Professor Steven Chown from Monash University gave a recent seminar regarding some of his work in the Antarctic. Much of his research has used physiological traits such as size, growth rate, etc. to look at many different ecological implications. Chown’s work in the Prince Edward Islands has specifically demonstrated that research on physiology, abundance, and distribution can help implement policies for conservation.
Prince Edward Islands
The Antarctic Treaty regulates all relations among the states in the Antarctic, and a part of this includes promoting scientific research. Some of their current priorities include managing non-native species, tourism, and climate change. The Antarctic Treaty works with collaborators and scientists like Chown to address these important concerns and priorities.
The Prince Edward Islands were the main destination of focus for Chown and his researchers. Marion Island in particular has been familiar with non-native species since 1949 when five cats (one female) were brought to resolve a mice problem. Unfortunately, the cats multiplied quickly and were more interested in eating petrels (seabird) than the mice. A cat eradication program was established and since the 1990’s it is believed that there are no remaining cats on the island. Although cats may no longer be a problem, slugs and springtails are.
A particular slug species (Deroceras panormitanum) has become very abundant on Marion Island. Chown’s team of researchers looked at the metabolic rate and slug distribution to gain more information about these invasive organisms. They discovered that the slug is very susceptible to desiccation (drying out) and thereby seeks out habitats with high humidity below the vegetation. These areas are like miniature rainforests for slugs. Although this preferred habitat is found in many areas of the island, the slugs are found mostly in coastal peak areas. Further investigation revealed that they have a low tolerance for salty soil and very low or freezing temperatures. This means that although there are a lot of slugs, they won’t go everywhere because they can’t survive all environments on the island.
Another interesting invasive species is the springtail (Pogonognathellus flavescens). Springtails seem to live only in patches of very specific areas on Marion Island. By analyzing the development of springtail eggs, Chown determined the species have a habitat preference for lowland conditions. Surprisingly, they aren’t found in all the preferred habitat locations on the island, just the tussock grassland habitats. This seemed confusing to researchers at first because the springtails are not really restricted to an area due to predators or competition from other species. The answer is simple…springtails are slow. Due to their limited ability to travel great distances the springtails are quite happy in their tussock grassland habitats.
If slugs and springtails can’t get very far on their own, then they must have had help from someone. Although we humans don’t move these organisms around on purpose, we are a great contributor to their movement. Chown’s solution to the problem is that you don’t put stuff on the ground. Due to this research, there is now an elevated area for helicopters to land, and other resources to prevent transportation materials to collect unwanted species. Some additional unwanted species can include plants which have seeds that get quickly dispersed by tourism and researchers (approx. 70,000 seeds). Since it is impossible to have everyone not touch the ground, vacuum cleaning and seed collection helps limit the plant seed dispersal and researchers can learn more about where the seeds came from. Also, to continually manage the introduction of further non-native species, supply chain managers of the Antarctic have a checklist to follow for everything travelling to Antarctica (click here for checklist).
Climate change, as mentioned before, is another Antarctic Treaty priority that researchers are working on providing additional information. Chown’s work on native and invasive species assists in these efforts. The native species have a low tolerance for high temperatures, but the invasive species like slugs and springtails have a low tolerance for low temperatures. By monitoring the physiological data of these organisms Chown can make forecasts and models about climate change that can help with conservation.
Chown’s physiological data and other research as well as policy efforts have greatly contributed to current conservation efforts in Antarctica. Not only has his work demonstrated the importance of taking physiological data in research, but also what can be accomplished when combining science and policy. It is through the collaborative efforts of research and policy makers that perhaps we can create management processes for multiple threats on our ecosystem.
- Trait-based approaches to conservation physiology: forecasting environmental change risks from the bottom up; Chown, 2012
- Macrophysiology for a Changing World; Chown & Gaston, 2008
- Challenges to the Future Conservation of the Antarctic; Chown et al., 2012
- Physiological tolerances account for range limits and abundance structure in an invasive slug; Lee et al., 2009
- Contingent absences account for range limits but not the local abundance structure of an invasive springtail; Treasure & Chown, 2013
- Scientific Committee on Antarctic Research (SCAR)