Tag Archives: climate change

Rising Sea Levels and the Bengal Tiger

Endangered Species Case Study: Bengal Tiger
by Krista Bergesen

Tigers have long thrived in a variety of habitats across the Asian continent. Extremely adaptable, these solitary hunters have found their niche in extremely different climates: from the the frozen forests in Russia to the much hotter, tropical climates in India and Indonesia.

However, at this time, it seems that tigers are losing habitat at too quick of a pace to stay a viable species. Because of human activities, tigers have been pushed into a small portion, only 7%, of their historic habitat, leaving only around 3,200 tigers left in the wild.

The Bengal tiger has long occupied vast areas of Indonesia and India, and an especially large portion in what is called the Sundarbans. This large forest of mangroves provides food and shelter to many different species, including around 400 Bengal tigers, an extremely large number  given the already dwindling population as a whole. Although the numbers are not conclusive, it is estimated that around 10% of the entire tiger population lives in this large stretch of mangrove forest.

The controlled environment of the Sundarbans strongly promotes biodiversity. Fish use the area beneath the submerged mangrove roots to breed, while the trees shelter the coastal and intertidal zones from cyclones, wind damage, and storm surges. As many as 50 reptile species, 120 fish species, 45 mammal species, and 300 bird species call this forest their home. And tigers here play a very singular role in the ecosystem, swimming between the islands of this area and collecting food from the marine life in addition to spotted deer for their diet.

This area, unfortunately, is in danger. And not just from poachers or deforestation, but from rising sea levels. Global warming has done it yet again. By the year 2070, the sea levels around the Sundarbans are predicted to rise 11 inches. With this drastic rise, the environment will no longer adequately support the tigers or many other species that thrive within the mangroves. And with accelerating habitat destruction, this large forest may not even exist in 50 years at all.

The effects are projected to be devastating. From the estimated 400 tigers alive now, the population is predicted to sink to around 20 breeding tigers because of the 96% decrease in habitat. In addition to the continued effects of poaching and deforestation, the rising sea levels could lead this subspecies into extinction, joining the 2 tiger subspecies already extinct.

The situation seems hopeless. However, local governments have the chance to conserve the threatened mangrove forest as well as curtailing the rampant poaching problem. Also, the region can increase sediment delivery and freshwater flows to the Sundarbans for replenishment of the land. Although this is probably easier said than done, it is hopeful that the situation can be resolved through progressive laws and environmental protection efforts. But it doesn’t end there. The globe as a whole needs to reduce greenhouse gas emissions, otherwise the above efforts and changes will be ineffective in saving the Sundarbans, and with it, its rich biodiversity.


Poston, Lee. “Climate Change Threatens to Wipe Out One of World’s Largest Tiger Populations this Century” <http://www.worldwildlife.org/who/media/press/2010/WWFPresitem14891.html&gt; 19 Jan. 2010. 22 Feb. 2010.

“New Study Shows Bengal Tiger’s Habitat in Danger.” <http://www.worldwildlife.org/who/media/press/2010/WWFPresitem14914.html&gt; 19 Jan. 2010. 22 Feb. 2010.


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Dying Coral Reefs

by Krista Bergesen

With the global climate changes going on right now, it may not be surprising to know that the aquatic life is also being affected. Displayed in every vacation resorts catalog and ocean documentary, coral reefs have formed an integral part of the planet’s oceans, providing a food supply, habitat, and protection for many other sea creatures.

Sometimes, it is easy to imagine coral as the dead, funny shaped rock that can be seen when you go scuba diving. Surprising as it may be, coral are actually living animals that eat, breathe, and reproduce.

Often mistaken for plants, coral use tentacles to sting and capture their prey of small fish and small animals. Hard to imagine, right?

It may be interesting to note that coral also located all across global waters. In colder northern waters, the coral don’t generally settle down into the picturesque colonies of the equatorial waters, but are still there floating aimlessly throughout the water. Large colonies are formed in the presence of algae, where the coral can feed off of the algae’s products of photosynthesis. At the same time, the coral produce CO2 to feed the algae. Not having to capture prey anymore because of this mutualistic relationship, the coral then produce the calcium carbonate exoskeletons that people usually identify with the species.

Coral reefs may look rock hard and impermeable, but they are surprisingly fragile.

Myriads of creatures graze on and make their homes in the coral. And the coral are always dying and re-growing their structures because of the constant attack they are under. A very delicate balance of destruction and growth has been maintained for millions of years between the coral and the rest of the ocean. It figures that humans would mess it up.

Instead of carrying fresh, clean water to the oceans, rivers now carry agricultural waste. Nitrates, phosphates, sewage, etc. now pollute the water. Recent evidence has found that coral now faces disease susceptibility from the sediment accumulation and increased exposure to land-based pathogens.

It doesn’t stop there, global warming has, not surprisingly, caused problems as well. As coral and algae colonies evolved together in a very narrow temperature range, the algae have begun to produce poisonous oxygen compounds called “superoxides” because of the higher oceanic temperatures. The coral will consequently expel the algae only to starve and turn a deathly white, giving the process the name of “bleaching.”

Coral reefs only form a small portion of the vast oceans, but their presence showcases the biodiversity and intricacy of the ocean’s natural systems. Widespread coral bleaching as well as pollution will change the face of the oceans as we know it through extinction. And this type of change cannot be undone.

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