At 3:00 P.M. on a lazy Saturday, I went to eat sushi with one of my best friends. We gobbled up our sushi like we always do. It was a pretty normal day. The issue is that every sushi lover is aware that the way we produce fish and other aquatic animals is not sustainable. It is quite unhealthy.

Demands on seafood are exponentially increasing. However, we can not expect everyone to cut sushi from their diet, but we can produce fish more sustainably and safely with cellular aquaculture.

Pollution is damaging our world. There are about 5.25 trillion pieces of plastic debris in the ocean. Every year, we dump about 14 billion pounds of trash into the ocean. 14 billion pounds! The average fishing boat weighs 3500 pounds. We dump the equivalent of 4,000,000 fishing boats in the ocean every year. The largest animal in the world, the blue whale, weighs 110,000–330,000 pounds. We roughly dump the equivalent of 70,000 blue whales of trash every year in the ocean.

85% of fisheries are overfished, and the remaining are fished to their maximum capacities. We catch about 200 billion pounds of fish every year and are harming other animals in the food web. This is exhausting the ocean’s ecosystems. Global fishing is 2–3 times bigger than what the ocean can support. Because of the trash in the ocean, eating seafood can be dangerous.

This brings me to another point, global warming. Overfishing exacerbates the effects of climate change.

There are also problems with food health and food prices. More than 90% of allergic reactions in the U.S. are from seafood, such as fish and shellfish. 3 billion people rely on seafood as their main source of food. However, seafood prices expect to rise by 70% by 2050, and we are at the highest seafood demand in history.

How can we stop overfishing? How can we create alternative protein from more safe, healthy, and sustainable methods?

Introducing Cellular Aquaculture

While cellular agriculture is the production of land animal products, such as beef, dairy products, and more, in labs, cellular aquaculture is the production of aquatic animals.

Similar to cellular agriculture, cellular aquaculture grows cells in vitro. In vitro means growing cells to create tissues identical to tissues in the host animal outside of the animal. We grow the same cells in a culture dish in a lab.

This might be your reaction:

Rest assured, cellular aquaculture is extremely beneficial. It will change our food industry and open so many doors for the future of food.

A benefit of cellular aquaculture is that we eliminate any harmful elements or contaminants found in the ocean. Seafood can have sources of mercury, toxins, poisons, pathogens, viruses, parasites, and microparticles of plastic due to plastic pollution. I am not telling you this to scare you or reconsider that yummy sushi, but to inform you that cellular aquaculture will eradicate this. Because cellular aquaculture is the production of fish grown in labs, we eliminate pollutants found in the ocean.

A challenge for cellular aquaculture is texture and price points. Similar to cellular agriculture, cellular aquaculture also has issues with mimicking specific elements of “normal” fish. Cooking cellular aquaculture products to simulate how fish is usually cooked is also another hurdle.

Fish Muscles

Fish muscles consist of three muscle types: red, white, and pink. The ratio of each type of muscle varies depending on different types of fish. Different fish have different patterns of red, white, and pink muscles. Different patterns of muscles = different fish.

Red muscle has a high density of mitochondria, capillaries (blood vessels that connect arteries to veins), glycogen, and lipids (fats). Red muscle is slow-twitch, which means red muscle requires oxygen. Red muscle is highly vascular. It also has the highest myoglobin content. Myoglobin is a red iron-containing protein, which stores oxygen in muscle cells. Myoglobin carries energy to muscle fibers.

Red muscles perform aerobic processes, which means they convert oxygen into ATP ( adenosine triphosphate, which is the main energy currency of the cell). Red muscle is for movement, specifically high sustainable swimming speeds. They are like marathon runners.

White muscle is essentially the opposite of red muscle. It has fast-twitch fibers, which means it does not rely on oxygen. Instead, white muscles draw energy from sugar through a function called glycolysis. Glycolysis is an anaerobic process, which means it creates bursts of energy. White muscle is not abundant in myoglobin. They are like sprinters in a 100-yard dash.

Pink muscle shares characteristics of red and white muscles.

To create cultured fish, we use these three tissues. Different fish products have different quantities and ratios of red, white, and pink muscles. Different patterns of muscles = different fish. For example, tuna species have lots of red muscles, and salmon has lots of white muscles.

The non-thunniform fish, skipjack tuna, and lamnid shark have different surface areas of red muscle. The skipjack tuna has the highest red muscle content. Thus, tuna has a higher myoglobin content and performs aerobic metabolism. Tuna are the marathon runners.

