Wednesday, May 30, 2012

Hooper's Super Meta Analysis

Hooper’s Super Meta Analysis
May 29th 2012 at noon I sat in a small classroom, Willamette 110 on the UO campus, which gave me flashbacks to the countless lectures I listened to about Physics for Scientists and Engineers, and the occasional fleeting memory of a summer O-Chem course that made me lament over lost sunny days.  The lecture I was about to attend by Prof. Hooper of Western Washington University, (bio: ), on biodiversity and ecosystem processes was already the best lecture I listened to in that room and he hadn’t even began speaking. 
With a methodical reading of his paper just published in Nature, “A Global Synthesis Reveals Biodiversity Loss as a Major Driver of Ecosystem Changes”  (it can be viewed at, ), which is a meta analysis that shows species loss has significant impact on primary production and decomposition, I was prepared with a couple questions I hoped to have answered. 
The first question that came to mind was, How can this new concept of biodiversity loss as a contributing factor to changes in ecosystem functions be explained and shared with the majority of the global population, those outside the scientific community?  I have found a disparity between the information available to the scientific community and to the general public about life altering effects to our ecosystem functions.  I thought the solution to my question was in the public lecture itself, but the audience seemed to be anything but the general public.  I recognized many students, professors, and those that I didn’t recognize had an aura of academia about them. 
In a continued attempt to find information suitable to the masses about biodiversity threats, without limitations such as verbose procedural terminology, AKA wordy words, I came across a paper by the lecturer himself titled, “10 things you can do to help biodiversity”.  It can be viewed here, .  Now I wasn’t lazily typing, the title is unassumingly in all lower case letters ,with simple words and start with the number “10”.  Along with the paper’s title and simple, almost childish, numbered list format, I found this paper to be non intimidating to those that are outside the scientific or academic communities. 
Another question I hoped would be answered was, How can one accurately study ecosystem functions and processes, which happen on such a large scale?  It seems near impossible to accurately study because one would need an entire world as a test plot.  It turns out this questions is a difficult one to answer and it was directed to the lecture audience before I had a chance to ask it.
Prof. Hooper’s lecture was very informative and allowed me to think of biodiversity and its effect on ecosystem functions in new ways.  If any blog readers have answers to my unsolved questions please share them with me and our global community. 

Too Much Jelly

Jellyfish could be one of the oldest multi cellular predators. We have found jellyfish fossils dating back 500 million years. The trick to their impressive resilience is probably due the simplicity of the organism. Basically all a jellyfish is, is a floating mouth gobbling up whatever it can get its tentacles on. Most jellyfish do not have a brain or bones, have a very simply nervous system, and are made up of 95% water. This animal definitely won't be the winner of any junior spelling-b. However, in its line of work it won't need that type of skill. It spends most of its time eating smaller fish or fish eggs and the occasional plankton. Although just because this animal is one of the simplest predators on Earth doesn't mean that it doesn't have some very valuable properties to medicine.

One of the most important contributions that jellyfish have given us is the ability to glow in the dark. Back in 2008 three researchers were awarded the Nobel Peace Prize in chemistry for their work on isolating the genes that caused jellyfish to have bioluminescen. They had worked with these proteins for a long time until they were able to identify which specific protein cause the jellyfish to have a green glow. This new found discovery, called green fluorescent protein, was used in making other animal cells glow. The discovery of the GFP was so important because it helps scientist watch how new nerve pathways are produced or how cancerous cells spread through out the body. Before GFP scientist could actually visualize what happens during cellular growth. When the cells are injected with GFP they glow and are easily visible. Those are just of a few major uses for the GFP gene but in short it is one of the most important discoveries for modern bio science. There is recent study going on right now where scientist are injecting marmoset monkey embryos with with the GFP gene using a virus. After this was done with 80 embryos were implanted into surrogate mothers which gave birth to 5 healthy glowing monkeys. These monkeys all express the GFP gene throughout their nervous system. This will help greatly in documenting how complex disease such as Parkinson’s effect the nervous system. GFP was definitely the most important discovery they gave us but not the only one. Right now some of the species' toxins are being tested for potential benefits. Since the jellyfish are very common and easy to catch scientist have started doing testes on jellyfish collagen as a good replacement for bovine or human collagen. This is becoming an increasingly promising candidate because of the large amounts of easily accessible jellyfish collagen. Jellyfish collagen also has a very good adhesion factors and binds very well with human cells. There is one jellyfish called Chrysaora quinquecirrha that is having its toxins tested and they have discovered that they have amazing antioxidant properties in them.

