Dangerous cargo: the accidental spread of alien organisms via commercial shipping

It's often said that whichever culture and environment we grow up in is the one we consider as the norm. Whilst my great-grandparents were born before the invention of heavier-than-air flying machines, I've booked numerous long-haul flights without considering much beyond their monetary and environmental cost. Yet this familiarity with our fast and efficient global transportation network masks an unpleasant side effect: it is second only to habitat loss when it comes to endangering biodiversity.

Although many environmental campaigns focus on fossil fuels, deforestation and unsustainable agricultural practices, the (mostly inadvertent) transportation of alien plants, animals and fungi from one region to another has quietly but catastrophically reduced biodiversity in many areas of the planet.

The earliest example I recall learning about was Stephen Jay Gould's heart-felt description of the extinction of French Polynesia's partulid tree snails at the hands of introduced carnivorous snails intended to control edible snail species (which were also deliberately introduced). While the nineteenth and early twentieth centuries saw large numbers of species intentionally established in areas far from their natural territories, the past half century has seen an acceleration in equally disastrous accidental introductions as a by-product of international trade.

A potential starting point for invasion ecology as a discipline in its own right was Oxford professor Charles Elton's 1958 publication The Ecology of Invasions by Animals and Plants. The International Union for Conservation of Nature's Red List of Threatened Species followed six years later. Clearly, the negative effects of our activities were starting to become known. But has enough been done to publicise it in the intervening decades?

The Red list is the most accurate data source for regional biodiversity and the population health of all organisms known to science; yet few non-specialists seem even aware of its existence. Indeed, several decades passed after the list's creation before invasive biology became an important subject in professional ecology. Over the past thirty years the topic has seen a ten-fold increase in publications and citations - a sign of recognition if ever there was one - although mainstream media appears barely aware of its existence.

The IUCN's Invasive Species Specialist Group aids governments and organisations in planning the monitoring, containment, and where possible, destruction of invasive species. It runs the publicly-available Global Invasive Species Database, but its online presence appears to be poorly funded, or at least coordinated. Rather than a central hub there is a plethora of websites featuring varying degrees of professionalism and some distinctly out-of-date content. Perhaps clients are given direct instructions, but as a member of the public I found the ISSG sites bewildering in their variety.

Needless to say, when it does come to taking action, it can be assumed that economic imperatives such as agricultural pests take precedence over preservation of other endangered species. The only country I know of that is attempting a nation-wide eradication of most invasive animals (note: not plants and fungi) is New Zealand, with our Predator Free 2050 project. However, I'm uncertain how realistic it is. Even pre-Covid it appears to have lacked a solid funding source and now - with thirty years and counting until the deadline - there's even less chance of a comprehensive removal of numerous pest species.

What the Predator Free 2050 plan doesn't include is the multitude of plants and animals that slip through the net, so to speak: the legion of species currently invading our offshore environment. It's one thing to actually see land-based plants and animals, but the ocean is largely unknown territory to most people. With over forty thousand cargo vessels moving around the globe every year there is plenty of opportunity for organisms, especially their larval forms, to be inadvertently spread to new territories via both hulls and ballast water. Whilst Killer Algae (a slight hint there in the common name for Caulerpa taxifolia) and the Chinese mitten crab aren't as well-known as Japanese knotweed and Common myna bird they are just two of the many dangerous invaders spreading ever further from their original territories.

It isn't just marine vessels that can carry such dangerous cargo: the immense amount of plastic waste in our oceans can serve as life rafts for the propagation of alien species, albeit at the whim of currents moving rather slower than diesel power. The problem of course is that the oceans are enormous and so the only time the issue becomes known about is when an invasive organism is spotted encroaching in coastal waters. Unfortunately, marine lifeforms can't be easily dealt with using the traps and poison that work on land-based entities; indeed, international regulations seem as much concerned with the dangers of anti-fouling systems as with the issues they prevent.

In 2011 the International Maritime Organization implemented guidelines to minimise vessel biofouling as it relates to the accidental incursions of invasive marine organisms. New Zealand was the first of several nations to execute their own national strategy that turned these guidelines into mandatory practice - and take them further. In addition, New Zealand's National Institute of Water and Atmospheric Research (NIWA) runs annual surveys, particularly around ports, but otherwise their funding appears inadequate to the immensity of the task. 

It's all very well keeping track of the ever-increasing list of resident invasive species around the nation's coastline, but little has been done to remove them. With about 150 types of alien organism now in residence around New Zealand's coast and the same again in occasional visitors, NIWA has been a partner in international competitions aimed at finding pest management solutions, at least for coastal ecosystems if not the deep ocean. Obvious solutions such as scrubbing hulls would just lead to direct contamination of ports, so some new thinking is clearly required.

