Science

Climate change is raising iodine levels in seaweed. Cause for alarm? We think not.

A recent publication in Global Change Biology, reported that changing atmospheric and oceanic conditions, due to climate change, are raising the levels of iodine in seaweeds that can transfer up the food web. We think this is a great paper, and we strongly believe that many aspects of the ocean should be analysed to model future ocean conditions. Most work on algae in respects to climate change have been limited to calcifying reds, and the coral symbiot zooxanthellae. Seaweeds are the second largest biomass harvested from the oceans and more research is needed for that market.

A few news articles ran with the idea that seaweeds are becoming toxic, and are making headlines. While humans need iodine, too much can cause some of the same symptoms as iodine deficiency, including goiter (an enlarged thyroid gland) (NIH). However, we suggest caution when saying all seaweeds will become toxic.

For instance in the paper the study species Saccharina japonica was used, which is a species that is known to already have high concentrations of iodine. Saccharina and other species of brown seaweeds (kelp/ kombu) have much higher concentrations of iodine than other species (see figure below). Most consumed seaweeds (dulse, nori, wakame) have iodine levels 5x lower than Saccharina, and even with increases from climate change would not be considered dangerous.

People around the world choose to eat seaweeds because it’s rich in minerals including iodine, and we suspect this fact will not change. We encourage people to pay attention to the nutrition labeling on seaweed foods and monitor how much they consume. When reading papers or nutrition labels, note the seaweed condition (Dry vs. fresh). Most weight in seaweeds is attributed to water, and a serving size between dry and fresh can be a large difference. We also want to emphasize that iodine is not accumulated in your tissues, such as heavy metals.

We hope good studies like this continue, but use caution when reading news that oversimplifies the results.

 Image from American Thyroid Association 2004.  Full article here

Image from American Thyroid Association 2004. Full article here

Seaweed common names: Kombu

There are many names for commonly consumed seaweeds. However, the species they refer to vary by region and culture. We will cover some of the most commonly used names for seaweeds, and review the differences between connotation and denotation. This series will review some of the most common common-names in use.

Previous posts include: Nori, Wakame, Laver


Kombu is a common name for seaweeds that typically belong to the group of brown seaweeds: Laminariaceae. Kombu is traditionally used for soup stocks, salads, and even fertilizer. Brown seaweeds are high in minerals and by adding them dishes one can improve the nutritional value of their food.

The word kombu is Japanese, but it’s thought to be borrowed from the Chinese. In old Japanese the word for seaweed was “me” as in “waka-me”. The predominant theory, is that kombu is derived from the Chinese word 昆布 kūnbù, which is traced back to the 3rd century in China. However, records from the 8th century are spotty at best in their descriptions of kūnbù, and it is impossible to know what species of seaweeds they were referring to.

Nowadays there are modifiers to separate the different species of kombu. (Borrowed from Wikipedia).

However, in other parts of the world the term kombu is used to describe other species of brown algae such as Saccharina or Laminaria. For example, the company Salt Point Seaweed calls Laminaria setchellii, California kombu.

Closing the nutrient loop with seaweed farming.

As discussed in the last post, agriculture runoff is a huge problem. Nutrients are running off the land and into our oceans.Today in a recent article from Scientific America, the idea was batted around to take up ocean nutrients with kelp then turn it into fertilizers. These fertilizers could then be used again on land to replenish the nutrients lost. Not only would this help close the nutrient loop, but also take excess carbon out of the oceans.

This is just another example how seaweeds can help reverse negative anthropogenic impacts to our oceans.

Seaweeds can facilitate symbiotic microbes in agriculture

Modern agriculture is a marvel of the 21st century. Crop production has surpassed our expectations, many times over, in the last 100 years. However, this production has come with a cost. What is now being called our nitrogen addiction, refers to the amount of fertilizers used on farmland. The traditional soaking of soil is inefficient and leads to runoff: where nutrients are leaked into other surrounding ecosystems or the waterways.