Jellyfish have given us an incredible discovery that has helped in so many ways. However, they aren't all smiles and sunshine. Recently there have been massive blooms in jellyfish populations all around the world and their numbers are growing out of control. This might sound like a good thing but it is a major problem in more ways than one. With such an increase in jellyfish numbers they are starting to cause damage to ecosystems around the world. There is a strong correlation with the rise in jellyfish populations and the rise in temperature of the oceans. These temperature rises have been caused by the increase in the atmospheric CO2 There are plenty of charts and graphs that show when plotted the direct impact that CO2 has on the global temperature. Now that the oceans are just a little bit warmer the jellyfish have been able to reproduce much fast. This is a common cause in the animal kingdom due to the nature of enzymes and cell reaction rates. Every cell and enzyme has a golden temperature zone in which it reacts a peak efficiency. Since the waters have warmed this has increased the rate at which jellyfish have been able to reproduce.

You might be thinking that this a beacon of light in world where everyone says that global warming is destroying diversity and ecosystems. However, this jellyfish bloom is definitely not a benefit to the oceanic diversity or the survival of many ocean species. Since there has been such a massive increase of jellyfish in they naturally have been eating more food. This has become a major problem in areas like the Caspian Sea and the Black Sea. The jellyfish are over eating and cause a dangerous drop in fish levels in many seas in the Mediterranean. This isn't only affecting the fish it also is effecting the other marine mammals that feed off the fish that live in those areas. Jellyfish blooms are having major affects on diversity that are trickling down the food chain. We have to take the bloom in jellyfish very seriously because we don't fully understand how this will affect the all of the ocean habitats. It could end up destroying coral reefs buy eating all of the natural fish that inhabit the corals. This would undoubtedly have major impacts on the reefs because of the complexity and fragility. Also they are out competing other fish in the ocean for food and could cause them to go extinct which could harm the shark populations. Sharks and reefs are too important to lose because they hold some major benefits contributing to modern medicine and we can't afford to lose these organisms. They aren't only disrupting local ecosystems they also have caused massive set backs to fishing industries. The large amount of jellyfish have been getting caught in nets with fish and they end up either ripping the nets from their weight or crushing the fish. This has caused loses in the fishing industry especially in areas like the Black Sea where the Box Jellyfish is an invasive species that was accidentally introduce to the sea. They have also cause major loses in the tourism market in Japan due to the blooms taking over the shore line. This is a problem for everyone not just biologist and it needs to be address very quickly. If the jellyfish keep reproducing at this rate they will eventually eat all of their food source and then start starving to death. We must find a solution to this problem fast or we might not be able to reverse the effects that the jellyfish have had on other marine life and themselves.


Web Sites and Articles Used

"The Nobel Prize in Chemistry 2008". 30 May 2012

"Sea Science 2010". South Carolina Department of Natural Resources.

