B(io)LOG (in English)

Caving at Riverbend Cave (Horne Lake)

2011-08-11T23:48:00.000-07:00

Last week-end, armed with a helmet, a head lamp, and wrapped in fleece, I visited Riverbend Cave at Horne Lake Provincial Park on Vancouver Island. The “Extreme Rappel Tour” took us 5 hrs into the cave, where we had to crawl through some very tight spaces, rappel down a seven-story shaft (the Rain Barrel, as it is called), and … little did I know, rock-climb back up the cliff on the way back out.

A few sensations to note about being in a cave... First, it’s cold – is was about 8 degree Celsius on the day we were there. And dark – the only illumination comes from your head lamp, so bring a spare. And surprisingly, it is so damp that the water vapour from our breath stayed floating in the air. Many of the pictures have speckles of water vapour in the frame. A very memorable experience came when we reached the end of the cave, turned off our lamps, and remained silent. We “experienced the cave”; its sounds, smells, feels, and, well, lack of sights. I’ve only ever experienced that level of pitch darkness once before, and that was at the end of a copper mine I visited.

I was rather anxious of the crawling through tight spaces (read: narrow tunnels), but I felt like a kid again and enjoyed that the most. I did come back rather bruised (particularly around the knees) – but I don’t remember making any of these, so it doesn’t matter. Saw a few impressive calcite formations (see pictures – one is of the bacon strips on the ceiling, and the other of me posing at the bottom of the Rain Barrel (the cliff from which we rappelled)). Notably, one was called the “Starship Enterprise”, but seeing the object for which it was named required a lot of imagination. Apparently the delicate cave structures have survived three major earthquakes, which is reassuring given the recent media coverage about how the region is more prone to mega-thrust earthquake than previously suspected.

Few animals to note: just a few insects. The guide told us that he’s seen salamanders a few times, but I did not see them. Apparently the cave used to house bats, but they have been scared away by cave visitors. Given that I am currently preparing a course on Infectious Diseases and that bats keep coming up as a vector or reservoir for many viral and bacterial species that can infect humans, I can’t say I was all too sad. Although, I did stumble upon an interesting article on White Nose Syndrome, a fungus that is infecting many bats in North America and is decimating the bat population. This fungus disrupts the hibernation pattern of bats and causes the bats to spend energy when they should be hibernating. It can even kill the poor little creatures. Upon learning about this disease, I decided that my Infectious Diseases course focused too much on human health. They’ll be a wildlife infectious diseases component now. Every adventure teaches me something that I can bring back to my class….

Infectious Cancers and Other Lessons in Animal Conservation

2010-01-06T17:29:00.000-08:00

Tasmanian Devil Facial Tumour Disease

You may recall the Tasmanian devil (of Looney Tunes fame) from your childhood days. It may surprise you to learn that this character is based on a real animal that lives in Tasmania, a large island-state off the southeast coast of Australia. The Tasmanian devil is the world’s largest carnivorous marsupial. It feeds on small preys such as birds, snakes and even insects. They are also scavengers, feasting on carrion. As marsupials, the young develop in a protective pouch like the kangaroo. To me, the devil looks like a cross between a rat and a dog, and it weighs between 10-20 pounds. The animal gets its name for the ferocious cries and growls it emits and the threat displays it produces when faced with a predator, while fighting for mate, or defending a meal. Tasmanian devils often bite one another while fighting, particularly on the face and neck.

In 1996, conservation authorities in Tasmania noticed that some animals had peculiar ulcers on the face. Further investigation determined that the ulcers were cancerous in nature. The tumours grew relatively rapidly, eventually preventing the animal from eating and causing death. Alarmingly, many animals were affected, and now it is estimated that the population has been halved as animals die from this disease. It is estimated that the species could go extinct within the next 25-30 years.

Tasmanian devil with facial cancerBBC Natural History Unit

Infectious Cancer?

This later fact should trouble you for many reasons. First, from a conservation point of view, the disappearance of the largest carnivorous marsupial represents a loss of the biodiversity for the planet. When animals go extinct, they don’t come back. As a molecular biologist, this case concerns me for an entirely different reason. An animal population seems to be decimated by cancer. And not just any form of cancer, but the same type: facial cancer. But wait. How could this be? Cancer isn’t infectious, is it? How is it then that many animals are dying of facial cancer?

Let’s review what cancer is. Cancer could be described as one cell in the body deciding it’s had enough of working “for the good of the group” and becomes a selfish rogue. This cancer cell stops doing whatever its function was (e.g. if it was a lung cell, it stops helping to transport gases in and out of the body), and it starts replicating out of control. There are several other changes that must occur, notably being able to evade the immune system (note: cells in our bodies often become cancerous, but our immune system usually identifies these rogues and kills them before they can do any harm). Finally, cancerous cells detach from the tissue where they formed, and invade the body. If they find their way to the blood or lymph system, they can travel elsewhere in the body, and form tumours somewhere else where they lodge (this is metastasis). Note that there was one source of cancer cells, despite multiple occurrences of tumours in the body. The initial lung cell that became cancerous is now found in your liver, your brain, your stomach, and causes damage in all of these places. Ultimately, the body breaks down because the tumours are impeding the function of normal tissues.

