Kelp Forest Algae

"Algae" is a term of convenience for all the "seaweeds", but many microscopic entities are also lumped in - and 3 billion years of confused history. It used to be simple to say "Algae are not plants", but that is now highly controversial. Green and Red algae are now included in clade Archaeplastida, sort of Plantae sensu lato (plants viewed broadly), with red needing a bit more "lato" than green. Brown algae are still safely not plants, but even that could change. Fortunately we can go ahead and eat them without waiting for all the confusion to be resolved.

I include Cyanobacteria on this page. They are no longer classed as algae, though still called "blue-green algae" by the health food industry (a more marketable designation than "pond scum"). Cyanobacteria are the sole generators of atmospheric oxygen, on their own or symbiotically inhabiting (in simplified form) the chloroplasts of both plants and algae.   Photo © i0087.

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Seaweeds were gathered from the shore by our pre-human ancestors for use as food, and we continue to eat them today. They provide important minerals, particularly iodine, which can be in short supply from other sources. Besides being eaten as vegetables, algae and cyanobacteria are major feedstocks for the food processing, dietary supplement and medicinal industries.

Very few sea vegetables are toxic, but some are. Cyanobacteria and single celled algae can be highly toxic, and increasingly infest our oceans due to climate change and human pollution.

Brown Algae   -   class Phaeophyceae of division Heterokontophyta of clade Chromista

The brown algae belong to division Chromista and are quite different from other seaweeds, more closely related to diatoms, downy mildew and other microscopic life forms (See Note-A2). They do have oxygen generating chloroplasts, but of a different type than those of plants.

Kelps   -   Order Laminariales

Kelps includes our most familiar seaweeds, particularly the giant kelp that litters our West Coast beaches after a storm. Kelps are of great economic, culinary and environmental importance.

Kelp - Japanese   -   [Konbu, Kombu (Japan); Miyeok, Dashima (Korea); Haidai (China): Laminaria japonica (and several other L. species)]
Konbu Kelp

This is edible kelp grown along the coasts of Japan, Korea and China - quite different from the giant kelp of California which is processed rather than eaten directly. The long wide fronds are dried and packaged for use particularly to make soup stock, but also for to use as wrappers for various prepared foods. Almost all this kelp used for food is cultivated rather than gathered wild which explains why there are so few crunchy critters growing on it.

This kelp is normally sold as flat dried sheets cut from the fronds but is also sold as narrow cut strips, salted and bagged in the refrigerated section. In Japan it is also pickled and and served as a snack to accompany green tea. The photo shows a piece of a frond as dried, and a shorter piece cut from the end after soaking. Details and Cooking.

Sea Tangle   -   [Atlantic Kombu, Oarweed; Laminaria digitata]
Pile of Brown Kelp

The name "Sea Tangle" properly belongs to the Atlantic kelp L. digitata, but many packages of kelp found in Asian markets here in Los Angeles are labeled "Sea Tangle". Actually, this commercially harvested kelp is closely related to the kombu kelps of East Asia and can be used similarly, but is not found in the Pacific at all.

The photo, clearly labeled Laminaria digitata, was taken in the eastern North Pacific (Washington State), so is probably the very closely related Laminaria setchellii, which is a little smaller. Both share the common name "oarweed". L. setchellii is harvested from Alaska to California, and some could be sold as Kombu in Asia, but the name "sea tangle" doesn't apply to it.   Photo by Leslie Seaton distributed under license Creative Commons Attribution 2.0 Generic.

Kelp - Giant   -   [Macrocystis pyrifera]
Giant Kelp

Along the temperate western coasts of North and South America, forests of Giant Kelp provide food and shelter for fish, crustaceans and other sea life. The greatest kelp forests in the world are off the coast of California where fronds can grow to 200 feet (60 meters), and in the warm sunlit waters of Southern California can grow more than 10 inches (25 cm) a day.

California kelp is both an important resource and important to the health of the marine environment so harvesting kelp is highly regulated here. The main threat to kelp forests is not harvesting but sea urchins. Order more Uni in your local sushi bar to help the spiny lobsters keep the sea urchin population under control.

Hundreds of tons of giant kelp are harvested every year for production of algin, a thickener and stabilizer used in products from toothpaste to beer to ice cream and to feed farmed abalone.   Photo © i0085.

Wakame   -   [Wakame (Japan); Miyeok (Korea); Qundaicai (China); Undaria pinnatifida]
Part Frond

Related to kelp, wakame is a popular seaweed for soups and salads, particularly in Japan and Korea. It has a softly crunchy texture and a pleasant slightly spinachy flavor. Most familiar in the U.S. as dry, brittle black tangles in plastic bags. It is also commonly available salted in bags in the refrigerated section of Korean markets.

