Blue crab, Callinectes sapidus, density and size in a salt marsh at low tide on the Coast of Virginia, Sept. 2021

While deconstructing a caging experiment at low tide in September 2021, researchers (Serina Wittyngham, Leah Scott, Andrew Nemeth, Emily Goetz, Esther Harper-Smith, David Johnson, and Cora Johnston) noticed blue crabs, Callinectes sapidus, ambushing fiddler crabs, Minuca (=Uca) pugnax, and purple marsh crabs, Sesarma reticulatum, from small, muddy pits in the marsh in Painter, Virginia, at low tide. On 28 Sept 2021, David returned to the marsh to estimate blue-crab density in the tall-form Spartina alterniflora (low marsh), the Sesarma-denuded zones and the short-form S. alterniflora (high marsh) zones by haphazardly tossing 15 1-m2 quadrats along a 200 m transect that crossed 6 creekheads. He also measured carapace width and the corresponding pit width and depth in which the crabs were found for up to 15 hapazardly encountered crabs in each of these zones (only 1 found in SSA). Sex was also noted. Surveys were conducted at low tide.