Thursday, September 3, 2015

Animalists: Those Pesky Omnivores!

This is Part II on The Case for Eating  Oysters, Mussels, and Other Invertebrates? NOPE, Here's Some Science. 

Edit: Part III is now available: On NOT Eating Oysters

The Sentientist shared a new blog post on her public Facebook profile (I'm not on her friends list and was directed to her page by another fellow vegan),  written by someone that calls himself  The Animalist, and described it as, "A round up of evidence for and against eating bivalves linking to my sentientist blogs." Excuse me, but I just want to ask,  What evidence? Opinions based on personal beliefs do not count as reliable evidence. Neither do wikipedia links or citing links to other blogs, but that's just the scientist in me, I guess?

On reading this "evidence"...

I have to admit that, as a scientist and someone that holds established and reliable sources as the best means to support an argument, I found the Animalist's post in support of eating invertebrates all over the place and mostly opinion-based without much reliable scientific evidence to back most statements. Hence, most of his points are based on opinions that are based on the convenience that we will most likely never be able to prove that invertebrates, such as bivalves and echinoderms, do not experience life in the same way that vertebrates do.

I am very much confused by his stance on what he labels himself. The Animalist claims to not want to be vegan but is OK in being labelled a vegetarian, yet refuses to accept that he is actually an omnivore. Remember in biology class when we learned that if an animal eats plants and other animals, then they are omnivores? Me too, but somehow he ignores that basic, established fact.

Image: Excerpt from the Animalist's Blog Post "Those Pesky Bivalves."

The other thing that baffles my mind is this closing statement at the bottom of this image (we'll go back to vertebrates in a moment):

Image: Excerpt from the Animalist's Blog Post "Those Pesky Bivalves."

The Animalist refuses to use concrete evidence and examples based on science, research, etc. in his claims that invertebrates are not sentient, yet he demands that if you disagree with his opinion-based stance, that you provide him with "concrete examples and evidence". Kind of not an even playing field, is it? This also means that whatever anyone says won't be enough even if it based on scientific literature.

Regardless, with this post, I attempt to show how unscientific the Animalist's case is. In support, I describe in agreement on why he is NOT a pescatarian or even a vegetarian because, as someone that eats animals, he is an omnivore. 

If you would like a scientific view on why there isn't an ethical case in eating mussels, oysters, and other bivalves as vegans, please refer to Part I, HERE, which discusses the Sentientist's blog posts on eating bivalves. 

In the same post, I establish why it doesn't make sense to attempt to apply the same definition of sentience to invertebrate species based on a world-view defined by human sentience. 

I also establish that bivalves are not synonymous to plants.

Statements are fully supported by scientific evidence and literature. 

 NOTE: As with my first article, I will directly quote reliable scientific literature and direct quotes from experts in the corresponding fields just so you know I'm not just making things up...

Image: Excerpt from the Animalist's Blog Post "Those Pesky Bivalves."

Invertebrates & the Animal Kingdom

 How do I know mollusks and echinoderms are animals and not plants? Because they have been classified under the Animal Kingdom.  In current times, classification of living beings is based on morphology and molecular data, which are used to establish evolutionary relationships between them. Let's have a look:


Again, both echinoderms and bivalves are clearly under the Animal Kingdom as determined by experts that study the evolutionary relationships of living beings. Plants, however, are not in the animal kingdom. 


The Definition of Omnivore

                                      Image: Excerpt from the Animalist's Blog Post "Those Pesky Bivalves."

Omnivores are defined as animals (like humans) that eat plants and other animals (like bivalves and echinoderms).

Vegans do not eat, use, or wear animals. Vegetarians do not eat animals but may eat and use animal products, such as eggs and dairy, leather, etc.; however, animals are not animal products, they are the actual animals. Pescatarians eat fish, but invertebrates aren't fish. Fish are vertebrates, and they are animals. Therefore, pescatarians are just omnivores that prefer fish. Someone that consumes invertebrates, which are well established as animals, then simply, still eats animals, and is therefore, an omnivore - like the Animalist. 

Back to the animal kingdom for a second...

What does the Animalist mean when mussels, oysters, clams, or sea urchins are not comparable to fish? They are clearly both animals for a reason, or does he mean that one is an invertebrate and the other one is a vertebrate, and therefore, have completely different physiologies? How does he determine that all those species are sentient? Where is the evidence? What basis does he use?

And WHO is everyone that has looked into this? Where is the research and the literature to back this claim?

                                              Image: Excerpt from the Animalist's Blog Post "Those Pesky Bivalves."

