Waste Regulation

In my last post, I discussed how Antarctica suffers from contamination from research stations. This makes regulation an important strategy to try and limit the impact of these activities on the environment.

Montreal Protocol

The Montreal Protocol, as I have mentioned in this blog before, contains two annexes that relate to waste and pollution. These two annexes are Annex III, waste disposal and waste management, and IV, prevention of marine pollution. Under the annexes, countries that own, operate and manage research stations should endeavour to dispose of the waste produced with consideration to the environment.

Annex III states that sewage should not be disposed of in the sea ice or on the ice shelf. But, what I find disappointing about this Annex is that it allows sewage to be disposed of directly into the sea. This clause states that where large amounts of sewage are disposed of in the sea, it should be treated by breaking it down (maceration), (Secretariat of the Antarctic Treaty, accessed through Secretariat of the Antarctic Treaty, 2011). It seems counter-productive to allow sewage disposal into the sea, but not onto the sea ice or ice shelf given that there are just as many or perhaps more species living in the sea. Additionally, sewage is more susceptible to spread across the ocean if it is allowed to be dumped here. This shows that while measures are put in place to reduce human impact, there are not strong enough, limiting the effect of them.

Analysing Annex III further, I discovered that pesticides are banned from the ice and sea, however pesticides used and discarded for scientific purposes are allowed. This hardly shows commitment to protecting the environment. Additionally, as mentioned in my post Antarctic Treaty post, under the Antarctic Treaty, there should be freedom of scientific investigation. This further limits the extent that scientific research stations are obliged to follow the regulations. The regulations concerning waste and waste disposal should apply to every user of the Antarctic though. If there are exceptions, countries will use scientific research as an excuse to allow harmful chemicals into the Antarctic environment. Furthermore, if research requires the release pesticides in the first place, perhaps this research should be questioned because it is harming the environment at the same time.

Sewage treatment facilities

A positive aspect resulting from the Protocol, however, is that it is incentivising countries to implement treatment facilities to reduce waste. The Guardian (2014) interviewed a cook on the McMurdo station who reported that waste that must be shipped costs money to dispose of. This indicates that regulation is increasing the research station’s costs. To deal with this, treatment plants are being built as an alternative to shipping waste out. Sewage treatment facilities remove unpleasant matter from the waste and then chemically or physically disinfect what’s left over (Gröndahl et al. 2009). Subsequently, the treated water is released into the environment without harmful chemicals in it. The critical question here is, are the sewage treatment facilities effectively removing harmful substances from the waste?

The Rothera Research Station (see figure 1) continued to dump human and food waste into the sea until 2003 when it built a sewage treatment plant (Hughes, 2004). Liquid waste was sterilised with UV which was then released into the North Cove (ibid). Hughes discovered that this plant has been successful at reducing concentrations of faecal coliform (a type of bacteria) in Rothera. Figure 2a) shows the distribution of this bacteria in 1999 and 2b) shows the concentration in 2004. It is evident that the plant successfully reduced faecal coliform concentration.

Figure 1. Map showing Rothera Station on the Antarctic Peninsula (far left). 

Source: CIRES (2013)

Figure 2. a) concentration of faecal coliform in February 1999

b) concentration of faecal coliform in February 2004.

Successful reduction of faecal coliform in Rothera resulting from the release of treated water. Source: Hughes (2004)

This example shows how sewage treatment plants can reduce the effect of sewage waste on the Antarctic environment.

How many research stations are building sewage treatment plants?

There are over 100 permanent, summer and field stations in Antarctica (Polar Conservation Organisation, n/d). Gröndahl et al. (2009) investigated 71 stations, table 1 shows the results. The authors found that 41 permanent stations operate with sewage treatment plants. Although this represents more than half of those studied, it also signifies that perhaps there aren’t enough operating given the severity of the contamination occurring.