Tuesday, May 29, 2012

What's Killing the "Killer"

Since the age of five I have always known what I wanted to do with my life: to get my degree in marine biology and become the leading field researcher on orcas. Ok, I know the leading researcher is a little far fetched, but a girl can dream right? I dreamt of spending hours in the open ocean conducting research studies on behavior, social interaction, migratory patterns, and more. Unfortunately, in the field of marine biology, it looks like by the time I graduate, these topics will be the least of interest. Most important to researchers right now is what is causing the death of orcas. Orcinus orca, the "killer whale" is a toothed whale found in the oceanic dolphin family. Most people know orcas as "FREE WILLY". Something is killing these animals and we need to figure out what it is and fast. The two most common and researched hypothesis are 1. Naval sonar research and 2. Water pollutants. There is a lot of controversy on sonar research and its effects on wildlife. Water pollutants on the other hand are pretty much accepted across the board. With orcas being apex predators they get second hand pollutants from the fish and marine mammals that they eat. However, there is a new emerging theory on the deaths of the killer whale that is gaining world wide attention and it involves airborne microbes.

The Research 

Thanks to researchers at the University of Washington and Global Research and Rescue, a new way of thinking about orca health is in motion. Studies are being carried out to analyze the content of exactly what is in killer whales lungs. In the study "Investigation into the Microbial Culture and Molecular Screening of exhaled breaths of Endangered Southern Resident Killer Whales (SRKW) and Pathogen Screening of the Sea Surface Microlayer (SML) in Puget Sound"  a pod of orcas were tracked and a pole with petri dishes attached at the end was used to capture the breath of the orcas when they surfaced. From this researchers have been able to analyze what the orcas are breathing. [Read original article here]

The plates (modified to be covered until the time of collection and closed immediately post 
collection) include: two sterile plates with no media, a blood agar plate, a salt enriched 
trypticase soy agar (TSA) plate, and a Sabouraud (SAB) media plate. 


Researchers found that "orcas are inhaling bacteria, fungi and viruses that were thought to be found only on land. Some of them are especially dangerous- and resistant to antibiotics" (Welch). Perhaps the most disturbing thing found in the orcas were microbes that have been known to cause pneumonia in humans. When you look back into the history of necropsy's, a autopsy of an animal, orcas that have been found washed up or stranded, out of the 46 that were analyzed, half of them died while sick with pneumonia. Coincidence?

Why this matters

Within the last few years genetic sampling has been done on a wide variety of orcas. It has been determined that there are actually several species of orcas. By breaking this once large group of animals into smaller groups, certain species are now found to be a lot more rare than previously thought. While a group of orcas known as the "puget sound orcas", found in Puget Sound, Washington many months of the year,  have not been considered threatened or endangered, with the current threats of pollution on its population, it is only a matter of time.

The research done by professors at the University of Washington and Global Reasearch and Rescue, suggests that not is water pollution affecting the marine life, but also airborne pollution. These diseases that are now floating around in the air are much more dangerous to the marine life than to humans. When a human inhales and exhales, we exchange about 20% of what is in our lungs. Compare this to an orca who is thought to exchange around 70% of what is in its lung in a single breath. Orcas are the perfect model for this research on airborne pollutants because they are literally found in every ocean. This gives us the opportunity to look at these animals and to see the bigger picture of everything that is happening in the marine ecosystems.

Although it is good that the issue of airborne pollutants on orcas is finally getting some press attention, this isn't the first research or account of these issues. Puget Sound Orcas, one of the few groups of orcas that is protected and considered threatened by the local government (although they are not classified threatened by the IUCN Redlist), have been known to have problems due to local air quality. "It's no secret that a stew of microbes from land regularly invades Puget Sound. Bacteria and nutrients from humans and animals have for decades been funneled into estuaries and bays, causing oxygen problems in Hood Canal and resulting in shellfish-bed closures". [Read more about the pollution in Puget Sound] Puget Sound Orcas are residential, meaning that they tend to stay closer to land and prey on fish rather than the transient orcas that stay further out to sea and prey on marine mammals. Below you can see their geographical range and how close to land these orcas stay. For any residential pod, this is a deathly combination because now they are getting pollutants in their water, food, and air.

The figure above shows the slight decline of the Puget Sound Orcas population over the more recent years.  With these facts and figures, Puget Sounds make the perfect model to study the effects of pollutants on the decline of population in marine life.

