All seaweeds are photosynthetic. The best-known truly "pelagic" seaweed (pelagic means living and growing at sea, independent of land) is Sargasso weed, a prolific brown seaweed of the genus Sargassum. This lush plant covers an area of 7000 square miles near the Bermuda Triangle, with a floating layer 1-2 feet thick; modest wave action sorts it out into long even rows that resemble a carefully-planted field on land. After several days of slowly chugging through the Sargasso Sea while taking transatlantic transect vertical plankton tows, I experienced a common visual hallucination and urge to jump off the boat and walk around on the Sargasso weed as had many mariners before me. The urge was compelling. I nearly had to be restrained.
Worldwide post-industrial healthy living consciousness has in the most recent score of years initiated a very deliberate increase in overt human dietary seaweed consumption, especially in the more-developed postindustrial nations where voluntary vegetarian and macrobiotic diets are increasingly popular. Most east Asian populations (Japan, Korea, china) continue to eat large amounts of seaweed per capita. Japan has the highest per capita dietary
Enormous quantities of raw seaweeds are harvested worldwide to feed the increasingly hungry world market for phycocolloids ( which are long chain polysaccharides relatively easy to extract with hot or boiling water). for tens of thousands of food, beauty products, and industrial applications. I do not even briefly believe that eating phycocolloids in highly-processed food can replace or equal dietary consumption of whole raw seaweeds for positive therapeutic or health consequences. Large coastal areas have been vacuumed clean of seaweeds with huge suction harvesters developed by the Norwegians.
Ascophyllum, or rockweed, has been commercially harvested in Nova Scotia for 40 years. From 1962-1986 harvest averaged 6000 tons per year. It was hand-harvested until 1970 when mechanical harvesters were introduced. In 1985 Harvest had increased to 10,000 tons. In 1987 it had increased to 30,000 tons after the introduction of suction harvesters. But by 1991 harvest had declined to 21,000 tons due to previous over harvesting and regrowth inadequate to replace harvested plants. Individual rockweed plants live at least 20 years. Since 1993 large areas of beaches in the eastern Canadian maritime provinces of Nova Scotia and New Brunswick have been denuded. There have been attempts by the harvesters to expand their harvests into Maine.
Environment Canada and Fisheries are trying to halt or at least control such egregious wasting of intertidal seaweed stands. That particular harvest is in support of the huge market for dried seaweed meal as a soil and veterinary/agricultural enhancer, providing an excellent source of minerals for wasted soils and malnutrited livestock. The brown algae Ascophyllum and Fucus spp. are the primary components of the agricultural product "Ag Kelp", although the exact species composition may vary considerably.
Acadian Seaplants has recently completed a large processing facility just north of the US-Canadian border in Nova Scotia. The capacity is allegedly over 100,000 tons per year of product. Help-wanted posters are displayed in many economically-depressed Maine coastal towns in hopes of luring poverty-stricken fishermen and anyone who will harvest with a mechanical harvester up to 6 tons a day of wet seaweed; the price paid for a ton is $25.00. Considering that most hand-harvested seaweed intended for food use sells for $25.00 a pound or much more, the disparity is evident. Huge quantities of live seaweeds must be harvested to eke out a living for the bulk market; contrariwise, at an average 10:1 dry-down from fresh to dried seaweed, hand harvesters can harvest only 60-70 pounds of live wet seaweed per day to make the same money as the 12,000 pounds per day bulk harvester. The food harvester gets as much per dried pond as the bulk harvester gets per wet ton.
Conservation groups as well as the small number of hand harvesters are extremely alarmed at the prospect of near-total scouring harvest of Maine coastal seaweeds. The state is considering a 5-year moratorium on all seaweed harvesting to study the situation. Hand-harvesters rightfully claim that they are in a much different class than the bulk harvesters and should not be kept from continuing their minimal impact harvesting. I have seen the results of 20 years of hand-harvesting in some bays of Maine and agree that the harvest is more than sustainable. I have personally observed similar sustained growth and regrowth in the areas where I have harvested seaweeds for over 30 years.
I believe that is long past overdue for the industries that need to use huge quantities of bulking phycocolloids and seaweeds for feed and fertilizer to start investing in huge offshore mariculture of fast-growing macroalgae. These seafarms could easily be fabricated from photo-resistant recycled plastics and anchored similar to existing Nori farm nets; or, be placed in shallow subtidal areas and fed municipal sewage runoff after either or both primary and secondary treatment of the sewage.
