Salt Marsh Observatory
Salt marsh monitoring data collected from the four New England National Estuarine Research Reserves (NERRs) from 2010 to 2017 were combined to form one homogeneous database. These data were collected as part of the NERRs System Wide Monitoring Program (SWMP) to help manage local and regional salt marshes. The goal for this particular project was to synthesize the SWMP data from salt marshes and identify significant changes over time in plant species abundance and marsh surface elevation as distinct from natural annual variation and provide products to help guide syntheses in different regions. As primary stakeholders, Reserve staff wanted to know if there were changes in their salt marshes and if such changes were reflected in the larger geography of New England.
Salt Marsh Biomonitoring:
Human impacts (e.g., nutrient enrichment or tidal restrictions) and environmental stressors (e.g., climate change effects such as precipitation rates and sea level rise) can drastically alter the spatial distribution and species composition of salt marsh plant communities. Changes in the biological structure of the marsh can result in reduced habitat and function. By closely monitoring the biological and physical variables of salt marshes over time, coastal researchers and resource managers will have a better understanding of how these estuarine systems respond to particular disturbances, and consequently, will be better equipped to protect the future health and integrity of coastal marshes. Surface elevation tables have been monitored annually at South Cape Beach Sage Lot Pond since 2013., In over 100 permanent, 1 m sq. plots spanning from the seaward edge of the marsh up into terrestrial upland communities, plant species are recorded by percent cover and density. In addition, crab burrow counts, plot photos, and presence/absence of crab and snail species are noted.
Submerged Aquatic Vegetation
Submerged Aquatic Vegetation (SAV – macro-algae and eelgrass)
One of the biggest contributors to poor water quality on Cape Cod is the addition of too much nitrogen to the bays. Septic systems are the primary source (only about 15% of the Cape is sewered, and septic systems do almost nothing to remove nitrogen), though fertilizer and air pollution also play a role. Delivered to the bay by groundwater or surface run-off, the nitrogen acts as a fertilizer leading to large algae blooms, which shade and kill eelgrass and deplete oxygen from the water. Surveying the distribution and species composition of SAV over time helps illuminate how this process may be changing in Waquoit Bay, revealing, for example, if new species of algae are becoming dominant, whether the little remaining eelgrass is disappearing, or whether climate change is affecting SAV distribution. Thus, the survey helps determine how natural and/or human-caused factors may influence the overall health and sustainability of the estuarine system. Surveys were done in 2004, 2007, 2011, and 2016. Analyses of intriguing trends related to nutrient inputs and increasing water temperatures, including declining eelgrass but variable changes in algae biomass were presented by Jordan Mora at the New England Estuarine Research Society Meeting in 2018
But why the decline? Shifts in macroalgal biomass in a eutrophic microtidal estuary
(Poster presented by Jordan Mora, 2018)
What’s Trending in Waquoit Bay? (2018 Presentation Research at the Reserve & Women in Science class, Jordan Mora)