How does this effect the rest of the marine life?

The new discovery of these land bacteria, fungi and viruses found in orcas is already starting to reach a broader scope in the science community. It has recently been confirmed that the air pollutants that these orcas are breathing are directly having an effect on the pollution of the water itself. [Read about air pollutants effects on water pollution] These air pollutants will eventually land on the water surface and form a very thin film known as the sea-surface micro-layer. Therefore, this becomes a much bigger issue extending to other things in the ocean that occupy the same range as the orcas. As mentioned in "Investigation into the Microbial Culture and Molecular Screening of exhaled breaths of Endangered Southern Resident Killer Whales and Pathogen creening of the Sea Surface Microlayer in Puget Sound", orcas can be a good indicator of biological integrity and marine environmental quality. By using them as a model we can study the effects of air pollutants on the marine ecosystems.

Rethinking Research

From this study, it can be seen that we need to take a broader look what is killing marine mammals and not limiting our thinking to things such as water pollution and sonar research. The fact that pneumonia, normally found only on land has been found in half of the 46 washed up or stranded orcas is a clear indicator that something else is going on. This is not to say that pneumonia or the other things being found in the lungs of orcas is the cause of the death in these killer whales, but it is at least is a factor to consider in looking at things such as a weakened immune system that could then lead to the death of these mammals from other things such as water pollutants. 

Links and Credit Images:

Images (In order of Appearance)

[Image Credit: PETE SCHROEDER]
[Image Credit: PETE SCHROEDER]
[Image Credit: PETE SCHROEDER]

References (In alphabetical order):

Essington, T. Klinger, T. Conway-Cranos, T. Buchanan, J. James, A. Kershner, J. Logan, I. West, J. (March, 2011) Biophysical Condition of Puget Sound. Retrieved May 25, 2012, from

Foote, A. Vilstrup, J. DeStephanis, R. Verborgh, P. Abel Neilsen, S. Deavile, R. Kleivane, L. Martin, V. Miller, P. Oixn, N. Perez-gil, M. Rasmussen, M. Reid, R. Robertson, K. Rogan, E. Simila, T. Tejedor, M. Vester, H. Vikingsson, G. Willerslev, E. (Februrary, 2011) Genetic differentiation among North Atlantic killer whale populations. Retrieved May 25, 2012, from

Genome Research. Killer Whales are probably several different species. Retrieved May 25, 2012, from

Mountain, M. (April 2012) Orcas Now  Being Poisoned by Air They Breathe. Retieved May 25, 2012, from

Schroeder, P. Raverty, S. Zebek, E. Cameron, D. Eshghi, A. Bain, D. Wood, R. Rhodes, L. Handson, B. Investigation into the Microbial Culture and Molecular Screening of exhaled breaths of Endangered Southern Resident Killer Whales (SRKW) and Pathogen Screening of the Sea Surface Microlayer (SML) in Puget Sound. Retrieved May 25, 2012, from

Welch, C. (April 2012) Killer Whales Facing an Airborne Threat. Retrieved May 25, 2012, from 

Monday, May 28, 2012

Biomedicines Blue Gold

Horseshoe crabs, Limulus polyphemus, evolved 450 million years ago.  They most commonly found in the soft, sandy, muddy bottom of the east coast.  Although they are commonly called crabs, they are more closely related to arachnids.  The population of horseshoe crabs along the Atlantic coast of the United States is listed as threatened.  While not listed as endangered yet, the population numbers have been consistently dropping year after year.  This is due to human predation and climate change.  The main prey of the horseshoe crab is shellfish and the fishermen along New England coast are concerned with the amount of shellfish the horseshoe crabs eat in respect to their business.  Another threat to horseshoe crabs is climate change.  As water temperature and sea level rises it has been correlated to have negative effects on the distribution and reproduction rate of horseshoe crabs.  Horseshoe crab eggs are a very important part of the food web.  Around only 10% of the eggs laid hatch.  This is because many of the shore birds eat the eggs, and the effects of a declining horseshoe crab population would scale through all the tropic levels.

