It is essential agricultural companies make sure the plant machinery they want transporting overseas is thoroughly cleaned before it goes on the ship, as soil can carry lots of pests and diseases to another country.
A recent study from AgResearch and Better Border Biosecurity (B3) investigated whether external surfaces of items carried by sea freight pose a risk to soil health.
They found soil typically contains microbes, such as plant pathogens. This can cause havoc on flora and fauna at the final destination due to invasive alliance species.
Mark NcNeil from AgResearch told Phys.Org: “While the presence of soil is perhaps not surprising, the presence of live bacteria, fungi, worms, seeds and insects associated with the soil was of greater concern.”
He noted that plant-parasitic worms, seeds, insects and spiders that were not already present in New Zealand had been transported on the sea freight there.
The consequences of alien species can be huge. According to Iberdrola, these include the introduction of new predators to the environment, which would threaten native species.
This could alter habitats, cause physical or chemical changes to the soil, and result in a loss of biodiversity, particularly on smaller islands.
Alien species could also lead to new parasites and diseases through hybridising with the native species.
As well as environmental conditions changing, the introduction of a foreign species could impact human health through the transmission of diseases.
Here, Mr McNeil stated, the “implications can be significant, as they have high levels of endemism and invasive alien species establishment can lead to extinction of species as well as biodiversity declines”.
Although this research, which was published in NeoBiota, was concerning, due to its environmental, economic and social consequences, another study reveals there is a higher risk of contamination by pests being carried on the footwear of international visitors.
Researchers from the Centre of Excellence for Biosecurity Risk Analysis at the University of Melbourne, together with AgResearch, found insects, spiders, snails, plants, roundworms and mites were discovered on shoes worn into the country or packed inside a suitcase.
However, there is hardly any difference between the impact of international or domestic tourism on the spread of exotic diseases, with the researchers saying: “Within-country tourism movements are [also] significantly correlated to the detection of exotic pests.”
There are no rules to regulate the spread of foreign species on tourist footwear, which could pose the same risk to biodiversity as sea freight.
Therefore, it remains to be seen whether sea freight companies will be subject to stricter regulations to protect the destination’s flora and fauna from soil contamination, in spite of the recent research.
However, this paper could encourage freight companies to conduct more thorough cleaning of containers before departure, as well as of the goods being transported themselves.
There might also be an inspection at the border, with entry refusal given to those containers or pieces of machinery that have not been adequately scrubbed down to remove any traces of pests.
