Pause for Thought

Since I started this blog three months ago, I have covered a wide range of topics. Given this and the enormity of this subject, I thought that this post should summarise the main findings so far.

Here is a summary of the key points and conclusions:

• Different parts of Antarctica are being affected differently. It is easy to consider Antarctica as one unified system which is affected the same when things happen because the whole continent looks homogeneous. For example, “Larsen B has collapsed, quick! We have to find a way to stop the whole continent from melting!” In reality, ice sheets in Antarctica are complex to understand because they are affected by climate change, ocean circulations…etc. The Bipolar Sea-saw Pattern can help explain one part of the observed sea ice changes, however it is only a contributing factor out of many.
• Tourism is a recent phenomenon and as tourist numbers continue to increase, and they will do in the future, animals are being affected in different ways. But the extent that they are affected differs between species. Tourism also has indirect impacts which are just as damaging to the environment, for example oil spills.
• International organisations such as the UN try to create treaties to regulate Antarctica. I have analysed regulation in terms of tourism and found that there are flaws in them. In my view tougher restrictions are required if the environment is to remain unaltered by human actions. Furthermore, regulation can have negative and positive impacts on animals in Antarctica, for example, whaling bans, krill and penguins. It is unlikely that international organisations foresee these indirect food chain effects and this reduces the impact of regulation.
• Krill are immensely important in the Antarctic food chain but fishing activities may be jeopardising them. However, it is difficult to understand whether krill populations are reacting to fishing or natural changes in sea ice extent caused by La Niña. Because of this, separating natural impacts and human impacts is more complex than it seems. 
• Fishing is harmful for fur seals and other mammals because debris lost in the ocean creates entanglement.
• Regulation seems to be the only way that humans are trying to make amends. It seems that banning happens less often.

My Thoughts

Furthermore, I would like to use this as an opportunity to evaluate what I have posted so far, giving my thoughts on what I think I have done well and not so well.

• Diversity: I have tried to include a range of case studies throughout the blog to make it more interesting, drawing on different animals and explaining the different effects where ever I can. For instance, my discussions have drawn on fur seals, Adélie penguins, Gentoo penguins, krill, South Polar Skua…etc. I also want to point out that it has been an enjoyable experience learning about these wonderful animals!
• Geographical dispersion: I have tried to include case studies from different parts of Antarctica to illustrate what’s happening everywhere. This has been supplemented with maps (see below). Antarctica is a large continent and different regions are affected by different activities. Having said this, I believe I have focussed on west side of Antarctica more than the east side. While writing and researching, I have discovered that there is little literature on the east side of Antarctica which is the main reason why. Perhaps this is because eastern Antarctica is less accessible than the west side so research tends to be focussed here.
• Maps: I understand that naming Antarctic islands, ice sheets and seas could be confusing and hold little meaning if no one knows where they are. So where I can, I have places maps throughout the blog and highlighted where my case study locations are. Hopefully I haven’t created an overload, but I feel they are necessary!
• Balance: I have given a balanced view of the impacts throughout the blog, presenting arguments for natural causes as well as human impacts.

Is it S.O.S Antarctica?

The name of my blog suggests that, because of the human impacts, Antarctica is sending a distress signal, asking humans to leave it alone! So far, I have been counting the negative and postive/ natural impacts and they currently stand at 5-3 to negative impacts. Perhaps the continent is in trouble... In my last post I will attempt to answer the above question based on my previous posts and the total score.

Finally I wish to explain what the next few topics are. In this final month or so, I aim to discuss:

• The impact of research stations on Antarctica. Yes research has discovered ways to correct human impacts, but are there any negative impacts?

• The Ozone layer. So far I have focussed on terrestrial and marine impacts, but what about the atmospheric impact?

Thank you for reading, until next week, I’ll end with this cartoon to prepare for the next post. 

 Figure 1. The impact of research

Entanglement

So far, my blog has mentioned the impacts that humans are having on a number of Antarctic species such as krill and Gentoo and Adélie penguins. Today's post will look at yet another animal whose habitat is in Antarctica, the fur seal. Croxall et al. (1990) conducted research investigating how fur seals are becoming entangled by various man-made products that are roaming the oceans near Antarctica. Figure 1 shows what I mean by entanglement. It is when the fur seal gets caught up in man-made materials that are non-biodegradable, such as polypropylene or nylon string and fishing nets. Fur seals become entangled by putting their heading into the loops of material in the ocean while swimming. 

