Getty Images/Flickr RF

You would be hard-pressed to find someone who doesn't have some fascination with the otter. These creatures have gained a place in our collective fancy thanks in part to their near-human features (including similarities to Sherlock actor Benedict Cumberbatch); their childlike playful nature, particularly with balls; and their humanlike behaviour, including a fondness for attention at times approaching egotistical.

Otters also have another incredible link to humans albeit the association is far more impactful. They can help us identify public health problems related to pollution and infections. Though they live a different lifestyle than us, their mammalian nature allows the opportunity to study what could happen to us as our world changes.

In the public health world, animals such as the otter are considered to be sentinels. This term refers to any animal whose biological, geographical and even psychological change in response to an environmental change can be used as a model to better understand how humans may be affected in the future. These factors can include a number of possibilities, from the impact of pollution to the spread of infectious disease. There are a number of such species and each contributes passively to a better understanding of our human future.

Back in 2003, a group of researchers from California tried to determine which human-related illnesses could affect otters and cause illness and even death. Although only a few were expected, the results revealed a number of human infections known to cause significant problems. Amongst them were the parasite Toxoplasma gondii, which infects hundreds of thousands of people every year; the fungus Coccidioides immitis, which causes a flu-like illness but can lead to fatal pneumonia and other complications; and even gastrointestinal diseases although they were not identified at the time.

Several years later, other researchers found out the nature of those intestinal pathogens. In 2010 a list was made. From E. coli to Salmonella to Campylobacter to cholera, otters appeared to have the same problems as humans with just as drastic results. Perhaps the most surprising was the presence of the normally healthcare-associated infection, C. difficile, which infected over 5 per cent of the studied population and killed nearly 10 per cent of them. The results clearly showed otters were more closely linked to us than we imagined.

The hunt for other possible pathogens has continued and last week, another pathogen made the list. This one is not only familiar to us but also held us in fear for an entire year: pandemic flu. A group of American researchers led by the Centers for Disease Control and Prevention were concerned about the onset of influenza in the otter during the pandemic. They collected serum samples from a group of sea otters from the coast of the State of Washington and tested them for any evidence of influenza infection. Remarkably, there were not only signs of flu infection, but also up to 70 per cent of them had been infected by the pandemic virus.

While the results offer an interesting perspective on the nature of flu infection in otters, the real outcome of this study reveals our relationship with otters is two-way. There are few to no means by which the otters could have been directly infected. Based on all the available information regarding the 2009 influenzavirus, spread was limited to human to human transmission. There was no indication that wildlife would have been involved to spread the disease.

There are only a few options. The most presumable route is sewage and/or runoff from the Pacific Northwest coast during the pandemic though the authors did not investigate this. They did suggest a link with a marine mammal known to catch the flu, elephant seals. Yet even in this case, the virus would have come from fecal matter discharged from shipping vessels. In either case, human activities had an effect on the health of the otters.

This study opens up a rather nasty can of worms when it comes to public health problems and who might be responsible. While this is only one case with one virus, a reciprocal route of repercussion is relevant. If human actions leads to the infection of these sentinel species, not only with flu, but perhaps other pathogens, then we are potentially responsible for the consequences. Solutions are thus only possible with a change in the same human activities that started the entire process. Or, to put it more bluntly, the wagging finger of blame for our health concerns ends up being pointed directly at us.

Although this study may not offer much in terms of making significant changes to the current environmental situation, it does offer hope for the future. As one researcher from the University of Oslo put it last year, our increasing knowledge about our relationship with otters in the context of health may offer an opportunity. Because they are beloved in so many ways, the realization our actions affect them may help to unify all groups to a common goal. The otter would therefore represent a universal symbol to represent our efforts to make our environment a safer and healthier place. With Earth Day on our doorstep, this small gesture to our furry friends might be the best way to mark our commitment to a better planet.

ALSO ON HUFFPOST: