36764884951_908ce338c3_nBelow you’ll see examples of common intertidal brown algae from exposed surf-swept shores of the northern Oregon coast. These are ones you are likely to encounter on the rocks or in and around tide pools, or as drift on the beaches. Some of these are common and easy to identify with the readily available field guides (see References, below). others are tricky, and I apologize for any misidentifications you find. I’m always updating this page, so I can fix errors once I’m aware of them. Please let me know if you notice a misidentification or want to help me solve an identification mystery. There’s nothing new here, just my view of common browns, and a natural history note if I can think off something that hasn’t already been said.

The organization more or less follows Kozloff (1993) and Lamb and Hanby (2005), showing species in the order they might be encountered in the field, from highest to lowest in the intertidal. Common names are my choice. I lean on WoRMS for scientific names, and Algaebase when I want to dig deeper. I learn a ton by browsing the pages of Kozloff (1993). All photos are from northern Oregon unless otherwise noted in the caption.

Rockweed, Fucus  Fucus grows most luxuriantly in sheltered sites. I guess all the images below are Fucus distichus, but I’m not certain. You’ll sometimes see it as Fucus gardneri. On surf-swept rocks it’s smaller than at protected sites, and frequently interspersed with Cladophora, Endocladia, and Pelvetiopsis. Fucus appears in Rockweed, Fucus and Common Marine Algae in the Northern Oregon Drift Line: A Gallery of Images.


Little Rockweed, Pelvetiopsis limitata – P. limitata is at home only on the exposed outer coast, where it is usually abundant on the tops of high intertidal rocks. Even though much more abundant here than Fucus, it is much less common in the drift line.


Sea Cauliflower, Leathesia marina – There are some similar saclike epiphytic browns, but I think this one is Leathesia marina. I found it on a piece of drift Sargassum.

A drift strand of sargassum with Leathsia
Leathesia marina, an epiphyte on Sargassum


36888542784_ae2a5af936_mFir Branch, Analipus japonicus-  I’ve also seen A. japonicus referred to as bottle brush. My sketch looks more like a bottle brush, so I’ve got to mention it. The images shown here are from the central Oregon coast. I’ve never noticed it on my home beaches in northern Oregon. Look for it in the mid- to low intertidal

Sea Palm, Postelsia palmaeformis- You can see stubby sea palms bobbing and poking through wicked surf, but on my home waters they tend to live out on exposed headlands where reaching them is tricky, even at the lowest tides. Detached clumps are fairly common in the drift line, so that’s what you see below.


Sea Cabbage, Saccharina sessilis- Sea cabbage is usually abundant on larger reefs. Depending on age of the blades and wave exposure, S. sessillis can give you a lot of looks. It’s one of the few kelps with no stipe, so that should help with identification. I rarely see sea cabbage in the drift line.


Feather Boa Kelp, Egregia menziesii – Feather boa is common on mid to low intertidal rocks, and not unusual in the drift line. It’s a photo-friendly brown, giving lots of good looks.


Winged kelp, Alariamarginata –  In exposed places with low rocks and active sand, it experiences seasonal burial. In some of the photos below you can see the “wings” near the base of the stipe. Alaria marginata appears in Seaweeds in the Sand.


Split kelp, Laminaria setchellii – Laminaria setchellii appeared in Seaweeds in the Sand because in some places, it experiences seasonal burial. It’s also featured in Kelp Curves because it’s just so dang photogenic.


Dense-clumped kelp, Laminaria sinclairii – I featured Laminaria sinclairii in Finding Yourself in the Infralittoral Fringe. In northern Oregon, it’s a good marker for mean lower low water.


Strap kelp, Lessoniopsis littoralis- I’ve also seen it referred to as northern tree kelp. You know you’re on the exposed outer coast when you run into Lessoniopsis littoralis.


Bladder chain, Stephanocystis osmundacea- My home beaches are a bit north of bladder chain strongholds. I only know it from the drift line.


Wireweed, Sargassum muticum – Not really at home on the exposed outer coast, small drift clumps is pretty much all I see of Sargassum muticum. Wireweed appeared in Common Marine Algae in the Northern Oregon Drift Line: A Gallery of Images.


Acid weed, Desmarestia – You can find this Desmarestia in low tide pools. It seems to tolerate active sand and sesonal sand burial.


Giant kelp, Macrocystis pyrifera – On my home beaches Macrocystis is subtidal, so I only know it from drift masses on the beach. Macrocystis drift is common enough that it appeared in my post, Common Marine Algae in the Northern Oregon Drift Line: A Gallery of ImagesMacrocystis is featured on the Monterey Bay Aquarium Logo.


Bull kelp, Nereocystis luetkeana – Bull kelp is subtidal, but in the wrack, it’s an important component of intertidal ecosystems. I wrote a little bit about this in Bull Kelp Drift: A Subtidal-to-Surf Zone Connection.


Pterygophora californica – Old growth kelp is mostly subtidal in Oregon, though you may run across it on the lowest tides. I don’t see it often, even on the drift line. The ones shown below were featured in Browns Put On a Shine in the Drift Line.


A Puzzler

How about this one? If you know what this one is, please let me know. Check out the bullae on the blades. The blades are so shiny they inspired Browns Put On a Shine in the Drift Line.

A mystery brown with shiny blistered blades


Druehl, L. D. and B. E. Clarkston. 2016. Pacific Seaweeds: A Guide To Common Seaweeds of the Pacific Coast. 2nd ed. Harbour Publishing Co.

Harbo, R. M. 2011. Whelks to Whales: Coastal Marine Life of the Pacific Northwest. 2nd ed. Harbour Publishing Co.

Kozloff, E. N. 1993. Seashore Life of the Northern Pacific Coast. 3rd ed. University of Washington Press.

Lamb, A. and B. P. Hanby. 2005. Marine Life of the Pacific Northwest. Harbour Publishing.

Mondragon, J., and J. Mondragon. 2010. Seaweeds of the Pacific Coast. Shoreline Press.

Sept. J. D. 2009. The Beachcomber’s Guide to Seashore Life in the Pacific Northwest. Revised ed. Harbour Publishing.

Web Resources

The brown algae page on the Netarts Bay Today website is one of the best references you’ll find for the Pacific Northwest.

Biodiversity of the Central Coast has a great page on browns.

Seaweeds of Alaska is a standard reference for the Pacific northwest. It has a great brown algae page.

You can, and should, scroll down to the brown algae section of Oregon’s Rocky Intertidal by Kate Krieg.

The Seaweed Sorter app is fun and very useful!

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