Table 1. The number of stations with sewage with sewage treatment plants out of a sample of 71. Source: Gröndahl et al. (2009)

Having said this, building a sewage treatment plant in Antarctica is particularly difficult. Climate, remoteness and wildlife disturbance are special considerations that have to be made when designing the plant and these factors contribute to the difficulty. Additional challenges are faced during operation of the plant. For example, if a spare part is required, getting replacements may take months due to remoteness. This means that contingency plans should be put into place, for instance, where is the sewage going to be stored in the mean time? Furthermore, because of the harsh climate, the plant must ensure that pipes don't freeze during operation (Connor, 2008). These factors mean that repairs or maintenance work is almost impossible to undertake, especially during the winter. Because of this, the treatment plants must be designed to require as little maintenance as possible. Difficulties like these can discourage countries from building sewage treatment facilities near their research stations. Therefore these problems can limit the uptake of treatment plants as an effective method to reduce waste discharge into the environment.

Moreover, despite Hughes’ successful results, it is important to bear in mind that not all sewage treatment plants have been successful. For instance, the Maitri plant experienced large reductions in the pH of wastewater and a large proportion of treated water was not biodegradable despite being treated (Ghosh et al. 1997). This was due to mechanical malfunctions. The purpose of treating water is to ensure that safer water is discarded into the Antarctic environment for the protection of marine life. If treatment plants are unable to produce safer water, then the plant is not worth having. This therefore highlights the importance of minimising operational problems and malfunctions. Although due to the problems mentioned above, this task is immensely difficult, showing that waste management remains one of the biggest challenges faced in Antarctica.

This post has shown that regulation can be effective if treatment plants are implemented, but the success of these are limited if they are not fully functioning. Moreover, The Montreal Protocol has obligations that must be followed when regarding waste and sewage disposal, although this is also successful to a limited extent due to exemptions given to scientific research. In my view, more stringent rules must be introduced if Antarctic marine life and nearby waters are to be restored to their natural state, i.e. that without human interference.

I have argued that it is possible for a sewage treatment plant to successfully treat sewage to release less harmful substances into Antarctic waters. This reduces the negative human impacts arising from research stations. Therefore, the future looks promising and because of this, the scores for negative human impacts verses positive/ natural impacts on Antarctica are 6-4.

All in the Name of Research…

Given that thousands of humans reside in Antarctica every year working in research stations, it is unlikely that the environment is going to remain unchanged. The reason for this is that humans create waste everywhere they go. Food and sewage waste are created by the simple act of living in Antarctica, but waste resulting from the research itself is also one of the main problems. Waste from building materials, batteries, fuel drums and laboratory chemicals (Aronson et al. 2011) are additional types of waste that the Antarctic is subjected to. This post will focus of sewage waste from chemical and human waste, discussing what the effects are.

I find this topic particularly interesting because in my view, researchers would not want to criticise their work. Much attention and credit goes to the research itself rather than the effects of the process that led to the discovery. This means that the extent of the waste problem may not be widely known. However, the waste problem was recently in the news (The National Geographic, 2014), where a study discovered that penguins’ tissues were found to be contaminated by a toxic flame retardant. The contaminants were being passed on by fish. The flame retardant supposedly came from waste from the McMurdo Station and another New Zealand base.

Chemical and human waste from the McMurdo Research Station

In the 1950s, before the Montreal Protocol (see my post on the Antarctic Treaty) and before any regulation, sewage was dumped into Winter Quarters Bay in McMurdo Sound (see figure 1) by those working in the McMurdo Station (Landis, 1999). The region earned a reputation to become 'one of the higher toxic concentrations of any body of water on Earth' (Aronson et al. 2011: 90), which certainly left a legacy on the environment. Contamination occurred from the disposal of heavy metals such as zinc and arsenic, polychlorinated biphenyl from abandoned sites (such as the Wilkes Station, see figure 2), and as mentioned, flame retardants (Tin et al. 2009).

