Invasive SpeciesCommon periwinkle

Littorina littorea
FOUND by 2018cat
Falmouth Maine
ID Confirmed
Quality checked by Bea Babb
Peer reviewed by
Field Notes
Coastal field notes: On Thursday, October 4, 2018, Mr. Wilson’s osprey science classes went to Mackworth Island Beach. The temperature was 61° Fahrenheit with a 30-40% chance of rain later in the day. The time was around 10:00 am and the climate was wet and windy with the tide going out and the full low tide being at around 12:45 pm. There were 7 groups in total at the coastal area, each with around 10 square meters of space by the shore. Each person in the group was looking for their own personal species and the 3-4 different types of crabs. My group found Asian shore crabs and green crabs, as well as common, smooth, and rough periwinkles. We also found both kinds of seaweed, knotted wrack and rockweed or bladderwrack. Each person in our group found their invasive species, showing that the area has been overcrowded with invasives. There was an overwhelming number of common periwinkle, the invasive species I was searching for. The amount of common periwinkle in our area made it almost impossible to find rough and smooth periwinkle, as they were outnumbered by around 30 to 1. The common periwinkle was found up and down the shoreline, coating rocks, and seaweed. These creatures take up so much space that the natives can’t seem to thrive like they used to.
A sketch of our study site.
Supporting Evidence
Photo of my evidence.
White opening. When hummed to, comes out of the shell to show black horizontal bands.
Photo of my evidence.
Purplish brown shell with a short spire.
Photo of my evidence.
Shallow whorls and rough ridges.
Species Observation: Species Looked For
Did you find it?: 
I think I found it
Scientific name:
Littorina littorea
Common name:
Common periwinkle
Sampling method: 
Just looking around
Photo of our sampling method.
Place Studied
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Map this species
N 43.640300 °
W -70.226000 °
Observation Site Information
A photo of our study site.
Coastal - Rocky intertidal
Trip Information
2018 Mackworth Coastal
Trip date: 
Thu, 2018-10-04 07:26
Town or city: 
Falmouth Maine
Type of investigation: 
Species Survey
Time of low tide: 


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The VS Team