Why seaweed is not a plant

Most notably, the mineral content of seaweeds is 10 times as great as that found in plants grown in soil; as a consequence, people who regularly eat seaweeds seldom suffer from mineral deficiencies. In addition, marine algae are endowed with a wide range of trace elements and vitamins.

Because they contain a large volume of soluble and insoluble dietary fiber, which are either slightly, or else completely, indigestible, seaweeds also have a low calorie count. A wild strain of Chondrus crispus , or Hana-Tsunomata in Japanese, appeals to both the eye and the palate.

This seaweed has a distinct crunchy texture and a milder taste than most other sea vegetables. Its flamboyant colors—pink, green, and yellow—are completely natural. Marine algae possess a fantastic ability to take up and concentrate certain substances from seawater. For example, the iodine concentration in konbu and other types of kelp is up to , times as great in the cells of the seaweeds as in the surrounding water, and the potassium concentration is 20—30 times greater.

On the other hand, the sodium content is appreciably lower than that of salt water. Depending on the species, fresh seaweeds are 70—90 percent water by weight. The composition of the dry ingredients in the different types of seaweeds can vary a great deal, but the approximate proportions are about 45—75 percent carbohydrates and fiber, 7—35 percent proteins, less than 5 percent fats, and a large number of different minerals and vitamins.

Broadly speaking, the proteins in seaweeds contain all the important amino acids, especially the essential ones that cannot be synthesized by our bodies and that we therefore have to ingest in our food. Porphyra has the greatest protein content 35 percent and members of the order Laminariales the lowest 7 percent.

Three groups of carbohydrates are found in seaweeds: sugars, soluble dietary fiber, and insoluble dietary fiber. Many of these carbohydrates are different from those that make up terrestrial plants and, furthermore, they vary among the red, the green, and the brown species of algae. The sugars, in which we include sugar alcohols such as mannitol in brown algae and sorbitol in red algae, can constitute up to 20 percent of the seaweeds.

The seaweed cells make use of several types of starch-like carbohydrates for internal energy storage; again, these vary according to species. For example, the brown algae contain laminarin, which is of industrial importance as it can be fermented to make alcohol. Norwegian winged kelp Alaria esculenta is appearing on the menus of top restaurants. Soluble dietary fiber, which is situated in between the seaweed cells and binds them together, constitutes up to 50 percent of the organism.

Composed of three distinct groups of carbohydrates, namely, agar, carrageenan, and alginate, fiber can absorb water in the human stomach and intestines and form gelatinous substances that aid in the digestive process.

Insoluble dietary fiber derived from the stiff cell walls of the seaweeds is present in lesser quantities, typically amounting to between 2 percent and 8 percent of the dry weight. Cellulose is found in all three types of algae and xylan another type of complex carbohydrate in the red and green ones. The primary mineral components in seaweeds are iodine, calcium, phosphorous, magnesium, iron, sodium, potassium, and chlorine.

Added to these are many important trace elements such as zinc, copper, manganese, selenium, molybdenum, and chromium. The mineral composition, especially, varies significantly from one seaweed species to another. Konbu contains more than —1, times as much iodine as nori. On average, dulse—a widely eaten red seaweed—is the poorest choice in terms of mineral and vitamin content but, on the other hand, it is far richer in potassium salts than in sodium salts.

In general, marine algae are a much better source of iron than foods such as spinach and egg yolks. Seaweeds contain iodine, although the exact quantities again vary greatly by species. The iodine content is dependent on where the seaweed grew and how it has been handled after harvest. Furthermore, the iodine is not evenly distributed, being most abundant in the growing parts and least plentiful in the blades. In particular, the brown seaweeds contain large amounts of iodine.

It is not known for certain why brown seaweeds contain so much iodine, but this is probably linked to their capacity for rapid growth. Iodide was found to act as the main antioxidant for this tissue. In addition, the study showed that the action of iodide was not accompanied by an accumulation of organically bound iodine. The history of the discovery of iodine as an element actually begins with seaweeds. He noticed that his chemical experiments with the seaweed ash gave rise to a violet-colored vapor that condensed as crystals on his copper vessels and, unfortunately, caused them to corrode.

Courtois convinced first his French, and later his English, fellow chemists that his discovery had important dimensions. Their work then rapidly led to the identification of the substance that was the source of the vapors. It turned out to be a previously unknown element and, as the color violet is called iodes in Greek, the new element was given the name iodine.

Terrestrial plants are a poor source of iodine, which can result in iodine deficiency in vegetarians and vegans. The accidental discovery of iodine in seaweeds is a wonderful example of how research and an open mind on the part of the researcher can lead to results that have a major significance for the economy and for human health. Despite their importance to human diet, seaweeds have often been regarded with disdain.

