What's it All About-Algae? Harvesting Sea Vegetables

December 1999 - January 2000

This is an article from WaveLength Magazine, available in print in North America and globally on the web.

by Deborah Leach

Bull kelp is fastest growing marine plant on the Pacific Northwest coast
Laurie MacBride photo

Out paddling you've seen lots of dif ferent types of seaweed floating on the surface, swaying beneath your boat and attached to rocks. Have you thought about eating these 'vegetables of the sea'? Did you know that some of them show up in Oriental restaurants and grocery shelves?

Seaweeds are multicelled algae that grow in marine environments, classified by botanists as red, brown or green. But don't worry about choosing the wrong one, all are edible.

Remember to gather seaweed from clean water uncontaminated by industrial pollution. Most algae are annuals, so spring is the best time to collect the tenderest plants. Since the holdfast (where plants attach to the bottom) can reproduce blades, be sure to cut well above the holdfast when foraging. A net bag is handy to hold harvested plants.

If the thought of eating kelp makes you yelp, relax. You may already have eaten seaweed in ice cream, cream cheese, sauces or salad dressings. If the label reads agar, carrageenan or algin, that's seaweed. Some fresh seaweeds can be eaten in salads; others cook like vegetables. Dried seaweed can be eaten as a snack or fried like chips; or it may be powdered to use as a seasoning. Dried kelp can be used to wrap food like sushi or soaked and added to salads or the cooking pot.

How Good Is It?

There are numerous kelp and seaweed products on 'health food' shelves. Nutritionally, seaweeds compare to vegetables and are a source of beta-carotene, B vitamins and vitamin C. Seaweeds have high concentrations of minerals (up to 40% by weight) like iodine, potassium and calcium. But I wouldn't say that seaweed is a nutritional powerhouse. For example, 1/4 cup of dried brown algae (alaria) contains the same amount of calcium as 1/3 cup of milk. Red algae are the richest in protein, between 10 and 25% protein by dry weight. This sounds impressive, but ten sheets of sushi seaweed contain as much protein as an egg.

But to their credit, the soluble fibres in seaweeds (which glue plant cells together) help to lower blood cholesterol, blood sugar and blood pressure. And the alginic acid (the sugar in brown algae) binds with heavy metals making them indigestible and speeds the elimination of body wastes.

Note: 'Super Blue Green Algae' is basically pond scum. Species like Spirulina are harvested and marketed as capsules or tablets for their alleged health benefits. Unfortunately, eating blue-green algae has been reported to cause nausea and diarrhea, as well as weakness, numbness and tingling in your hands and feet. Health Canada advises consumers that products containing blue-green algae may contain toxins harmful to the liver. Don't go there!

Red Algae:

NORI Red algae is called nori in Japan and red or purple laver in Western countries. Nori has the mildest flavour of all seaweeds, so is a good one to taste first.

PORPHYRIA Porphyria consists of single thin blades, sometimes grey or brownish purple and iridescent or oily in appearance. Porphyria perforata is ruffled and perforated. The Japanese dry and press its cousin Porphyria teneri into thin, black crispy sheets to roll around rice for sushi. Sheet or sushi nori can be lightly toasted over an open flame or electric burner, then cut with scissors or crumbled over salads, stews or casseroles.

DULSE The spicier dulse (Rhodymenia palmata) is more commonly found in New Brunswick and Maine. The rust-red blades found in tidepools and sea-filled crevices vaguely resemble a waving palm. Fresh dulse tastes like potato peelings.

Brown Algae

Brown kelp is harvested commercially for its algin which absorbs huge quantities of water for emulsifying and binding in ice creams, puddings, drugs, paints and make-up and stabilizing the foam on your beer or McDonald's shake. Brown kelp is used in BC to collect herring roe-on-kelp (a delicacy in Japan) each spring. A local company, Barkley Sound Kelp, sells several varieties of dried brown algae for snacks and cooking.

BULL KELP The long brown blades that look like streamers floating along the surface belong to bull or ribbon kelp. Nereocystis luetkeana is the botanical name for the kelp with the thick bulbous stems or stipes. Mercia Sixta told me she has a great recipe for bull kelp pickles. The whip-like strips can be cooked as a vegetable. Dried bull kelp can be toasted and crumbled into flakes to make a seasoning salt for salads, soups and stews. Try using half kelp powder in place of salt in a recipe.

GIANT KELP You may have thrashed through dense beds of pale yellow-brown floats and blades close to the open ocean. This giant or macro kelp (Macrocystis integrifolia) has a mild flavour. Thin, wavy dried giant kelp can be used to wrap sushi, stirfried or added to soups, stews or grains. Barkley Sound Kelp even recommends sprinkling the dried kelp on salads or sandwiches as a garnish. Go for it!

KOMBU You have to bet that kombu, with a name like Laminaria groenlandica, was a delicacy where baidarkas started paddling. Kombu grows in a dense underwater forest of broad, flat black-brown blades where there is substantial water motion. Japanese prepare dashi, a multipurpose stock, from their 'kombu'. Out of the package, kombu sticks could be used to swizzle a Bloody Mary or Caesar. Adding kombu to a bean dish you are making cuts cooking time and makes the beans easier to digest. Remove the kombu before eating the beans. See Kombu Stew.

ALARIA Alaria marginata is the North American relative of Japanese wakame (Undaria). This kelp has a short stalk continuing as a midrib up a long, wavy-edged blade. It is common in the lower intertidal zone on exposed rocky shores, and thrives in rough wave conditions. Tender, tasty fronds of alaria have a milk flavour, without a fishy taste. Soak small pieces of dried alaria in water for 30 minutes to use in salads, soups, stews or stir-fries. Use alaria instead of grape or cabbage leaves to wrap rice, meat, vegetables or seafood.

Green Algae:

ROCK WEED You may have seen swollen yellow-green 'gloves' of seaweed in clumps on shorelines in the intertidal zone. This would be rock weed, sea wrack, bladder wrack or popping crack and officially called Fucus furcatus. Many northern European countries use the young stems in salads. Karen Cline from Valdez, Alaska makes Bladderwrack Tea by adding it to boiling water and steeping for five minutes. She says it makes a sweet bouillon.

SEA LETTUCE The bright green blades that look like cellophane are called sea or water lettuce or green laver. Ulva lactuca is found on rocky shores and in rough weather blades break off and are found in coves and mud flats. In the spring, collect tender leaves to add to a salad or soup. Enjoy your spring paddling and seaweeding.

Deb Leach, a nutritionist, took her naturalist training through the Marine Mammal Research Group in Victoria