Figure 1. Winter Quarters Bay in McMurdo Sound. Adapted from University of Nebraska-Lincoln (2005)

Figure 2. Abandoned Wilkes Station

One example of the effect of contamination from the McMurdo research station is a change in the behaviour of heart urchins. Lenihan (1992) conducted an experiment in Winter Quarters Bay. The author compared the burrowing behaviour of heart urchins near the McMurdo station with those near the Jetty and Cinder Cones stations, which are supposedly uncontaminated. The results found that 'heart urchins did not burrow into Winter Quarters Bay bottom sediment' but they did in Jetty and Cinder Cones bottom sediments (ibid: 321). This shows that the behaviour of heart urchins has changed due to contamination. In particular, urchins are finding the seabed toxic which shows that their habitats have become unsafe for them. Therefore one key finding from this study is that contamination has reached the bottom of the seabed. The potential effects of this can even alter survival rates because if urchins do not reach the seabed, they are susceptible to predators. Furthermore, some heart urchins are being killed because of the concentrations of metals found. Biodiversity in Antarctic oceans, is therefore being threatened by human actions.

A study conducted by Negri et al (2006) investigated contamination in sediments, bivalves and sponges in McMurdo Sound, which lies in the same region as the McMurdo Station. Figure 3 is a map showing where the McMurdo Station is, relative to the sampling sites used in the study. Metal concentrations were measured in Antarctic soft shell clam, called Laternula elliptica, because they are largely abundant which means they are good indicators of metal accumulation (ibid). Sediments extracted from the sponge tissue from the clam found the highest concentrations of copper, zinc, silver, lead and cadmium (ibid) compared to the other sites. This shows just how contaminated McMurdo Sound has become due to anthropogenic activities. Additionally, in the book 'Need for real world assessment of the environmental effects of oil spills in ice-infested marine environments. POAC 81. The 6th international conference on port and ocean engineering under Arctic conditions, Quebec, 27-31 July 1981. Vol. II', Robbilliard and Busdosh found that the concentration of the soft clam in Winter Quarters Bay has substantially reduced. This evidence also shows that these metal substances are harmful to marine life in the Antarctic waters.

Figure 3. Map of McMurdo Sound and Negri et al. (2006)'s sampling sites. 

So in summary, while research centres are an opportunity to find out more about human disturbance in Antarctica, they also, ironically, contribute to the disturbance as well. Biodiversity in Antarctica is unique to Antarctica and is being threatened by research stations’ waste. This effect is exaggerated by the expansion of research centres across the continent. Above, I mentioned that these studies represent the legacy of past waste disposal. Since the Antarctic Treaty, regulations have been implemented to prevent waste and contamination from affecting this pristine environment. It’s just a shame that past actions are having long term effects on the marine life in Antarctica. Was the regulation implemented too late? According to Negri et al., Winter Quarters Bay may have supported a rich community of benthic organisms prior to pollution from the McMurdo station, but communities have failed to recover since regulation was implemented. This indicates that perhaps it may have been.

It is important to stress that this post is not a criticism of the research undertaken, as written in my previous post, research is immensely valuable. It finds the effects of human activities and therefore helps find solutions. Rather, this post is a way of analysing the unintended consequences of the research. As was the case with regulating tourism, I emphasise again that more needs to be done to regulate waste. Next time, I focus on waste regulation. The scores for negative human impacts verses positive/ natural impacts on Antarctica are 6-3. 

The Usefulness of Research Stations

Research centres in Antarctica are widespread. Figure 1 shows just how many research centres, permanent or otherwise are present in Antarctica today. In fact, there are approximately 4,000 scientists and technicians living and working in the station during the summer and approximately 1,000 working there during the winter (Gröndahl et al. 2009). Because the research population is in the thousands, human impact on the environment will be significant given the sensitivity of the Antarctic environment. Furthermore, it can be argued that the Antarctic is becoming disturbed due to permanent human residency and man-made construction (ibid).

Figure 1. All the research stations in Antarctica. Adapted from Antarctic Glaciers (2013)

Setting up centres in Antarctica are supposedly justified by their work on measuring:

• The ozone layer and patterns of change
• Atmospheric chemistry
• Global sea level changes
• Information on climate change

…and much more.

