Knotted Wrack (Ascophyllum nodosum), Wet, Live, Whole Leaf, 1 Pint Volume

from $80.00
Quantity (1 Pint Volume):

Live Rockweed (Ascophyllum nodosum)
Please note this is a live marine specimen.

Rockweed (Ascophyllum nodosum), also known as Norwegian Kelp or Egg Wrack, is one of the most common and ecologically important seaweeds found along Maine’s rocky intertidal shores. Recognized by its long, olive-green fronds with distinctive air bladders, this durable brown alga provides critical habitat for countless marine species and helps stabilize the coastal ecosystem.

Sustainably hand-harvested from the mid-tidal range of the Gulf of Maine, Rockweed is ideal for aquaria, classroom demonstrations, and marine biology studies. Its variable coloration—from deep green to golden brown—reflects the natural effects of sunlight and tide exposure.

Key Facts:
Common names: Rockweed, Norwegian kelp, egg wrack
Scientific name: Ascophyllum nodosum
Location: Rocks and ledges in the mid-tidal range
Seasonality: Available year-round in great abundance
Colors: Ranges from deep dark green to brown to sun-bleached yellow
Size: 3” up to 6’ long (larger available upon request)
Collected: Hand-harvested
Quantity: 1 pint volume
Note: This is a live marine specimen. Natural variations in size, color, and appearance from photos should be expected. If you would like any specimen preserved, please send a request to: info@gulfofme.com

Live Rockweed (Ascophyllum nodosum)
Please note this is a live marine specimen.

Rockweed (Ascophyllum nodosum), also known as Norwegian Kelp or Egg Wrack, is one of the most common and ecologically important seaweeds found along Maine’s rocky intertidal shores. Recognized by its long, olive-green fronds with distinctive air bladders, this durable brown alga provides critical habitat for countless marine species and helps stabilize the coastal ecosystem.

Sustainably hand-harvested from the mid-tidal range of the Gulf of Maine, Rockweed is ideal for aquaria, classroom demonstrations, and marine biology studies. Its variable coloration—from deep green to golden brown—reflects the natural effects of sunlight and tide exposure.

Key Facts:
Common names: Rockweed, Norwegian kelp, egg wrack
Scientific name: Ascophyllum nodosum
Location: Rocks and ledges in the mid-tidal range
Seasonality: Available year-round in great abundance
Colors: Ranges from deep dark green to brown to sun-bleached yellow
Size: 3” up to 6’ long (larger available upon request)
Collected: Hand-harvested
Quantity: 1 pint volume
Note: This is a live marine specimen. Natural variations in size, color, and appearance from photos should be expected. If you would like any specimen preserved, please send a request to: info@gulfofme.com

Knotted wrack pile.

Knotted wrack pile.

Tidepool Tim says,  “Knotted wrack is the MEGA - SEAWEED of the Maine coast! There are umpteen millions of tons of it sloshing back and forth along the rocks with each and every crashing wave, boat wake, and tidal current night and day. This rockweed forms a dense mat that keeps the beach cool and or warm as the tide goes out. A quick peek under this seaweed will reveal armies of belligerent green crabs, scattering scuds, and docile periwinkles awaiting the incoming tide. Some knotted wrack plants in our bay grow as long (tall) as 8' stretching up from their tiny suction-cup like holdfast on the rocks and reaching skyward to catch the energy of the sun. At high tide we can see schools of young herring (yum - sardines!) and various shrimp species swimming amongst the fronds. At low tide we slip and slide across this carpet to get down to the low water mark where we collect most of our sea life critters. During storms, large masses of knotted wrack are torn from their ledges and they float windward landing on beaches like huge windrows of hay - sometimes 1/2 mile long and 6' in diameter. As spring and summer heat up this mass of rockweed slowly rots down into the beach sediments and will disappear back into the sea!”