Application of a watershed ecological risk assessment in developing a nitrogen management strategy
Waquoit Bay is a small estuary on the south shore of Cape Cod, Massachusetts. Population in the watershed has increased approximately 1 5 fold in the past 50 years, and residential land use has increased tenfold from 2 percent of the watershed in 1950 to 20 percent in 1990. Of particular concern is nitrogen loading primarily via groundwater from on-site septic systems, fertilizers and atmospheric deposition. Adverse ecological impacts have included: growth of nuisance macroalgae, decreases in water quality, loss of bay scallops and loss of eel grass (Zostera marina) in Waquoit Bay and adjoining coastal ponds. A watershed-based ecological risk assessment was applied to assist in the development of management strategies for the bay. Management goals for the watershed were identified by stakeholders. Endpoints of the risk assessment were derived from the management goals and included: areal extent and patch size of eel grass beds and macroalgal mats, and habitat quality as evidenced by physical, chemical and biological water quality. Ecological response of the endpoints to the nitrogen loading was examined with a regional analysis of eel grass cover, land use, and predicted nitrogen loading in similar embayments of Cape Cod. The uncertainty analysis of the risk assessment allows prediction of the probability of success for a given management strategy; for example, what would be the probability that eel grass would return by reducing the nitrogen load through the implementation of various management strategies. This example shows the utility of the ecological risk assessment approach for developing optimal management strategies to increase the probability of achieving management goals.
- OSTI ID:
- 230928
- Report Number(s):
- CONF-9511137-; ISBN 1-880611-03-1; TRN: IM9623%%238
- Resource Relation:
- Conference: 2. Society of Environmental Toxicology and Chemistry (SETAC) world conference, Vancouver (Canada), 5-9 Nov 1995; Other Information: PBD: 1995; Related Information: Is Part Of Second SETAC world congress (16. annual meeting): Abstract book. Global environmental protection: Science, politics, and common sense; PB: 378 p.
- Country of Publication:
- United States
- Language:
- English
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