How shipping can help to avoid pandemics


Diseases like Covid-19 are passed from animals to humans. They spread because of animal trafficking, deforestation and human encroachment into wildlife habitats. Maritime shipping plays an important role here that needs to be addressed.

By Olaf Merk

Cruise ships played a highly visible role in spreading Covid-19
(Photo: Kotenko Oleksandr/Shutterstock)

The exact causes of Covid-19 are still unclear. Yet it is highly probable that it is a so-called zoonotic disease, transmitted from animal to human. Around 60% of existing human infectious diseases are zoonotic, including highly lethal ones such Ebola, Aids, SARS, West Nile Fever and the plague. Zoonotic viruses cause no symptoms in the host animal; for humans they can be deadly.

The main factor behind zoonotic diseases is humanity’s relation with nature. Viruses spill over to people as a result of the exploitation of the globe’s fauna, such as hunting and wildlife trade. Human encroachment into other species’ natural habitats, for instance through logging, mining cultivation or urban development, has increased contact with wild animals and heightened virus spill-over.

“Highly efficient transport networks can propel localised virus outbreaks into worldwide pandemics.”

As humans continue to invade unexplored wildlife areas, more zoonotic diseases are likely to jump the boundary between species and afflict us. Fully 75% of the emerging infectious diseases are zoonotic. Of these, almost half are linked to changes in land use, principally for the production of meat, soy and palm oil.  As science journalist David Quammen, author of “Spillover: Animal Infections and the Next Human Pandemic” put it back in 2012: “If you shake a tree, something will fall out.”

Carrying ballast

The physical interconnectedness of our globe through a finely-woven web of transport links has huge benefits for mankind.  The downside: highly efficient transport networks can propel localised virus outbreaks into worldwide pandemics – as happened with Covid-19.

The main responsibility falls on maritime shipping. This is nothing new – infectious diseases have spread aboard ships for centuries, including the plague in the Middle Ages and the lethal 1918/19 influenza. The role of shipping as an amplifier of infectious diseases has waned somewhat with the decline of sea-borne passenger transport. But ships still spread viral diseases, as the many cases of Covid-infected cruise ships show. A significant part of the spread of Covid-19 in Australia has been associated with infected passengers disembarking from a cruise ship in Sydney.

The ballast water dumped by ships contains alien invasive species
(Photo: Denys Yelmanov/Shutterstock}

Ships also carry pathogens in much more oblique, but no less dangerous ways: via ballast water. Ballast is an essential component of seafaring. During a voyage, vessels take on board sea water to replace weight lost through fuel and water consumption while at sea. The ballast reduces hull stress, optimises manoeuvrability and improves propulsion. No longer needed, the water is dumped into the sea again.

This simple practice can have lethal consequences. Ballast water contains a multitude of microbes, small invertebrates, larvae, and bacteria. Removed from their habitat and dumped elsewhere, they become “aquatic invasive species’ that can cause havoc in their new ecosystem.

“The 1991 cholera epidemic in Peru is believed to have been introduced into three ports through ballast water.”

The 1991 cholera epidemic in Peru is believed to have been introduced into three ports through ballast water from Bangladesh. The disease subsequently spread throughout Latin America, killing more than 10 000 people by 1994. The use of ballast water has been much stricter regulated in recent years, nevertheless it remains a primary conduit for invasive alien species worldwide – with immediate consequences for human health.  

A seamless (virus) supply chain

With a share of 80% of global freight, maritime shipping is the mainstay of the frictionless and cost-efficient transport chains that lubricate global trade. And therefore it is also implicated in the causal chain that links international trade into the causes of pandemics – both directly and indirectly.

Pangolins are the most trafficked wild animal
(Photo: Afrianto Silalahi/Shutterstock)

Legal and illicit wildlife trade is one aspect. Hundreds of millions of plants and animals are moved around the planet every year, with an estimated annual economic value of over USD 300 billion. Several zoonotic infectious diseases have emerged in part due to the human-animal contact that occurs along the wildlife trade chain.

