by Life Enthusiast Staff
Knotted wrack (Ascophyllum spp.), Rockweed, bladderwrack (Fucus spp.)
Description: There are several species of the genus Fucus, and one species of Ascophyllum with several different forms or "scads." The Fucus species generally have dividing, Y-shaped, flattened blades with a prominent midrib. Fucus species may reach 2 or 3 feet in length and are not easily distinguished from each other.
Fucus vesiculosus has paired air bladders within the blades that "pop" when they are stepped on. These bladders keep the seaweed afloat so its photosynthetic tissues are more effectively exposed to sunlight. Breeding receptacles are football-shaped structures at the tips of the plant-orange if male and olive-green if female.
F. spiralis lacks bladders and has twisted fronds and numerous tufts of dark brown hairs scattered across the surface. Receptacles at the tips of the plants are "winged"--having a narrow, shelflike tissue bordering each one. F. distichus (subspecies edentatus, evanescens, and fileformis) are distinguished by the shape of their receptacles, which are 2 to 4 inches long and have a pointed tip.
Ascophyllum has long fronds without a midrib and narrow, unflattered, straplike blades with air bladders that grow singly and are scattered throughout the plant. Receptacles are small, pea-sized, yellow structures (found during the winter) along the length of the plant and attached by short stalks. A. nodosum has been reported to have a life span of about 20 years and is the dominant species of the sheltered and semi-exposed intertidal zone.
Habitat: These algae form the prominent "rockweed" zone of the intertidal region in northern New England. This is the generally dark brown area that is very slippery to those walking on rocky shores and ledges.
F. spiralis is found at the upper level of the intertidal zone, F. vesiculosus forms a band toward the middle, and F. distichus subspecies are found in tide pools in the high intertidal and extend into the shallow subtidal zone. Ascophyllum prefers shores protected from heavy wave action and may also be found in tidal pools of salt marshes. Some of the less common forms of Ascophyllum (i.e.. A. nodosum ecad scorpioides) are free-living, growing unattached and often entangled in Spartina salt-marsh grass.
Foraging: Ascophyllum and Fucus are perennials. Because they grow slowly, it is best to collect them after they have washed up on the beach after a storm.
Uses: The main uses of Ascophyllum and Fucus are as fertilizers, soil conditioners, and sources of micronutrients in animal feed supplements. Studies have shown that seaweed fertilizers promote plant growth by supplying necessary minerals and growth hormones, and by improving soil structure. Studies have shown that when these seaweeds are used in animal feed, cows produce more milk, chicken eggs have better pigmentation, and horses and pets are generally healthier. These seaweeds are also important packing materials for shipping live lobsters and marine bait worms. A special form of Ascophyllum called wormweed (A. nodosum ecad scorpioides) is a gold-colored seaweed with very fine fronds that grows in localized areas and is used exclusively for the sand and bloodworm bait industry.
Processing: Local farmers gather rock-weed for use as a fertilizer and soil conditioner, and simply bury it in their gardens. When used as an animal supplement, the algae are dried in commercial dryers to 10 to 12 percent water content and milled to various particle sizes. Some is processed into liquid fertilizer. Alginates are extracted chemically and used in bulking, gelling, and stabilizing processes. Products using alginates include charcoal briquettes, cosmetics, ceramics, cheese, paint, asphalt, rubber tires, polishes, toothpaste, ice cream, and paper.
Nutrients: Very high in magnesium, and high in protein, vitamin A, iodine, bromine, and phosphorous. Also contain sugar, starch, vitamin C, vitamin K, vitamin E, zinc, potassium, calcium, sodium, sulfur, chloride, silicon, iron, manganese, copper, zinc, cobalt, titanium, hydrogen, molybdenum, lead, barium, boron, radium, and trace elements.
Oarweed, Kelp - Laminaria longicruris
Description: This brown kelp has a very long, narrow stipe (which may be 6 feet long) transforming into an elongated, flat blade with no midrib. The stipe becomes somewhat swollen and hollow before it joins the blade. Blades are fairly thick in the midsection, thin and a bit ruffled at the edges, and may be 6 to 30 feet long and very wide. Laminaria has a large branched holdfast. Plants range from olive-tan to olive-brown.
Habitat: A dominant plant of the coast, it grows in dense forests below low tide mark, from the shallow subtidal to deep water along much of northern New England's shores.
Foraging: Peak harvest for Oarweed is in April and May. Blades are harvested by cutting with a knife or sickle at low spring tides.
Uses: These kelps are a prominent source of algin and food in the Oriental market. Traditionally they have been a source of iodine and potash. Their stipes were used to open wounds, aid in cervical dilation, and induce abortions. Oarweed is harvested in Maine for health food stores where it is sold as "kombu." Prepared plants may be cooked as a vegetable or added to soups. As with the other kelps, oarweed is a natural source of monosodium glutamate.
