Salinity In Earth Harbor

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East Harbor is a 291-ha back-barrier salt marsh and coastal lagoon located within the Cape Cod National Seashore (CCNS), N.Truro, Massachusetts (Thiet et al. 2014a). East Harbor was artificially isolated from Cape Cod Bay in 1868 when the original 300-m wide inlet was diked due to the construction of a causeway for use by trains and automobiles (Portnoy et al. 2005). In 1894, a drainage system was installed that allowed freshwater to escape the system (Portnoy et al. 2006), but sea water could not enter the system due to a one way flapper valve (Portnoy, 2005; Smith & Medeiros, 2013). The exclusion of the tides caused the salinity to decline from 25-30 parts per thousand (ppt) into brackish water with a salinity of around
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I established the location of each transect using ArcGIS software (VERSION). In the Northwest Cove and the Main Lagoon, the transects ran NE to SW, were parallel to each other, and roughly 350 m apart. There were a total of two transects in the Northwest Cove and six transects in the Main Lagoon, while Moon Pond had 6 transects that were roughly 50m apart. Each transects was run once every other week in May and June, and then every week in July and August if weather allowed. I did not sample on days with inclement weather, such as high winds, heavy rain, or …show more content…
The age score used in the field consisted of three categories (1-3). A horseshoe crab was marked as (1) if its eyes were still very clear, and if its prosoma showed no signs of epibionts, had a lustrous sheen to it and a mottled pattern of black colored lines. A horseshoe crab marked as (2) had obvious mating scars if female, had some epibionts, and while it still showed a lustrous carapace, it was starting to show wear and tear, the mottling was not as apparent and the eyes were also not quite as clear as a one. In order to be marked as (3), the horseshoe crab had to look much more worn, with larger numbers of epibionts, and a worn shell that lost its lustrous qualities and no longer had any

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