There are many great places to observe salt marshes along the Great Marsh, a coastline feature that extends from Cape Ann in Massachusetts to southern New Hampshire. And there are several specific locations identified by other EarthCaches which describe what a salt marsh is as well as it's relationship to vegetation, fish and bird habitat, agriculture and so forth.
This location in Essex Mass is as picturesque and has as much geological significance as any of those but the purpose of this EarthCache is not to repeat information but to briefly highlight the on-going research relative to the impact of climate change on salt marshes and this is a location with observable changes.
Ground zero on the grounds of the Allyn Cox reservation in Essex, Mass is overlooking a salt marsh and the river headlands of the Essex River. It's a spot called Clamhouse Landing. Archeological investigation found that Indigenous people lived here 2,500 years ago where they shellfished and shucked clams with stone tools. You are standing on a mound of clamshells covered by a thousand years of organic debris.
The National Oceanic and Atmospheric Administration (NOAA) begins their comments by telling us that 'salt marshes are coastal wetlands that are flooded by salt water brought in by the tide. They note that salt marshes...also protect shorelines from erosion by buffering wave action. They report in depth on the impact that climate change will have and you can read it here.
NASA scientists map global salt marsh losses. According to a NASA study the world has lost 561 square miles of salt marshes over the past 20 years. Salt marshes are both an indicator of and protector against climate change. Marshes sequester carbon in their vegetation, peat moss and other organic debris. NASA conducted a global change analysis of satellite images collected between 2000 and 2019 quantifying loses, gains and recoveries of salt marsh ecosystems analyzing data from Landsat 5,7 and 8. Landsat is a joint mission of NASA and the U.S. Geological Survey. More about that can be found here
The U.S. Environmental Protection Agency (EPA), has reported on the effect of climate change in coastal environments. They wrote " the effects of climate change have been observed and...salt marshes are drowning" The biggest effect in estuaries may come from warming water and rising sea levels" That report is here.
Massachusetts Division of Fisheries and Wildlife has a climate action tool and "report on the ecology and vulnerability of the coastal salt marsh." The study notes that salt marshes are vulnerable to inundation as sea levels rise. The go on to write that "research suggests that when sea level rise exceeds a certain threshold marshes convert to tidal flats. Thresholds (>2mm or 0.08 inches per year) have already been crossed in southern new England. The report is here.
The University of Chicago, Marine Biological Laboratory, reported on March 28, 2023 that "most of the worlds salt marshes could succumb to sea level rise by turn of the century. Read more here.
There are many more scientific organizations doing studies that can be researched.
Sit on the benches here and enjoy the beautiful vistas today and ponder the alarms being sounded by these agencies and institutions.
To claim a find for this EarthCache tell me what you can observe as you look around that is evidence of the type of change to the area as noted above.
Please do not post your answers or related pictures in your logs or I will delete the log.