Murdoch’s leading biosecurity expert has led the longest-running monitoring program of insects on a passenger vessel, finding over 73,000 insects of more than 200 different species on a single ship.

Cruise vessels can pose a high risk to fragile marine and terrestrial ecosystems such as Barrow Island through the introduction of pest species.

A team of researchers led by Professor Simon McKirdy, Pro Vice Chancellor of Harry Butler Institute for Sustainable Development at Murdoch University, has now identified just how significant that threat is.

Prof. McKirdy’s team recently completed a study into the presence of invasive insect species aboard a cruise ship that had been re-purposed as an accommodation facility.

While previous studies had been conducted into the presence of marine pests and rodents aboard such vessels, this was the first study of its kind to be conducted on stowaway insect species.

“Large sea-going passenger vessels can pose a high biosecurity risk for marine species, however this risk is rarely documented in relation to insects,” Prof. McKirdy said. 

“Our research presents the results from the longest-running and most extensive monitoring program of insects undertaken on board a passenger vessel.”

During 19 months of research aboard the Europa, a ship that had previously cruised the Baltic Sea, Prof. McKirdy and his research team collected and identified more than 73,000 insects of more than 200 different species.

These included a range of cockroaches, moths, flies, mosquitos, wasps, ants and beetles; four of which were identified as non-indigenous to Australia and included the ‘destructive flour beetle’ or Tribolium destructor, a high-risk species to Australia. 

This discovery triggered a program of treatments to the vessel, aimed at eradicating the threat.  

“This effort totaled more than 13,700 human hours and included strict biosecurity protocols to ensure that this and other non-native species were not spread from the vessel to Australia,” Prof. McKirdy said. 

The extensive eradication program implemented on the Europa encompassed all decks of the ship and was the most comprehensive and longest-running monitoring and eradication program recorded on any vessel.” 

Prof. McKirdy said that despite the considerable time and resources that were allocated to the eradication, it still was not possible to identify the complete source of the target organisms due to the vessel’s complexity, size and age, which allowed areas in which treatment access was limited and sufficient food sources for the insects to persist.  

“Fortunately, in the case of the Europa, sufficient resources were dedicated to the detection and response to non-native species. This allowed for a wide-ranging vessel surveillance and eradication plan to be implemented and no new species were introduced to Australia.

“It is important not to underestimate the importance of this in preventing the spread of the non-indigenous species detected on the Europa to Australia.
 
“Cruise ships are ideal structures for the survival of different types of insects and represent a real potential biosecurity threat. However, if stringent biosecurity measures are put in place this risk can be managed.

“At a time when this sector of tourism is growing a more detailed assessment of the biosecurity threat posed by cruise vessels needs to be undertaken, particularly for those visiting more remote regions around the globe,” Prof. McKirdy said.

“Stringent biosecurity protocols including screening will enable early warning of potential non-native species and decisive action to be taken before costly pest eradication programs are required.” 

A paper on the research can be found in the journal, Scientific Reports.