The probable contamination of domestic, non-industrial sewage with heavy metals is the most likely hazard; oil-soluble toxins would probably not be a significant factor unless oil-producing microalgae(diatoms) living epiphytically on the macroalgae (seaweeds) were abundant enough to absorb oil-soluble toxins from industry, agriculture and lawn care which spill into sewage plants when storm sewers empty into domestic sewage drains (a practice which must be eliminated as soon as possible; domestic sewage is too valuable to contaminate and treat as useless waste; it should be used to grow even just useful biomass if not particularly useful food and or industrial crops such as fiber plants or seaweed phycocolloid plants). In addition to direct soil and animal feed applications, seaweed extracts are sprayed directly onto crop plant leaves to facilitate "foliar feeding" through the leaf stomates.
Irish moss is also vacuum-harvested; such harvesting is a serious threat to both intertidal and subtidal ecosystems. The bycatch of other seaweeds and fauna is horrific. Another red alga, an agarophyte (produces agar), Gracillaria spp. had been mostly eliminated by aggressive harvesting on several Caribbean islands to support a booming male virility tonic folk industry for both local and export consumption. These are basically favored hot water extracts. From Belize (where I purchased a bunch for personal delights and consumer testing; at least there were no noticeable adverse reactions) to the Virgin Islands "Seaweed Drink" is popular; it must be effective.
To counter the near eradication of the wild populations, local scientists and fishermen and seaweed harvesters joined to develop rope and net mariculture similar to Nori culture; small sets of wild Gracillaria and related red seaweeds are placed in regularly-spaced places in twisted plastic rope and suspended in seawater and allowed to grow to harvestable size. On at least 8 islands, including Jamaica, Trinidad, St. Lucia, Barbados, and the process has been very successful after some lumpy trial and error in matters of placement and anchoring. So much so that there is a booming industry in the re-emergence of traditional phycocolloid-containing local food products beyond the "Sea Moss" virility drinks. Frankly, what once thrilled me, now saddens and worries me: my doctoral work was in Phycology, the study of algae; for me it was a combination of cell biology and ecology. Although I started out in freshwater algae, once I had taught in the algae course at Woods Hole and gone out collecting (amongst phycologists, "harvesting" is an extremely pejorative term, unacceptable to serious scholars and friends of the seaweeds) the gorgeous huge marine algae, seaweeds, growing on the rocky stretches of the Massachusetts' coast, I became an instant fan of these exquisite plants. In truth, I was thrilled at their many industrial, medicinal, and culinary uses. I did not envision the realities of imminent over harvesting back in 1967.
I left UMASS-Amherst to be a visiting professor at UCLA where I taught the Marine Botany class, an advanced class on marine algae, large and small. I was totally excited by the lush growths of huge kelps, enormous greens, bountiful reds, and of course my special friends, the diatoms, solitary and colonial unicellular algae living inside fantastically-ornamented glass cell walls, all thriving on the rocky shores of California. Within a month of my arrival at UCLA the plumbing controlling high-pressure crude oil on the drilling rig # 3 offshore from Carpinteria, CA failed and a huge quantity of thick black viscous and sticky petroleum began to coat the coast repeatedly as surge after surge of crude oil spewed into the sea and washed ashore on the breakers, killing the entire intertidal zone for hundreds of miles. Not only were the extant seaweeds killed, but the perfect rock surfaces were filled and coated with tar which proved unfit for seaweed growth for a year or more.
This was not an isolated one-time event; perhaps much more than aggressive harvesting, crude oil from shipping disasters and the known accepted everytime spillage as crude oil is loaded on and off oil tankers is probably the greatest environmental hazard for seaweeds worldwide. Onshore and nearshore pollution from both sewage and industrial wastes also makes large areas unsuitable for further seaweed growth. I have observed steady and sometimes abrupt decline in the total area and biomass and species diversity in all three of the coastal locations where I have lived and harvested sea vegetables, New England, California, and Washington. I personally believe that here is a great future in pelagic sea vegetable farming with huge floating artificial substrates in the open seas if sufficient capital is available.
My personal and professional rules for seaweed harvest are very basic: choose the cleanest waters you can find and verify by talking to locals and calling ecology and health agencies before harvesting sea vegetables. Cut the seaweeds from rocks using stainless steel scissors, leaving the holdfasts and some plant material for regrowth; each specific seaweed has its own special harvest and processing requirements (see Lewallen and McConnaughey). Harvest only what you will actually be able to process and use; try harvesting on cloudy cool days at low tide when the individual plants are not heat or drying-stressed, which means they will transport better and tend to yield a much tastier product.
I try to dry my seaweeds outside in the full sun for 4-10 hours all in one day; if this is not possible, I dry them, or finish drying them, inside at 80-100 degrees F using wood heat and small muffin fans for air circulation. I place them in airtight opaque containers immediately after they are totally dried.