The cancer process that I have described happens inside one animal. There is no transmission to another animal. Transmission between animals is where viruses and bacteria excel. Viruses and bacteria are very small foreign organisms that take over or impede your cells from functioning properly. You have experienced them as flus and cold and other infections. They infect one organism, replicate, and then spread to the next animal, where they cause identical symptoms. Looking at what is happening among the Tasmanian devils, it seems a bacterial or viral agent is at play. Yet when you look at what is causing the disease, it’s clearly cancer. What’s going on?

A solution to this enigma was first proposed in 2006 (1), when it was discovered that the cancerous cells found in the facial tumours of diseased devils all came from the same source. This was identified through chromosomal analysis which confirmed that the cancerous cells in all diseases animals were clones of one another (this was recently confirmed by another study (2)). How could this be? Well, in a way, cancerous cells are very good at replicating and invading other tissues, so it’s not that surprising. What is surprising is that they have spread to other animals. Let’s review a bit of the life history of Tasmanian devils. They often bite one another on the face in fights. Perhaps when an infected animal bit another it left some of its cancerous cells in the wound of the second. Those newly transferred cells then began to replicate and do what cancerous cells do, and the second animal developed cancer. Bingo: infectious cancer!

You should be very alarmed by now. If you have ever come in contact with someone with cancer, have you increased your risk of developing cancer yourself? In fact, in the scientific literature, there is one reported case of a surgeon who inadvertently cut himself while operating on a tumour and did get sick. There are also reports of organ recipients getting cancer from the organs they received, pregnant women transmitting cancer to their unborn child, and twins in the womb exchanging cancerous cells. There is also a report of an unusually infectious venereal cancer in dogs …But these are exceptions, and for a very good reason. Remember that the immune system is very good at recognizing cancerous cells. It’s also very good at recognizing “self” from “non-self” cells, i.e. cells that come from your own body and cells that do not. The general response when the immune system encounters a “non-self” cell is to destroy it. That’s why organs have to be typed and matched in organ donations. If the immune system of the organ recipient recognizes the organ cells as “non-self”, it will attack and destroy the transplanted organ. So, while it is theoretically possible for cancer to be passed between humans, many things have to go wrong for cancer to develop.

So what went wrong in the Tasmanian devils? One hypothesis was that Tasmanian devils are too similar to one another, and their immune system therefore has a hard time differentiating between self and non-self cells. In 2007 (3), a research group demonstrated that this was indeed the case. In the past, the devil population has gone through what is called a bottleneck, meaning that the population dwindled to a very small number. The animals that survived repopulated Tasmanian, but they had to do so with a substantial amount of inbreeding: close relatives were mating with one another. The problem with inbreeding is that the DNA of close relative tends to be very similar. There is not much variation. Effectively, it’s as though the current devil population are nearly identical clones. When a cancerous cell from another animal “infects” their body, their immune system is not able to tell it apart from their own cells, and they are prone to the disease.

So there you have it: the facial tumour disease probably developed in one animal around 1996. Ever since then, the cancerous cells from that one animal have been passed around. They are spread between animals through biting. All animals are vulnerable because they are too genetically similar and their immune system is not able to detect and defend against the cancerous cells.

Lessons Learned

So what are the lessons learned from this case?

First, cancers can be infectious. They don’t tend to be, but under specific sets of circumstances, they could be. Humans have a very diverse set of genes that control the “self” from “non-self” recognition system. In fact, it’s been suggested that the reason it is so diverse is to prevent infectious cancers. So you can rest soundly, this will probably not happen (but there are always exceptions!) in humans.

Second, given the low degree of genetic variability in the devil population, it’s unlikely that the devils will evolve a way to resist the infection. This is another reason why a large amount of animals need to be protected when establishing conservation strategies. If there aren’t enough animals protected and preserved, there is not enough genetic diversity, and inbreeding will cause this (and other) problems that threaten the viability of the species.

References

Pearse Am, and K Swift (2006). Transmission of devil facial-tumour disease. Nature 439:549.
Murchison Ep, Tovar C, Hsu A, et al (2010). The Tasmanian devil transcriptome reveals Schwann cell origins of a clonally transmissible cancer. Science 327:84-87.
Siddle HV, Kreiss A, Eldridge MDB et al (2007). Transmission of a fatal clonal tumor by biting occurs due to depleted MHC diversity in a threatened carnivorous marsupial. PNAS 104(41): 16221-16226.

Silicon to be Replaced by Proteins?

2008-12-08T12:23:00.000-08:00

I’m revamping my Molecular Biology course and have stumbled upon a few interesting nanotechnology topics that might be of interest to some people…

A few years ago, I attended a very interesting lecture about the use of biological molecules in building computers. Why, you might ask, would you want to use biological molecules to build computers? The answer is that biological molecules are small – typically on the order of nanoscale (one millionth of a millimeter), whereas most silicon-based chips are at the microscale (one thousands of a millimeter). Thus, if we could use proteins and DNA to build the logic gates and memory circuitry, we could miniaturize computers by at least 1,000 fold. This could have many applications, not the least of which are medical applications. Think of injecting small robots into your bloodstream that are autonomous and can direct themselves to the appropriate location, execute repairs, and leave your body without the intervention of surgeons. It gives a whole new meaning to “take two pills and call me in the morning”.

