//
you're reading...

Conservation

From ancient blood come modern cures, or, How Horseshoe Crabs and Medicine Intertwined

Gorman, R. (2020). Atlantic Horseshoe Crabs and Endotoxin Testing: Perspectives on Alternatives, Sustainable Methods, and the 3Rs (Replacement, Reduction, and Refinement). Frontiers in Marine Science. Retrieved from https://www.frontiersin.org/article/10.3389/fmars.2020.582132

Sometimes it’s not just “snake oil”

Figure 1: “Limulus polyphemus – Atlantic horseshoe crab in Florida, USA”  by James St. John, December 2012. www.flickr.com/

It’s true, there are many “remedies” out there that do nothing—like wearing copper bracelets to help with arthritis or taking elixirs made from mineral oils and not much else, but other times nature provides us with substances that are infinitely more useful. In the midst of the COVID-19 pandemic, some of you may have seen news about squalene (an oil found in shark liver) and how it is used in vaccine production. As much as this has conservationists worried about shark populations, another marine organism has been supplying humans with a key extract for testing vaccines for contamination since the 1970s: horseshoe crabs. In this case, we’re not using oil; rather, we’re after their blood and a very specific cell extract within it. Not only is horseshoe crab blood needed for testing vaccines, but also for making sure every IV drip, implanted port, or injected medicine is free of toxic bacterial remains.

Horseshoe crabs are therefore harvested on a regular basis from wild populations and bled in specialized facilities before being released back into the ocean. As more vaccines and medicines are produced globally, we are now collecting over 500,000 horseshoe crabs each year to keep up with the pharmaceutical demand. Combine this with changing habitat conditions, and that ~8-30% collected horseshoe crabs die after being returned from these periodic blood drives, scientists are concerned these creatures may be dwindling in numbers.

As more discussions about the sustainability of collecting these animals happen, social science is entering the picture to get a better idea of what stances different industries are taking. In a new series of interviews, Dr. Richard Gorman has tried gauging what a small number of people within the pharmaceutical and conservation fields think about approaching the issue from the “3R” perspective. The 3Rs stand for “the ambition to replace, reduce, and refine the use of animals in science” – something that does not seem to have been considered when it comes to horseshoe crabs, but could be incredibly helpful in taking some pressure off their wild populations.

Figure 2: “Blue blood” by Sue Gerhart, 2004. www.flickr.com/ The hemocyanin in the blood gives it a distinctly blue hue when compared to our red, hemoglobin-rich blood.

Can we reduce?

When compared to previous harvests of crabs (e.g. for fertilizer in the late 1800s), the yearly haul of horseshoe crabs is much smaller. That doesn’t mean it can’t be reduced further. The majority of those interviewed in pharmaceutical, biotech, and conservation fields recognized reducing the number of crabs collected as the ideal option, even if it is a difficult goal. It’s been suggested that raising a stock of horseshoe crabs solely for scheduled bleeding would be the best solution since conditions and the health of the animals can always be controlled. Unfortunately, horseshoe crabs are not always easy to keep and breed in captivity. What’s more helpful, though, is getting creative with the biomedical technology since using smaller amounts of cellular extract would directly translate to fewer crabs being collected. Either way, it’s a long road ahead on the reduction front.

Can we replace?

Replacement here means substituting the blood extract with something else from a non-animal source. Prior to using horseshoe crab blood in the 1970s, scientists had relied on testing medicine batches on rabbits and waiting to see if the small mammals displayed symptoms. We don’t want to repeat that pattern. The good news? A synthetic form of the horseshoe crab’s protein was developed in 2001! The bad news? It hasn’t been as well received or embraced by the pharmaceutical industry, mainly because of concerns over how to mass-produce it, and questions on if the synthetic version works equally well. Positive steps were taken in 2019, though, with the European Pharmacopoeia recognizing the synthetic test as equally sensitive to the one made from the horseshoe crab’s protein. The larger issue at hand now is bringing the biotechnologists and conservationists closer together to recognize there are ways to strike a compromised balance that meets some of the goals of each industry. It will all have to be monitored carefully since there are a lot of separate pressures facing these crabs.

Can we refine?

If we aren’t able to reduce or replace horseshoe crab blood yet, is it possible to make the process less of an ordeal for them? Some researchers gave suggestions ranging from limiting the volume of blood drawn (and maybe removing the cells we need before reinjecting the rest of the blood back to the animal) to exploring breeding a “lab strain” of horseshoe crabs meant exclusively for regular sampling. To date though, efforts for refinement aren’t openly discussed due to the confidential or secret nature of many biomedical companies.

Figure 3: “Horseshoe crab pile” pixabay.com/ Horseshoe crabs depicted here ensuring the next generation will be born! Breeding late in spring ends up supporting many other species—especially the migratory birds that use the Atlantic Flyway that feed on the thousands of baby horseshoe crabs that hatch out a month later. We’re not the only ones benefiting from this ancient species!

And in the end?