That unpleasant smell is due to a number of gases that are not dangerous, but are the source of odors that we consider offensive. In a bowl mix together the oats, seeds, seaweeds, salt, and baking powder. Add water and mix well until the dough becomes sticky. Divide the dough into two and place one part on a piece of baking paper. On top of the dough add another piece of baking paper and roll the dough out as thinly as possible between the two. With a knife or pizza wheel cut the top baking paper and divide the dough into squares without cutting through the bottom paper.

Remove the top baking paper and place the dough and the bottom paper on a baking sheet. Repeat the procedure with the other part of the dough. Often growing in towering groups, kelp form dense clusters in shallow waters, creating communities that are like underground forests. Giant kelp can grow over 33 meters long, and scientists have recorded ten to twelve inches of growth a day in giant kelp that live in Monterey Bay off the coast of California. Besides being an important food source in parts of the world, seaweeds also contain anti-inflammatory, anti-microbial and cancer-fighting compounds that are used for medical purposes, according to the National Ocean Service.

Seaweeds have been used for thousands of years for their health-promoting properties. Seaweeds also play an important role in underwater ecosystems. They provide food and shelter for fish and other marine animals like sea urchins and crustaceans. Living at the base of the food chain, they support many other life forms in aquatic communities.

Just like other photosynthetic organisms, seaweeds produce oxygen as a byproduct of photosynthesis. It is estimated that algae produces 30 to 50 percent of Earth's oxygen, which sustains humans and other species that live on land and in the sea. As it captures carbon, seaweed also helps to reduce the acidity of the ocean. Seaweeds reduce pollution by absorbing excess nutrients and toxins — like organic chemicals and heavy metals — from the water.

A common feature found on our kayak tours around Vancouver Island is the presence of seaweeds in their many shapes and forms. They can be very tiny, or very large — growing to over 30 metres long. They have many plant-like features but are not true plants; they are algae. Seaweeds are not true plants because they lack a vascular system an internal transport system for fluids and nutrients , roots, stems, leaves, and enclosed reproductive structures like flowers.

Because seaweeds are in constant contact with the water, they are able to absorb all that they need directly. Instead of roots, seaweeds have holdfasts, which attach them to the sea floor. Seaweeds are multicellular algae known as macroalgae — or, simply, "big algae. They are shaped like plants for a reason. To Shetterly's way of thinking, many seaweeds have the appearance of miniature trees. Calling them weeds does them a disservice.

We also tend to use the word weed, she points out, to refer to something that we think has little value. That line of thought brought out one of the favorite quotes from her research.

It's from Paul Molyneaux, who has written about commercial fishing for The New York Times and who won the Guggenheim Fellowship to study sustainable fisheries in several countries: "We don't know how to assess the value of species within their ecological community.

So, we tend to think of them as worthless rather than priceless. The rest represents seaweed extracts for a wide range of uses.

China and Indonesia are the largest producers of seaweeds grown in aquaculture farms. The United States and Europe are quickly catching up. Maine is fast becoming the largest seaweed producer of edible and commercial seaweeds in the United States. It is almost impossible to go through a day without encountering seaweed.

Its uses, Shetterly says, fall into two broad categories: processed foods and processed non-foods. Many processed food products contain seaweed. Two soft-food examples are puddings and edible oils. Nori, the Japanese name for seaweed, is part of a common daily diet in Japan and is used in such items as rice balls, sushi roils and salads. The Japanese eat more seaweed than any other culture, which some nutritionists say has led to the country's high life expectancy.

Many processed non-foods contain seaweed. These include toothpaste, cosmetics, soaps, medicines, pet foods, cattle feeds and farm fertilizers. The gel is also used by the printing industry as a component in the gloss or coating in glossy papers, as part of the fluids used in fracking and by medical and other labs in petri dishes to grow tissue cultures, according to Shetterly. Seaweeds are slippery and slimy for a reason.

When Shetterly gives talks about seaweed, something she wants to get out of the way at the beginning is that, yes, seaweeds are slippery and slimy. Without the gel, the fronds would either self-amputate or they would amputate their neighbors. The other thing is that the gel protects seaweeds from sun damage when they are exposed to the sun during low tides.

When the tide is extremely low, and we have very low and very high tides here, the seaweed will lie against the rocks. Not only that, but all sorts of animals that live on the fronds are protected as they lay between the fronds and the rocks during low tide.

The gel coating protects the seaweed and the seaweed protects the tiny animals from the sun by keeping them damp and briny while they wait for high tide to return.