Not only do horseshoe crabs provide ecosystem benefits, but also have uses for biomedical research.  In the 1960’s Dr. Frederik Bang discovered that when he injected bacteria into the horseshoe crab large amounts of clotting occurred.  It was later discovered by Dr. Jack Levin that the clotting was due to the presence of endotoxins produced by the bacteria.  Horseshoe crabs’ blood is a hemolymph based off of copper which makes it blue.  Since horseshoe crabs have evolved so long ago, they have a very primitive immune system.  This primitive immune system evolved to be sensitive to endotoxins.  This endotoxin was believed to have been expressed in cyanobacteria millions of years ago.  Horseshoe crab blood is used to test the purity of drugs and implants.  In the presence of bacteria or endotoxins the blood coagulates and localizes around the area of impurities.  This is because horseshoe crabs have an open circulatory system and wall off the infected areas to stop the infection from spreading.

Biomedical companies use a technique called Limulus Amebocyte Lysate (LAL) which uses the horseshoe crab hemolymph to detect the presence of gram negative microbes.  Laboratories use LAL tests on human injectables such as insulin.  These medications cannot exceed the test limits set by the FDA.  LAL tests are also used on artificial implants such as kidneys and heart valves.  LAL test provide a quick and sure way to determine if the medication or device is sterile.

The medical products are placed in to a reconstituted test tube of LAL.  If the LAL coagulates then the batch of product is contaminated and must be thrown away.  A wide array of biomedical products that people use every day is tested in this manner.  Every shot you have received has past this test to make sure you would not get sick from contaminated medications.

To produce LAL horseshoe crabs must be caught and bleed.  A sterile needle is inserted into the animal and the blood is collected.  It is then centrifuged to separate the amoebocytes from the liquid plasma and then freeze dried for distribution.  This process, while not perfect, has a 10% mortality rate for the horseshoe crabs.  It has been estimated that a quart of LAL is worth $15,000.  The high cost and need is leading researchers to isolate and clone the toxin detecting gene.  If this is possible, LAL can be produced without harming the horseshoe crabs.

The value that these horseshoe crabs provide to the biomedical community is invaluable.  But so is the value of the shellfish to the fishermen of the New England coast.  Horseshoe crabs are most commonly used as bait by these fishermen and are now being regulated on the amount and size of horseshoe crabs they are able to collect.  Horseshoe crabs are used to bait traps for eels and conch, which is an extremely profitable business itself.  This single species is being fought for by three different groups; the fisheries, biomedical, and environmentalists.  All three of these groups what something different from this single species.

Now with the threat of bioterrorism, the LAL tests are used even more.  All vaccines and other injectable medications are thoroughly tested for contamination intentional or not.  With these new demands the horseshoe crab biomedical field needs a larger supply of LAL.  The current policies and processes that the biomedical companies use still kill 10% of the horseshoe crabs used but could be much higher once placed back into the wild.  Current research is looking for alternative ways to produce LAL due to the increasing demand and decreasing population of horseshoe crabs.  Only now are researchers tagging horseshoe crabs and tracking their locations to find effective ways to manage their populations.

But not only do the three groups, fisheries, biomedical, and environmentalists have a hand in the decline of the horseshoe crab populations.  After doing some genetic research, evidence suggests that climate affects horseshoe crab distribution and interbreeding.  Genetic diversity is the basis of a stable and sustainable population.  A study done in 2005 determined that male horseshoe crabs migrated but female horseshoe crabs did not.  This could lead to local extinctions if the males of one area all left.  This study also provides information that could lead to new conservation methods.  Restriction on the number of females captured could help keep populations present in all areas, as well as the relocation of males from different areas to keep the genetic diversity high between all populations.  As more research is done and the more we learn about horseshoe crabs, the better we will be able to keep them around and available for all those who depend on them.

