Polar bears face a wide variety of threats in different combinations which affect their population. The following threats I will talk about are, climate change, hunting, toxic pollution and oil exploration.
Climate change - is the biggest threat to the Polar bears at the moment. The ice in the arctic sea is melting at an alarming fast rate. Polar bears require ice to survive, without ice they are unable to access their food, resting areas and unable to make dens. Even though Polar bears are great swimmers global warming is making the swimming conditions dangerous for the bears. This is having a big impact on thier population size.
Toxic pollution - As the apex predator the bears are exposed to a high amount of pollutants through their food. Many persistent organic pollutants were used in the past to kill pests. Some of the pollutants are not widely used today, however there is still some used today. The pollutants are transported to the south by wind and water currents. When the pollutants reach the arctic they get deposited on the water and ground and they made it to the food chain. The animals at the bottom of the food chain would consume these pollutants and as the larger animals ate them, the pollutants within the smaller organism were then past onto the larger animal. The larger animals consume many of the smaller ones so the pollutants are highly concentrated within that animal. Bears with high levels of pollutants have a low level of vitamin A, thyroid hormones, and some antibodies. They are highly important for the animal’s biotical function, such as, growth, reproduction and the ability to fight of diseases.
Oil exploration - Bears may come into contact with oil spills which can reduce their insulation of their fur and waterproof coat. The bear will have to use more energy to keep warm and compensate for the energy loss by consuming more food. With the ice melting by global warming this may be difficult for the bear. The oil spills may also affect the whole food chain.
Hunting - Polar bears are one of many victims killed for sports. They are also killed for their fur, which is used in the trading industry. Around 60% of the Polar Bears population is located in Canada. The only nation to allow hunting of Polar bears by non-native and non-citizens is Canada. Around 700 bears are killed annually from hunting; this prevents their population to rise to a healthier number.
Other populations affected.
Seals are threatened by the same factors as Polar Bears. The biggest threat to Seals today is hunting. They have been hunted commercially for a long period of time for sports, their pelts, their meat and their bubbler. The Caribbean Monk Seal became extinct because of over hunting by humans in the 1950’s. Today, all pinnipeds are protected by the Marine Mammal Protection Act in the U.S and there are several species protected under the Endangered Species Act.
Climate change affects the seals just as much as it affects the Polar Bears. Seals need ice banks to make breathing holes, to rest on and they need ice cover to protect their cubs from predators. With the increase in the global temperature the ice is melting at a fast rate so there is less protection for the cubs than there was many years ago when the temperature of the globe was at a healthy level.
Toxic Pollution also affects Seals the same way as it does to Polar Bears.