The photo specimens are dried tangle (center), salted tangle briefly soaked (lower right) and a single piece from the salted tangle spread out (upper left). This is a short length cut from one side of the central stem.

Wakame has recently been found to contain a substance that stimulates production of a fat burning protein, so expect it to become better known in the West. It has become a troublesome invasive weed along the coasts of non-Asian countries, so eat up!   Details and Cooking

Cuvie   -   [Tangle; Laminaria hyperborea]
Whole Algae Shreded Algae OK, I'm making a presumption that the contents of the can was L. hyperborea, because that's the kind of kelp they have up there around Russia. The paper compliance label stuck to the bottom just said "Laminaria" - everything else on the can was in Russian.

The kelp strips were mild with a pleasant flavor, probably it's used on the zakuska table. Clearly the Russians didn't quite understand American labeling law, because the compliance sticker listed Laminaria last. Ingred: Laminaria, vegetable oil, onions, vinegar, salt, sugar, garlic, coriander, pepper.   Left photo by Sergey S. Dukachev Distributed under license Creative Commons Attribution-ShareAlike 3.0 Unported, Right photo © cg1.

Arame   -   [Eisenia bicyclis]
Whole Algae

This seaweed is popular in Japan where it may be served alone, mixed with other seaweeds in a seaweed salad, used as a garnish or included in many kinds of dishes. It is normally sold dried, and takes a very short soaking cycle before it is usable. It has a light semi-sweet flavor and is high in calcium, iodine, iron, magnesium, other minerals and vitamin A.   Illustration copyright expired

Fucus & Sargassos   -   Order Fucales

Most Sargassos fasten themselves to the ocean bottom near shores, but some are free floating out on the open sea, especially after being broken free by storms.

Hijiki   -   [Hijiki, Hiziki (Japan); Gulfweed (US); Hai zao (China); Sargassum fusiforme]
Illustration of Hijiki

This seaweed is found along the coasts of China, Korea and Japan, but also along the Atlantic coast of North America. Used as a sea vegetable in Japan, it was brought to North America by the Michio Kushi Macrobiotic movement. and it is now fairly common in Japanese restaurants here. It is imported from Japan, China and Korea in dried form. Hijiki is also used to color Konnyaku Jelly. This seaweed is now cultivated along the coast of China and the Korean coast facing China.

Hijiki is high in dietary fiber and a number of important minerals, particularly iodine, calcium and magnesium, but it is also high in inorganic arsenic which has resulted in cautionary pronouncements by a number of governments, including the US Department of Agriculture. The arsenic content is not likely to be dangerous in the quantities consumed in normal culinary usage, the warnings being mainly for "health nuts" who tend to overdo "healthy" things. As shipped it is black and very tough, so needs long soaking and cooking to be edible. It has a nutty flavor which is enjoyed in soups and vegetable dishes.   Illustration by Kontaro Okamura, copyright expired .

Bladderwrack   -   [Fucus vesiculosus]
Frond on beach

Bladderwrack is used mainly as a food flavoring and additive, and as a medicinal, particularly for iodine deficiency and certain female problems.   Photo by Stemonitis distributed under license Creative Commons Attribution-ShareAlike 2.5 Generic. .

Red Algae   -   division Rhodophyta of clade Archaeplastida

Red Algae (see Note-A3) is adapted to living at greater depth than green and brown algae, but not all do so. Its pigment reflects red light and absorbs blue, the color that penetrates deepest. Red algae are now widely accepted as plants - but only by the broadest definition of "plants", so acceptance isn't universal and is subject to change without notice.

Nori   -   [Laver (Europe), Nori (Japan), kim, gim (Korea), Porphyra yezoensis and P. tenera, sometimes other species]
Nori sheets

This algae is farmed intensively in Japan, Korea and China. Once harvested it is shredded and made up into paper-like sheets very much the way handmade paper is made. These sheets are lightly toasted which turns them green. They are used as a wrapping for sushi and as a garnish and as a flavoring in soups.

In Wales similar algae is used to make Laverbread (Bara Lawr) by boiling the seaweed, then mixing it with oatmeal and frying it. In the British Isles it is gathered wild in Wales and Scotland rather than being farmed.

Red Algae is high in protein, iron and iodine as well as containing significant amounts of vitamins B2, A, D and C.

Red Tosaka   -   [Tosaka-nori (Japan); Jiguancai (China lit "cockscomb vegetable"); Meristotheca papulosa]
Red Tosaka

This Indo-West Pacific algae is popular in Japan as an appetizer or salad and is also popular in Taiwan. Note that in Japan there are green and white seaweeds also called "Tosaka" and similarly used.   Photo © i0086.

Irish Moss   -   [Carrageen, Chondrus crispus]
Irish Moss

Found along the Atlantic coasts of North America and Europe in the intertidal and subtidal zones, this branching and generally reddish or purplish seaweed grows to about 9 inches long, It can turn green in strong sunlight. Similar species are found and harvested off Korea and Japan.