Doesn’t sound so bad, what the problem with extra nutrients in the water? Well, the added nutrients cause boom bust cycles of other plants and algae that can tip the balance of an ecosystem. Currently there are numerous microalgae blooms off the coast of the USA, all are said to be a factor of agriculture runoff. This has caused an outcry for more responsible farming practices in reducing their nutrient loading.

One group in the UK has started using algae extracts and microbes to help crop efficiency. They claim that the seaweed extract facilitates microbes that help crops take up more water and nutrients, and therefore can reduce the amount of farm input by 20%. By reducing the amount of water and fertilizer used, the runoff will be far less than without the seaweed’s help. This could end up being a key strategy for responsible farming practices.

Moss Landing Marine Labs gets funding to study macroalgae in livestock feed

As previously discussed on this blog back on October 22nd, we mentioned researchers at UC Davis discovered that methane from cows can be dramatically reduced by including some red algae in their diets.

It was just announced Friday (Oct. 26th, 2018) that Moss Landing Marine Labs was awarded Seagrant funding to investigate and culture other methane reducing alga species. This funding was a part of the $6 million invested in ocean research projects by the Ocean Protection Council.

Dr. Graham of Monterey Bay Seaweeds will be joining the research team and sharing his expertise on land based algal culturing.

Eating brown seaweed can aid in weight loss

Jamie Oliver is a well known chef in the UK who is a strong advocate for cooking with seaweeds. Recently an article in Magenta reported that Jamie owed his own weight loss to eating more seaweed.

The science of which goes back to a study published in the journal of Food Chemistry (2014). The study found that alginate, a sugar derived from brown seaweeds, inhibited pancreatic lipase by a maximum of 72.2% (±4.1) with synthetic substrate (DGGR) and 58.0% (±9.7) with natural substrate. Concluding that eating brown seaweeds could potentially reduce the uptake of dietary triacylglycerol aiding in weight management.

Weight loss is just one more reason why more chefs are starting to use seaweeds in their dishes. Jamie lists a few seaweed incorporated recipes on his website that are free to use.

Below is a video featuring Jamie on the Daily Mail explaining why he believes seaweeds are such a good superfood.

Seaweed and cow gas

Cows have gotten a lot of attention lately as they were found to be one of the largest producers of methane in the USA. Methane is a greenhouse gas that is 23 times more powerful than CO2 in it’s ability to heat the atmosphere, and the entire population of cows contributes just as much as cars to climate change. Cows digest their food by fermentation in their gut. Fermentation leads to gasses, which are then mostly belched out of the cow’s mouth.

This has lead many animal nutritionists to investigate alternative feed ingredients that could mitigate the amount of methane produced by cows. Researchers from the University of California, Davis, found that methane emissions were reduced by 24 to 58 percent in cows that ate a type of red seaweed.

While this tech is very promising, the bottleneck is currently the lack of red algae production. Land based aquaculture is costly, while offshore aquaculture comes with more regulatory hurdles. To have seaweed integrated into feeds, massive large scale aquafarming needs to become a reality.

Concerned about plastic pollution? Seaweed can help.

Plastics are everywhere. If you take a minute to look around your house, it’s really quite astonishing how much of it we use. It’s no wonder why plastics became so ubiquitous: it’s a cheap, flexible, and durable material. The issue is that these durable materials have been commonly used for single-use disposable items such as eating utensils, bags, containers, straws, packaging, bottles, the list goes on and on.

These single use items typically end up in the trash and can take up to 6 generations to breakdown. Plastics in the ocean have been accumulating at a far faster pace than their ability to break down. Some studies suggest at this rate there will be more plastic than fish in the oceans by 2050. To make matters worse, as plastics break down they create smaller and smaller plastic particles, commonly referred to as micro-plastics. Micro-plastics have made headlines in the last decade as, to our horror, we have discovered that we consume them constantly. Micro-plastics have been found in seafood, beer, salt, chicken, and water.

In response some cities have banned some plastic items, most notably bags and straws. However, this is a drop in the bucket and banning plastics entirely would be a political and economical nightmare. Luckily, seaweed is here to the rescue. A few clever groups have found ways to replace single use plastics by using seaweed extracts. So far we have seen seaweed replace packaging, straws, bottles, and even surf boards. These items are not only biodegradable, but generated from a sustainable resource. Look for more and more of these items to pop up in the near future.