Tuesday, May 22, 2012

Butterflies. The Forgotten Pollinators.

Bees and butterflies make the world go round. They are able to achieve this seemingly impossible task by giving all the plants on the planet the ability to reproduce by spreading pollen from one plant to another. Unfortunately, the populations of both these insects, that provide this vital ecosystem service, are declining. Bee population declines have been widely studied because of the agricultural sectors reliance on their pollination and the mysterious causes behind their disappearance. The dwindling butterfly populations, on the other hand, have largely been ignored. Of the 30 or so federally listed endangered or threatened butterfly species, only half have received an approved recovery plan.
Diversity amongst one species of butterfly
Butterflies, like many other species, are being allowed to disappear because they lack attributes that immediately benefit people.Their contributions to an ecosystem's overall functioning are not acknowledged as good enough reasons for proper conservation strategy implementation. Bees and butterflies are not treated equally because bees are highly efficient pollen collectors and have easy to maintain hive communities. These differences are what make bees so much more valuable to people than butterflies. But just because bees are better at collecting the pollen does not make them any more important to ecosystem or plant survival than butterflies.

Monarch Butterfly's Migration Pathways
The differences between bee and butterfly pollen collection are numerous. Unlike honeybees, butterflies have an erratic, inefficient pattern to their flight. This unpredictable trajectory provides pollination to areas that bees would otherwise never frequent. Providing these areas with new pollen sources allows for greater genetic diversity within communities that would not have been attainable with just bee pollination. Butterflies are also able to see the color red, whereas bees can not, so they may be better suited to pollinate red flowers than bees. Another distinct difference between bees and butterflies is the distance that some species travel. The Monarch Butterfly's (Danaus plexippus) continental migration is a great example of the capabilities that butterflies have for spreading pollen.

Butterflies first appear in the fossil record during the Eocene Epoch (50 Mya), which is about the same time period that modern grasses and forbs were beginning to break from the shadows of the forests that covered much of the planet. This means that these grasses and flowers co-evolved with the first butterflies, making them forever linked in existence to each other. Certain plant species, undoubtedly, evolved without the aid of bee species, making them undesirable for bee pollination. This is why it comes as no surprise that certain native wildflower populations have declined at a similar rate as the butterfly communities they rely on.
Monarch Butterfly on a milkweed plant.

Plants play an integral part in nearly every part of a butterfly's life cycle. Adults lay their eggs on a specific species of plant. The larvae then feed on leaves and pest species, which builds up a chemical defense mechanism that, in turn, makes them undesirable to predators. Finally the adults feed off the nectar from the flowers of the plant. Every stage of the the butterfly's life relies on another type or part of plant for survival.

A perfect example of this co-evolution/co-endangerment of two species is the case of Fender's Blue Butterfly (Icaricia icarioides fender) and Kincaid's Lupine (Sulphur Lupine). This type of butterfly has a very unique life cycle which takes longer to reach reproductive maturity than most species, making them especially vulnerable to biodiversity threats. The video below describes the Fender's life cycle and its association with Kincaid's Lupine.
This example shows just how intricate some of these species relationships are and how much they rely on one another for survival. In a study done at Oregon State University, the researchers found a distinct correlation between the number of butterflies and the number of its associated host plant. If one of these species is reduced in number, there will be a similar reduction in the other. The main threats that are effecting butterfly species are habitat destruction, pollution and pesticide misuse.