DNA seems a very likely candidate for building logic gates, and perhaps I’ll discuss them here soon. In the meantime, I just wanted to mention the potential of proteins in serving in memory chips. Proteins are the workhorses in your body. They do everything from digesting bread, to synthesizing fats from ingested sugars, to pigmenting your skin, to making up the bulk of your hair.

One protein in particular, rhodopsin, has attracted a lot of attention for its nanotechnology potential. Rhodopsin is a protein found in your eyes. It is found at the back of the eye and serves as a sensor for light of a specific wavelength (i.e. colour). When light of a specific colour strikes rhodopsin, it causes the protein to change its shape. This change generates a signal that your nervous system interprets as the perception of light or colour. The critical property of this protein is that it can exist in one of two forms, one when it has been hit by light of a certain colour, and another in the absence of light.

Now think of a small cube, maybe 1cm by 1 cm by 1cm that you fill with an ordered array of rhodopsin. You know where each molecule of rhodopsin is in this cube. Each molecule of rhodopsin is tiny – so tiny in fact that we know its atomic composition in great detail. Each molecule lives at a particular place in the cube, and it exists in one of two shapes. Since each rhodopsin lives at a certain fixed physical address, you can shine a laser (i.e. light of a specific wavelength) at that spot and change the shape of one specific rhodopsin molecule in the cube.

Does this start to sound a little bit like the memory of a computer? A memory chip (or a CD or DVD for that matter) is simply a material on which there are several “cells” that live at specific addresses and that exist in one of two states: ON or OFF, or another way of thinking about it is 1 and 0 (the famous binary code). Typically, each of these cells is microscopic.

Hopefully, you see the parallel with the cube of rhodopsin. It’s the same thing, except that the rhodopsin cube encodes the information at a 1,000 fold smaller scale. So for a similar sized disk, you could encode 1 meg of information with silicon technology, or 1 gig of information with biological nanotechnology.

A few issues remain to be worked out. How to “reset” the protein once you have changed its shape, for example. However, this technology is very promising…

Migratory Bird Watch

2008-11-09T14:33:00.000-08:00

I know that I said that my next post would be about one of the many topics we discussed in my Molecular Biology course last month, however, something’s come up. Last Wednesday, I played hooky with the two resident ecologists at the University and we went to the George C. Reifel Migratory Bird Sanctuary in Delta, BC, Canada. My colleagues were investigating the area as a potential site for a field trip for their ecology course. My excuse was that I have to oversee everything for the life sciences courses (haha – what a thinly veiled excuse for playing hooky!). The snow geese were said to be in town, and lured by the prospect of a sighting or two (or a thousand), we headed to Delta.

It was a delightful day, not least of which was due to the fantastic weather we enjoyed. This was my third visit to the Reifel Sanctuary. This time, I was accompanied by bird watchers. If you have the opportunity, it’s really worthwhile to visit this site with people who love birds. Not only will they point out where the birds are (you are very likely to miss out if you are not an avid birder), but they will also tell you about the natural history of each species, and (this turned out to be important for my personal safety) which birds have a mean temper and that you should keep a safe distance from…

We saw many bird species. Bald eagles, sand hill cranes, snow geese, mallard ducks, more mallard ducks, still more mallard ducks, wood ducks, other ducks I could not name, blue herons, some other type of heron that was perched on a tree, chickadees, pigeons, coots, hawks, red robins, trumpet swans, and others I could not name. No owls (although we were told they were on site). And most impressive of all, the sky was FILLED with migrating birds. There’s a constant background noise made by the migrating flocks of birds that’s quite soothing.

All and all, a very good day, and I recommend it to all… I think Nobi and Mai have decided to bring their students there for their ecology courses in the coming months… I wonder if there’s any way to link this to Molecular Biology somehow? Why should they have all the fun?

Biology to return...soon

2008-10-26T17:34:00.001-07:00

... Just posted a new entry on the MacLeans.ca OnCampus Blog , on the merits of using case study pedagogy in the science classroom (image to the left shows some of my students working through a case study).

As I now have some time to update my blogs (having recently finished teaching a Molecular Biology course), you can soon expect some entries in this blog on biological topics... I plan to do a little piece on phage therapy, golden rice, and HIV/AIDS, three topics that generates lots of discussion in my classroom...

Coming soon!

Community Day – The best way to freshen up a course is to cancel class

2008-10-09T18:16:00.000-07:00

I was recently invited to contribute to a blog for MacLeans.ca On Campus. This blog, written by a group of 5 university professors, is a place where "A varied group of professors and education researchers come together to discuss their experiences teaching and how to improve the undergraduate experience." Yesterday, I made my first contribution.

Quest University had its first Community Day of the academic year yesterday, and I wanted to write about our experiences. My blog entry is reproduced here, for your reading pleasure...

One day each term, when the students least expect it, all classes are canceled at Quest University Canada. These days are called “Community Days”. We just had a Community Day today.

I would love to claim this was our idea, but it was inspired by a similar event that takes place at the Lester B. Pearson United World College of the Pacific near Victoria BC (an innovative international high school). What’s the goal of this Community Day? It’s threefold.

First, sometimes you just need a break. Quest teaches on the fast-paced block scheduling plan. Students take one course at a time, 3 hrs each day, for 3 ½ weeks. It is an intensive way to learn: students must stay on task and manage their time effectively because assignment due dates come up fast, and before you know it the course is over. You need a breather, a chance to revitalize, interact informally with all students and faculty, not just the ones in your 20-student class.