Red muscles content varies in fish

You might be thinking: “But, salmon is pink!” This is pretty fascinating: salmon’s red color is unique due to the astaxanthin the salmon consume.

Astaxanthin brings out the orangey/pinky hue

Fish muscles and land animal muscles are very different. There is a reason we cannot eat raw chicken or pork like we can eat raw fish. Gravity is the playing factor.

Land animals have to support themselves because of gravity. Fish do not have to support themselves because they float in water. Fish counteract gravity with buoyancy.

So, the only way to (safely) eat land animal muscles is to cook it. Once cooked, the tissues combine and form a juicy piece of meat. Whereas, the muscles (red, white, pink) in fish do not have to be cooked. They can be enjoyed raw. 🍣

Creating Alternative Protein

To create cell-based fish, the cells undergo a process:

Overview: A cell-based seafood production system consists of appropriate cell type(s) from the tissue of the host animal, a growth media for proliferation and differentiation of cells, and a bioreactor to create larger quantities of the cells.

First, scientists need to collect primary cells (red, white, or pink) from the animal.

Two good options for primary cells are myosatellite stem cells and induced pluripotent stem cells.

  1. Myosatellite stem cells are multipotent which means they can change into different muscle tissues.
  2. Induced pluripotent stem cells are pluripotent which means they can change into different kinds of cells in the body.

Although these cells are beneficial, they do have consequences. For example, myosatellite stem cells have a limit for multiplying, and induced pluripotent stem cells are hard to control.

We take the primary cells and create muscle tissue through a process called tissue perfusion. Tissue perfusion means the cells differentiate (cells change from one cell type to another). This is done through a process called myogenesis.

Myogenesis begins with starter cells that have the potential to become muscle tissue. The next stages of creating muscles are creating muscle components, myoblasts, myotubes, and myofibers. Myogenesis gives the cells a growth medium and nutrients to grow and duplicate as well as scaffolds for support.

The end goal of this step is to create myofibers, which are the building blocks of muscle tissue. We specifically need to make proteins in myofibrils called actin and myosin.

The growth medium provides the cell with nutrients and everything they need to grow. This mimics what the cells would be exposed to in the original fish, swimming in the ocean.

What the medium MUST include:

To trick the cells into thinking they are in their host, they need to have the right ingredients in the serum. Some factors are oxygen requirements, buffer capacity and pH, temperature, and serums.

Oxygen varies between how much red, white, and pink tissues are in the cell cultures. Fish generally have a lower oxygen requirement because of their tissues compared to land animals.

Buffering capacity. We can control the buffering capacity of the medium. The buffering capacity is a cell’s ability to maintain a neutral pH in the presence of metabolic products such as lactic acid.

Temperature. Depending on the location and what kind of climate fish live in, we monitor different temperatures. Fish near the Arctic or the poles or the equator require varying temperatures to suit adaptations to climate. Some temperatures at 0–10 Celsius and others need to be 5 Celcius. Some species like the demersal icefish lack hemoglobin, but have a high level of mitochondria, which are rich in fats, proteins, and enzymes. Overall, fish can generally be in cooler temperatures, which reduces maintenance costs. I will discuss different requirements for different species later in the article.

Serum. Currently, scientists use fetal bovine serum (FBS) and fetal calf serum (FCS), which are crucial for proliferation, but have cons. The growth serum is expensive, contains animal ingredients, and could carry mammalian viruses. They are also made from animals. We are looking for substitutes that do not use animal ingredients and are more sustainable.

Overall,

Primary cells + medium = cell lines

The scaffold shapes the unstructured meat. Imagine the cow is a fish and the steak is a cultured fish!

To create the proteins actin and myosin, we need to use biocompatible scaffolds. Scaffolds are a 3D support system to help form the structure of the cells and help them differentiate. For the cells to stick to the scaffolds, they need to have the right proteins. For mammals, the protein glycosylation is beneficial. Scientists are researching to find a glycosylation-like option for cell-based fish.

Scaffolds are essentially like the popsicle molds that you pour the liquid into to create popsicles.

Some possible scaffold options are scaffolds used for other organisms, such as plants and yeast. These are the decentralized plant tissue, chitin/chitosan, and recombinant collagen.

Scaffolds for aquaculture cells are new and research is still occurring.