While, bees and butterflies have many differences, the challenges their species face are nearly identical. Habitat loss is the one with the most effect on butterflies however. Most of the habitat destruction occurs from changing the land use to agricultural or development purposes. Habitat loss has such a dramatic effect because it limits the nectar and pollen sources available to the butterflies and also eliminates vital nectar corridors for species traveling long distances rely upon as resting and breeding areas along their way. Butterfly's unique ecosystem services can no longer be ignored or the other species's extinctions will soon be collateral damage of our flawed conservation system. A more ecological approach must be taken, where protection of the butterflies will protect the areas and plants that they inhabit rather than having to choose between species.
New restoration strategies must be formulated to keep butterfly and host plant populations healthy. Butterflies can act as "umbrella species" that protect more than one species. By using butterflies in this manner they will provide an even larger cultural ecosystem service than they already do. They would become a symbol of its declining habitat and the symbiotic relationship it shares with its habitat. One of the new methods we can employ could be having private homes and schools begin to breed native butterflies for educational purposes. Unlike bees, butterflies are never going to harm you and most of them rely on beautiful, native flower and fruit species for their survival. Small steps towards restoration will have huge impacts for certain species, like Fender's Blue, and can easily be achieved by the individual. All it takes is a small bit of education to make a difference for an endangered species.

The pollination done by butterflies may be just a small slice out of the pollination pie but it is a niche that other species do not cover. If this niche is ignored, there could be a domino effect of other areas being degraded and whole ecosystems vanishing because of the imbalances created by the original disturbance. Butterflies may seem like small organisms that play a tiny role in the larger scheme of things but it is still an important part of a system that must be recognized if restoration efforts are ever going to be successful. No longer can our policies be governed by the interests of a few but rather be based on science and empirical data collected through methodical research. The survival of too many species are being put into question by the actions of humans, for once we must reverse this trend and begin to become the reason for the survival of these species.

Work Cited

Beneficials in the Garden.  2005. Earth-Kind Program, Texas A&M University. 17 May 2012

The Butterfly Conservation Initiative. 2012. Florida Biodiversity Foundation Inc. 16 May 2012.

Waltz, A. E. M. and Wallace Covington, W. (2004), Ecological Restoration Treatments Increase Butterfly Richness and Abundance: Mechanisms of Response. Restoration Ecology, 12: 85–96. doi: 10.1111/j.1061-2971.2004.00262.x

Wilson, Mark, P. Hammond, C. Shultz. "The interdependence of native plants and fender's blue butterfly". 1997.Oregon State University.

Doctor Pooh: The Use of Bears in Medicine

Bears have been an important part of our history, dating back to the earliest civilizations where they were integrated into religion and medicine.  Although they have less of a central role in modern religious and cultural practices, their importance in medicine is just as significant as ever.  In particular, studying the physiological processes bears undergo while denning is useful for understanding common diseases among humans, such as osteoporosis, renal disease, and diabetes.  Bears are also used for direct medicinal purposes by those who continue to practice traditional Chinese medicine.
Ursus americanus
During the colder months when food is scarce, most bear species begin a period of hibernation lasting three to five months.  Hibernation is a relatively uncommon behavior, developed as an adaptation for surviving prolonged periods of harsh conditions. During these times, animals become unresponsive and drastically lower their body temperatures and metabolic rates.  Bears on the other hand, maintain their normal body temperature and are alert to potential dangers around them.  For this reason, this bear behavior is referred to as denning.  While denning, bears are immobile, and do not eat, drink, urinate or defecate.  Their ability to continue to regulate essential physiological processes is therefore quite impressive.   Studying the physiology of denning bears has been of great significance for researchers trying to understand human diseases associated with immobility, such as osteoporosis.

Osteoporosis occurs when the rate of bone reabsorption exceeds that of bone formation, and can be caused by disuse or changes in bone mineral density.  Although the bones of denning bears endure long periods of disuse, they never develop osteoporosis.  Research with the American black bear, Ursus americanus, has shown that while other hibernating animals undergo bone loss, bears simply undergo high rates of bone turnover, with increases in both the rates of formation and reabsorption.  Since bears do not urinate or defecate during hibernation, it is thought that the blood calcium concentrations remain stable and interact with calcium hormones and other growth factors to increase the rate of bone growth. The accelerated rate is then equivalent to the higher rate of loss associated with disuse.    Studies have also found that unlike humans, bears exhibit no significant increase in porosity with age or inactivity, and instead increase cortical bone bending strength.  By studying the physiological processes responsible for these phenomena, new treatments and preventative medicines may be created for human use against osteoporosis.