The Animalist would like us to accept that because they don't have, eyes, brains/nervous systems like the ones humans and other animal species have, sea urchins (and bivalves) are just like plants. Except, sea urchins are nothing like plants, they are animals with nervous systems. Plants are not animals and do not have any kind of nervous system. 

Image: Excerpt from the Animalist's Blog Post "Those Pesky Bivalves."

Note: I'm going to skip on the explanation that animals are not plants because I hope that we all realize by now that plants are in the plant kingdom and animals are in the animal kingdom. You can look more into that topic in Part I.

Sea Urchins & Brains

Although I am unsure how the Animalist determines which species are "sentient" or not since I'm not aware of any crab or shrimp that has a central nervous system or a brain, as in humans, I'd like to show you the story that science has to tell us about sea urchins...

When it comes to sea urchins, no they do not have eyes in the sense that we and other animals have eyes, but "it looks like the entire surface of their bodies are acting as one big eye..." said researcher Sönke Johnsen, a marine biologist at Duke University."  Johnsen is further quoted by the same article saying, "We think of animals that have a head with centralized nervous systems and all their sense organs on top as being the ones capable of sophisticated behavior, but we're finding more and more some animals can do pretty complex behaviors using a completely different style." (Choi 2009)

Blevins & Johnsen (2010) state that their research study is the "first demonstration of spatial vision in an echinoderm sheds further light on the complex optical structures and photobehaviors found in this phylum."

What was that again about no eyes, Animalist?

"It appears that sea urchins may use the whole surface of their bodies as a compound eye, and the animals' spines may shield their bodies from light coming from wide angles to enable them to pick out relatively fine visual detail....Some of the animals may interpret the object as a predator and flee, while others identify it as shelter and head towards it. What is more surprising is that the urchins' vision is as good as Nautilus and horseshoe crab vision, which is quite impressive for an echinoid that has turned its whole body into an eye." (Knight 2010) 

And on the claim that they "do not have centralized nervous systems" as basis for the Animalist to decide it's ok to eat them, the fact remains that sea urchins and ALL echinoderms, HAVE nervous systems:

Johnsen stated that, "Although sea urchins don't have brains, "it could be their entire nervous system more or less acts as a brain," Johnsen said. "In our case, we vertebrates have nervous systems that are more or less controlled by a central brain, but sea urchins have a pretty diffuse nerve net, where no region looks like a central processing unit as far as we can tell." (Choi 2009)

"The adult echinoid nervous system is comprised of 5 radial nerve cords, which are joined at their base by commissures that form a ring surrounding the mouth (Cobb, 1970Cavey and Markel, 1994)... Tube feet, spines and pedicellariae have ganglia and a complement of sensory and motor neurons...The arrangement of the nervous system in echinoderms is a feature that distinguishes them from other deuterostomes (chordates and hemichordates). Echinoderm nervous systems are dispersed, but they are not a simple nerve net. The adult is not cephalized, yet the radial nerves are segmentally organized (Burke et al 2006)."

Johnsen also states that, "We think of animals that have a head with centralized nervous systems and all their sense organs on top as being the ones capable of sophisticated behavior, but we're finding more and more some animals can do pretty complex behaviors using a completely different style...In the beginning, people built robots like they would humans, with powerful central processing units, complex sensors and fairly complex rules for doing things...Now they're finding it might be a lot better with a distributed system with many little processors and simpler sensors and simple rules, which end up creating fairly complicated behaviors as emergent properties, just as how a flock of birds can make intricate patterns without any one bird choosing these patterns." (Choi 2009)

So basically, not having a nervous system with a brain does not mean you are a living plant-like rock creature incapable of experiencing the world...plants don't have nervous systems. Echinoderms (and Bivalves) DO HAVE nervous systems regardless of how simple you believe they are. 

As I quoted on Part I

On the Environmental Aspects

The issue that I have with using Wikipedia as the sole evidence for a claim is that Wikipedia articles, such as the one linked on the Animalist's post, do not always cite reliable evidence, reliable sources, scientific research, or official publications. They can also be very one sided if written by someone with a specific interest, or they can just be outdated.

                                           Image: Excerpt from the Animalist's Blog Post "Those Pesky Bivalves."

I do have to make a clarification that the article quoted on the Animalist's blog post above makes reference to eating these sea urchins because they are aggressive invasive species outcompeting local species of sea urchins in a region they once were not found in. However, I find making the case of eating sea urchins because they are invasives is a stepping stone to making the case to kill other invasive animal species, such as lion fish, which have become an ecological nightmare in parts of the United States.  

Regardless, intensive oyster farming is NOT free of negative impacts as the Animalist claims. 