Before I explain the impact of these centres directly on the Antarctic environment, I want to give you a few examples that demonstrate the value of research centres.

Vostok

Information on climate change is found by taking ice cores and using them to infer past climate as well as current climate. A Russian station called the Vostok research station was established in 1957. A reasonably famous study undertaken in 1999 by the Vostok station was the use of ice cores to reconstruct the climate in the past 420,000 years (Petit et al., 1999). Ice cores enable the reconstruction of past environments because trapped are in the ice indicate past atmospheric conditions, i.e. concentrations of carbon dioxide and methane. These help determine what climate was like. The results from Vostok are shown in figure 2.

Figure 2. Results from the Vostok ice core. Data shows the climate record for the past 420,000 years. Main finding: anthropogenic activity has increased the levels of methane and carbon dioxide. Source: Petit (2007) in Knight (ed) 'Glacier Science and Environmental Change', p. 404.

The findings from this research project were relevant because they showed that carbon dioxide and methane levels now surpass levels in any of the past 400,000 years. Thus, this research presented solid evidence for anthropogenic climate change.

Halley Bay 

Another major finding from research stations in Antarctica was the hole in the ozone layer, found from research undertaken at the Halley Bay (now known as just Halley) research station in 1985 (Farman et al., 1985).

As can be seen, research centres have made significant contributions to climate, climate change and atmospheric conditions. The research conducted is not only for the purpose of human benefit, recall the discovery of the hole in the ozone layer. This shows that Antarctica is benefiting from the research. 

Having said this, in making some of these important discoveries, sometimes the condition of the Antarctic environment has been compromised and this is what I will explain in my next post.

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!

License to Krill II

Last week, I looked at the impact of a whaling ban on krill population and penguin populations. This post will discuss natural causes of changes in krill population that humans have no (direct or indirect) impact on. Like last week I will continue my focus on the West Antarctic Peninsula (WAP).

Figure 1 shows the change in winter sea ice extent from 1980 and 2010 and it is evident that there has been a reduction in winter sea ice extent during the period.

Figure 1. Winter sea ice extent in 1980 and 2010. Adapted from: Lenfest Ocean Program, (2011)

What is causing reduced sea ice extent?

Trivelpiece et al. (2011) and Vaughan et al. (2003) argue that this region has experienced a 5-6^oC increase in mean winter air temperatures in the past 50 years and this is resulting in decreased winter sea ice extent. Figure 2 shows a gradual increase in mean winter temperatures from 1950 to 2000. The grey region is of particular interest because it shows a warming trend from 1980 to 2001.

Figure 2. Mean winter temperatures at the Faraday Station. Adapted from: Lenfest Ocean Program, (2011)

By comparing figure 2 with figure 1, it is possible to correlate an increase in mean temperatures with reduced sea ice extent. However there are also other factors affecting sea ice extent.

Atmospheric and oceanic temperatures are changing in the WAP region due to changes in the El Niño Southern Oscillation (ENSO). This is reducing sea ice extent. El Niño is a weather event that occurs in the Pacific when there are weaker trade winds and this alters the climate in the surrounding regions, notably South America and Australia. During El Niño, warm water that would normally be in the West Pacific flows to the East Pacific and atmospheric pressure falls. South America experiences unusually wetter climate while regions near Australia experience more drought-like conditions. La Niña, on the other hand, is the opposite effect where atmospheric pressure increases, trade winds blow more intensely and cold water flows to the west Pacific.

Shevenell et al. (2011) explain that during La Niña events, there are higher sea surface temperatures in the WAP and this reduces sea ice extent. The reason for this is that there is high pressure in the Bellingshausen Sea (see figure 3) which brings warm air towards Antarctica, causing reduced sea ice extent. Furthermore, north easterly winds dominate which Harangozo (2006) and Quetin et al. (2007) find is negatively correlated with sea ice extent (strong north easterly winds lead to reduced sea ice extent) because it does not provide good conditions for ice formation. Furthermore, Shevenell et al. (2011) mention that there are positive feedbacks that enhance this effect, which can explain how winter sea ice extent falls even when there is no La Niña event. 