What the heck is seaweed anyway?

Sometimes we take our phycological education for granted and forget that algal terminology can be a bit confusing. Let’s review some basic concepts to ensure that we are all on the same page when thinking about seaweed.

Alga = singular

Algae = plural

Algaes = not a real word

Microalgae = single cell algae species

Macroalgae = multi-cellular algae species = seaweed

3 branches of algae = red (Rhodophyta), green (Chlorophyta), brown (Ochrophyta)

Kelp = a branch of brown seaweeds (Laminariales)

Plant = Photosynthetic thing on land

A very brief overview of the evolution of photosynthetic organisms.

In the beginning there was a bacterium that learned a neat trick. This bacterium contained pigments that allowed it to capture sunlight and convert it into energy via photosynthesis. The bacterium was engulfed and incorporated by another single celled organism (a eukaryote), this event is called primary endosymbiosis. Its a partnership between the two cells (bacterium and eukaryote) similar to the photosynthetic algae that like inside corals. Through this process red, and then later green, algae came into existence. After this primary endosymbiotic union, secondary and even tertiary endosymbioses occurred - algal cells themselves getting engulfed and incorporated to give rise to other algal groups including macroalgae, browns, and terrestrial plants. If you want to dive into the specifics of how scientists discovered this, here is a good paper outlining how the genetic code of algae lead to the discovery.

pic.plastid.evol.scheme.jpg

It may seem a little complicated, and in fact it is, its very complicated. But it is super cool and for this reason we don’t like algae being called plants; it’s like calling “fish” … “humans.” On a more humorous note, we do encourage people to call plants, “land-adapted algae”. Again, check out algaebase.org to review all of this and see where your favorite seaweed fits in.

Could you survive by only eating seaweed?

If you look at the nutrient label on the packaging of any food item, you would see the groups: calories, protein, carbohydrates, fat, sodium, and occasionally other items such as minerals. We are all familiar with calories being the amount of energy within the food. “Calorie counting” is a common practice for people looking to watch their weight, as consuming calories faster than you can metabolize them can lead to weight gain. However, without calories your body wouldn’t have energy to survive.

Calories in your diet come from fat, proteins, organic acids, and especially carbohydrates. Carbohydrate is an umbrella term for all types of sugar, starch, cellulose, and even dietary fiber. The sugars in most algae though, are not digestible by most humans. The sugars in most algae are known to be β(1→4) linkages in glucan polysaccharides. Most of the human population lacks the ability to digest these types of sugars as we are adapted to eat alpha(1→4) linkages in glucan polysaccharides (i.e. sucrose), and therefore, we don’t get the energy associated with these calories from most seaweed sugars.

There is one human population in Japan, however, that can digest these sugars. Apparently these Japanese have become hosts to common gut bacterium (Bacteroides plebeius) that exhibits polysaccharide-degrading enzymes. This is likely due to many generations of seaweed consumption and adaptation.

Just for fun, let’s see how much seaweed you would need to consume to get enough energy to survive. Assuming you are not Japanese, the only calories will be protein derived. The average person needs 2000 calories a day to maintain. You get about 4 calories per gram of protein. Now let’s use dulse as our reference seaweed. Dulse has 3.5% protein content. That means you would need to eat at least 31.49 pounds of dulse to satisfy your caloric needs. Now this is only in reference to calories, almost no single food item has all the nutrients the body needs for survival, so please don’t try this diet at home.

Which seaweeds are toxic?

You might occasionally hear about toxic algae in the news. Toxic algae will always be in reference to microalgae, or harmful algae blooms (HABs). HABs are responsible for shellfish poisoning and what are known as red tides. HABs can exist in salt or fresh water bodies and are toxic if consumed.

While seaweeds are classified as macroalgae. There are currently no known poisonous or toxic seaweeds in existence. There are a few seaweeds that produce acid (acidweed), but these are no more acidic than your own stomach acid and would not harm you if consumed.