Figure 1. Entangled Antarctic fur seal

Antarctic fur seals are commonly found in the South Georgia and the South Sandwich Islands (see figure 2) and this is where Croxall et al. focus their study. The authors reported observations of fur seals that had man-made objects around the seals’ necks (referred to as neck collars) for 142 days at Bird Island (as shown in figure 2) from 1988 to 1989.

Figure 2: South Georgia and the South Sandwich Islands. Adapted from Cool Antarctica (2001) and Wikitravel (2011)

This study helped identify the extent of entanglement in South Georgia. Here is a summary of the main findings of the research:

• At least 0.1% of the total Bird Island population had a neck collar during the study period, of which 59% was due to packaging bands made from polypropylene straps, 16% was due to nylon strings and 13% was due to fishing nets.
• Males accounted for 71% of entanglements and young accounted for 88% of entanglements.
• 135 males and 55 females were observed to be entangled.
• 19% of the collars were loose enough to remove.

The table below, table 1, also shows the results.

Table 1. Observed Antarctic fur seals with entanglements at Bird Island and the type of collar. Source: Croxall et al. (1990)

There are some inadequacies in this research however. The authors claim that '15 were most probably of animals seen more than once or whose collars were subsequently removed’ (p. 223) so they did not count these in the results. Hence the total number of fur seal included in their results (i.e. the minimum number observed) is 208, not 223 (see table 1). I find this problematic because how can the authors be certain that a fur seal was observed more than once? The authors don’t mention that they were tagged or tracked in any way and due to the homogenous characteristics if fur seals, perhaps there is measurement error in the observations.  

Also, there are complications in measuring the exact proportion of the total population that is affected because the whole population is not observed. Many young don’t appear ashore and they could have neck collars. A further consideration is what about the fur seals that are entangled in the sea and don’t make it back to the island? Antarctic fur seals can go weeks in the oceans (National Geographic, 2014) so these seals are not observed. Hence, this sample is too small to infer the full extent of the total fur seal population affected by man-made debris.

Despite this, this research has shown that humans are involved in the entanglement of fur seals. Man-made debris is floating around in the waters surrounding Antarctica, causing danger to the Antarctic fur seal (see figure 1). Despite no permanent residents in Antarctica and despite its isolation from the rest of the world, man-made plastics, strings and ropes are still present in this environment. 

Where is it coming from?

The debris, i.e. nylon ropes, packaging plastic bands and rubber rings, comes mostly from fishing activities (Ivar do Sul et al. 2011). Other studies have found entangled seals in Signy Island, which is part of South Orkney Islands (Dunn and Waluda, 2008), and Marion Island, which is in the Southern Ocean (Hofmeyr et al. 2002). Both these studies concluded that entanglement is linked with fishing activities. The fishing industry is motivated by profit making which stems from the western capitalist society. The use of these materials is an efficient way to maximise catch and minimise costs, but fishing companies are less concerned about the effects of disposing ropes and nets into the sea.

Effects

Finally, what are the effects of entanglement? Although it might seem obvious, there are indirect impacts that surprised me. Below is a summary of the impacts of entanglement on fur seals (Hofmeyr et al., 2002 unless stated otherwise):

• Individual suffering
• Restriction of movement
• Drowning
• Strangulation
• Infection (even if the plastic collar is removed, the open wound can cause infection)
• Inability to protect itself from predators
• Starvation due to reduced ability to catch prey
• Female fur seals spend longer at sea than seals that are not entangled. This means they leave their pups unprotected for longer, making them more likely to die (Croxall et al. 1990)

Sum up

The idea that Antarctica would be excluded from human impact forever is deluded. Despite its isolation from the rest of the world, it seems that human impact is reaching a truly global scale. Antarctic oceans are being polluted by plastics and other man-made debris which is affecting Antarctic fur seals. What I want to demonstrate from this post is that man-made debris is inescapable wherever you go and Antarctic wildlife is bearing the brunt.

My next topic is scientific research. Are sites of scientific research doing more harm than good? One of the major concerns about research centres in Antarctica is waste disposal, so this topic follows on well from this post. The scores for negative human impacts verses positive/ natural impacts on Antarctica are 5-3.

Thanks for reading!