Processing: Oarweed may be air- and sun-dried (or smoke-dried over a woodstove) and sold whole or milled and sold as seasoning.
Nutrients: High in calcium, potassium, magnesium, iron, and trace minerals such as manganese, copper, and zinc. Also provides chromium, instrumental in blood sugar regulation; and iodine, essential to the thyroid gland.
Sugar Kelp - Laminaria saccharine
Description: A brown kelp with a strong, root-like holdfast supporting a flexible, cylindrical stipe and a blade that is commonly 6 feet or more in length. The margins of the mature blade are quite thin and often very ruffled. When dry, sugar kelp is covered with a sweet, white substance- hence its name saccharine, which means "sugary."
Habitat: L. saccharine is found attached to stones and shells below the low tide mark, in areas ranging from the shallow subtidal to around 60 feet deep. Dense masses of these long, leathery blades moving back and forth in the water resemble an under water forest.
Foraging: Peak harvest for sugar kelp is in late spring (for high vitamin C) and summer (for high sugar alcohol) content. Blades are harvested by cutting with a knife or sickle at low spring tides.
Uses: Similar to those listed for L. Iongicruris.
Nutrients: Very high in iodine and bromine. High in protein and sugar. Also contains starch, nitrogen, vitamin K, vitamin B12, vitamin C, sodium, chloride, rubidium, radium, cadmium, cobalt, boron, manganese, nickel, glutamic acid, and trace elements.
Horsetail Kelp, Fingered Kelp - Laminaria digitata
Description: Plants are olive-tan to olive-brown. A mature plant is broad at the base, becoming heart-shaped and deeply cleft with 6 to 30 narrow, flattened blades growing from a single stipe - hence its name digitata meaning "fingered." Its stipe is relatively short and thick and becomes flattened toward the blade. The holdfast is heavy, close, and fibrous. Horsetail kelp grows to 3 feet long.
Habitat: This kelp is found most abundantly below the low tide mark in areas exposed to heavy surf or strong tidal currents and occurs occasionally in tidal pools. A deepwater form of this plant may also be found in coastal waters at depths of 40 to 60 feet.
Foraging: Horsetail kelp has an annual blade with a perennial holdfast and fruits in winter. Harvest in the spring for high vitamin C but low starch. It is harvested at very low tides with sickles.
Uses: In the health food industry, it is used as a flavoring in soups and especially in baked beans. It may also be used as a cooked vegetable.
Processing: This kelp is dried, (either air-dried over a clothesline or smoke-dried over a wood stove) until plants are just pliable, then folded or pressed, and packaged in plastic bags It may also be milled and used as a seasoning.
Nutrients: Very high in iron. High in iodine, bromine, phosphorous, boron, and zinc. Also contains protein, sugar, starch, vitamin A, vitamins B1 and B12, vitamin C, calcium, magnesium, sodium, cobalt, chloride, potassium, sulfur, silicon, vanadium, soluble nitrogen, strontium, aluminum, rubidium, radium, copper, manganese, titanium, nickel, and trace elements.
Edible Kelp, Winged Kelp - Alaria esculenta
Description: This single-bladed kelp is olive brown, about 6 inches wide, and 6 to 12 feet long with a distinct flattened midrib, thin ruffled edges, and small, spatula-shaped leaflets (reproductive blades called "sporophylls") growing near the base of the stipe. The blade is usually frayed or split toward the tip.
Habitat: Alaria is often found attached to rocks just below low tide out to 25 feet in areas exposed to strong tidal currents and waves.
Foraging: Alaria is a biennial (lives for two years) with a peak harvest in May and June. It is harvested from boats with long-handled hooks or hooks attached to long ropes. It is also collected by wading out in hip boots at very low tides and cutting the algae from rocks using a sickle. Regeneration is ensured when the main blade is cut 2 to 3 inches above the stipe and the sporophylls are retained. Leaving some of the blade allows the plant to regrow for another harvest while the sporophylls will produce spores, allowing the plant to reproduce sexually.
Uses: The scientific name esculenta means "edible" and describes its primary use as food. Alaria is often sold in health food stores as "wakame."
Preparation: Before using, soak fronds (and/or midribs) in fresh water for two days. Reproductive "leaflet" blades may also be eaten. Alaria is eaten fresh-chopped and added to a salad-or it may be sun-dried, crumbled, and used as a salty seasoning. It is best to store dried Alaria in sealed plastic bags to retain freshness.
Nutrients: Very high in calcium and vitamin A. High in vitamins B2, B6, and B12; and vitamin K, iodine, and bromine. Also contains sugar, starch, vitamin C, nitrogen, boron, radium, rubidium, cadmium, cobalt, nickel, and trace elements.