Imagine the survival strategies needed to live in the world’s largest desert, Antarctica, with less than 12cm of rain a year (Parmalee XV). Natural occurrences threaten the lives of penguins constantly. But how can they adapt to rapid global change, pollution, and food losses? “When I am working with penguins, I feel really at one with nature, and watching their daily struggle for survival in one of the harshest environments on earth makes me realize how powerless they are to control their own destiny. It is not the penguins that are destroying their environment, it’s us” (Rouse and Rich 2007). Environmental change no matter how significant first affects the biota most susceptible, then the ripple is felt throughout the entire trophic pyramid. It has been said that “Penguins are sentinels of the marine environment, and by observing and studying them, researchers can learn about the rate and nature of changes occurring in the Southern Ocean” (Boersma 597).
“Climate warming and sea-ice reduction have induced population responses among Adélie, chinstrap, and Gentoo penguins” (Boersma 599). Global warming spans all land, oceans and atmospheres. Unpredictable changes do not give the organisms a chance to react evolutionarily or even behaviourly. When rain or snow increases over the continent, penguins risk being buried or their nests destroyed (Boersma 601). Precipitation is not the only change visible to the penguins. Sea ice, wind directions, and temperatures all have a feedback loop set into motion by global warming and therefore affect penguin habitats and breeding tactics. Species in the tightly spun food web are directly associated with the presence or absence of the sea ice in the southern hemisphere. If sea ice-dependent organisms like krill disappear, the entire trophic web might collapse taking the penguin down with it (Ainley 63).
Some organisms follow the ebb and flow of sea ice seasonally with their breeding, drifting, and migrations. Once that cycle is disrupted by reduced ice, populations of once plentiful creatures will be reduced. Krill has a direct relationship with sea ice. Since penguins predominately consume krill, they are forced to hunt longer, swim farther, or change food sources. “The evidence we have is unequivocal: Without enough sea ice, these birds can’t reach what must be very productive areas of the ocean during wintertime. This is removing the Adélie [penguins’] ability to exploit the areas they were able to exploit at one time. That’s probably why the chicks aren’t surviving” (Montaigne 217). The warming globe generates rising seas.
Sea level rising/Temperature
When Antarctica globally warms, ice shelves melt and glaciers fall into the coastal waters. When that surplus of fresh ice water enters the salt water, it causes the future sea level rise to reach an estimated 16ft (Montaigne 208). A negative feedback loop exists when the open oceans (formerly ice covered) receive more solar heat, warm up and prevent new sea ice from forming. This can further modify the ocean circulation patterns. Global sea rise will destroy the coast of Antarctica and lead to more landslides and constant erosion. Weather patterns will also change dramatically on the continent. “The increased precipitation impedes breeding success in other ways as well. There have been an increase in severe snowstorms on the Antarctic Peninsula, with snows so deep that penguins are literally buried as they sit on their nests” (deNapoli 250). If weather and climate change quickly, biota and especially penguins have limited time to adapt, but rather must react to it. “The warming of the Antarctic Peninsula also has global implications, for already the heat that has pared over the region has led to the breakup of eight ice shelves. The most notable has been the Larsen B Ice Shelf, a floating sheet of ice-once the size of Connecticut-that disintegrated in 2002” (Montaigne 208).
What is causing this shift of warming air melting the southern ice continent? First, greenhouse gases have accumulated in the upper atmospheres and warmed the tropical and temperate regions. This warming air drifts downward to the South Pole. Warm air moves physically to the locations of cold air, much in the way hot air rises in buildings. “This growing contrast may be responsible for altering a Southern hemisphere climatic pattern known as the
Southern Annular Mode or SAM. The SAM has kicked into high gear in recent decades, which has strengthened westerly winds around Antarctica and pulled in warmer moister air from the north, (Montaigne 209). Warm wind meets the ice shelves and slowly melts it.
The second cause is also anthropogenic in origin. “In the mid-to–late twentieth century, the widespread use of refrigerants containing chlorofluorocarbons (CFC’s) began to destroy ozone (O3), an important component of the atmosphere that absorbs and blocks harmful ultraviolet radiation” (Montaigne 210). If that is not enough to harm the icy landscape of Antarctica, the ozone layer has a giant hole above the continent of ice. That layer would have protected the land from melting. But now the sun rays can fully penetrate the land glaciers and ice can and will melt. The sun now has a direct portal with which to illuminate the Antarctic surface which ultimately melts the ice. The high
albedo of ice would reflect back some solar energy, but not enough to reverse the effects of direct UV radiation. However much solar pollution is harming the southern hemisphere, it has to contend with more chemical pollution than ever before.
