Too many nutrients can cause more algae growth than an estuary can support. Excess algae leads to decreased oxygen in the water and other symptoms that if left unchecked can completely devastate a marsh. This process is known as eutrophication. Scientists are now developing a tool to help address eutrophication in estuaries.

On June 12th and 13th, scientists from around New England gathered at the Wells Reserve to discuss the computer model ASSETS (Assessment of Estuarine Trophic Status). The model uses five key indicators to assess an estuary’s risk for dangerous levels of eutrophication. Of these indicators, four are based on aquatic vegetation.

ASSETS has already been applied to 152 estuaries worldwide. Of these, 86 are United States estuaries expected to worsen by the year 2010.

During the workshop, scientists examined preliminary results concerning five local estuaries. It was discovered that marshes missing one of the indicators invariably had skewed results. Suggestions made to correct this issue are currently under consideration. Dr. Suzanne Bricker, the lead scientist on the ASSETS program, said “…we’re happy to incorporate things to make it better.”

An estuary assessed using ASSETS is given a score of low, moderate low, moderate, moderate high, or high. A result of “high” indicates high probability that an estuary’s state will worsen in the coming years. These straightforward results are easily understandable and based on concrete scientific data, which makes them both accessible to the non-scientific community and credible.

The Wells Reserve has provided essential data for testing and analyzing the ASSETS program. Because of this, ASSETS has already been used to assess the Webhannet and Little River estuaries. In reference to these studies, Dr. Michele Dionne of the Wells Reserve said “We now have a baseline picture of the eutrophication status of these systems against which to measure future change.”

ASSETS is one of the first tools to directly link human impact and eutrophication within an estuary. Officials, conservationists, and scientists alike can use this information to target and aid at-risk estuaries.

For more information on the ASSETS program, visit eutro.org and eutro.us.

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