Arctic hitchhikers

Arctic hitchhikers

Top image: Coal ship from Europe at the mining settlement Svea in Spitsbergen. Photo: Chris Ware.

A novel study is investigating the potential for non-native organisms to “hitchhike” with marine vessels and invade Svalbard waters. The results will have impact on the future management regime for the marine environment of the High Arctic. 

26 July 2013
Text: Eva Therese Jenssen / UNIS

In 2011 researchers from the University Centre in Svalbard (UNIS), Tromsø University Museum, the Institute of Marine Research, and the University of Tasmania started investigating the potential for shipping to facilitate species introduction to Svalbard, and the risk that introduced species would have impact on this vulnerable High Arctic region.

So far only two studies have investigated shipping as a pathway for species introduction to the Arctic and both focused on the North American Arctic. The Svalbard project, entitled “Arctic Stowaways”, is the first study ever to focus on the European Arctic.

Prevention over eradication
One of the most serious pressures on the natural environment today is the impact caused by introduced species. In the marine environment it is almost impossible to eradicate non-native species once they have been introduced.

Shipping to Svalbard has expanded significantly over the last couple of decades, according to the Governor of Svalbard. No true alien marine species have been recorded as established in Svalbard waters. But with the expected climate warming researchers fear that a range of southerly species might establish themselves in the High Arctic. The challenge is that alien species are often introduced to new environments by human activities. In the ocean the dispersion of non-native species is often facilitated by ballast water or “hitchhiking” on the ships’ hulls. In other words, marine species may “stowaway” on ships and invade new habitats. From other parts of the world we know that shipping is responsible for the introduction of several particularly invasive alien species.

So according to the scientists, the best and most effective way to prevent invasion in High Arctic waters is to introduce management regulations that prevent ships from introducing new species.

Hidden invasion
Chris Ware, PhD student at the Tromsø University Museum and the University of Tasmania, is lead investigator in “Arctic Stowaways”.

Chris Ware

Chris Ware. Photo: Sarah Lovibond.

Ware has investigated the potential for “alien” invasion of the Svalbard environment before. Previously, as a student at UNIS he set up a free shoe-cleaning service at the airport in Longyearbyen. The soil he collected from travelers’ shoes was inspected for non-native seeds, and those found were planted and monitored under Svalbard summer weather conditions. The result was that 26% of the seeds managed to germinate.

Now, his PhD project focuses on the hidden invasion threat posed by marine vessels travelling into Svalbard waters. In the Arctic Stowaways project, Ware and his colleagues focused on the two main carrier elements for marine organism dispersal: ballast water and biofouling.

The research team worked on coal ships arriving to the ports of Svea (Svalbard’s main coal mining community), Longyearbyen and the Russian settlement Barentsburg. They also inspected other kinds of vessels that docked in Longyearbyen during the summer of 2011 for the presence of biofouling.

The samples and associated data were collected in order to determine the diversity and composition of species transported by ship vessels, and by doing so evaluate associated potential hazards and risks.

Ballast water
The research team sampled ballast water from eight coal ships docking in Svea, Barentsburg and Longyearbyen in the summer of 2011. The vessels, sailing from the Netherlands, Portugal and the United Kingdom, took on ballast water in the port of origin before sailing northwards. Nearly any small thing in the water column can be transferred to the ballast tanks, including organisms as minute as viruses, bacteria and phytoplankton, and bigger organisms such as juvenile crabs or shrimp.

Some of the ships bound for Svalbard exchanged ballast water in the open ocean en route to the High Arctic as a means to limit the likelihood of species introduction to the local Svalbard ports. When ships discharge ballast water collected from the coastal port of origin and take on oceanic ballast water, many of the original organisms are either discharged or killed.

The scientists collected samples to assess the number of organisms that can survive transport in ballast water tanks, and the types of organisms collected. The team decided to focus on the larger zooplankton, but also collected data on the amount of ballast water discharged, locations where ballast water was sourced and exchanged (if done so) and the voyage duration.

– We still haven’t identified and counted all the species collected in the ballast water samples, as we are still awaiting results from DNA barcoding of the organisms, Ware explains.

The sailing time from the port of origin up to Svalbard has great impact on the survival rate of organisms in unchanged ballast water. One of the sampled vessels started its journey from Portugal and did not exchange ballast water before docking in Longyearbyen.