Figure 3: Bellingshausen Sea in West Antarctica. Adapted from The Encyclopedia of Earth

Sea Ice Extent and Krill Population

You must be wondering how sea ice extent is related to krill population. One way sea ice helps the krill population is through providing a habitat for microbial communities that young krill use as a source of food (Quetin et al. 2007). This improves their chance of survival and helps increase the krill population in the summer (ibid). Additionally, high sea ice extent and duration is positively correlated with reproductive success of krill (Loeb et al. 1997). The fact that winter sea ice extent is reducing means that there will be a smaller krill population surviving to the summer without the microbial communities to feed on. Hence, krill population will decline in the long term if La Niña events are frequent. Even under normal conditions when there is no La Niña event, there could be lagged responses in the system as it gets used to the normal climatic conditions. This can result in long term variability in krill populations. 

Hopefully in this post I have shown that krill populations are not solely affected by human actions. Natural climate variability is often under-stated in the media and in literature about wildlife. Today, I have highlighted how complex it is to try and understand how humans and natural variability affect Antarctica. 

This post has helped level the playing field, so the updated scores are now negative impacts 4, positive/ natural impacts, 3. Next week, I will move on to the effects of plastics on Antarctic seals. There are no surprises as to which way the scores will lean next week...

How Krill Variability Affects Penguins

This post will focus on how krill variability in the West Antarctic Peninsula (WAP) and Scotia Sea affects populations of Adélie and chinstrap penguins via the food chain.

Whaling

As mentioned in my previous post, krill fishing has become one of the main drivers reducing krill population and increasing competition for krill. But this is not the only impact that humans have had on krill population. Indirectly, through the introduction of whaling and sealing restrictions, competition for krill is increasing, causing stress among krill population. In turn, this is causing a decline in the populations of Adélie and chinstrap penguins.

For example, the International Whaling Commission banned the whaling of blue whales in 1966 (National Oceanic and Atmospheric Administration Fisheries, 2014) which is increasing the population of baleen whales (blue whales are a type of baleen whale) and therefore increasing demand for krill. This reduces available krill to penguins, particularly because blue whales’ diets consist mostly of krill (ibid). More competition for krill means that krill populations may decline even further than they have. Trivelpiece et al. (2011)'s research project in the South Shetland Islands in the West Antarctic Peninsula (see figure 1) discovered that Adélie and chinstrap penguin populations have declined more than 50% in the last 30 years, which is approximately during the same time that whaling bans were introduced in the Antarctic. 

Figure 1. Map showing the South Shetland Islands and the West Antarctic Peninsula. Source: Lenfest Ocean Program, (2011)

This suggests that humans have indirectly affected penguin populations via the food chain and the impact on krill population. Whaling bans therefore have a positive impact on whale populations, but a potentially negative impact on penguin populations. The fact that this happens demonstrates the interconnectedness of Antarctic wildlife and the importance of krill in the food chain. It also highlights the complexity of food chains. Food chain processes are natural and once humans alter these mechanisms, many species, not just one, are affected. Even if humans have good intentions (e.g. to protect whales), there can be negative indirect effects as well. 

Trivelpiece et al. (2011) further mention that the effect of a reduction in krill availability for penguins is predicted to increase as krill fishing increases. Humans, therefore, have a variety of impacts on whale, penguin and krill populations and these impacts are all holistic. The impact that humans have had on Antarctica is both positive (on whales) and negative (for penguins and krill). Because of this, I will classify the total impact as neutral, so for the first time in my blog, the impacts cancel out and the scores remain unchanged! Just to remind you, they stand at negative impacts 4, positive/ natural impacts, 2.

Next week I will explore an argument against anthropogenic causes, focussing on how natural climate variability can cause changes in krill population. Thanks for reading!