While Dr. Gorman’s interviews are only the tip of the iceberg (or horseshoe crab pile as it were), it’s good to know the welfare and use of these creatures is being discussed. It will likely take mixing approaches, and each step of the industrial chain will need to step up and participate if we want to make progress to lessen the stress on the wild populations. The responsibility can’t only lie with the companies extracting the blood—we all benefit from these organisms, so let’s make it a combined effort to change their future!

Discussion

No comments yet.

Post a Comment

Instagram

  • by oceanbites 3 months ago
    Happy Earth Day! Take some time today to do something for the planet and appreciate the ocean, which covers 71% of the Earth’s surface.  #EarthDay   #OceanAppreciation   #Oceanbites   #CoastalVibes   #CoastalRI 
  • by oceanbites 4 months ago
    Not all outdoor science is fieldwork. Some of the best days in the lab can be setting up experiments, especially when you get to do it outdoors. It’s an exciting mix of problem solving, precision, preparation, and teamwork. Here is
  • by oceanbites 5 months ago
    Being on a research cruise is a unique experience with the open water, 12-hour working shifts, and close quarters, but there are some familiar practices too. Here Diana is filtering seawater to gather chlorophyll for analysis, the same process on
  • by oceanbites 6 months ago
    This week for  #WriterWednesday  on  #oceanbites  we are featuring Hannah Collins  @hannahh_irene  Hannah works with marine suspension feeding bivalves and microplastics, investigating whether ingesting microplastics causes changes to the gut microbial community or gut tissues. She hopes to keep working
  • by oceanbites 6 months ago
    Leveling up - did you know that crabs have a larval phase? These are both porcelain crabs, but the one on the right is the earlier stage. It’s massive spine makes it both difficult to eat and quite conspicuous in
  • by oceanbites 6 months ago
    This week for  #WriterWednesday  on  #Oceanbites  we are featuring Cierra Braga. Cierra works ultraviolet c (UVC) to discover how this light can be used to combat biofouling, or the growth of living things, on the hulls of ships. Here, you
  • by oceanbites 7 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Elena Gadoutsis  @haysailor  These photos feature her “favorite marine research so far: From surveying tropical coral reefs, photographing dolphins and whales, and growing my own algae to expose it to different
  • by oceanbites 7 months ago
    This week for  #WriterWednesday  on Oceanbites we are featuring Eliza Oldach. According to Ellie, “I study coastal communities, and try to understand the policies and decisions and interactions and adaptations that communities use to navigate an ever-changing world. Most of
  • by oceanbites 8 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Jiwoon Park with a little photographic help from Ryan Tabata at the University of Hawaii. When asked about her research, Jiwoon wrote “Just like we need vitamins and minerals to stay
  • by oceanbites 8 months ago
    This week for  #WriterWednesday  on  #Oceanbites  we are featuring  @riley_henning  According to Riley, ”I am interested in studying small things that make a big impact in the ocean. Right now for my master's research at the University of San Diego,
  • by oceanbites 8 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Gabby Stedman. Gabby is interested in interested in understanding how many species of small-bodied animals there are in the deep-sea and where they live so we can better protect them from
  • by oceanbites 8 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Shawn Wang! Shawn is “an oceanographer that studies ocean conditions of the past. I use everything from microfossils to complex computer models to understand how climate has changed in the past
  • by oceanbites 9 months ago
    Today we are highlighting some of our awesome new authors for  #WriterWednesday  Today we have Daniel Speer! He says, “I am driven to investigate the interface of biology, chemistry, and physics, asking questions about how organisms or biological systems respond
  • by oceanbites 9 months ago
    Here at Oceanbites we love long-term datasets. So much happens in the ocean that sometimes it can be hard to tell if a trend is a part of a natural cycle or actually an anomaly, but as we gather more
  • by oceanbites 10 months ago
    Have you ever seen a lobster molt? Because lobsters have exoskeletons, every time they grow they have to climb out of their old shell, leaving them soft and vulnerable for a few days until their new shell hardens. Young, small
  • by oceanbites 10 months ago
    A lot of zooplankton are translucent, making it much easier to hide from predators. This juvenile mantis shrimp was almost impossible to spot floating in the water, but under a dissecting scope it’s features really come into view. See the
  • by oceanbites 11 months ago
    This is a clump of Dead Man’s Fingers, scientific name Codium fragile. It’s native to the Pacific Ocean and is invasive where I found it on the east coast of the US. It’s a bit velvety, and the coolest thing
  • by oceanbites 11 months ago
    You’ve probably heard of jellyfish, but have you heard of salps? These gelatinous sea creatures band together to form long chains, but they can also fall apart and will wash up onshore like tiny gemstones that squish. Have you seen
  • by oceanbites 12 months ago
    Check out what’s happening on a cool summer research cruise! On the  #neslter  summer transect cruise, we deployed a tow sled called the In Situ Icthyoplankton Imaging System. This can take pictures of gelatinous zooplankton (like jellyfish) that would be
  • by oceanbites 1 year ago
    Did you know horseshoe crabs have more than just two eyes? In these juveniles you can see another set in the middle of the shell. Check out our website to learn about some awesome horseshoe crab research.  #oceanbites   #plankton   #horseshoecrabs 
WP2Social Auto Publish Powered By : XYZScripts.com