R/EH-6

Impact/Outcome:

This section describes how this project has advanced scientific knowledge and/or made a difference in the lives of coastal residents, communities, and environments. Maryland Sea Grant has reported these details to the National Oceanic and Atmospheric Administration (NOAA), one of our funding sponsors.

SUMMARY: Researchers produced a deeper understanding of the conditions under which underwater grasses grow and shared these findings with policy-makers working to restore this important vegetation.

RELEVANCE: Underwater grasses (known as submerged aquatic vegetation or SAV) play an important ecological role by improving water quality and providing food and refuge for marine life. But they have declined in the Chesapeake, and restoration efforts have shown mixed results.

RESPONSE: Research by Michael Kemp of the University of Maryland Center for Environmental Science documented conditions that best promote restoration and conservation of submerged aquatic vegetation. Growth rates increase with the grass beds' size, density, and height; Kemp and a coworker quantified minimum requirements for growth. Bigger grass beds slow down the waves within them, allowing water-borne particles to settle. The particles can act as fertilizer, and the clearer water allows more light to reach the grasses and promote their growth. Of particular interest, the restoration of damaged or destroyed grass beds requires better growing conditions than those required to maintain existing beds, which has implications for managing restoration. This project built on an earlier one that studied the ecological role of grass beds.

RESULTS: Kemp has shared the results and participated in semi-annual meetings with federal and state agencies through the Chesapeake Bay Program's SAV Workgroup. The findings will aid resource managers in constructing models to simulate the effects of different management methods and of climate variation on the Bay's SAV restoration.