Incredibly there are only 14 reported deaths ever linked to eating seaweed, and the reports state that it’s not the seaweed itself but bacteria that had grown upon the seaweed. We say incredible because there are huge populations (Japan, Korea, China) that consume raw seaweed daily, while in the USA there are 31 reported deaths by E. Coli every year.

Can seaweed combat climate change?

The United Nations Intergovernmental Panel on Climate Change (IPCC) has just released a report on the current state and predictions of anthropogenic climate change as a followup to the Paris Agreement. The Paris Agreement was an international treaty, pending ratification, with the goal of preventing the average global temperature from reaching 1.5 C above pre-industrial levels. The IPCC laid out the global consequences if the 1.5 C threshold is exceeded. The results were not good: sea level rise, ocean acidification, species extinctions, increasing storm frequency and intensity (as we watch hurricane Michael make landfall less than 1 month after hurricane Florence). The IPCC stated that if we can’t develop technology to remove CO2 from the atmosphere these scenarios will come to fruition sooner than previous studies indicated.

The oceans act like a giant CO2 sponge and over 1/3 of anthropogenic CO2 is absorbed into the sea. Increasing CO2 in the ocean causes the water to become more acidic. Ocean acidification has strong negative effects on a number of organisms, especially calcifying or shell building animals. The IPCC is focused on removing CO2 from the atmosphere, but perhaps taking CO2 out of the oceans would also be a key strategy in reducing anthropogenic climate change.

Could seaweeds be used to take CO2 out of the ocean? Like terrestrial plants, algae uses the process of photosynthesis to take up CO2 and release oxygen, locking carbon away in it’s tissues. This idea of decarbonization by algae has been tested by a group in Korea, and they found that they could use natural or constructed kelp beds to take up and store 10 tons of carbon per hectare every year. Another research team made a rough calculation that global macroalgae could pull down up to 268 million tons of carbon per year.

The problem with using macroalgae for carbon storage is that algal tissues will eventually break down and through bacterial decomposition CO2 will be re-released. There have been a few ideas of what to do with all the carbon sequestered in seaweed: some suggest sinking it to the bottom of the ocean while others say to use it as a bio fuel to reduce the use of fossil fuels.

Reducing emissions will go a long way in avoiding many of the doomsday scenarios, but doesn’t address the current and near future ocean acidification issues. While seaweed can’t solve climate change, it will undoubtedly play a major role in curtailing CO2 within the oceans.

Of Carrageenan and Health

Image of Mazzaella laminarioides by M. Graham.

We’ve lost count of how many times we’ve been asked about carrageenan and it’s ability to cause cancer. Controversy swirls around this molecule and it’s easy enough to google ‘carrageenan’ to find calls for banning its use. For those of you unwilling to read the entire post, let us summarize that carrageenan does not cause cancer! Like any good conspiracy theory, the claim is built off of a grain of truth. A study referencing the wrong molecule exaggerated it’s effects and became sensationalized by the media. That study has been refuted numerous times by a variety of academic and government agencies. However, the damage was done, and the internet is a very unforgiving place for misguided information. We will review the uses, definitions, and conflicting studies behind this controversy.

What Is Carrageenan?

Carrageenan is a component of some red seaweeds most notably Chondrus crispus, also known as Irish moss. The molecule itself is a sugar, a polysaccharide to be exact. There are a variety of carrageenans that are described by their bonding configuration and molecular weights (Mw). These varieties, like most molecules, can take their shape through chemical processing to fulfill different functions. Typically, carrageenan refers to the sugar used in the food industry (Mw 200k-800k Da) as a thickening agent, and can be found in many common household items. The sugar is also non-digestible to humans (stay tuned for upcoming post) making it a sought after additive for low calorie sweets treats. Irish moss has been harvested for over 14,000 years for human consumption, and carrageenan has been used as a thickening agent since at least the 19th century.

Where is the grain of truth?