Gathering seaweed, kelp and nori
SEAWEED SAFETY: When are seaweeds not safe for food and medicine?
CAUTION: Those rare individuals who are iodine-sensitive should avoid consumption of the large northern kelps often sold as: Kombu, Norwegian Kelp, or Icelandic Kelp; These brown algae, mostly Laminaria spp., can have up to 8000ppm iodine. Nori tends to have the least iodine of the commonly eaten sea vegetables at 15ppm.
Although all seaweeds are innately safe to eat, they can become dangerously contaminated by sewage, industrial, mining, agricultural, and radioactive wastes where they grow. Infectious microbes and parasites are usually absent from seaweeds in cold northern waters. In warm tropical seas, Cholera is transmissible
Most North American dietary sea vegetable harvesters are very proud of harvest place and practice (see list of reliable harvesters at end; they all harvest by hand and in small amounts). In England, sea-dumped London-sourced radioactive medical waste contaminated Laver (Nori) used abundantly in Laver Bread, and other dietary seafoods and caused radiation sickness in coastal villagers who consumed those seafoods.
Nori (several species of the red algal genus Porphyra) is probably the most popular seaweed for eating, both historically and today. It is yummy in soups, re-wetted in salads, just as a dried snack, toasted lightly in a dry iron skillet, deep-fat-fried with cooked rolled oats as the Celtic "Laver Bread", and as a food wrap in sushi. Nori sheets are a manufactured food product. Nori was eaten abundantly by indigenous peoples wherever both occurred. It tends to have a sweet, meaty flavor pleasant to most palates.
Dulse, another red alga, is another easy to eat snack but quite salty and often a little fermented in the marketplace; its relatively high fatty acid content results in rancidity after a year or more in storage.
The large brown"kelps" (Kombu/Laminaria groendlandica, Sugar Kelp/Laminaria saccharina, Wakame/Alaria spp.) can be eaten just dried but usually are easier to eat when cooked with grains, legumes or miso soup broth.
The bright green dried fronds of the local giant kelp, "Bull Kelp"(Nereocystis luetkeana). are a great snack, salty and high in vitamins and minerals (up to 50% dry weight), particularly potassium, protein and free amino acids.
Other brown algae, Hijiki/Cystceria geminata, Sargassum/Sargassum mutica, Sea-palm, are usually best cooked with wet food as in soups, miso broth, grains, legumes, vegetable pies and stews.
Sea Lettuce (Ulva lactuca and Monostroma spp.) has a strong seafood taste and odor but is easy to eat as a snack or in salads since it is quite delicate after drying and crumbles easily into tiny tender pieces.
How Long Do Seaweeds Keep After Harvest? In proper storage, most totally-dried sea vegetables stay nutritionally and medicinally secure indefinitely. The minerals do not degrade; the phycocolloids slowly fragment over years; the pigments slowly fade, especially the chlorophylls; fats slowly become rancid; proteins fragment slowly to polypeptides and amino acids.
What Health And Nutritional Benefits Can Result From Regular Seaweed Consumption? From my perspective, sea vegetables are an essential component of all therapeutic diets. Seaweeds, eaten regularly, are the best natural food sources of biomolecular dietary iodine. Seaweeds do not seem to accumulate fat-soluble pesticides and industrial wastes such as PCP, PCB and dioxin, unlike marine animals; the latter are also good sources of dietary iodine. Land-based vascular plant iodine content tends to be low. No land plants are reliable sources of dietary iodine. Food crops grown on mineral-depleted soils from poor agricultural practice usually contain inadequate amounts of dietary iodine. Iodine is the essential element in most thyroid hormones, natural and synthetic. Iodine is also essential for the maintenance of normal mammary gland architecture and salivary gland health.
A note: What exactly does "eaten regularly" imply? To me, it means eating 5-15 grams of
Dietary Minerals: Sea vegetables are excellent sources of most minerals, especially: potassium, sodium, calcium, magnesium, sulfur, nitrogen, iron, zinc, boron, copper, manganese, chromium, selenium, bromine, vanadium, nickel; often better sources than meat, whole milk, or eggs and usually better than any land plants. This means that high-quality sea vegetables can be used to compensate for the frequent low mineral content of food plants and animals grown "factory-style" on mineral-depleted soils. (See: Bergner).