Second, it promotes student interactions. The morning schedule of a typical Community Day consists of team building and leadership exercises, preferably outdoors. Some of the activities today included trust exercises and the raising of a student-made Quest flag (we first had to dig a hole, then carry a tree log up a hill, then raise the log and stabilize it with ropes once it stood reasonably erect). Oh, I know – a lot of you are probably rolling your eyes, covering your mouth and thinking “and they call this a university? What’s the academic merit of doing that?”. I probably would have been right there with you a few years ago. Sure, it’s unorthodox. But having seen its effects in the classroom first hand, I am now a convert.

Do you know what happens when you set up a situation where students must bond, trust one another, exercise leadership abilities and have fun together? Do you know what happens when you then put them together in a 20-student classroom and ask them to contribute to a class discussion?

You cannot shut them up!

They feel comfortable with one another, they trust that their peers (and their teacher) will accept them, and they do not fear being ridiculed. A non-academic activity goes a long way towards improving the academic quality of my classroom. I’ll sacrifice a day of class any day if it means that the questions and insights that are shared and asked in my classroom are more numerous, more honest, more in-depth, and are contributed by a larger percentage of the students.

Third, the afternoons of a Community Day are generally spent asking for the students’ input on building this university. Quest opened its doors to students a mere 13 months ago. A lot of its policies, practices, and even its identity are currently being developed. The philosophy at Quest is that students wouldn’t be told what to do: study this course and that – they would be active participants in their own education. They are guided through the design of their own degree. They also contribute in building this university. Today, the topics under discussion were student admission, student retention, fundraising (since we are a private non-profit institution), energy-conservation on campus, and student life. It’s amazing what different perspectives students can have on an issue than faculty. It was very refreshing to hear their take on what matters. And they also provided tons of ideas for improving this place.

At the end of the day, when the Community Day is over, you get buy-in. You get the sense that Quest belongs to all of us. That we each have a hand in shaping it. That we are not a number but an important member of a community. That this place is special. It re-infuses energy into all students and faculty and into every classroom. And at the end of the day, we are all reminded that there is no other place we would rather be.

So now you decide – wasn’t a day of “fluff” a valuable part of a student’s education?

Sky Diving - Why Would a Brain Want to Do Such a Thing?

2008-04-21T13:55:00.000-07:00

Sky diving was a very cool experience, and I suspect some more may be in my future (and yes, that's me jumping out at 10,000 feet).... But let's ask the question: why would anyone want to jump out of a flying plane, at 10,000 feet of altitude? The answer, of course, is complex. However, we do know something about the brain's reward circuitry. The reward centre of the brain (ventral tegmental area, nucleus accumbens, and others) are a part of the brain that functions to make an individual survive, and reward the person when he or she does something good for survival. Typically, this is sex or food, that kind of thing. Cells in this part of the brain talk to each other by releasing a chemical called dopamine. So whenever you do something good for survival, dopamine gets released in the reward centre, making a person "feel good", and that much more likely to repeat the behaviour that caused the release of dopamine in the first place.

Incidently, novel activities cause the releas of dopamine in that part of the brain. So we enjoy doing things that are new and different. We don't want to overload that system, but novelty is something we appreciate.

Drugs of addiction are addictive because they stimulate that part of the brain: they potentiate (increase) the release of dopamine in the reward centre. So drugs of addiction take over the control of a portion of the brain designed to reward an animal for certain behaviours. It's easy to see how such drugs become addictive: the brain "feels good" each time you take them and makes the person much more likely to repeat the behaviour (i.e. drug taking) that caused the release of dopamine in that part of the brain.

It turns out that some people are less sensitive to dopamine in that area of the brain. Some people have "mutant" D4DR dopamine receptors. By the way, this is not unusual in and of itself: we all have different varieties of different genes in our body - if we didn't, we would all be clones and look identical. However, what has been observed is that people who have the mutat D4DR receptor in the brain tend to score higher on sensation-seeking personality traits (Note: this is not a necessary relationship, it's only a "more likely" type of a relationship). In otherwords, we have noted a correlation between the "adrenaline junky" personality type and havingD4DR receptors in the brain. If you take a moment, you will realize that this makes sense. If you brain is a little insensitive to dopamine, it will take a larger stimulation for your brain to respond to the dopamine release. So a person with a D4DR dopamine receptor needs to experience "stronger sensations" to "fell as good" as a person with the "normal" version of the dopamine receptor to feel.

Incindently, people who score high on the novelty-seeking trait tend to also have a greater likelihood of developing a drug addiction. Part of the reason is that they are simply more likely to try the drug in the first place. Part of the reason is that if they have a brain that is insensitive to dopamine (D4DR receptors) , and they have access to a chemical that is likely to stimulate their brain to levels comparable to what other people experience daily for doing "simple" activities such as eating food and having sex. So in effect, these people are more likely to use drugs of addiction because it allows them to regulate ther dopamine levels and experience "feeling good" to levels comparable to those of controls. That's the theory, anyways.

Based on my past history of SCUBA diving and now sky diving, I suspect I have D4DR receptors in my brain. This is only a guess, based on the noted association between personality trait and dopamine receptor type. I don't know for sure.