Of course, the use of cargo ships is unlikely to reduce any time soon. Our global marine transport network is far from in decline and many nations lack the stringent precautions that New Zealand and Australia are now implementing. It has been estimated that cleaning hulls to prevent biofouling could reduce global marine fuel consumption by 10%, so perhaps this commercial benefit may win over those reluctant to spend heavily on prevention measures. But just as fishing vessels are still getting away with immense amounts of by-kill, merchant shipping in many areas of the world appears to be a law unto self.

Preserving regional marine biota is just as critical as land-based environmental protection. Allowing species to proliferate outside their normal range can only lead to deleterious changes - and when combined with our warming, increasingly acidic oceans, this does not bode well for all life on Earth, especially a hungry Homo sapiens. Just because we humans spend most of our time on land, we cannot afford to ignore the far larger ecosystems of the seas.

Fundamental fungi: the forgotten kingdom vital to our future

At the end of 1993 the Convention on Biological Diversity came into force. A key piece of global legislation in the promotion of sustainable development, it marked a change in focus for environmental concerns. Whereas previous high-profile conservation efforts such as those of the World Wide Fund for Nature or Greenpeace were frequently aimed at individual species or regional ecosystems, the legislation initiated by the 1992 Earth Summit in Rio de Janeiro was aimed at the biota of the entire planet. However, there are still segments of enormous ecological importance that are lacking sufficient research.

I've previously discussed how little attention general-readership natural history pays to the kingdom of fungi, which may have somewhere between 1.5 million and 3.8 million species. Of these, less than 150,000 have been scientifically described. Clearly, this is one life form where our knowledge barely covers the tip of the iceberg. It's hardly as if this attitude is a new one, either. While Linnaeus produced comprehensive editions on plant and animal taxonomy in the 1750s, it took over seventy years for anyone to bother with fungi: it wasn't until 1821 that another Swedish naturalist, Elias Magnus Fries, produced an equivalent work called Systema Mycologicum.

Thanks to the majority of fungal material living either underground or in dark, damp environments such as leaf litter, the kingdom fails to get the attention it deserves. Even the forms we see more regularly, such as mushrooms and symbiotic lichen, engender little interest. Many people no doubt still mistake the former as plants - and are scared off any interest in the wild forms due to the dangers of poisonous species - while the latter are rarer in polluted, i.e. urban, environments and fail to compete in sight and scent with the glories of the flowering plants.

In the eight years since I wrote about the lack of interest in fungi, I've found reason to mention the long-forgotten kingdom in various important contexts. For a start, numerous animals and plants are becoming critically endangered due to fungal pathogens accidentally being spread by global travel. In addition, research over the past three years has shown that Aspergillus tubingensis and several other types of fungi show promise as a bio-friendly solution to plastic waste. Finally, last month I looked at non-animal protein substitutes, including the mycoprotein-derived Quorn.

Despite the potential of these various forms of fungi, the organism's losses due to rapid environmental changes don't appear to be garnering much attention. The IUCN Red List, which tabulates the differing levels of threat faced by all life on Earth, only shows 343 fungi as currently endangered; this contrasts with over 43,000 plants and 76,000 animals on the list. Undoubtedly, the Kingdom Fungi is being given an underwhelming amount of attention just as we are discovering how important it is to maintaining ecosystem stability and for the future of our species.

Recently published reports of studies conducted in the Amazon region show that deforestation has a long-term impact on soil biota, which in turn affects the entire local ecology. Studies of a range of habitats, such as primary forest, agricultural land (including monoculture), pasture/grazing, forestry plantations and secondary/regenerated forest showed that although overall fungal mass might remain consistent, species diversity is far lower outside of the original rainforest. The lack of fungal variety was linked directly to the lack of plant diversity in those biomes, with recovery a slow or unlikely prospect due to the newly-fragmented nature of the landscape preventing efficient dispersal of fungal spores.

There are some obvious points that agribusiness seems to ignore, such as the effects of pesticides and fertilisers on local fungi and the loss of microhabitats vital to maintaining a healthy variety of fungal species. If only more generalist fungi can survive the change in land use from the wonderful diversity of the rainforest (with up to 400 fungal species per teaspoonful) then this may have repercussions for future farming. As an example, the fungus Fusarium oxysporum has a phytopathogenic effect on agricultural plants including palm oil, but without competition from a wider cross-section of fungi (for example, Paraconiothyrium variabile) it could spread rapidly within a dismal monoculture environment. 

As a predominantly visual species, we humans are unthinkingly biased about the natural world based upon what we see: think cute giant panda versus the unappealing aesthetics of the blobfish. It really is a case of out of sight, out of mind, but unfortunately no amount of spin doctoring will make fungi as much loved as furry mammals. Yet our attitudes need to change if we are to maintain the delicate ecological balance; fungi are highly important for recycling nutrients, regulating carbon dioxide levels, and as a source of food and pharmaceuticals. Yet they remain the soil equivalents of the ubiquitous underwater copepods, unsung heroes of the global ecosystem. It's about time we took a lot more notice of this forgotten kingdom.

