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
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
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
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)]
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.
Kelp - Giant -
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.
[qundaicai (China), miyeok (Korea), Undaria pinnatifida]
Related to kelp, wakame is a popular seaweed for soups and salads,
particularly in Japan, It has a softly crunchy texture and a pleasant
slightly spinachy flavor. Most familiar in the U.S. as dry, brittle black
tangles in cellophane bags it is also commonly available fresh salted
in bags in the refrigerated section of markets serving Oriental
The photo specimens are dried tangle (center), fresh salted tangle
briefly soaked (lower right) and a single piece from the fresh tangle
spread out (upper left), being a short length cut from one side of the
central stem. Fresh salted wakame, soaked for a short time and the salt
rinsed off, has a much fresher flavor and crunchier texture than soaked
dried and I particularly recommend it for salads.
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!
[Tangle; Laminaria hyperborea]
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
Attribution-ShareAlike 3.0 Unported, Right photo ©
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
Illustration copyright expired
Fucus & Sargassos - Order
FucalesMost Sargassos fasten themselves to the ocean bottom near shores, but
some are free floating out on the open sea.
[Hiziki; Sargassum fusiforme]
This seaweed is used mainly in Japan, though its use has been brought
to North America by the Michio Kushi Macrobiotic movement.and it is now
fairly common in Japanese restaurants. It is imported from Japan in dried
form and is soaked and cooked for consumption. Hijiki is also used to
color Konnyaku Jelly.
Hijiki is high in dietary fiber and a number
of important minerals, but it is also high in inorganic arsenic which has
resulted in cautionary pronouncements by a number of governments. 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 things.
Bladderwrack is used mainly as a food flavoring and additive, and as a
medicinal, particularly for iodine deficiency and certain female
Photo by Stemonitis distributed under license Creative
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]
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 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
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");
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]
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
Illustration from Koehler's Medicinal-Plants, copyright
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 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
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.
[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. The photo specimen is from
India, sold as Dagad Phool, essential to Goda Masala, a curry powder used in
the Marathi cuisine of Goa and Karnataka.
Details and Cooking.
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.
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 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
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 (A5) have
brought heavy fines in California, but the claims continue. Promoters
haven't been able to get it accepted as a general food either because it
looks bad, tastes bad and is generally heavily contaminated with insects,
copepods (tiny crustaceans) and worse - it's pond scum, simple, but not
Spirulina is promoted to extreme vegetarians as a source of Vitamin B12
which they desire to get from non-animal sources (of which there aren't
any), but any usable B12 in Spirulina appears to comes from insect and
copepod contamination. The more contamination the more B12.
Photo by Joan Simon licensed under
GNU Free Documentation License v1.2.
Fat Choy - Black Moss -
[Hair Moss; Fat Choy = "Hair Vegetable"; Nostoc
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
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.