If you want to see how you score on this persoanlity trait, you can take this Sensation-Seeking quiz at the BBC website. Obviously, this is not an "official" study of your brain, this is for recreational purposes only.

For those of you out here without this trait, I leave you with this video of my jump... Live vicariously through me!

Soaring like an Eagle...

2008-04-20T22:22:00.000-07:00

Ok, so this entry does not have much to do with biology (perhaps a little bit more to do with physics). After exploring the depths of the sea, I decided that it was time to explore the world from an eagle's point of view. I went sky diving along with 14 of my students today. We headed to Pitt Meadows to do our first tandem jump. I think it is safe to say that great fun was had by all. If you get the chance to try it, do. Here are a few shots of my super instructor Rob and myself (thanks to Derek for taking these shots). We dove 10,000 feet. At 5,000, our chute opened. I think the freefall was everyone's favourite. Personally, I really liked the first 5 seconds, when I completely forgot to do everything Rob had told me to do and we were somersaulting out of control. It was very disorienting, and reminded me of when I did gymnastics as a child. The moment the chute opens, the wind stops rushing in your ears, its quiet, and peaceful... and the views! The views! Ahhhh... to be an eagle. I think this sealion may be ready to transform herself into an eagle...

Bald Eagles are Back in Squamish!

2007-12-23T21:23:00.000-08:00

Well, it's that time of year again... The bald eagles are back! For my second consecutive year, I am volunteering with Eagle Watch, the local Squamish organization that provides free information and telescope use for any visitor wishing to see the eagles passing through our area. The Chum salmon this year was a small run compared to previous years. So on my first shift, there were "only" 60 eagles along the ~200 meter length of the dike in Brackendale. This is small in comparison to the 600 or so that were counted at that location last year at the same time. However, that was 2 weeks ago. I suspect the numbers are up since then, as judged by the numerous eagles I encounter on my morning jogs every day. My next shift is on boxing day, and I am looking forward to it!

In the meantime, here is a brief video I took a couple of weeks ago. It features a juvenile (less than 5 years old) eagle eating a salmon.

If this movie does not load, you can view it here.

Enjoy!

Neuroscience of Love

2007-07-04T11:00:00.000-07:00

This month, I am doing some course development, and I am spending quite some time on a first year Neurosciences course. Studying the brain was my passion 10 years ago. I didn’t pursue it in graduate school because I was somewhat troubled by the ethics of cutting someone’s brain open while they were conscious, sticking electrodes in there, and sending electricity to “see what happens”. I’m being facetious, of course, because this sort of thing does help neurosurgeons map the brain of their patient during neurosurgery. …But it just seemed to me that we know very little about.. well, what makes us us.

Neuroscience of Love
For the past week-end, I have been preparing a class on sex and hormones. It’s fundamentally a class on the neurochemistry of love. This field has really blossomed since I last studied it. Using imaging technologies like functional MRIs, scientists have been studying what happens in the brain of people who say they are “in love”. I was astounded by some of the findings I read about, and I thought I would record them here. Perhaps someone else will find them amazing, too.

Love is Blind and Stupid
First, perhaps not surprisingly, it turns out that the portions of the brain involved in reward (yes, those are the ones that are affected by elicit drugs) get turned on. It feels good to be with someone you love. Ok, this is no surprise to me. But what I found really cool is that people seem to grow “a little more stupid” by being in love. A portion of their pre-frontal cortex, usually involved in making social judgements and decisions (critically evaluating other people) gets shut off when one is "in love". So in essence, love truly is blind and stupid!

You Smell Nice! - Advertising your Genome
On another related matter, that of choosing your lover… It turns out that people find the smell of people who have a different MHC gene (major histocompatibility complex – this is a gene that is involved in immunity – defending you against outside invaders like viruses and bacteria) more appealing. Why would that be? The idea is that by choosing a mate with a different MHC gene, a couple will increase the diversity of their babies’ MHC genes, increasing the babies’ odds of a good immune system. So, you ask, is this the elusive human pheromone? Not likely, since a pheromone is defined as a chemical that triggers a behaviour in another member of the species. Displaying your MHC scent does not make members of the opposite sex flock to you, it only advertises your genome to everyone. One might wonder then, why the perfume industry is doing so well. Wouldn’t perfume mask these kinds of intrinsic scents? It turns out that people tend to select commercially-available perfumes that complement and even enhance their MHC smell. So in essence, Chanel, Lancome, Elizabeth Arden and company are helping you advertise to the world: “Hey, there are my genes… Interested in what you smell?”

Isn’t that amazing?

Wild or Aquaria Encounters? - The lesser of Two Evils...

2007-05-06T16:24:00.000-07:00

In Response to John's Comment
John posted an interesting comment last week (5 May 2007). In his comment, he asks the following questions: "Which is the lesser evil? An aquarium where a relatively few animals kept in captivity bring awareness and enthusiasm to a large population of humans? Or "Eco-tourism", where few humans encounter a large number of creatures in their natural habitat, and run the risk of disrupting the lives of a larger number of creatures?"

So Many People Have Pondered That Question...
It's an interesting question, on that has kept a large number of ethicist and biologists occupied over the years. Consequently, I feel capable of pronouncing myself only on my very own values and beliefs, and feel in no way that I hold the absolute truth.

