Asian shore crab

On Thursday, October 9th, 2018, half of my grade took a field trip to Mackworth Island, on the coast of the Atlantic Ocean. It was a cloudy day with temperatures in the lower 60ºs. We were looking for invasive coastal species from the shoreline to the high tide line. We were set up in a transect, with a marker every 10 meters. There were about 11 other groups with their own section on the shoreline. I was specifically assigned to find the Asian shore crab. Other members in my group were assigned to different types of crabs, periwinkle, and rook weed/ knotted wrack.The whole shore was covered in Rockweed and Knotted wrack on top of many rocks and sand. It was very slippery. In order to find species, you had to lift up the Rockweed and Knotted wrack. I did not find any Asian shore crabs, however there were a couple people from seperate groups who found one. We only found invasive Green crabs. We found around 20. This is causing the survival of the other crabs to be very difficult. We found many common periwinkles (invasive) and smooth, but no rough periwinkles or Rapa whelks. The absence of specific species in our area proves that the invasive species are taking up the resources needed for survival in our specific area.