Eelgrass in the Great Bay Estuary declined in both distribution and biomass between 2011 and 2012, continuing the long-term trend of eelgrass loss. In 2012, eelgrass was once again mainly present in the Great Bay itself with limited distribution in Portsmouth Harbor and Little Bay. Eelgrass distribution in Great Bay decreased 1.5% between 2011 and 2012 with no change in biomass. In Great Bay,eelgrass distribution has declined 36% since 1996 and biomass is a quarter of what it was in the early 1990s. Nuisance macroalgae in Great Bay continued to proliferate in 2012 and to impact eelgrass by smothering eelgrass shoots and reducing shoot density. In the Piscataqua River, a new, small bed of eelgrass was present in 2012. The eelgrass bed in Little Bay that first appeared in 2010 retracted by 28% between 2011 and 2012 and had very low percent cover in 2012. In 2012, no significant change in eelgrass distribution or biomass was seen in the Portsmouth Harbor and Little Harbor area of the estuary. Overall, eelgrass distribution in the Estuary from 2011 to 2012 decreased 3.9%. The long-term trend of eelgrass decline in the Great Bay Estuary continued in 2012, with a loss of eelgrass distribution of 37% estuary-wide since 1996.
Piscataqua Region Estuaries Partnership
Short, Frederick T., "Eelgrass Distribution in the Great Bay Estuary for 2012" (2013). PREP Reports & Publications. 2.