Annie's Philosophy...
On the one hand, I came to love the sea life on the BC coast (which subsequently fueled my desire to SCUBA dive) through my involvement with the Vancouver Aquarium Marine Science Centre. There is no doubt in my mind that I would have had NO IDEA how absolutely breathtakingly beautiful these sea creatures were without first coming into contact with them at the Aquarium.

However, having said this, I think I prefer encounters in the wild. My experience has been that despite disturbance of the wildlife, the encounters are fewer and more respectful in the wild. When you are playing with a one-ton sealion or a sharp-teeth shark or a powerful and inquisitive octopus in the wild (see attached picture of my friend offering his hand to a local octopus) , there is always the possibility that the animal will harm you. So you have to keep a respectful distance and appropriate behaviour in all encounters.

I counter the view that we should never be interacting with animals in the wild (lest we disrupt them) with the solemn reminder that WE ARE ANIMALS OURSELVES, and therefore, a certain degree of interaction with ANY wildlife is completely natural.

I have been fortunate enough to experience an encounter with dolphins while on a dive, and it was nothing short of magical. I have always thought dolphins "cool", but until I swam with them, I do not think I really, truly, appreciated them. These dolphins approached me out of their own volition. I will treasure this experience for the rest of my life - I am not so sure seeing a dolphin in an aquarium has the same power. And even though only a smaller percentage of the population is exposed to the wild life through natural encounters, there are always movies and pictures - I would wager a bet that Jacques Couteau's films have ignited more than a few people's passion for marine life.

So, to recap: I am not opposed to aquariums, but I think nothing beats a wild encounter in terms of raw emotional power and I don't think animals suffer too much from this as SCUBA divers are weak/hapless animals in their sea, and sea creatures can defend themselves!

Note: I realise this "we're not causing too much damage" attitude may not hold as well in popular dive destinations, particularly in warm, easily accessible tourist destinations. However, through tight regulations and monitoring, even these tourist destinations could remain fairly pristine...

Sealion Encounters, Part II

2007-03-14T11:18:00.000-07:00

The most exhilarating experience I have had while SCUBA diving came from diving with sealions at Hornby Island, BC (one of the islands between the British Columbia mainland and the Island of Vancouver).

Natural History of the Hornby Sealions
Each winter, male sealions come to feed on the plentiful herring that is gathering to spawn in the Hornby Island area. It’s their vacation, leaving the females and young in Mexico and California. The local sand stone geology of the area makes for relatively good visibility and a shallow shelf on which SCUBA divers can rest. Sealions are *much* larger than seals, and they can stand on their front limbs. Although I’ve been told that three species of sealions can be found at Hornby, I’ve only ever encountered two: the Stellar sealion (much more playful, and featured in all of the videos that I am putting on this page), and the California sealion.

A Unique Experience – Time and Time again
After my first experience, I began an annual migration to Hornby Island myself, to swim with the playful sealions of the area. It can be a little intimidating have an animal that weights one tonne barrel through water heading straight for you… But they veer off at the last second, gracefully. They nibble on your hood and fins and gloves, they imitate your behaviour underwater. At the surface, they bark at you with their fishy breath. There’s no other feeling quite like it! On my last trip, I had a concussion and broken ribs (from a skiing accident the night before), so I could not SCUBA dive. I decided to snorkel with them instead. Imagine my delight when I discovered that they were just as interactive! I highly recommend the experience to anyone interested. Keep in mind that these are wild animals – keep a healthy respect, and recognize when their playfulness may be too much for a simple human to bear. The boat is always just a short swim away…

Annie and a Sealion, Kissing

2007-02-25T13:43:00.000-08:00

My blog is lacking pictures of late... Here's one of Annie kissing a Stellar sealion at Hornby Island, BC.

In Response to Reid

2007-02-15T10:52:00.000-08:00

Pour la version française de mon blog, visitez ce lien.

I want to respond to Reid, who posted a very thoughtful response to my last blog. He raises a few very important points, and I thank him for bringing them up. Here is my reply…

Pesticides are Not Evil

First, I realized from reading his comments that I need to qualify my position on DDT, lest it be misunderstood. I hope I was not perceived as “jumping on the bandwagon” and promoting a strictly evil perception of pesticides. I am not advocating a complete ban on pesticides. DDT and other pesticides are needed to control insects, most notably malaria. Furthermore, agriculture simply could not produce as much unspoiled food as it does without the use of pesticides and herbicides. However, the important point is that we must use these chemicals responsibly, because once released into the environment, they do not decay easily and they influence the ecosystems in which they are released. In addition, insects WILL develop a resistance to any pesticide we use, so responsible use is necessary to ensure that pesticides will work when we really need to defend ourselves against a bug invasion.

How Do I Know What I Know?