Dr. Joanne K. Tobacman is the most cited reference in carrageenan attacks. In 2001, she published a review of carrageenan and it’s effects on health in the journal of Environmental Health Perspectives. She cited a study from 1982 that linked degraded carrageenan (also known as carrageenan gum or poligeenan Mw 20k-40k Da) to cancer in lab animals. In her review she also cited a number of papers investigating degraded carrageenan causing intestinal inflammation leading to ulcers and lesions. In her paper, Dr. Tobacman suggested that the use of carrageenan be reviewed by the FDA and change the restrictions to the molecular weight requirements as a food additive.

The rebuttal

It turns out that the term carrageenan was misused in the previous studies. Dr. Myra L. Weiner published a paper refuting Dr. Tobacman in 2016 in the journal of Food and Chemical Toxicology called ‘Parameters and pitfalls to consider in the conduct of food additive research, Carrageenan as a case study’. Dr. Weiner’s followup paper in 2017 again stated the importance of defining the molecule in question and illustrated the root of the issue in regards to carrageenan. Dr. Weiner laid out the argument that previous studies misused the name carrageenan by confusing degraded carrageenan and poligeenan with non-degraded carrageenan, lacking fundamental understanding of physical/chemical and toxicological properties. Non-degraded carrageenan is used as a food additive, while degraded carrageenan and poligeenan are not. The process to degrade carrageenan requires high heat (95C) and acid (<1pH) which neither occur within the human body. Weiner concluded that the non-degraded form of carrageenan, typically refereed to simply as carrageenan, was perfectly safe for food use and it has continued to be used to this day.

Going forward

The FDA supports carrageenan use and classifies it as meeting organic standards. The EU has also re-evaluated carrageenan as safe, with a clear banning of poligeenan defined by molecular weights. However, there is still pressure to remove the sugar from commercial products. There are still hundreds of ‘nutrition/ health’ articles out there sounding alarm bells to not use products containing carrageenan.

We certainly understand the importance of understanding the food you are consuming, and it’s a shame that some companies have caused such distrust among consumers. There has been so much positive change recently to correct this consumer trust, but there is still a long way to go. The wealth of information on the internet is daunting and confusing when it comes to nutrition. We have embedded all the links to the actual publications and government reports within this post. You can read the letter from the FDA to Tobacman rejecting her petition to ban carrageenan.

TAKE HOME MESSAGE: The production of carrageenan is in fact another safe and positive reason to support the rise of seaweed farming in the US and globally. If you hear otherwise, you are probably reading an article recycling the misinformation described above. Always check with your source ….

Do you have a question about seaweed, do you ask a phycologist or an algologist?

It’s tempting to simply add ‘ology’ to the end of a word when referring to the study of a subject. For that reason many people often refer to a person who studies algae as an algologist. The true meaning of algologist is ‘one who studies pain’. From the Latin root word algos meaning pain.

The correct term for the study of algae is phycology, from the Latin root phycos meaning seaweed. The use of the term algology, as the study of algae, is so prevalent that most dictionaries will define it as ‘the study of algae: see phycology’. To make matters worse I have seen algology defined simply as phycology.

Be warned, when using the correct terms phycology or phycologist, be prepared for people and computers to correct you with, “Do you mean psychology?”

AlgaeBase: One of the best algae resources available!

Have you ever gone to your favorite sushi spot and ordered a side seaweed salad made of wakame? While the connotation is that wakame refers to the intertdial species Undaria pinnatifida, the literal translation from Japanese is ‘seaweed’. An alga’s common name can vary by region and language while the scientific name is a global standard. These scientific or ‘Latin’ names can change over time as new discoveries appear; this was the case in the early 2000s with the leaps made in genetic sequencing technologies.

If you ever want to know the history of an alga’s Latin name, or know the common name in any part of the world, look no further. AlgaeBase.org is by far one of the best algae resources available to the public. On AlgaeBase you can look up common names of algae and find all names ever associated with it. You can also find other species information such as ecology, images, global distribution, and common uses. Each bit of information is linked to a vetted document, typically a peer-reviewed journal.

Take a minute and visit the site. Poke around and look up some of your favorite seaweeds, you might be surprised with what you find.