Invasive SpeciesCommon periwinkle

Littorina littorea
FOUND by ren
Cape Elizabeth
ID Confirmed
Quality checked by mr p
Peer reviewed by TE GRH MJ
Field Notes
The group of scientists stepped off the bus and at about 9:15 and were greeted by Kettle Cove’s gray cloudy skies. The grass was covered with a silver coating of dew from the night before. The water was choppy that humid October morning . Our group traveled from the left side to the right side of the beach, and quickly found the species. It was a cloudy day with the sky 100% covered in clouds. The air temperature was 65 degrees fahrenheit, there was no precipitation at the site. The wind direction was northwest and the wind speed was 26.7 miles per hour. High tide started at 2:38AM to 2:42PM. Low tide started at 8:38AM to 9:06PM. On the right and the left side of the beach there are rocks. On the right side the rocks were more downhill and flat, in the middle of the rocks there is a beach with lots of empty shells and small rocks. The scientists all came off the bus in wonder if they would find their species or not. The group spent their time capturing evidence of the species and finding the species. The citizen scientists surprisingly found the species very quickly. The teachers ended the time at the beach and the scientists stepped back onto the busses.
A sketch of our study site.
Supporting Evidence
Photo of my evidence.
During the trip to Kettle Cove beach in Cape Elizabeth, the scientists found the Common Periwinkle. Some evidence that shows this is the Common Periwinkle is. . . The lip of the common periwinkle meets the whorl at an angle greater than 90 degrees. This is not the rough periwinkle because the rough periwinkle’s lip meets the whorl at an angle less than 90 degrees.
Photo of my evidence.
This is the Common Periwinkle and not the Smooth periwinkle. The group knows this because the Smooth Periwinkle has a spiral on its shell, like the Common periwinkle. This spiral isn’t like the spiral the Common periwinkle though. This spiral has a flatter though slightly pointed spiral on the shell. Also it is not the Smooth periwinkle because the opening of the shell is shaped more like a tear then a circle.
Photo of my evidence.
This is the Common Periwinkle because of the dullish brown color. According to Vital Signs web page for the Common Periwinkle. The Common Periwinkle is often a grayish purple or a dull brown color. In this picture the color is a dullish gray, according to the vital signs Common periwinkle web page.
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 43.561526 °
W -70.218049 °
Observation Site Information
A photo of our study site.
Coastal - Rocky intertidal
Trip Information
Kettle Cove 2017
Trip date: 
Tue, 2017-10-24 09:00
Town or city: 
Cape Elizabeth
Type of investigation: 
Species Survey
Time of low tide: 
Tue, 2017-10-24 08:30


I love your detailed notes section; it really captures the place and time of this investigation.