Ok, onto the question of whether DDT is benign or whether it really causes physiological effects in animals, most notably birds and mammals. First, by pointing out the references that he did, Reid is providing me with an excellent opportunity to talk about the importance of SOURCE of information. You cite a report from the American Council on Science and Health. Is this organization impartial? Who are they? Who sponsors this organization? In fact, I had never heard of them before, so I did a bit of research and discovered that this organization receives a significant portion of its funding from the chemical and pharmaceutical industry. Knowing this, how much credibility do you want to ascribe to their reports? As for the webpage whose link Reid provided, it is a person’s personal webpage, expressing this person's opinion. He is entitled to them, and he makes a case for them, but personally, I prefer to go to government-sponsored sources of information, preferably peer-reviewed, when I seek impartial information. Websites you may want to consider to research health information are the National Institutes of Health (NIH), which is the US’s foremost health research agency, Pubmed which is a database of most of the published, peer-reviewed health research ever produced (it is maintained by the NIH for the scientific community), and the World Health Organization (WHO), which is the United Nation’s agency for health. Researching these sites, I think you will find little doubt that DDT is linked to thinning of eggshells, and that while it has never been conclusively demonstrated that DDT causes cancer in humans, it has been shown to cause it in other mammals (Find the NIH report HERE). From this information, I have decided that we should be careful about using DDT without restrictions.

Climate Change, DDT, Cigarettes, and Other Controversial Issues

On the grandeur question of which information you should be listening to when you are bombarded with often contradictory information, sometimes from several trustworthy sources… well, that is the world we live in, isn’t it! People have been examining the evidence for and against global climate change for at last 40 years and not being able to reach any decisive conclusion… but now, the evidence seems to be finally swaying in one direction. The responsibility of an educated person in the 21st century is to be mindful of the credibility of the sources of information one gets, to weigh the evidence from those sources that are trustworthy, to make your mind based on the evidence presented, and finally, to keep an open mind, if new evidence challenges your previous decision. That sort of flexibility and critical thinking is what’s needed to lead a judicious life in the 21st century.

Reid: A Critical Thinker in the 21st Century

Reid - I hope this answers your questions and concerns. Thank you again for bringing this up. This was an excellent question (triggered by your own critical mind!), and I will be expecting more of these from you and others in the future!!! :)

Eagles and Valentine's Day - the DDT Connection

2007-02-11T21:25:00.000-08:00

Allow me to attempt a tour de force and link the subject of the last blog entry, bald eagles, with the holiday on everyone’s mind this month (whether you want to admit it or not), Valentine’s Day.

DDT is the Link
The 1950s were blessed with a wonderful new chemical called DDT (Dichloro-Diphenyl-Trichloroethane), which killed every insect known to man, and hence could be used in a myriad of industries from agriculture to head lice treatments. Unfortunately, like everything that seems too good to be true, DDT turns out to be… well, let me put it to you this way: its use is now completely banned in North America. The red flags were first noticed when the number of bald eagles started dwindling in the United States. Pretty soon, the link was explained: DDT causes thinning of eggshells, and hence lost eagle clutches. The eagle population was nearly decimated, but luckily the problem was caught in time, DDT banned, and eagles are now rebounding.

DDT Affects Sexual Behaviour, Too!
But wait – DDT had other interesting effects on animal development and behaviour. It turns out that DDT is mistaken for estrogen (the “female sex hormone”) by the body of many animals. On a strongly DDT-contaminated site in California, male gulls developed oviducts (typically a female reproductive organ). Many males also failed to engage in reproductive behaviour, and the scarcity of reproductively competent males meant females had few males to help them rear their young. As any single-parent will tell you, it is difficult to do it all on your own. To solve this conundrum, some female-female pairs arose to care for the young, the so-called “lesbian gulls”. (Ref.: Fry & Toone, 1981). If you think that’s unexpected, check out this BBC article about a similar environmental pollutant that is transforming polar bears into hermaphroditic mammals (having both male and female sex organs!).

Your Woes?
DDT takes a long time to decay in the environment, and while it has been banned since 1972 in the United States, it can still be detected in most of our bodies (yes, YOUR body too – In fact, 4 prominent Canadian politicians were recently tested for pollutants in their bodies and found to be “contaminated” (link to the CTV report HERE). DDT is thought to affect the reproductive behaviour of many amphibian, reptile, bird, and mammal populations, but the big question on everyone’s mind is: Is it affecting OUR sexual development and behaviour?

Are Men Becoming Extinct?
In the recent movie Children of Men, the human species has become infertile, leading to hopelessness and the collapse of civilization. Is this science-fiction or a preview of things to come (yikes!)? The incidence of cryptorchidism in human males (a condition where the testes fail to drop after birth – a vital development since the testes need to be at a slightly lower temperature than the body to ensure the sperms’ survival) appears to be on the rise, more than doubling since the 1950s (Ref.: Carlsen et al., 1992). Testicular cancer has tripled in the last 50 years (Ref.: Giwercman & Skakkebaek, 1992). Sperm count also appears to be declining across the board in all human populations (Ref.: Carlsen et al., 1992). Whether the environmental estrogen mimics are causing these alarming trends is a matter of some debate, but it is one that needs to be resolved soon!

Of Eagles of Men
DDT almost wiped out eagles from the face of this planet, and it is possible that the same thing is happening to us now. More studies are required, but evidence is accumulating that environmental pollutants affect sexual behaviour in many animal species. Humans are part of this biosphere – we cannot escape it. So this Valentine’s Day, as you celebrate the fact that your sexual behaviours are still intact, take a moment to ponder that every chocolate you eat may contain traces of DDT…and may be altering the behaviour you will display in future Valentine’s Day…

Of Eagles, of Men

2007-01-28T18:00:00.000-08:00

Pour la version française de mon blog, visitez ce lien.

