Ten Things You May Not Know About Seaweed

  1. Seaweed is actually an algae. When most of us think of algae, we think of that green, scuzzy film that covers unused pools, back alley puddles, and that creepy pond behind my grandparents’ house.  But algae actually comes in two forms: microalgae (the green scum), and macroalgae (seaweed). 

Microalgae are the tiny (sometimes even single-celled) species of algae that can only be seen by the naked eye when they group together in large numbers, such as on the surface of standing water or on the walls of your fish tank. Macroalgae is much more structured, and easily visible without a microscope—you’ll immediately recognize it as a plant. Seaweed is a macroalgae, and a delicious one… see our Tasting Day blog post for proof! Side note: While ‘seaweed’ and ‘kelp’ are often used interchangeably, they’re technically different.  Broadly speaking, seaweed can be broken down into three groups:  red, green, and brown.  All are properly called ‘seaweed’, but ‘kelp’ refers to a specific subcategory of brown algae (anything in the order Laminariales).

  1. There are over 12,000 known species of seaweed. Most of these fall into the “red” category (over 7,000 species), but brown (~2,000 species) and green (~1500 species) are also huge groups.  Of these 12,000 known species, we have about 700 of them right here along the California coast.

Ocean Source uses about ten of these species in our products, and each one is very different. We’ll use thinner seaweeds—Sea Lettuce or Laver, which is only 2 cells thick!—for more delicate textures, and heavier seaweeds like Laminaria and Mazzaella for jerkies or in burgers. And, of course, there’s the delicious Sea Palm, which is great in everything. For those of you who wish to do your own foraging, the good news is that there are no known toxic species of seaweed. Along the California coast, the only (known) species to look out for is Acid Kelp.  It produces sulfuric acid when disturbed, so while not technically “toxic”, you definitely don’t want to eat it.

  1. Seaweed is incredibly good for you. People are calling seaweed the next superfood (it’s even been called “the single most nutritious food you can eat”), and for good reason. Many seaweeds contain more calcium than milk and more protein than meat. Like all other vegetables, it’s extremely low in calories—a full cup of raw seaweed only has about 20 calories in it. Additionally, it’s a great source of several important but fairly uncommon nutrients: it has vitamin K, loads of potassium, and, most importantly, iodine.

Iodine is not found in most other foods (the most common place to get iodine today is probably table salt), but mild deficiencies are becoming increasingly common.  Not getting enough iodine is a difficult issue to identify, but it can cause such symptoms as fatigue, depression, a difficulty in losing weight, even lower IQ scores for your kids if you’re deficient while pregnant.  But that’s not all! Seaweed is a great source of antioxidants, and may even help prevent cancer.

  1. The first seaweed appeared during the Miocene era. The Miocene era started about 23 million years ago and ended about 5 million years ago, but this doesn’t mean that humans and seaweed diverged only 23 million years ago—scientists think that our last common ancestor was likely over one billion years ago! Birds such as ducks, plovers, owls, and crows also appeared in their modern form during the Miocene era.

Scientists believe that this is about when humans and chimpanzees split into two distinct species, with the first hominins—early bipedal ancestors of humans—appearing at the end of this era.  One other notable animal was the pelagiarctos: a giant, bone-crunching species of walrus. So cool.

  1. Feeding seaweed to cattle could reduce methane output by up to 99%. Putting seaweed in cow food is not a new idea. The ancient Greeks used to feed seaweed to their cattle as far back as the first century B.C., although they almost certainly had different motivations. But more recently, a team at James Cook University in Australia found that replacing just 2% of a cow’s feed with seaweed—comparable to adding a “smattering of herbs to a roast chicken”—reduced methane production by 70%.

And one species of seaweed, called Asparagopsis taxiformis, reduced methane by 99%.  That’s a whole lot of cow gas, and it’ll add up—the United Nations Food and Agriculture Organization (FAO) reports that cows collectively release seven billion metric tons of CO2-equivalents every year.

