Invasive SpeciesCommon periwinkle

Littorina littorea
FOUND by Moody Teenagers
Cape Elizabeth
ID Confirmed
Quality checked by Fanning
Peer reviewed by Purple Perywinkles
Field Notes
Stepping off the bus around 9:00 am at Kettle Cove Beach we are greeted with a mild wind making the 60º temperature seem colder than it actually is. We are here looking for the Common Periwinkle and data about the species to add to the Vital Signs website. Thick layers of seaweed cover the rocks like blankets and small tidepools scatter between. The tide is low, but slowly rising. The waves are small, but choppy due to the wind. Making our way across the seaweed covered rocks we’re careful not to slip. Once we reach one of the many tide pools, we bend down and lift away a heavy layer of wet seaweed, crabs darting away at our entrance, clusters of dark gray periwinkles greet us and we easily pop one off.
Supporting Evidence
Photo of my evidence.
We think we found the Littorina littorea, better known as the Common Periwinkle. We believe that we found this because the shape and texture of the shell is wider and smooth, common characteristics of the species. Also, the tip of the spiral was more green and faded than the rest of the shell another common characteristic of the species.
Photo of my evidence.
We think we found the Common Periwinkle because the color matches the description, which is a very bland, and sort of faded brown. Another reason is the opening in the shell had white rings around it, and there was also a white inner lining before the snail, just as described on the Species ID card.
Photo of my evidence.
We found the Common Periwinkle on the rocks, right by a tide pool as shown in the picture. It was easy to find right by a tide pool because the Common Periwinkle gets it’s oxygen from water and can only survive out of water for a limited amount of time, so we assume they always stay by water to live.
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 43.561100 °
W -70.217500 °
Observation Site Information
A photo of our study site.
Coastal - Rocky intertidal
Trip Information
Kettle Cove
Trip date: 
Tue, 2017-10-24 09:30
Town or city: 
Cape Elizabeth
Type of investigation: 
Species Survey
Time of low tide: 
Tue, 2017-10-24 08:26


I love your poetic AND accurate description of the day and your site. Sounds like a great day to be in the field! and what a great group name!