An American in Squamish

One of the ironic things about working with many Americans is that none of them have ever seen a bald eagle in the wild (the bald eagle being the national bird of the United States). Ever since moving to Vancouver ten years ago, I have done an annual pilgrimage to Squamish, a location that boasts the largest grouping of bald eagles in North America (if only for the duration of the Holiday period (December-January)).

Eagles and Celebrity Watching

Since a pilgrimage to Squamish was not necessary this year (I moved here last summer!), I decided that I should involve myself with the Eagle Watch Program. This is a community-organized, volunteer-run program made available to tourists and other eagle enthusiasts that come to view the eagles. The dike, built along the Squamish River, makes for a perfect viewing area, and on a good day, a visitor may see up to 600 eagles across the river at any given time. The volunteers are there to adjust binoculars made available free of charge to the public, and answer questions. This year was my first year as a volunteer interpreter. I was highly impressed by both the dedication of the volunteers who organize and run this program, and the visitors, whose wonder and awe reminded me of just how lucky I am to be living here. There are also bonuses. Apparently, the highlight of last year’s volunteers was a chance to chat with Justin Timberlake and Cameron Diaz as they stopped to see the eagles on their way back from Whistler..!

A Feast of Salmon

The humans come here to see the eagles…but what is it that brings the eagles here? The Squamish River has a few very healthy salmon runs. The eagles congregate here from many different places because the salmon is plentiful, and they can feast on it. Having spawned, the salmon dies, and this very nutritious meal is easy pickings for eagles.

The Old and the New

The most common question I was asked this year was the distinction between the “completely brown” eagles and the ones “with the white head”. Are the brown ones the female? Answer: No! The brown ones are the immature eagles. Until the age of approximately 4-5 years of age, eagles have mottled, brown feathers that make them difficult to see among the branches of the tree (camouflage!), and also signal to other eagles that they are not a threat. I’m going to try to embed two videos in this blog (bear with me, it’s my first time using U-Tube) – one of an immature eagle feeding on a salmon, and one of a mature eagle feeding on a salmon. Can you tell them apart?

If you are having trouble seeing these videos, you may have beeter luck by going directly to the U-Tube website:
HERE || and HERE

Squamish: Eagles Capital

Having traveled up and down the coast on diving trips, I have some serious doubts about the validity of the claim that Squamish holds the largest number of eagles. I recall quite clearly seeing many many many more eagles near Port Hardy at the northern tip of Vancouver Island one summer. However, getting to Port Hardy is no walk in the park. It is probably fair to say that Squamish is the most easily accessible town from which the largest concentration of eagles may be seen… And that is something to boast about…

P.S. All of my American co-workers have now seen an eagle!

P.P.S. Check out this cool site, which contains a link to a live camera aimed at an eagle’s nest.

P.P.S.S. Please, please, please, leave me comments! It would be nice to know I am not just writing to myself... :)

Captivated by the Underwater Realm of BC

2007-01-25T20:29:00.000-08:00

Vous trouverez la version française de mon blog en suivant ce lien

Why British Columbia

After graduation, what kept me in B.C. was not the beautiful mountainous landscapes, the serenity of the temperate rainforests, the laid-back life style, or the delicious Vancouver asian cuisine that most people will cite you. As a (somewhat fanatical) SCUBA diver, I feel privileged to have witnessed the dazzling array of colours created by the arrangement of a multitude of critters that colonize every rock and crevice in the coastal waters of the Pacific Northwest.

My First SCUBA Dive

I remember my first dive quite vividly (in the Squamish area, site of my new home, coincidently). What struck me then was how alien the life forms were. Gravity is not a factor in the development of an underwater body plan. Air and food are extracted directly from the surrounding medium, so respiration and digestion systems are radically different. I might as well have been on Mars. I remember thinking that most people, who only get the opportunity to look at the surface of the ocean, had never seen these creatures; most people didn’t even imagined that these bizarre and beautiful animals lurked mere meters away from the surface of the ocean.

I was Hooked

I felt privileged to have caught a glimpse of an unexplored part of our planet. I was hooked, and I wanted to learn more about these weird and amazing creatures. This was the launch of an 8 year quest for me, one that culminated in me authoring a chapter on marine life in a book on Stanley Park ecology.

Underwater Chemists

I’m sure you’ve often heard that one of the reasons to save the Amazonian rain forest is because it may contain some species as yet unknown to science that could hold the key to a cure for cancer. It turns out that the same is true of the marine critters that inhabit our coast. Nudibranchs (sea slugs) and sponges are quite common in our waters (see some representative snapshots I brought back from my little expeditions). Both types of organisms are expert chemists: they produce a lot of novel organic compounds that they use to repel would-be predators.

Fighting Cancer and Other Illnesses

I have a friend whose Ph.D. project involves collecting sponge and nudibranch species, grinding them down, separating the various chemical components that they produce and applying them to cancerous cells (click here to view her laboratory's website). It is her hope that one day, she will find one chemical that will inhibit the growth of cancerous cells, offering a potential treatment for this dreadful disease (everyone in my family eventually succumbs to this disease, so here’s hoping she finds something soon! :) ).

Protecting the Environment

Personally, I would advocate preserving marine habitats for the simple reason that they are beautiful to behold, but for those pragmatics out there, the cure to your future disease may soon come from the ocean. Knowing this, can anyone possibly argue that our oceans are not worth preserving?