Eco-friendly eats: the potential of new foods to save the planet

Back in 2015 I wrote a post about the potential for insect-based protein to become a much more common environmentally-friendly food in the near future. Although it may be rather better for the environment than traditional ingredients, Western cultures have a cultural bias against eating anything with more than four limbs. So what are the alternatives to conventional farming and fishing that can be eco-friendly but don't rely on insects as their source material?

As someone who hasn't eaten meat in over three decades, I was interested to read that Helsinki-based Solar Foods have found how to create a protein flour from almost nothing. Hydrogen-eating soil bacteria are being used to generate a taste-free product called Solein, intended as an additive in place of other protein sources and also serving as a medium for growing lab-cultured meat. There's even the potential for it to become a livestock feed; could it replace the environmentally appalling Palm Kernel Expeller?

It might sound fantastic, but the issue of course comes down to economics. Current estimates suggest it will be five to ten years before Solein can compete with soya on a commercial scale. It has even been predicted that this sort of precision fermentation may cost as little as ten percent of conventional animal-derived protein by the mid-2030s, indicating a potentially key role in food technology over the next few decades.

This is in marked contrast to growing real meat via laboratory cultures, such as from stem cells. Synthetic meat may be far more ecologically sound than livestock farming (did you know that it takes 15,400 litres of water to produce a kilogram of beef?) but cultured animal flesh is still some years from viability; after all, it's only seven years since the first bio-reactor burger, produced for an eye-watering $300,000!

The United Nations is promoting a reduction in meat consumption to fight climate change, so what are the current options for those wanting to change their diet to reduce agricultural land usage, greenhouse gas emissions and water consumption/pollution? The oldest alternatives to animal protein such as soy or gluten are known allergens, so although these are increasingly widespread - think of the vast number of tofu-based products that have become available over the past twenty years - they are not a completely satisfactory solution. In addition, soya agriculture in developing nations has been linked to critical deforestation, some of which has been committed illegally.

Mycoprotein-based foods (i.e. those derived from fungi) are one possibility. Since the early 1990s, Quorn products have become available in nineteen countries. It has a very small environmental footprint, can be fermented rapidly and is a high-quality form of nutrition. There is some evidence for it being mildly allergenic, but the main sticking point to it spreading to international markets appears to have been due to failure to comply with food standards authorities. My main issue with the product is that for something consisting primarily of fungal filaments grown on glucose syrup, it is very expensive!

Algae is another potential source of meat replacement. Fake shrimp made primarily from red algae (itself a food for real shrimp) are said to be close to the texture and flavour of the real thing. Considering the carbon mileage of commercial shrimp fishing, this product alone could be of tremendous benefit to the environment - including of course to the sustainability and preservation of shrimp species themselves.

An unlikely substitute for meat, at least in terms of texture if not nutrition or taste, is the unripe jack fruit. In the last two years here in New Zealand it has risen from zero to hero and can now be found in supermarkets as a basic canned product as well as being served in vegetarian fast food options; before 2018 I had never seen jackfruit, despite it having been cultivated in Asia for at least six thousand years.

All this isn't to say it will be easy to make a global transition to non-meat diets. Quite apart from the powerful cattle and fishing lobbies, some alternative products use genetically-modified ingredients, which is still a key political issue in many nations. However, with even fast food companies falling over themselves to offer lacto-vegetarian and vegan dishes, the public is slowly but steadily increasing its green eating credentials. Whereas there used to be a clearly defined boundary - at least in more affluent nations - between most people and the vegetarian minority, the likes of the Impossible Sausage and Beyond Burger are now appealing to both groups, the intention obviously being to minimise disruption to the meat-lovers' diet.

With the global human population forecast to peak at over nine billion later this century, responsible eating cannot come a moment too soon. It's slowly beginning to dawn on both Westerners and elsewhere that the rights of the individual to consume a high fat, highly processed, red meat-heavy diet has led to a situation that is bad both for them and for the quality of life of future generations.

Over-exploitation of seafood stocks is already having a profound effect on local ecosystems such as the Sea of Cortez, so a reduction in both types of protein is essential to the long-term health of the oceans as well as the land. Luckily, new start-ups and established companies are beginning to find alternatives that can appeal to even the most ardent of meat eaters. The trick is to find a satisfying diet (that's just what you eat, not something to slim by) that can aid your personal health as well as reducing your carbon footprint, water usage, and other environmental factors. The good news is that the number of options is only going to increase. Why not check one out today?