There are viral consequences of habitat encroachment and traditional food systems, warns Australian medical researcher Professor Nathan Bartlett.
Species survival is intricately linked with human actions, especially those related to habitat encroachment and our reliance on traditional food systems.
While sustainability often focuses on resource management, the broader picture includes understanding how these actions impact both species and disease transmission in ways we cannot predict.
In recent decades, habitat encroachment has emerged as a critical driver of species decline and an unrecognised catalyst for disease transmission.
As humans push deeper into natural habitats, the once-clear boundaries separating different species blur, leading to increased interactions between wildlife, domesticated animals and humans. This convergence of species, driven by deforestation, urbanisation and agricultural expansion, creates a fertile ground for pathogens to cross species barriers.
The emergence of diseases such as Hendra virus and Nipah virus are stark reminders of this reality. These viruses, which originated in bats, found new hosts in domesticated animals and, eventually, humans. Such spillovers highlight the unintended consequences of bringing species together that would not normally interact.
Reduced species diversity, another consequence of habitat loss and agricultural intensification, further exacerbates the risk and impact of disease outbreaks. A rich diversity of species in an ecosystem often acts as a buffer against the spread of infectious diseases. However, when species are lost, this buffer weakens, allowing pathogens to move more freely among the remaining species, including humans.
Intensive farming practices are particularly concerning in this regard. The overcrowding of genetically similar animals in confined spaces not only facilitates the spread of pathogens but also accelerates their evolution. The frequent outbreaks of avian influenza bird flu are a direct result of such practices.
These high-density environments provide a perfect breeding ground for the virus, enabling it to mutate rapidly and sometimes acquire the ability to infect humans.
A recent example of this is the 2009 H1N1 swine flu pandemic, which emerged when different flu viruses mixed within a single host, in this case, a pig. Flu viruses are particularly adept at swapping genetic material, creating new strains with pandemic potential.
Our traditional food systems, which rely heavily on the exploitation of wild species, further complicate the scenario. The consumption of bush meat and the trade of exotic animals bring humans into direct contact with species and pathogens they would otherwise rarely encounter.
This close contact increases the likelihood of diseases jumping from animals to humans, as seen with coronaviruses and lyssaviruses. The global COVID-19 pandemic has already demonstrated how devastating such spillovers can be.
These interactions between species and the resulting disease transmission are not just hypothetical risks, they are real, ongoing threats.
While we cannot predict every outcome of our actions, we can recognise patterns and take preventive measures. Protecting natural habitats, promoting sustainable farming practices, and rethinking our reliance on traditional food systems are crucial steps in mitigating these risks.
As scientists, we need to think beyond the immediate benefits of conservation and sustainability. It calls for a deeper understanding of how our actions affect the complex web of life on Earth. As we strive to protect species, we must also consider how our choices influence the dynamics of disease transmission and, ultimately, human health.
Species survival is not just about preserving biodiversity for its own sake, it’s about safeguarding the intricate relationships between species, their environments and the pathogens they conceal.
Our own health and survival are intertwined with the health of ecosystems and the species that inhabit them. By addressing habitat encroachment and re-evaluating our traditional food systems, we can reduce the risk of future pandemics and ensure a healthier future for all species, including humans.
ED: Professor Nathan Bartlett leads the HMRI (Hunter Medical Research Institute) Infection Research Program, focusing on how environmental changes influence the spread of infectious diseases.