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Biodiversity and human health: Less biodiversity, more infectious diseases?

Healthy humans depend on a healthy environment. Clean air, fresh water, safe and nutritious food, culture and inspiration are just some of the services that well-functioning ecosystems provide. Despite our reliance on nature, the species and ecosystems that support healthy environments are being lost at alarming rates, resulting in environmental degradation and knock-on effects for human health. The novel coronavirus is a prominent example that sheds light on the close links between the loss of biodiversity and habitats on one hand and healthy functioning human societies on the other.

Land-use change, habitat loss and degradation, overexploitation, pollution, invasive species and climate change all contribute to biodiversity loss. In the Arctic, climate change is the most serious threat to biodiversity, aggravating all other threats (Arctic Biodiversity Assessment).

As biodiversity declines and ecosystems degrade, the environment’s ability to provide essential life-sustaining services is hampered – often at the cost of human health and well-being. According to a 2015 state of the knowledge review on the link between biodiversity and human health published by the Convention on Biological Diversity (CBD) and the World Health Organization (WHO), biodiversity loss is happening at unprecedented rates, impacting human health worldwide. These negative outcomes include an increased risk of infectious diseases emergence and spread: “Infectious diseases cause over one billion human infections per year, with millions of deaths each year globally. Approximately two thirds of known human infectious diseases are shared with animals, and the majority of recently emerging diseases are associated with wildlife.”

The complex link between biodiversity loss and infectious diseases

Some parasites that affect animals can infect and cause disease in people, becoming a primary issue for food safety and human health, as the Arctic Biodiversity Assessment (ABA) states. Human population growth and the loss of large areas of undeveloped land lead to increasingly close contact between humans and wildlife, providing the opportunity for pathogens to “jump” from animals to humans. This has led to several severe disease outbreaks, including Ebola, SARS and most recently the novel coronavirus. Especially in populations that rely on wildlife species, such as Northern communities and Indigenous peoples, the “sustainability, security and safety of ‘country foods’ are of concern” (ABA).

“Sustaining the biodiversity of our natural environments is paramount for human health and well-being. Destruction of habitats by human activities increases our interactions with new pathogens - ones we have little or no defense against. If we want to prevent future outbreaks we need to support biodiversity, not destroy it.” Mark Marissink, the Chair of the Arctic Council’s Conservation of Arctic Flora and Fauna Working Group

To support this work, CAFF’s Arctic Migratory Birds Initiative (AMBI) seeks to better understand challenges to Arctic-breeding migratory bird conservation, including how migratory birds are affected by contaminants and the illegal wildlife trade.

“AMBI is working to address threats to Arctic birds for example illegal bird hunting and trade by working with countries inside and outside of the Arctic. What is happening to the birds in some areas of the world will have implications when the birds return for the Arctic environment, given the potential for infectious diseases to be transmitted from wild animals and affect people’s health,” says Evgeny Syroechkovskiy AMBI Chair, Ministry of Environment and Natural Resources of the Russian Federation.

“These birds leave the Arctic, and are subject to—in many cases—unknown levels and effects of pollution in their stopover sites. On top of that there are enormous levels of commercial illegal take of these birds for wildlife markets, where they may be placed alongside other species and animals. All this poses risks for disease emergence. We can do something about this by addressing threats to Arctic birds.”

Concerns and hope for Arctic biodiversity

In 2013, ministers of the eight Arctic States noted with concern that Arctic biodiversity is being degraded, with climate change posing the most serious threat. In their joint declaration, the Kiruna Declaration, the ministers therefore welcomed the Arctic Biodiversity Assessment, the first Arctic-wide comprehensive assessment of the status and emerging trends in Arctic biodiversity. While the assessment, developed by the Conservation of Arctic Flora and Fauna Working Group (CAFF), outlines concern for degradation of Arctic biodiversity and habitats, it also emphasizes that in the Arctic there is still opportunity to act to reduce the long-term ecological damage from human activity that characterizes many other parts of the world.

The data and information that the assessment provided, have been reported to the CBD, leading to recognition by the convention of Arctic biodiversity conservation as an emerging issue and a request for further reporting from the Arctic Council.

The action plan to implement the ABA recommendations serves an important function in achieving global biodiversity targets (the twenty Aichi Targets contained in the Strategic Plan for Biodiversity 2010-2020) in the Arctic, the Sustainable Development Goals (SDG), and the new Post-2020 Global Biodiversity Framework currently under development.

“Our global biodiversity frameworks are moving to the next phase of action, rendering 2020 a biodiversity super year. Now more than ever, as we clearly see links between biodiversity and human health, we need to approach this process with increased commitment and dedication to support the environment so it can continue to support us.” Mark Marissink

In the face of the current pandemic, this mission is as important as ever. The UN Environment Programme emphasized in a statement on COVID-19, “[i]t is precisely because of the interconnected nature of all life on this planet, that an ambitious post-2020 biodiversity framework matters greatly, and we remain committed to efforts to make this happen.”

Interlinkages between biodiversity and human health

Biological diversity, or biodiversity, means the variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems.

“[B]iodiversity gives rise to a range of health benefits. For example, the variety of species and genotypes provide nutrients and medicines. Biodiversity also underpins ecosystem functioning, which provides services such as water and air purification, pest and disease control and pollination

However, biodiversity can also be a source of pathogens leading to negative health outcomes.

A second type of interaction arises from drivers of change that affect both biodiversity and health in parallel. For example, air and water pollution can lead to biodiversity loss and have direct impacts on health.

A third type of interaction arises from the impacts of health sector interventions on biodiversity and of biodiversity-related interventions on human health. For example, the use of pharmaceuticals may lead to the release of active ingredients in the environment and damage species and ecosystems, which in turn may have negative knock-on effects on human health.”

Excerpt from: "Connecting global priorities: biodiversity and human health" World Health Organization and Secretariat of the Convention on Biological Diversity, 2015