Maritime shipping plays an important but hardly recognised role in this. Take trade in pangolins, one of the possible intermediary hosts of Covid-19. Pangolins are the most trafficked animal in the world, mostly because of their scales which are used in traditional Chinese medicine. An estimated 596 000 pangolins were illegally traded between 2016 and mid-2019 –  usually via ocean transport, with scales concealed in boxes or sacks in shipping containers and declared as fish or other cargo. Arrests, prosecutions and conviction rates are low, also because of corruption at certain seaports.

The forest for the trees

Another example of shipping’s role in the loss of biodiversity is its indifference towards illegal forestry. Depending on the source, illegal logging accounts for 5% to 40% of global wood production. Too many in the maritime supply chain turn a blind eye on illegal wood trade. Working in separate systems, suppliers, transporters and government agencies report forest products differently, which makes identification of – and action against – illegal wood trade difficult.

Shipping plays an important role in the illegal wood trade
(Photo:  Infinitum Produx/Shutterstock)

Law enforcement is weak in many ports. Some have become downright hubs for “wood laundering”, where the origin of the wood is covered up before it reaches its final destination. Ship operators and agents that do not check the legality of the cargo they transport enable such practices. The anonymity of shipping containers helps, as do vessels operating under “flags of convenience” with little regulatory scrutiny. Critics lament “a lack of due diligence, a denial of responsibility, and even of culpable negligence”.

Lessons to learn

The reaction of transport policy-makers to Covid-19 has so far been to address the immediate effects of the pandemic. Soon, the focus should shift towards how future pandemics can be avoided, and such a strategic reflection will need to consider the role of maritime transport.

Such a strategy should identify shipping-related measures to halt the future propagation of pathogens. It should also address the causes of pandemics, such as wildlife trade, deforestation and other pressures on biodiversity loss via changes in land use. Governments should not be shy about making financial help for shipping companies conditional on the implementation of measures which will help prevent the next zoonotic disease developing into a pandemic.

“Seaports should up their game and improve their capability for effective scrutiny of cargo.”

Maritime transport companies, for their part, could use their pivotal role in supply chains to better scrutinise their cargo. The ongoing digitalisation of the maritime supply chain improves the traceability of cargo and its characteristics, including its legality. That way, shipping companies could show they are serious about implementing due diligence on the cargo they transport.

Seaports should also up their game and improve their capability for effective scrutiny of cargo. Several ports have created Wildlife Traffic Monitoring Units to detect and prevent the illegal transport of wildlife. Seaports should also include combating illegal timber and wildlife trade as objectives in their sustainability strategies, and be accountable for their actions on this. 

Certainly certified

The shipping sector can also do a lot to contain further deforestation around the globe. Commitments to move cargo only for clients that comply with certification schemes that protect natural forests would go a long way. These are common in palm oil, timber and paper supply chains, but rarer in the soy and cattle sectors.

Deforestation is a result of export-oriented, intensive agriculture which needs sea transport
(Photo: Rich Carey/Shutterstock)

Examples include schemes run by bodies such as the Roundtable on Sustainable Palm Oil (RSPO), the Forest Stewardship Council (FSC), the Programme for the Endorsement of Forest Certification (PEFC), the Round Table on Responsible Soy (RTRS), the Amazon Soy Moratorium, and the Zero Deforestation Cattle Agreements and, for fish, the Marine Stewardship Council (MSC).

Last but not least, the international community will do well to think more about the role of maritime shipping in relation to biodiversity – in the oceans as well as on land – and include it in multilateral agreements. The new UN Global Biodiversity Framework, currently in preparation under the Convention on Biological Diversity, will define targets and pathways for the conservation and management of biodiversity for the next decade and beyond. It seems like a good opportunity for a strong signal that long-term lessons from the current Covid-19 health crisis are being learned.


Olaf Merk is ports and shipping expert at the International Transport Forum. Views are his own.