEEA Update workshop and guidance document
2003-2005	Application of NEEA/ASSETS methodology to update 13 North and Mid Atlantic systems and development of a human use indicator to complement the ASSETS eutrophication indicators through a partnership with UMD, UNH, UMASS, Maine State Planning Office, and EPA (funding through CICEET – Cooperative Institute for Coastal and Estuarine Environmental Technology)
2003	Application of the NEEA/ASSETS methodology to 10 estuarine and coastal systems in the European Union (Portugal); Research into the addition of typology criteria for eutrophication symptom range definitions
2004	Development of the http://www.eutro.org/ website, listing ASSETS scores for systems from the US, EU (Germany, Ireland, Portugal) and China   COMPASS initiative, bringing together an ad hoc group from the EU and US in order to examine a possible harmonization between OSPAR-COMPP and ASSETS
2005	Application of ASSETS methodology to North East National Estuarine Research Reserve(NERR) systems using the System Wide Monitoring Data (SWMP) (funding through CICEET – Cooperative Institute for Coastal and Estuarine Environmental Technology) Preparation of a University of Maryland Center for Environmental Studies – NOAA partnership in order to apply the NEEA/ASSETS methodology via an online survey and National Workshop to update the National Estuarine Eutrophication Assessment for 138 US estuaries and coastal waterbodies Preparation of a joint US-EU-China initiative (NOAA-IMAR-SOA) in order to apply ASSETS to Chinese coastal systems, and further develop and test the methodogy