Active Removal Of Radioactive and Heavy Metal Toxic Cations: The phycocolloids, Algin in all
Vitamins: Most sea vegetables are excellent sources of the known vitamins (A, B's, especially B12, C, D, E, and K) as well as essential fatty acids. Powdered Bladderwrack has been mixed with olive oil as a safe effective alternative to cod liver oil. Nori is very rich in vatamins A & C. Special Therapeutic Uses: Lower Respiratory Problems: Phycocolloid carageenan gel, boiled out of red algae, notably Irish Moss (Chondrus crispus), Grapestone (Gigartina spp.) and Iridea, is both partially digested and absorbed as small globular polymeric masses. This gel is effective long-term treatment for damaged lungs, particularly after pneumonia, smoking, emphysema, chronic bronchitis and possibly Mycoplasma and Chlamydia.
Lung Function: Regular consumption of Hijiki and Sargassum, brown algae, seems to aid respiratory function, improving lung capacity and gas exchange efficiency.
Herpes Outbreak Relief: The red alga, Dumontia, is dried, powdered, encapsulated, and used as a genital herpes suppressant. Sources for Dumontia are listed on the net under genital herpes. I discourage using Dumontia because of very limited amounts of wild plants. Prionitis Lyallii, a much more abundant tidepool red alga from California to Alaska, is used similarly. It has not been tested clinically or in any long-term treatment programs.
Shingles Outbreak Relief: Three different red algae harvested in Southeast Alaska by R. Ellis and Natasha Calvin, are also dried, powdered and encapsulated and taken in prescribed dosages regularly to suppress outbreaks of Shingles, Herpes zoster. They are called Alaska Dulse together.
Erectile Dysfunction: Tropical species of Gracilaria, an agarophyte red seaweed, are used to prepare a male virility drink variously called Seaweed Drink or Sea Moss Tea in the Caribbean.There seems to be improvement in both desire and performance. Local demand was sufficient to foster nearly total elimination of these seaweeds on many islands. The drink is prepared similarly to the respiratory gel described above, namely, by repeatedly boiling the same algal mass until no more gel remains. I tried the drink on Caye Caulker several times and concur that desire for coital intimacy seemed to be enhanced.
Tissue Repair: I use a broth of powdered Sagassum muticum (a large local brown alga) and unpasteurized 3 year old Barley Miso paste for all cancer. radiation, chemo, post-surgical, and wholebody impact trauma (acute auto crashes, falls) patients. I recommend twice daily, AM and PM, mixing 15 ml of miso paste with 5 gm of Sagassum powder in about 300 ml of hot (120 F) non-chlorinated water. For cancer patients I also recommend 15 ml fresh pressed sheep sorrel (Rumex acetosella) juice from live plants twice daily with food. For trauma patients I recommend 20-40 Hawthorn berries (Crataegus oxycantha or C. monogyna) or 5 ml Hawthorn Tincture three times daily with food. Japanese studies show very positive clinical and preventative anti-tumor, anti-metastatic success using seaweeds, especially Sargassum.
Nervous Disorders: Attention Deficit Disorder (ADD), Hyperactivity, Insomnia, Depression, Hostility and Schizophrenia are often markedly improved if not resolved by regular consumption daily of 3-5 gm powdered kelp, especially Bull Kelp (Nereocystis). I assume here we are treating basic long-term malnutrition, especially mineral deficiency. Hay Fever and Asthma are also helped by 3-5 gm powdered kelp daily.
Phytoestrogens: Many seaweeds contain significant amounts of lignans which are readily converted by intestinal microflora to non-steroidal estrogenic molecules which bond preferentially to ErB, the recently discovered estrogen receptor site. There are often more lignans in selected seaweeds than in legumes, whole grains, vegetables and fruits.This may explain their apparent therapeutic and preventative value against estrogen-driven neoplasms.
Cardiac Troubles: Regular consumption of Kombu (Laminaria spp.) tends to result in lowered blood pressure, plaque removal from arteries.
Breast Cancer: Regular dietary consumption of Wakame and other brown algae may prevent breast cancer. Fucoidan:Fucoidan is a sulfated polysaccharide extracted from many brown algae with hot water. It is a potent antiviral; it can inhibit virus attachment onto host cells, inhibit cell penetration, and inhibit viral intracellular replication. It shows strong activity against Herpes Simplex 1 HIV 1 and H-Cytomeglovirus. It also inhibits lung metastases. It shows strong antitumor activity by enhancement of inflammatory responses and upregulation of leukocytic phagocytosis. It is more antiproliferative than comparable doses of Heparin. All human cells studied are found to have receptor sites for Fucose, the end-group sugar on Fucoidan.This molecule is perhaps most important in the therapeutic future for seaweeds. I hope that it will be given as whole seaweed powders rather than industrial extracts with their inevitable contaminants. Pretreatment with Fucoidan significantly reduces hemorrhagioc shock pooling increase in the vascular bed after surgery.
Research continues. Eat sea vegetables today!!!