It is unclear where the Animalist gets the scientific data to claim that not a single "sentient" being is harmed or killed during oyster and mussel farming since the oysters and mussels have not been established to be non-sentient and are, well, killed (see Part I). Either way, intensive farming of these animals does have negative impacts, which affect other species.

A review of the ecological effects of oyster aquaculture in New Zealand, which was commissioned by the Northland Regional Council (Forrest, Elmetri, Clark (2007)) found that their: 

"review indicates that, other than a field investigation of seabed impacts in Mahurangi Harbour, little is known about the actual effects of oyster farming in New Zealand....Although the general effects of oyster farming are known, and their ecological significance can be evaluated, it is evident from our assessment that there are many knowledge gaps and areas of uncertainty."

Collectively, these sources of information reveal key areas of actual or potential risk from intertidal oyster cultivation as:

 Image: Page iii  excerpt from the " Review of the Ecological Effects of Intertidal Oyster Aquaculture in New Zealand"

I'm not going to go through each issue because I am only trying to point out that one cannot make claims that oyster farming or any other kind of farming does not have any kind of impact. 

What would farming these animals look like for 7 billion people - hand harvesting oysters for 7 billion people? Not likely. How would that affect the ecology? Lastly, it would be naive to think that the same types of farming systems would apply world-wide since marine environments and animal species vary depending on the region. 

As for mussel farming, please review the potential negative effects, which includes a research study as reliable literature, briefly discussed in Part I

Although, to supplement my previous argument, a Sweden-based study by Carlsson et al. (2012) found that, "the establishment of the Lysekil mussel farms increased the local sedimentation rates and affected underlying sediment by consistently increasing benthic oxygen demand and nutrient release...the continuous loading of mussel biodeposits gradually in creases the demand for oxygen to reoxidize reduced compounds, leading to oxygen depletion and stimulating the production of supports the correlation between elevated TOU [oxygen uptake], SRRs [sulfate reduction rate] and nutrient release, and negative effects on benthic RPD [redox potential discontinuity (RPD) layer indicates the depth of oxidized sediment] and BQI [benthic quality index]. (Hargrave et al. 2008). " I fail to see how anyone can claim no animal is harmed or killed with events, such as oxygen depletion in bethic zones. 

Image: Excerpt from the Animalist's Blog Post "Those Pesky Bivalves."

Lastly, I will say that these are just a few examples. I do not want to get too deep into the environmental impacts of farming/aquaculture because I do not believe that has any relevance in making a case of eating an animal species or not as it relates to veganism. 

In Conclusion

The Animalist excludes certain animal species from his "activism against speciesism" by applying unsupported ideologies of sentience to animal species that are NOT humans or even vertebrates because their nervous systems are set up different to our own - all based on zero evidence. He also fails to make a case for the claim that bivalve farming is free from "killing or harming or depriving one single sentient being" or any "sentient casualty".

The Animalist also makes it clear that he and the others mentioned below support an omnivorous diet for themselves since, as the scientific community has established, bivalves and ALL invertebrates are animals. Vegans, do not eat animals, and once again, invertebrates are all animals.

Image: Excerpt from the Animalist's Blog Post "Those Pesky Bivalves."

Note to the Animalist & Sentientist:

It's not personal, so I hope there will be no hard feelings. I went into science for the biodiversity, and I stayed because of ecology. I just want to prevent the dissemination of inaccurate scientific information, particularly when it is being used as the basis to exploit a species of animal.


The author of this post has a B.S. in Biological Sciences with an emphasis in Marine Science and a M.Sc. in Conservation & Ecology with an emphasis in research. Other experiences include, but are not limited to, aquaculture, molecular biology, fungal and plant symbiosis, and invasive species ecology. The author is also vegan, which means the author does not consume or consciously exploits any species of animal. 


Blevins & Johnsen (2010), Spatial vision in the echinoid genus Echinometra,  J Exp Biol 2074249-4253.

Burke R et al. (2006), A Genomic View of the Sea Urchin Nervous System.  Developmental biology; 300(1):434-460.

Carlsson et al. (2012), Effects of mussel farms on the benthic nitrogen cycle on the Swedish west coast, Aquacult Environ Interact, Vol. 2: 177–191.

Forrest, Elmetri, & Clark (2007), Review of the Ecological Effects of Intertidal Oyster Aquaculture. Prepared for Northland Regional Council. Cawthron Report No. 1275, 25p.

Knight (2010), Sea Urchins Use Whole Body As Eye, J Exp Biol 213i-ii.

Smith (1991), A Question of Pain in Invertebrates, ILAR J, 33 (1-2): 25-31.

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