Invasive SpeciesGreen crab

Carcinus maenas
FOUND by Yellow Team 2
ID Confirmed
Quality checked by Mrs. Griffith
Peer reviewed by Yellow Team Members
Field Notes
We are happy because we get to go find crabs! Questions and problems we ran into were that we had to dig through lots of seaweed/rock to find crabs. We can hear and smell the ocean, the waves, the salty air, see seaweed, smell mud, and hear the scurrying of crabs. We are surprised of what we found and didn't find because we found an awful lot of green crabs and few native crabs.
A sketch of our study site.
Supporting Evidence
Photo of my evidence.
The species that we found does have five spines.
Photo of my evidence.
The crab we found was aggressive.
Photo of my evidence.
The species we found had thin and sharp claws .
Species Observation: Species Looked For
Did you find it?: 
I think I found it
Scientific name:
Carcinus maenas
Common name:
Green crab
Is it alive?: 
Some dead & some alive
Count of individuals: 
3/4 - Completely covered
Eggs (animals)
How big is it?: 
5 - 10 cm
Is it male or female?: 
Can't tell
Sampling method: 
Quadrat (randomized- placement)
Photo of our sampling method.
Place Studied
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Map this species
N 44.881829 °
W -67.131555 °
Observation Site Information
A photo of our study site.
Coastal - Rocky intertidal
Trip Information
Reversing Falls
Trip date: 
Fri, 2017-09-22 09:00
Town or city: 
Type of investigation: 
Species and Habitat Survey
Eastern Coastal
Time of low tide: 
Fri, 2017-09-22 08:00
Habitat Observations
Species diversity: 
1 different species
Evidence of vectors: 
Water temperature: 
Dissolved oxygen: 



We are some students in Machias, and we are working on an invasive species project. We are trying to find out more information from scientists. Can your citizen scientists help?

Where did green crabs come from and how did they get to Maine?

How do they affect other marine animals?

Did you study any other invasive species on our coast?

Thank you for reviewing our mission! It means so much!! -Yellow Team 2

You got it with the 5 spines - a green crab indeed. Nice observations, and great, clear pictures.