Native SpeciesKnotted wrack

Ascophyllum nodosum
FOUND by 2018cbb
Falmouth Maine
ID Confirmed
Quality checked by Wilson
Peer reviewed by Addy T.
Field Notes
The day we went outside to find invasive species was cool, cloudy, and windy. It was 61°.The tide was pretty high but it was going out. I was looking for knotted wrack. We had seven groups looking on the shore we had about 20 feet of space to look. Each group was looking for 6 to 7 species. I found knotted wrack. We also found green crabs, asian shore crabs, smooth periwinkles, rough periwinkles, common periwinkles, rock weed, blue mussels, and a moon snail shell. I was surprised by the number of green crabs. We found invasive species of crabs and not native species of crabs. The biodiversity here isn’t great. When it came to the forest, we were looking for many different species. I was looking for morrow’s honeysuckle. I didn’t find it. It was shocking to see the overwhelming amount of giant knotweed close to the shore.
Supporting Evidence
Photo of my evidence.
Axial growth pattern that grows from one stem.
Photo of my evidence.
Rubbery branches grow up to 60 cm long and egg-shaped air-bladders found along branches.
Photo of my evidence.
Knotted wrack has an olive-yellow color. Bladderwrack had paired vesicles. This species doesn’t.
Species Observation: Species Looked For
Did you find it?: 
I think I found it
Scientific name:
Ascophyllum nodosum
Common name:
Knotted wrack
Sampling method: 
Photo of our sampling method.
Place Studied
We’re sorry, JavaScript is required to view the map. If JavaScript is you may wish to upgrade to a newer browser in order to view this map.
Map this species
N 43.640300 °
W -70.227100 °
Observation Site Information
A photo of our study site.
Coastal - Rocky intertidal
Trip Information
2018 Mackworth Upland
Trip date: 
Thu, 2018-10-04 15:06
Town or city: 
Falmouth Maine
Type of investigation: 
Species Survey


Your coordinates put you in South Portland. Please post updated coordinates here in the comments so we can update your location and make your data useful to scientists and others.

The VS Team

The coastal study was done in (upland Mackworth trip)