– The survival rate of the organisms in the ballast water was low. The 8-10 day long transit made sure that many of the organisms did not make it alive up to Svalbard, says Ware.

Two coal ships, originating from the Netherlands and the UK, arrived in the Russian settlement of Barentsburg after a journey of approximately 6-8 days. Neither exchanged ballast water en route to Svalbard. Here the scientists found a higher proportion of live organisms.

The five ships sampled in Svea all originated from the Netherlands, but all five had exchanged ballast water mid-ocean before arriving in Svalbard.

– Exchanging ballast water before arrival in Svalbard is at present a voluntary measure, explains co-investigator Inger Greve Alsos of Tromsø University Museum.

– And the evidence suggests that the organisms collected mid-ocean often are used to living conditions similar to what we find in Svalbard, thus the preventive measure of exchanging ballast water is perhaps not as effective as previously assumed, she says.

– The amount of surviving coastal organisms in our samples indicates that the effect of ballast water exchange was limited. Therefore, the rationale for ballast water exchange to be undertaken between all ports and Svalbard should be thoroughly evaluated, say Ware and Alsos.

Sampling ballast water

Collecting ballast water samples in Barentsburg. Photo: Chris Ware.

Biofouling
The researchers also looked at “biofouling”, the accumulation of microorganisms, plants, algae or animals on the wetted surfaces of vessel hulls. As a source of introducing non-native species, biofouling has been neglected relative to ballast water. However, in recent years there has been a growing concern for biofouling in the sub-Antarctic waters. Today, some countries are moving towards requiring biofouling inspections on vessels before sailing to the sub-Antarctic region. But no such standard exists for Svalbard or the High Arctic – yet.

Inspection of vessel hulls is usually done by divers, but in the extreme conditions of Svalbard, the team decided to use an underwater remotely operated vehicle (ROV) with a mounted camera to get a clearer underwater view of the vessel hulls. The team surveyed several cruise and expedition ships in addition to research, cargo and private vessels. For each of the surveyed vessels they also identified the age of antifouling paint, the duration of previous port layovers and the average speed of the vessels.

– Our survey shows clear evidence of a positive association between biofouling and older antifouling paint, slower vessel speeds, and longer layover periods in ports. The one recreational vessel surveyed had extensive biofouling, probably due to overwintering in a mainland Norwegian port. Recreational vessels are the most common type of boat visiting Svalbard and they also visit many locations around Svalbard; their potential to introduce species to Svalbard is high, according to Ware and Alsos.

As with the ballast water issue, the scientists point out that there is no perfect solution to prevent the alien hitchhikers from attaching to the vessel hulls.

– Antifouling paint is a widely used measure; however, it does not completely prevent organism dispersal. It is like brushing your teeth once a week and expecting them to stay clean, Alsos explains.

Management recommendations
The sampling and data analysis will permit the scientists to identify bioinvasion hazards. They have, among other things, employed a pathway analysis based on the regional shipping network and climate similarity, identifying a number of vessel types and pathways with the potential to transfer suitably adapted non-native organisms.
– We find that marine vessel traffic to Svalbard is highly connected to worldwide ports, many with environmental conditions similar to those in Svalbard, says Ware.

Their analysis also indicates that predicted ocean warming will increase the similarity to over 100 ports worldwide which host large numbers of known invasive species, furthering the potential for establishment of dispersed alien species.

– This study is important in evaluating the environmental impact of introducing non-native species into Svalbard waters: a warmer climate will place Svalbard further south – climatically speaking – and will therefore render Svalbard increasingly vulnerable to ship-mediated species invasion, says Alsos.

According to recent reports from the Norwegian authorities the number of ships sailing from Europe to Asia via the Northeast Passage has increased significantly over the past couple of years, thanks to a warmer Arctic climate and the receding sea ice cover. In 2010 only four ships sailed along the Northeast Passage; in 2012 the number had increased to almost 50.

The analyses are still a work in progress and the project’s conclusion will result in recommendations to the Governor of Svalbard about the effect of existing regulations and a discussion of the need for further development of management strategies to maintain a rigorous regime to protect the marine environment in and around Svalbard.

This project has received funding from the Svalbard Environmental Protection Fund, Tromsø University Museum and the Fram Centre.

This article was first published in Fram Forum 2013.

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