The following is a revision of the 2010 eelgrass status report submitted to the Piscataqua Region Estuaries Partnership by Dr. Fred Short, correcting an error in eelgrass percent cover classification discovered by PREP staff during their QA/QC process. Eelgrass in the Great Bay Estuary in 2010 was once again mainly present in the Great Bay itself with limited distribution in Portsmouth Harbor. In 2010, Portsmouth Harbor experienced a 9% loss of eelgrass distribution since 2009, for a loss of 47% of the Harbor’s eelgrass distribution since 1996, an alarming trend. For the third year in a row in the Piscataqua River, there was no eelgrass. A small eelgrass bed appeared in Little Bay close to an expanding bed in Great Bay. Eelgrass distribution in Great Bay itself increased slightly between 2009 and 2010. In Great Bay itself there has been a 68% loss of eelgrass biomass since 1996 accompanied by a loss of 31% of eelgrass distribution. Nuisance macroalgae in Great Bay continued to proliferate in 2010 and impact eelgrass by smothering eelgrass shoots and reducing shoot density. The abundance of epiphytes growing on eelgrass in Great Bay greatly increased between 2009 and 2010. Eelgrass distribution from 2009 to 2010 in Great Bay Estuary increased 1.3%, with a 35% overall loss of distribution since 1996 in the Estuary. The very slight 2010 gains are largely a result of plant reproductive response to nitrogen stress and the 2010 growing season’s ideal weather conditions for eelgrass growth. The long-term trend of decline continues.
Piscataqua Region Estuaries Partnership
Short, Frederick T., "Eelgrass Distribution in the Great Bay Estuary for 2010" (2012). PREP Reports & Publications. 4.