Irish moss is harvested as a source of carrageenan. This substance is used as a thickener for soups and to make jellies. Industrially it is used as a thickener and and stabilizer in ice cream, luncheon meats and other processed foods and also for fining beer and wine. It has a long history of medicinal use in Europe as well.

Irish moss is always harvested wild, with Canada the major harvester at about 10,000 tons per year followed by France at about 1,260 tons per year.   Illustration from Koehler's Medicinal-Plants, copyright expired.

Green Algae   -   division Chlorophyta of clade Archaeplastida

Green Algae (see Note-A1) is now widely accepted as a plant, and more securely so than red algae. It is best known from the genus Ulva, Sea Lettuce or Green Laver.

Sea Lettuce   -   [Green Laver, Ulva lactuca and other species]
Sea Lettuce

Sea lettuce is found in tidal and near tidal seawater worldwide, generally anchored to rocks or other algae. It is eaten raw in salads and cooked in soups, particularly in Scandinavia, Great Britain, Ireland, China, and Japan.

Sea lettuce is small, generally around 6 inches long but can grow to three feet. It is almost transparently thin and consists of a single frond anchored at one point. It may be ruffled or somewhat divided, generally resembling the lettuce leaves after which it is named.

Most sea lettuce is gathered wild as it grows prolifically wherever there are sufficient nutrients, but some is farmed.   Photo by Kristian Peters licensed under GNU Free Documentation License v1.2.

Sea Grapes   -   [Green Caviar; Latu Arusip, Ar-arosep, Arosep (Philippine); Latok (Malay); Umi-budo (Okinawa); Nho bien (Viet); Caulerpa lentillifera]
Fronds of Seagrape

This seaweed is now successfully farmed in the Philippines, where it is liked raw with vinegar as a snack, or in a salad with chopped onions, tomato and a dressing of fish sauce and vinegar. It is eaten similarly in Okinawa, Japan. Known to be high in iodine, it has a light pleasant seaweed flavor and a satisfying crunchiness when bitten. The stems are tough and stringy, but small and entirely tolerable (swallow them, you need more fiber anyway).

The photo specimens were packed in salt, sold at a local Philippine market for 2015 US $4.99 for a package weighing about 4 ounces. About half the weight was in salt, but when the seaweed is rinsed and re-hydrated it'll probably weigh about the same. We have included our ubiquitous red kidney bean for scale.

Sponge Seaweed   -   [Ch'onggak (Korea); Codium fragile]
Fronds of Sponge Seaweed

This coastal seaweed is found worldwide, even on the coast of Antarctica. It is a siphonous alga, meaning its round branches are composed of a tangle of near microscopic filaments, each filament being a single multinucleate cell. This accounts for its spongy texture. Its branching fronds grow up to about 12 inches long.

This seaweed is used in various skin rejuvenation products, but in Asia, particularly Korea, it is used for food, particularly as a flavor and aroma modifying ingredient in kimchee. It has a distinctive aroma compared to other seaweeds.   Details and Cooking.   Photo by Flyingdream contributed to the Public Domain .

Chlorella   -   [Chlorella vulgaris of class Trebouxiophyceae]

This single celled algae was, in the 1940s and 1950s expected to, by now, be one of the most important food crops in the world. This did not happen for a number of reasons. Production proved far more expensive than expected, it proved entirely indigestible unless its cell walls were broken down by processing, it proved difficult to make anything from it that you'd actually want to eat, and methods were found to greatly improve output of conventional agricultural products.

Today chlorella is sold mainly as a health food supplement. It has been found effective at removing toxic heavy metals and dioxins from the body. It is also thought effective for treating radiation poisoning, reducing blood pressure and cholesterol, and improving immune function, though these claims are not without contention,   Drawing of Chlorella regularis believed to be in the public domain.


Lichens are symbiotic composite organisms consisting of a fungus body within which live either single cell algae or cyanobacteria. This relationship, playing on the strengths of each, allows the organism to live in extremely harsh environments, from arctic tundra to dry deserts and on bare rock, though they are also abundant in temperate and rainforest environments. Lichens are used as food by many cultures around the world sometimes as a survival essential and sometimes as a delicacy.

Live Lichens Iceland Moss   -   [Cetraria islandica of family Parmeliaceae]

Not actually a moss, and not confined to Iceland, though it is particularly lush there. It grows in Arctic and sub-Arctic environments all around the northern hemisphere, and much farther south in alpine regions. For a lichen, it has an unusually erect growth habit. It is eaten by various northern peoples, and it is also used medicinally. The photo specimen is from central Sweden. Details and Cooking.   Photo by Amphis contributed to the public domain.