Oil Spills and Pollution
Each year, countless tons of pollutants flow into the waterways from the mainland, sink from atmospheric deposition, release from the earth during drilling, or are purposely disposed of by human hands. How can aquatic creatures avoid a polluted water column? Non-digestible items like plastic trash pose not only a choking risk, but also intestinal blockages. Some pollution, such as plastic or Styrofoam©, looks edible to the penguins and even reminds them of krill, while other heavy metals sink into the
benthic sediments until
filter feeders stir it around. High levels of mercury, lead, and cadmium have been found in penguin tissues (Vega et al 466). “Birds have been used as indicators of mercury contamination since the 1950’s” (Applequist, Drabaek and Asbirk 244). In one study, penguin droppings were analyzed for content and organochlorine pesticides (OCP) like DDT were found. Yearly trends of OCP were observed and identified sources from climate warming and melting glacier influx (Sun et al 905). The actual mechanism of
bioaccumulation in the higher trophic levels from start to finish requires further study.
Oil and fuel also exist in the oceans. Even a small coating of oil on feathers can expose the flesh and lead to hypothermia, drowning and starvation (deNapoli 38). Oil on the ocean emerges from several methods, 1) oil spills from wrecked ships or drilling 2) leaking old ships and tankers 3) emptying of ballasts, bilges and tanks. Most of those activities occur close to the coast and, therefore, to penguin and other seabird habitat. When the penguins go out for their daily forage, they get coated with the slick, come back to shore and, while attempting to preen their feathers, the penguins spread oil all over their body (deNapoli 98). Millions of gallons of oil enter the ocean each year. Inevitably, sea life comes into contact with it. “Robben Island, seabird ornithologist Bob Rand made the following observation, ‘Soiled penguins died on the beaches or lingered on the islands to perish of hunger. Where nesting birds were affected, chicks also died. No matter how small the contamination, the birds refused to take to the water” (deNapoli 147). The ocean pollution affects all of the sea life and limits the amount of fish available for consumption.
“For over three decades, the world’s marine fish stocks have come under increasing pressure from fishing, from loss of habitats, and from pollution. Rising sea temperatures and the increasing acidity of the oceans are placing further stress on already stressed ecosystems. Illegal fishing and unreported catches undermine fishery science, while subsidies continue to support unsustainable fishing practices” (The World Bank 2009). Fish sustain human and organism diets all over the world with the biggest and most advanced competitor being the human. According to the FAO, a fishery is typically defined in terms of the " activity leading to harvesting of fish. It may involve capture of wild fish or raising of fish through aquaculture. A unit determined by an authority or other entity that is engaged in raising and/or harvesting fish. Typically, the unit is defined in terms of some or all of the following: people involved, species or type of fish, area of water or seabed, method of fishing, class of boats and purpose of the activities". The definition often includes a combination of fishers in a region, identifying the specific fishing gear for the catch. There is no mention of fishery competition between sea life and humans. Take the Atlantic anchovy (Anchovia) as an example. Humans eat them occasionally whereas cephalopods, penguins, cormorants, terns, sea lions and dolphins rely most exclusively on them (Skewgar et al 45). Now compare a million dollar fishing fleet’s yield to the aquatic birds. Which strategy is most likely straining the fishery? Strangely enough, the anchovy fishery is also related to penguin ecotourism. If anchovies disappear, so will the penguins. Food scarcity may ultimately force these birds toward extinction (deNapoli 82). When common prey items disappear, penguins venture out much farther and deeper for nourishment. By doing that, they are further risking their lives by exposing themselves to possible predation and negative interactions with sea vessels. Alternative food sources such as gobe, krill, hake and squid could supplement the penguin diet but are not preferred. Those alternatives are being caught by fishers as well and contributing to further overfishing practices:
By improving governance of marine fisheries, society could capture a substantial part of this $50 billion annual economic loss. Through comprehensive reform, the fisheries sector could become a basis for economic growth and the creation of alternative livelihoods in many countries. At the same time, a nation’s natural capital in the form of fish stocks could be greatly increased and the negative impacts of the fisheries on the marine environment reduced. (The World Bank 2009)
With little to no open-water regulation, it is impossible to know which vessels are responsible. Coastal countries attempt to manage fisheries and catch rates. Globally, United Nations Convention on the Law of the Sea (UNCLOS) is in place to manage fisheries and maintain continuity between the oceans. With millions of boats heading to sea daily, direct scrutiny of fishing habits, procedures and catch statistics seem practically impossible. Unfortunately, the harmful habits of some fishers sour the image of ecologically responsible ones. Penguins are not only competing with fishers for sustenance, but the fishing nets left behind by fishers can sink them. Unintentional bycatch affects thousands of organisms annually. Most
bycatch and accidental drowning by nets go unreported each year (deNapoli 85). Most nets are rarely visible underwater, and with penguins swimming so quickly, they could not sense the danger of these nets. Baited fishing also causes penguin killings. When penguins see a fish dangling on a long line, they accidentally consume the hook, fish and some of the line. They eventually drown underwater.