Changes in percentage of porosity in humans and black bears with age
Donahue, et al. 2006

Porosity in cortical bone. A) active bear B) bear in hibernation
6 Donahue et al. 2006
Similarly, studying polar bears is also valuable for learning about diabetes.  Like humans with Type 2 diabetes, polar bears are resistant to insulin, meaning higher concentrations of insulin in the body do not effectively metabolize carbohydrates or suppress the release and metabolism of stored fat.  In humans with type 2 diabetes, this process causes an increase in blood sugar and blood lipid concentration, which creates greater risk of atherosclerosis.  Polar bears however, are still able to effectively metabolize carbohydrates and regulate lipid release, even with high insulin concentration and insulin resistance associated with their pre-denning state.  Successful treatments for type 2 diabetes could be discovered with increased knowledge of the polar bear's metabolic pathway.  Unfortunately, due to the vulnerable state of their species, research is near impossible.

One reason why studies of the American black bear have been successful is the availability of animals.  American black bear populations are listed as Least Concern on the IUCN's Red List of Threatened species, and populations have generally been increasing across the United States and Canada.  The opposite is true for the polar bear, which are now listed as Vulnerable with declining populations.  The primary cause is shrinking ice sheets caused by global warming, which have caused a decrease in habitat and resulted in increased energy expenditure while traveling farther distances. 

Unfortunately, human threat to bears doesn't end with habitat destruction.  Asiatic black bears, Ursus thibetanus, face an additional threat: hunting and commercial trade.  These bears are primarily captured for the use of their gall bladder and bile, which are used in traditional Chinese medicine to treat pain, inflammation, protect the liver, and break up gall stones. Although alternative synthetics have been created and equivalent plants and herbs have been discovered, there is still relatively high demand among the wealthy and those who are distrusting of modern medicine.  
Ursus thibetanus
As a way of preventing Asiatic black bears from increasing their status from Vulnerable to Endangered while meeting the demand for bile, commercial bear farming was introduced in China in 1984. These businesses still significantly impact wild bear populations through the repeated capture of wild bears in order to stock and maintain the supply of bile.  Some farms have claimed to breed individuals to reduce population decline, however, most do not make any attempt at husbandry.  Today there are approximately 14,000 bears held in captivity for this purpose.  Furthermore, the methods used for capture, captivity, and bile extraction are extremely detrimental to the health of the bears.  The animals are all kept in small metal cages, some of which completely restrict movement.  Many individuals are missing paws or large sections of limbs as a result of trapping methods.  Those with wounds are often untreated and develop infections.  The bile is extracted regularly through an implanted tube, metal catheters, or through a permanent hole in the abdomen to the gall bladder.  Bears often develop infections from the holes pierced through their abdomen and can endure complications when bile bleeds back into their body.  These processes are all quite painful, as bears have been observed chewing their paws or uttering distressing sounds.  Many have broken teeth and bleeding mouths from repeatedly biting at the cages.

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However, there is hope for these bears.  Organizations like Animals Asia are working to eliminate bear farming practices. It is a constant struggle between the animals' unrecognized right to live free from torture against the human sense of entitlement.  Although there is great value in traditional medicines from nature in terms of health benefits and heritage, sometimes the cost is too great.  The use of bears in medicine can be a fantastic tool, but it should not come at the expense of individuals or the species.  These species are important for preserving biodiversity, ecosystem health, and most importantly, an intrinsic right to exist.  There is also much that we can learn from bears regarding the biological processes associated with common diseases.  For these reasons, we should actively work to improve the health of current populations and preserve all species of bears by reducing habitat destruction and eliminating poaching and bile farming.


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