10. Some grow 20 inches in a day.

Diver in a kelp forest(Img Cred: Wikimedia, Magnus Manske)

Kelps are one of several categories of seaweed. But they are not plants, they are a type of brown algae. The largest kelp species, of the Macrocystis genus, can grow up to 20 inches per day and 260 feet tall.

Laminaria species are most common in New England, living in the zone between low tide and deeper ocean waters, and they shed their blades—the equivalent of plant leaves—annually.

Instead of roots, kelps have holdfasts that anchor the algae to the sand or rock, but do not absorb nutrients like plant roots do. Many kelps have gas-filled bladders called pneumatocysts that hold the blades up near the ocean surface so they can photosynthesize.

10. Some grow 20 inches in a day.

9. As diverse as rainforests

Wolf fish live in and protect kelp beds.(Img Cred: Wikimedia, Haplochromis)

Kelp beds support a diversity of life that rivals that of rainforests. They provide habitat for fish, lobsters, and countless invertebrates. Sea otters forage kelp beds for food and use them as floating nurseries for their pups.

But a sudden crash of just one species can throw the entire ecosystem off-balance. For example, sea urchins prey on kelp, but when left unchecked, they quickly kill off all of the kelp, leaving the underwater landscape bare of most species except for the urchins. Such areas are called urchin barrens and are caused by overfishing or overhunting of sea otters, which are natural sea urchin predators.

In New England, overfishing of large fish species like wolf fish and cod led to the explosion of green sea urchins and a decline of kelp beds. Urchin harvests in the 90s brought back the kelp beds. But overfishing continues, leaving only a few species—crab and lobsters—to dominate the food web.

This lack of diversity makes the ecosystem even more vulnerable to species declines.

9. As diverse as rainforests

8. Kelp beds are a huge carbon sink.

A sea otter feeds on a purple sea urchin.(Img Cred: Wikimedia, Clayoquot)

Kelp beds and forests store about 60 million metric tons of carbon worldwide, according to the International Union for the Conservation of Nature.

One March 2011 study in the journal Global Change Biology estimates that if sea otter populations—which protect kelp forests by feeding on sea urchins—were restored, kelp forests would recover and draw an additional 10 million tons of carbon from the atmosphere.

On the European carbon trading market, this much carbon is worth an estimated 500 million Euro ($700 million) in carbon credits. Carbon credits are an international currency used to limit the amount of carbon dioxide and other greenhouse gases that industries are allowed to release into the atmosphere.

8. Kelp beds fight global warming

7. It can induce labor

Dried kelp(Img Cred: Wikimedia, Lyzzy)

Laminaria is commonly dried and applied directly to the cervix in order to induce labor. The seaweed has hygroscopic—water absorbing—properties, which means it draws water from the tissues it comes into contact with. When placed against the cervix, the hygroscopic action causes the cervix to dilate.

Laminaria is also used to widen the cervix before abortion and other gynecological procedures.

The use of kelp for these purposes has been compared to pharmaceutical drugs on the market and found equally if not more effective.

Pregnant women should not eat Laminaria because it can upset the normal balance of pregnancy hormones.

7. It can induce labor

6. It may fight chronic disease

Sea belt, a Laminaria species found in the Atlantic ocean.(Img Cred: Wikimedia, Citron)

Though no human clinical trials have been conducted to support the claims, some people use kelp in the form of dietary supplements to lose weight, and treat illnesses such as high blood pressure, cancer, HIV, heartburn, and constipation.

Preliminary experiments suggest that there could be truth to some of these claims, but further research is needed because the potential medicinal properties of ocean organisms is largely unexplored.

Kelps are rich in antioxidants which are known to reduce cancer cell growth, and some sugars in Laminaria have virus-fighting properties and blood-thinning properties similar to that of heparin—a drug used to prevent stroke. Some kelps also contain compounds, such as histamines and an amino acid called laminine, that can reduce blood pressure.

6. It may fight chronic disease

5. We eat it every day

Kelp candy(Img Cred: Wikimedia, Kahusi)

The sale of kelp in food products is a $7 billion per year industry in Japan and it makes up ten percent of their diet. It is made into noodles, added to soups, served as a side vegetable, and can even be found in candy. The dried kelp that may wrap your sushi is known as kombu. Though kelp does not yet feature prominently in the American diet, we consume $1 billion worth of the seaweed in the form of additives to food and other products. Alginate—a carbohydrate extracted from kelp--is a thickening agent in toothpaste, ice cream, beer foam, yogurt, and skin creams. It is also used for fertilizer, food for livestock and pet fish, and as ingredients in pharmaceuticals. In the past, kelp has been used to make paper and burned to produce the potash in gunpowder and for use in the glass-making process. Today, potash is now most commonly mined from rocks.

5. We eat it every day.

4. Can reduce cancer risk in women

This mollusk may already know the medicinal properties of kelp.(Img Cred: Wikimedia, Flickr upload bot)

An unknown component of kelp has been found to reduce levels of the sex hormone estradiol, according to a 2005 study. High levels of this hormone have been linked with a higher risk of breast, endometrial, and ovarian cancers, so lower levels may lower cancer risk. Researchers think that antioxidants in the seaweed may be the active compounds responsible for decreasing estradiol. Dietary kelp supplements have also been found to lengthen menstrual cycles—another factor known to correlate with a reduced risk of cancer. Bladderwrack (Fucus vesiculosus), the seaweed used in the study, is the most common form of seaweed sold in the United States.

4. Can reduce cancer risk in women

3. It is easy to farm

Range of different kelp species(Img Cred: Wikimedia, Chumwa)

Kelp grows naturally along the coast of every continent except Antarctica and it has been collected and eaten by humans for centuries. But traditional kelp harvesting involves cutting kelp from the shore, which can damage the environment. America’s first commercial kelp farm, Ocean Approved, opened in 2008 in Casco Bay, Maine, and is taking a different approach to the harvest. This commercial farm grows the seaweed on floating rafts similar to those used for growing oysters.

Once the kelp grows to about seven feet in length, the rafts are hauled in and the kelp is removed. It is then harvested, boiled, frozen, and sold for about $20 per individual “plant.” With the use of rafts, the farmer’s growing area is no longer limited, and the fragile coastline is protected.

3. It is easy to farm

2. It’s more powerful than spinach.

Spinach makes Popeye strong, but kelp will make you stronger. (Img Cred: Public domain)

Kelp contains 15 times more iron than spinach, three times more calcium than milk, and is rich in potassium, magnesium, and vitamin C, K, riboflavin, and folate. It is also low in cholesterol and is a good source of fiber. People with thyroid conditions sometimes eat kelp because it is naturally high in iodine. However, people with hyperthyroidism—an overactive thyroid—are cautioned to avoid it. Kelp is also very high in sodium, so it is not recommended for those with high blood pressure. The seaweed also tends to accumulate heavy metals as it grows, which are harmful in high amounts.

2. It’s more powerful than spinach.

1. It can fuel your car.

Ethanol fuels can be made from kelp.(Img Cred: Wikimedia, Mariordo)

The ocean contains half of all biomass on the planet, but it is an untapped resource. Kelp can be fermented or converted to biofuels like ethanol and methane, and because it contains far less cellulose than land plants, can be converted much more easily.

Kelp is far less damaging to the environment than other biofuel crops because it grows quickly and without fertilizer. It also requires no fresh water or land to grow, so there is no need to worry that such a biofuel crop would displace food crops and raise prices.

But scientists still need to fine-tune the conversion process and to figure out ways to harvest the plant in high enough quantities to make it a viable alternative energy source.

1. It can fuel your car.