Two often over-looked forms of penguin threats occurred in Namibia. The first was
guano gathering from penguin colonies used for fertilizer production. “In July 2003, Guano Green Fertilizers Ltd. secured a 0% interest rate in a joint venture with Namibian Guano Islands. The tenants to harvest guano on the islands of Ichaboe and Mercury off Namibian coast have been secured. While there may be other guano-harvesting companies operating in the region, this one company alone has been granted to harvest 4 million pounds of guano per year from two of the African penguins’ main breeding grounds” (deNapoli 103). This not only disrupted the entire ecosystem with the shoveling, heavy equipment digging up the land and removing the top layers of earth, but interrupted breeding, foraging and mating from the excessive foot traffic, sounds, and movement. Secondly, penguin eggs were harvested in the millions. “Starting shortly before the turn of the twentieth century and continued unchecked until 1969 (when a ban was finally enacted), millions of eggs were taken from the African penguins’ breeding colonies. Collected commercially for human consumption, the eggs were initially used as an inexpensive source of protein for the poor; but eventually became a luxury food item” (deNapoli 103-104). The African penguins have little chance to recover from these dramatic losses. Some describe their future outlook as doomed.
In addition to food shortages, penguins also deal with global weather unpredictability. Global weather patterns have a direct effect on penguin populations:
In the 1982-1983 El Niño, 77 percent of the entire Galapagos penguin population starved to death, and a further 66 percent of them perished in the 1997-1998 El Niño….Galapagos penguins, which live right on the equator in the Galapagos Islands, are particularly vulnerable to these episodes of extreme weather. In addition to being unable to find enough food to sustain themselves during El Niño years, Galapagos penguins will cease breeding. As a result, no new penguins are born to replace those that are lost due to age, illness or starvation, further contributing to the decline in the population. (deNapoli 249)
Global oscillation systems such as El Niño or La Niña affect hurricanes, global rainfall, water temperature, circulation models and migratory patterns in biota. When prey is forced to follow water circulation patterns, predators then pursue the prey, which could lead to strandings, food chain disruption, and starvation (Le Bohec et al 2493). Global computer models help scientists attempt to predict the next oscillation cycle. Some can even model penguins’ future and climate effects.
Historical records have indicated that penguins do respond to these climatic events. Some colonies have even been abandoned if the region warmed or if sea ice changed too much (Emslie et al 257). This would show that penguins sense the subtleties in the environment. Migration patterns or behavior changes could evince a reaction that penguins experience with the changes. “Oceanographic responses to large-scale climate signals, such El Niño Southern Oscillation (ENSO), are directly related to the variability observed in these populations” (Ballerini 255). Habitat displacement, breeding interruption, chick deaths, and starvation could all reduce the penguin populations. ‘Every-year breeding’ seems to show a visceral reaction to the changing clime. Although breeding each year tolls the parents heavily, the behavior must be a survival technique. “Female penguins are probably more likely than males to die during El Niño because of poor body condition. If the sex ratio becomes skewed—and it was already biased toward males…population recovery will be slow, because so many males will not find mates” (Boersma 601). All of these threats to penguin survival has not slowed the human infatuation with them.
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