  1. Seaweeds are the basis for all life on earth. Together, seaweeds and phytoplankton are responsible for all primary production in the oceans. Remember the food web from elementary school? Primary producers are at the very bottom of the food chain—they don’t eat other organic matter to survive, but are themselves eaten in tremendous numbers by the next lowest animals on the chain, jump-starting the entire ecosystem. In the case of seaweed, they produce via photosynthesis, and feed everything on the plant either directly or indirectly.

This makes sense—there are nine times as many seaweeds (macro and microscopic algae) in the oceans as there are plants on land, allowing them to reach primary production levels that can be 10 times greater than the most efficient agriculturally-based systems we’ve developed on land.  Additionally, thanks to their numbers, seaweeds and other algae produce a full 70% of the world’s oxygen.  The message here is clear: to save the planet, we might want to start with the seas.

  1. Seaweed used to be a food only for nobility. In Japan, only nobility consumed seaweed during the Asuka and Nara periods (about 600AD-800AD). During this time, the Daihoritsuryo (Japan’s first known written legal code) enumerated 30 different types of sea vegetables that vassals must pay to their lords as tax. The preferred seaweed for tax was Laver, which we here at Ocean Source still gather and use in our products today.

Consumption by the general public didn’t start until about 1700, when, according to the accepted narrative, the Shogun of the time demanded a daily supply of fish be brought to him in the city that would later become Tokyo. To meet this demand, the local fishermen started farming fish by using bamboo to fence in parts of the Tokyo Bay. Eventually, they noticed that Laver was growing on theses fences, and commercial seaweed aquaculture was born!

  1. You’ve almost definitely eaten seaweed within the last 24 hours. Seaweed extracts have been used as a thickening additive in foods since the fifteenth century. Currently, the most common use is probably in the form of carrageenan, which comes from red algae. It’s often used to bind foods together (particularly dairy and meat products), as well as used as a thickening agent in such products as chocolate, many dog foods, and even toothpaste. Many vegan and vegetarian products that need a gelatin will substitute carrageenan instead of true gelatin, which is usually made by boiling cow or pig skins, hooves, bones, and/or ligaments.

But it’s not just red algae—a product called Alginate can be extracted from Brown Algae, and this is used to thicken water-based products.  Many cosmetic creams, ranch dressing, and even the molds used to cast prosthetic limbs use alginate!  If you’ve eaten ice cream, taken cold medicine, or used soap recently, you have seaweed to thank.

  1. Seaweed farming is one of the most sustainable methods of food generation around. Not only does it require zero chemicals, it’s a true zero-input system: you don’t need food, land, fertilizer, or fresh water. In addition to soaking up nitrogen from the water, seaweed can provide food for humans (we don’t think about it too much, but the green stuff that wraps your delicious sushi rolls is Nori, a type of seaweed!) and can even be turned into biofuel for cars.

While different species are more productive at different times of the year, seaweed can be grown year-round (unlike traditional crops) and can be harvested almost constantly. This, in addition to the incredible growth rate and amazing health benefits, is causing scientists to call seaweed the superfood of the future.  Join Ocean Source as we do our part to feed the planet while we save the Earth. Eat blue!

  1. There have been arguments made for placing red seaweed in its very own kingdom. Kingdoms, you may remember from high-school biology, are the highest-level division of life. Currently, we recognize six: plants, animals, fungi, protista (algae, molds, etc), bacteria, and archaea (essentially another form of bacteria). Red algae, however, has a trait that separates it from every other kingdom that we know of.

Red algae is the only organism on Earth that is known to have three life cycle stages—most other plants and even other algae only have two. To think about this, it might be useful to compare something like Nori, a red algae, to a typical plant. Picture a plant: it may have a flower, which will need to be pollinated in order to produce fertilized seeds.  However, if it does this, the seeds disperse and will grow into a new plant.  Red algae, however, are a little more complex. First, the gametes (think eggs and sperm—Stage One) are released.  Then, these will fuse together on the female structure, forming an entity that will release spores .  These spores will geminate into a smaller, crustlike alga (Stage Two), which looks and behaves so vastly different from “adult” Nori that it has been described as a completely different genus. This form lives on the shells of animals, eventually releasing different spores that will turn into the third life stage—the edible form of Nori that we see in sushi restaurants.