Large-scale bioreactor tanks resemble beer brewery tanks

Bioreactor tanks are closed machines that monitor many factors. Bioreactor tanks produce biomasses of cells and monitor many elements inside the machine. Bioreactor tanks need to monitor lactic acid build-up, oxygen, temperature, nutrients, CO2, and scaffolds.

Bioreactor tanks have two purposes. One, to make the cells multiply, and two, to scaffold and differentiate cells. Fish cultures are easier to monitor because they generally require lower temperatures.

The goal of this phase is to compound the cells. However, a challenge with bioreactors is scaling up these machines to increase production.

Requirements For Different Cultured Seafood Species

Depending on different temperatures and environmental elements, fish have to be cultured differently.

Here are some different aquatic species and their growing conditions:

Fish cultures vary depending on climate as well as different species of fish. A skipjack tuna culture will be different from a non-thunniform culture because the skipjack tuna has more red muscle than the non-thunniform fish. Because skipjack tuna has a higher myoglobin content, it performs aerobic metabolism.

There are 32,000 kinds of species of fish. That means 32,000 types of cell cultures. Thousands of cells to choose from…

Many mollusk cultures have a high buffering capacity compared to mammalian cultures. A higher buffering capacity entails that mollusks can tolerate a higher pH level.

Mollusk cultures are more difficult to grow in vitro compared to fish and mammalian cultures. Scientists are targeting how to create long-term proliferative, cell lines.

In the past, crustacean cell culture research has been used for aquaculture and pharmaceutical industries. They have been generally investigated to learn how to improve primary cell isolation.

To bring crustacean cells into the fray for sustainable seafood, we need to learn how to create specific cell lines, such as muscle and fat.

Also, crustacean cells can be cultured at lower temperatures and do not require carbon dioxide exchange. Lower temps and CO2 requirements make the process of creating cultured seafood easier than mammalian cultures.

Companies Making A Splash In The Industry

As a true sushi connoisseur, I am excited about companies working on creating lab-grown seafood.

Blue Nalu is a pioneer in producing lab-grown fish. They are dedicated to producing cellular aquaculture products that are tasty, healthy, safe, and sustainable. They also diversify our ocean by not overfishing popular fish species. Some current projects they are working on is creating fresh and frozen fish, such as yellowtail, mahi-mahi, red snapper, and more.

Blue Nalu produces real seafood products that are just as nutritious and delicious as fish from conventional fishing. They create whole muscle, cell-based seafood products, in which living cells are isolated from fish tissue, placed into culture media for proliferation, and then assembled into great-tasting fresh and frozen seafood products. While growing fish in cell cultures has its challenges like taste and price, it will greatly improve our sustainability. Blue Nalu is creating sustainable and healthy fish in labs without compromising taste.

Finless Foods is reimagining seafood through culinary innovation. Finless Foods is modeling cell tissues of fish meat and growing them synthetically. Finless Foods is working on creating the giant bluefin tuna. They are also working on sea urchins, eel, and pufferfish.

A challenge that Finless Foods is working to solve is the texture of their lab-grown fish. Researchers and scientists are looking into how to adjust their methods of synthetically growing fish in cell cultures to also have the same texture as fish in the ocean.

For cellular aquaculture products to survive the market, they MUST taste like fish and other aquatic animals.

Some other important companies disrupting the fishing industry are Wild Type, Shiok, Avant Meats, and SeaFuture.

These companies are working on the next big thing with sea animals. Cellular aquaculture provides healthy protein alternatives that do not involve slaughtering animals and ultimately producing a sustainable protein alternative while supporting animal welfare.

Beneficial Impacts And Key Takeaways

Although cellular aquaculture is a novel field, it has the potential to improve our seafood production and aquaculture systems. It can help right the wrongs of the food industry.

A quick review:

Cellular aquaculture will:

  • Improve sustainability and scalability with seafood.
  • Mitigate overfishing. Roughly 0.97–2.7 trillion fish are caught and killed every year. With cellular aquaculture, we can reduce the trillion by 100%.
  • Improve human health and safety. Because we grow fish in labs, we will not consume pollutants from the ocean. 8.3 million tons of plastic/trash enters the ocean yearly. Cellular aquaculture helps our oceans and is a stepping stone to improving food safety.
  • Right the wrongs of the aquaculture industry.

Check out the companies — Blue Nalu, Finless Foods, Wild Type, Shiok, Avant Meats, and SeaFuture.

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