Dried Lichens Dagad Phool   -   [Kalpasi, Phathar Ka Phool, Chadilo, Black Stone Flower; Parmelia perlata of family Parmeliaceae]

This lichen is essential for making a proper Goda Masala, a curry powder used in the Marathi cuisine of Goa and Karnataka. It's flavor is considered very important to the cuisine of that region. The photo specimens were from India. Details and Cooking.

Lichens Reindeer moss   -   [Caribou moss, Reindeer lichen; Cladonia rangiferina - also - Cladonia portentosa of family Cladoniaceae]

These slow growing lichens are found in Arctic, sub-Arctic and alpine regions all around the northern hemisphere, and are extremely cold tolerant. They are the major food for the Sami's reindeer, and are also eaten by people, after having been removed from the reindeer (some disassembly required). Alaskan inland people eat them directly after crushing and boiling them. Details and Cooking.   Photo by Verisimilus distributed under license Creative Commons Attribution-ShareAlike 3.0 Unported.

Dried Lichens Wila   -   [Bryoria fremontii of family Parmeliaceae]

This lichen grows in hair-like clumps from tree branches, but is not parasitic. It inhabits the Mountain West of North America from the south of Alaska almost to Southern California. Some also grows in Russia and northern Europe. It was an important food for Native Americans and is still occasionally eaten as a traditional food. Details and Cooking.   Photo by Millifolium distributed under license Creative Commons Attribution-ShareAlike 3.0 Unported.

Mounted Lichen Rock Tripe   -   [Iwatake (Japan); Seogi (Korea); Umbilicaria esculenta of family Umbilicariaceae]

This fungus grows on rocks in East Asia, including Korea, China and Japan. It is edible if properly prepared. In Korea it is often pan fried with pine nuts, and in Japan used for tempura. The photo is actually U. americana, but it's closely related and looks pretty much the same. Details and Cooking.   Photo by Daderot contributed to the Public Domain .


Structure Chart Cyanobacteria (see Note-A4) is an often blue-green bacteria, some varieties of which adhere to each other in long strands that mat together into a mass resembling algae. While some formerly dormant varieties are now causing problems with toxic blooms (due mainly to human pollution), we cannot be too resentful of them. Cyanobacteria are solely responsible for the oxygen in the atmosphere (Click on drawing for larger and more).

Originally they made oxygen all by themselves but now many live in the chloroplasts of plants and algae where they are the engine that actually generates the oxygen. Apparently some eukaryotes ingested cyanobacteria but found them indigestible. The cyanobacteria found the insides of the eukaryotes cozy and settled in. The several types of chloroplasts show this happened more than once.

Spirulina   -   [Arthrospira]

Spirulina is the commercial name for Arthrospira, a Cyanobacteria that forms into spiral threads that can be harvested as pond scum. Spirulina proper is a different bacteria and is not used for food.

This algae was a significant nutrient for the Aztecs and still is for some African tribes, but its commercial potential has been overblown. Wild, unsupportable claims by health food purveyors have brought heavy fines in California, but the claims continue. This is not to say it is not nutritious, it is, containing a fairly balanced protein, many vitamins, minerals and nutritional pigments, as well as fatty acids

The problem here is that all these nutrients can by obtained at much lower cost from other sources. Promoters haven't been able to get spirulina accepted as a general food either, because it looks bad, tastes bad and can be heavily contaminated with insects, copepods (tiny crustaceans) and worse - It's grown in open ponds.

Spirulina has been promoted to ethical vegetarians as a source of Vitamin B12, which they desire to get from non-animal sources (of which there aren't any in nature). It does contain a significant amount of a form of B12 not usable by the human body, but any usable B12 in Spirulina appears to comes from insect and copepod contamination (animals, in other words). The more contamination the more B12.   Photo by Joan Simon distributed under license Creative Commons Attribution-ShareAlike 3.0 Unported.

Fat Choy - Black Moss   -   [Hair Moss; Fat Choy = "Hair Vegetable"; Nostoc flagelliforme]

Not actually a moss, this land dwelling cyanobacteria forms long strands that look like hair. It is harvested in the Gobi Desert and the Qinghai Plateau, but harvesting has been restricted due to resulting erosion. Due to increasing cost, sellers have responded in the time honored Chinese way - by adulterating the product. Real Fat Choy is dark green - the adulterant strands, made from starch, are usually black. Real Fat Choy will stand up to over 30 minutes of simmering, but adulterant strands will disintegrate.

The photo specimen skein was purchased from a large Asian market in Los Angeles. It was 16 inches long and folded over, weighed 3-5/8 ounces (100 grams) and smelled like drying grass. Individual hairs are no thicker than human hairs, but are actually made up of many microscopic strands. For nutrition and possible health consideration see Details and Cooking.

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